PROCEPT INC
SC 13D/A, 1997-09-03
BIOLOGICAL PRODUCTS, (NO DIAGNOSTIC SUBSTANCES)
Previous: FLAG INVESTORS VALUE BUILDER FUND INC, 497, 1997-09-03
Next: NUVEEN JOHN COMPANY, 8-K, 1997-09-03





                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D

                    Under the Securities Exchange Act of 1934
                                (Amendment No.1)*

                              Procept Incorporated
                                (Name of Issuer)

                     Common Stock, par value $.01 per share
                         (Title of Class of Securities)

                                  742 683 10 5
                                 (CUSIP Number)

                    Paramount Capital Asset Management, Inc.
                         c/o Lindsay A. Rosenwald, M.D.
                               787 Seventh Avenue
                               New York, NY 10019
                                 (212) 554-4300

                                 with a copy to:

David R. Walner, Esq.                                Monica C. Lord, Esq.
Paramount Capital Asset                              Kramer, Levin,
   Management, Inc.                                   Naftalis & Frankel
787 Seventh Avenue                                   919 Third Avenue
New York, NY 10019                                   New York, NY  10022
(212) 554-4372                                       (212) 715-9100

      (Name, Address and Telephone Number of Person Authorized to Receive
                          Notices and Communications)

                                 August 22, 1997
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  which is the subject of this  Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following:
   |-|

Note: Six copies of this statement, including all exhibits, should be filed with
the  Commission.  See Rule 13d- 1(a) for other  parties to whom copies are to be
sent.

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

                               Page 1 of 10 pages




<PAGE>




CUSIP No. 742 683 10 5                13D                     Page 2 of 10 Pages


- --------------------------------------------------------------------------------
      1    NAMES OF REPORTING PERSONS
           S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Paramount Capital Asset Management, Inc.
- --------------------------------------------------------------------------------
      2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)      |_|
                                                            (b)      |_|

- --------------------------------------------------------------------------------
      3    SEC USE ONLY


- --------------------------------------------------------------------------------
      4    SOURCE OF FUNDS*

           OO (see Item 3)
- --------------------------------------------------------------------------------
      5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
           ITEM 2(d) or 2(e)

                                                                     |_|
- --------------------------------------------------------------------------------
      6    CITIZENSHIP OR PLACE OF ORGANIZATION


           Delaware

- --------------------------------------------------------------------------------
           NUMBER OF       7       SOLE VOTING POWER
             SHARES
          BENEFICIALLY             None
            OWNED BY    ------------------------------------
              EACH         8       SHARED VOTING POWER      
           REPORTING                                        
             PERSON                16,744,828**             
              WITH      ------------------------------------
                           9       SOLE DISPOSITIVE POWER   
                                                            
                                   None                     
                        ------------------------------------
                          10       SHARED DISPOSITIVE POWER 
                                                            
                                   16,744,828**             
                          
                        ------------------------------------
                          

                          
- --------------------------------------------------------------------------------

      11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON


           16,744,828**
- --------------------------------------------------------------------------------
      12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW 11 EXCLUDES CERTAIN SHARES*

                                                                     |_|
- --------------------------------------------------------------------------------
      13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

           55.0%**
- --------------------------------------------------------------------------------
      14   TYPE OF REPORTING PERSON*

           CO
- --------------------------------------------------------------------------------

** Consists of (i) 5,973,334  shares of Common Stock issuable upon conversion of
Series A Preferred Stock which are presently  votable on an as-converted  basis,
and (ii)  10,771,494  shares of Common Stock  issuable upon exercise of warrants
and conversion of notes, which, accordingly, are not presently votable.




<PAGE>

CUSIP No. 742 683 10 5                13D                     Page 3 of 10 Pages


- ---------------------------------------------------------------------------

      1     NAMES OF REPORTING PERSONS
            S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

            Aries Domestic Fund, L.P.
- --------------------------------------------------------------------------------
      2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP  (a)      |_|
                                                              (b)      |_|

- --------------------------------------------------------------------------------
      3     SEC USE ONLY


- --------------------------------------------------------------------------------
      4     SOURCE OF FUNDS*

            OO (see Item 3)
- --------------------------------------------------------------------------------
      5     CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
            ITEM 2(d) or 2(e)

                                                                       |_|
- --------------------------------------------------------------------------------
      6     CITIZENSHIP OR PLACE OF ORGANIZATION


            Delaware

- --------------------------------------------------------------------------------
            NUMBER OF           7         SOLE VOTING POWER
              SHARES                     
           BENEFICIALLY                   None
              OWNED BY    ------------------------------------------------------
                EACH            8         SHARED VOTING POWER       
            REPORTING                                            
             PERSON                       5,860,690**               
              WITH        ------------------------------------------------------
                                9         SOLE DISPOSITIVE POWER    

                                          None                                  
                          ------------------------------------------------------
                               10         SHARED DISPOSITIVE POWER              

                                          5,860,690**                           
                          ------------------------------------------------------

      11    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

            5,860,690**
- --------------------------------------------------------------------------------
      12    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW 11 EXCLUDES CERTAIN SHARES*

                                                                     |_|
- --------------------------------------------------------------------------------
      13    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

            19.2%**
- --------------------------------------------------------------------------------
      14    TYPE OF REPORTING PERSON*

            PN
- --------------------------------------------------------------------------------

** Consists of (i) 2,090,667  shares of Common Stock issuable upon conversion of
Series A Preferred Stock which are presently  votable on an as-converted  basis,
and (ii) 3,770,023 shares of Common Stock issuable upon exercise of warrants and
conversion of notes, which, accordingly, are not presently votable.




<PAGE>

CUSIP No. 742 683 10 5                13D                     Page 4 of 10 Pages

- --------------------------------------------------------------------------------
     1      NAMES OF REPORTING PERSONS
            S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

            The Aries Trust
- --------------------------------------------------------------------------------
     2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP  (a)      |_|
                                                              (b)      |_|

- --------------------------------------------------------------------------------
     3      SEC USE ONLY


- --------------------------------------------------------------------------------
     4      SOURCE OF FUNDS*

            OO (see Item 3)
- --------------------------------------------------------------------------------
     5      CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
            ITEM 2(d) or 2(e)

                                                                       |_|
- --------------------------------------------------------------------------------
     6      CITIZENSHIP OR PLACE OF ORGANIZATION

            Cayman Islands
- --------------------------------------------------------------------------------
            NUMBER OF               7         SOLE VOTING POWER
              SHARES
           BENEFICIALLY                       None
             OWNED BY       ----------------------------------------------------
               EACH                 8         SHARED VOTING POWER     
            REPORTING                                                 
              PERSON                          10,884,138**            
               WITH         ----------------------------------------------------
                                    9         SOLE DISPOSITIVE POWER  
                                                                      
                                              None                    
                            ----------------------------------------------------
                                   10         SHARED DISPOSITIVE POWER
                                                                      
                                              10,884,138**            
                            ----------------------------------------------------
     11     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

            10,884,138**
- --------------------------------------------------------------------------------
     12     CHECK BOX IF THE AGGREGATE AMOUNT IN ROW 11 EXCLUDES CERTAIN SHARES*

                                                                     |_|
- --------------------------------------------------------------------------------
     13     PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

            35.7%**
- --------------------------------------------------------------------------------
     14     TYPE OF REPORTING PERSON*

            OO (see Item 2)
- --------------------------------------------------------------------------------

** Consists of (i) 3,882,667  shares of Common Stock issuable upon conversion of
Series A Preferred Stock which are presently  votable on an as-converted  basis,
and (ii) 7,001,471 shares of Common Stock issuable upon exercise of warrants and
conversion of notes, which, accordingly, are not presently votable.




<PAGE>

CUSIP No. 742 683 10 5                13D                     Page 5 of 10 Pages

- --------------------------------------------------------------------------------
      1     NAMES OF REPORTING PERSONS
            S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

            Lindsay A. Rosenwald, M.D.
- --------------------------------------------------------------------------------
      2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP  (a)      |_|
                                                              (b)      |_|
- --------------------------------------------------------------------------------
      3     SEC USE ONLY


- --------------------------------------------------------------------------------
      4     SOURCE OF FUNDS*

            OO (see Item 3)
- --------------------------------------------------------------------------------
      5     CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
            ITEM 2(d) or 2(e)

                                                                        |_|
- --------------------------------------------------------------------------------
      6     CITIZENSHIP OR PLACE OF ORGANIZATION


            United States

- --------------------------------------------------------------------------------
            NUMBER OF       7         SOLE VOTING POWER
              SHARES
           BENEFICIALLY               None
             OWNED BY      -----------------------------------------------------
               EACH         8         SHARED VOTING POWER       
            REPORTING                                           
              PERSON                  16,744,828**              
               WITH        -----------------------------------------------------
                            9         SOLE DISPOSITIVE POWER    
                                                                
                                      None                      
                           -----------------------------------------------------
                           10         SHARED DISPOSITIVE POWER  
                                                                
                                      16,744,828**              
                            ----------------------------------------------------

      11    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

            16,744,828**
- --------------------------------------------------------------------------------
      12    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW 11 EXCLUDES CERTAIN SHARES*

                                                                        |_|
- --------------------------------------------------------------------------------
      13    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

            55.0%**
- --------------------------------------------------------------------------------
      14    TYPE OF REPORTING PERSON*

            IN
- --------------------------------------------------------------------------------

** Consists of (i) 5,973,334  shares of Common Stock issuable upon conversion of
Series A Preferred Stock which are presently  votable on an as-converted  basis,
and (ii)  10,771,494  shares of Common Stock  issuable upon exercise of warrants
and conversion of notes, which, accordingly, are not presently votable.




<PAGE>



                                  SCHEDULE 13D


         This Amendment No. 1 amends and  supplements the following Items of the
Reporting  Persons'  Statement  on  Schedule  13D,  dated  July 10,  1997,  (the
"Schedule").

ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

         References  to the  exercise  price of the Class B Warrants  are hereby
amended  from $.5859 per share to $.46875  per share (see Item 6).  Furthermore,
the information  contained in Item 3 to the Schedule is hereby amended by adding
the following:

         On August 22,  1997,  in  accordance  with Section 9.15 of the Purchase
Agreement,  Aries Domestic and Aries Trust,  exchanged their shares of Purchased
Common for 28,000 shares of Series A Preferred  Stock,  stated value $100.00 per
share, of the Issuer.  The Series A Preferred  Stock is convertible  into Common
Stock at an initial conversion price, subject to adjustment as set forth in Item
6, equal to $.46875 (the "Series A Preferred Conversion Price"), representing an
initial conversion rate of 213.333333 per share.


ITEM 4.  PURPOSE OF TRANSACTION.

         The  information  contained in Item 4 to the Schedule is hereby amended
and supplemented to read in its entirety as follows:

         The  Reporting  Persons  acquired   securities  of  the  Issuer  as  an
investment  in the  Issuer.  Except  as  indicated  in this  Schedule  13D,  the
Reporting  Persons  currently have no plans or proposals that relate to or would
result in any of the matters  described in subparagraphs (a) through (j) of Item
4 of Schedule  13D.  Pursuant to Section  7.19 of the  Purchase  Agreement,  the
Reporting  Persons  have the right to appoint a majority  of the  members of the
Board of Directors of the Issuer;  provided,  however,  that,  to the extent the
exercise of such right would violate Rule 4460(i) of the National Association of
Securities Dealers'  Marketplace Rules, the Reporting Persons shall not exercise
such right until the earliest of (i) the date of approval by the stockholders of
the Issuer of the transactions (the "Transactions") contemplated by the Purchase
Agreement and the Letter of Intent between the Issuer,  Paramount Capital, Inc.,
Aries Trust and Aries Domestic (the "Letter of Intent"), (ii) the date that Rule
4460(i) no longer applies to the  Transactions and (iii) September 30, 1997 (the
earliest such date, the "Approval  Date"),  nonetheless,  the Reporting  Persons
currently  have the right to appoint at least three  directors or observers.  In
connection with the Transactions, Mr. Michael S. Weiss joined the Issuer's Board
of Directors pursuant to the Purchase Agreement and the Letter of Intent and has
been elected by the Board of Directors of the Issuer to serve as the Chairman of
the Issuer's  Board of Directors.  The A Notes provide that the Issuer shall not
declare or pay any dividend nor make any other  distribution  or redemption with
respect to any shares of its capital stock without the prior written consents of
Aries  Trust  and  Aries  Domestic,  provided,  however,  that  the  Issuer  may
repurchase  shares of its Common Stock from officers,  Directors or employees of
the Issuer upon any such person's termination or resignation.  Furthermore, upon
the Approval  Date,  the Series A Preferred  Conversion  Price shall be reset to
equal the lesser of (x) $.29 and (y) 50% of the average closing bid price of the
Common Stock for either (i) the five (5)  consecutive  trading days  immediately
succeeding  the Approval  Date,  (ii) the thirty (30)  consecutive  trading days
immediately  preceding  the  Approval  Date or (iii)  the  five (5)  consecutive
trading days immediately  preceding the Approval Date, whichever is lowest (such
lesser price, the "Approval Price").  Additionally,  upon the Approval Date, the
conversion price of the


                               Page 6 of 10 Pages

<PAGE>



A Notes and the exercise prices of the class A Warrants and the Class B Warrants
shall be adjusted to equal the Approval  Price.  Pursuant to Section 7.31 of the
Purchase  Agreement,  the Issuer has  covenanted  to keep  available  sufficient
authorized but unissued shares of Common Stock to fulfill its obligations  under
the Purchase Agreement, and it appears the Issuer will need to take such actions
as are necessary in order to comply with this  covenant.  The Reporting  Persons
may from  time to time  acquire,  or  dispose  of,  Common  Stock  and/or  other
securities  of the Issuer if and when they deem it  appropriate.  The  Reporting
Persons may formulate other purposes, plans or proposals relating to any of such
securities  of the  Issuer to the  extent  deemed  advisable  in light of market
conditions, investment policies and other factors.


ITEM 5.  INTEREST IN SECURITIES OF ISSUER.

         The  information  contained in Item 5 to the Schedule is hereby amended
and supplemented to read in its entirety as follows:

         (a) As of August 22,  1997,  Dr.  Rosenwald  and  Paramount  Capital,
             through  acquisition  of the  shares  by Aries  Trust  and  Aries
             Domestic,  may be deemed beneficially to own 16,744,828 shares or
             55.0% of the Issuer's Common Stock,  and Aries Domestic and Aries
             Trust may be deemed to beneficially  own the following  number of
             shares of Common Stock:


             Aries Domestic                                       5,860,690
             Aries Trust                                          10,884,138

             Each Reporting Person disclaims  beneficial  ownership of all the
             Common Stock other than the respective  Purchased Common, if any,
             actually held by such Reporting  Person.  Of the shares of Common
             Stock of the  Issuer  that the  Reporting  Persons  may be deemed
             beneficially to own, only the 28,000 shares of Series A Preferred
             Stock may be  currently  voted,  which  shares,  which vote on an
             as-converted  basis and are initially  convertible into 5,973,334
             shares of Common Stock,  represent 30.3% of the outstanding  vote
             of the  stockholders  of the Issuer (10.6% for Aries Domestic and
             19.7% for Aries Trust).

         (b) Dr. Rosenwald and Paramount Capital share the power to vote or to
             direct the vote, to dispose or to direct the disposition of those
             shares  beneficially  owned by each of Aries  Domestic  and Aries
             Trust.

         (c) Other than the  purchase of the Common  Stock,  the A Notes,  the
             Class  A  Warrants  and  the  Class B  Warrants  pursuant  to the
             Purchase  Agreement and the exchange of the Purchased  Common for
             Series A Preferred Stock, the Reporting  Persons have not engaged
             in any transactions in the Common Stock of the Issuer in the past
             60 days. See Item 3.

         (d) & (e)   Not applicable.


                               Page 7 of 10 Pages
<PAGE>

ITEM 6. CONTRACTS,  ARRANGEMENTS,  UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT 
TO SECURITIES OF THE ISSUER.

         The  information  contained in Item 6 to the Schedule is hereby amended
and supplemented to read in its entirety as follows:

         Pursuant to the  Certificate of Designation  for the Series A Preferred
Stock,  if, upon any of the closings of the Company's next offering or series of
offerings  of equity  securities  with gross  proceeds  in excess of  $2,000,000
("Qualified  Offering"),  the  resulting  conversion  price,  exercise  price or
effective price per share of Common Stock  ("Qualified  Offering Price") in such
Qualified Offering is less then twice the Series A Preferred Conversion Price at
such time, then the Series A Preferred Conversion Price shall be reduced at such
time to equal fifty percent (50%) of such resulting  Qualified  Offering  Price.
The Series A  Preferred  Conversion  Price is  subject  to certain  antidilution
adjustments.  In  addition,  the Series A Preferred  Conversion  Price in effect
immediately  prior to June 30, 1998 (the "Series A Reset Date") will be adjusted
and reset  effective  as of the Series A Reset Date if the  average  closing bid
price per share of Common Stock for the 20 consecutive  trading days immediately
preceding the Series A Reset Date (the  "12-Month  Trading  Price") is less than
140% of the then  applicable  Series A Preferred  Conversion  Price (a "Series A
Reset  Event").  Upon  the  occurrence  of a  Series  A Reset  Event,  the  then
applicable  Series A Preferred  Conversion  Price will be reduced to be equal to
the greater of (i) the 12- Month  Trading  Price  divided by 1.4 and (ii) 25% of
the then applicable Series A Preferred  Conversion Price. The Series A Preferred
Conversion Price will similarly be reset in connection with any reduction in the
conversion price, exercise price or effective price per share of Common Stock of
the Issuer of any equity  securities sold in a Qualified  Offering  analogous to
the above described reset or, alternatively,  on June 30, 1999. Unless converted
earlier,  the  Issuer has the right at any time after the Series A Reset Date to
cause the Series A Preferred  Stock to be  converted,  in whole or in part, on a
pro rata basis,  into shares of Common Stock on 60 days' prior  written  notice,
provided  that the closing bid quotation for the Common Stock as reported on the
NASDAQ,  or on such exchange on which the Common Stock is then traded or listed,
exceeds  300% of the  Series A  Preferred  Conversion  Price for 20  consecutive
trading  days  ending  three  trading  days  prior to the date of the  notice of
mandatory conversion.  Pursuant to the Purchase Agreement, in the event that the
Issuer does not obtain the Required Shareholder Approvals (as defined in Section
7.27 of the Purchase  Agreement) by September 30, 1997,  each of the Aries Funds
shall have the right, for a period of 10 years, at such Aries Fund's  respective
election (the  "Non-Approval  Put") (i) to require the Issuer to repurchase with
cash,  within two  business  days after  request  is made  therefor,  all or any
portion of the shares of Series A Preferred  Stock then owned by such Aries Fund
for $140 per share tendered for such  repurchase,  (ii) to require the Issuer to
issue A Notes,  within two  business  days after  request is made  therefor,  in
exchange  for all or any portion of the shares of Series A Preferred  Stock then
owned by such Aries Fund, in a principal  amount of $140 per share  tendered for
such repurchase or (iii) any combination of the above.  The Issuer and the Aries
Funds  have  agreed to amend the  exercise  price of the Class B  Warrants  from
$.5859 per share to $.46875 per share  while  keeping  the  aggregate  number of
shares of Common  Stock  initially  subject to such  Class B Warrants  constant.
Paramount  Capital is the investment  manager of the Aries Trust and the General
Partner of Aries  Domestic  and in such  capacities  has the  authority  to make
certain  investment  decisions on behalf of such entities,  including  decisions
relating to the  securities  of the Issuer.  In connection  with its  investment
management  duties,  Paramount  Capital  receives  certain  management  fees and
performance  allocations from the Aries Trust and Aries Domestic.  Dr. Rosenwald
is the sole shareholder of Paramount  Capital.  Additionally,  on June 29, 1997,
the Issuer entered into a Letter of Intent with Paramount Capital, Inc. pursuant
to which it is contemplated that Paramount  Capital,  Inc. will act as financial
advisor and placement  agent for the Issuer in future capital  raising and other
strategic transactions. Dr. Rosenwald is the sole shareholder and Mr. Weiss is a
Senior Managing Director of Paramount Capital,  Inc. Except as indicated in this
13D  and  exhibits,  there  is  no  contract,   arrangement,   understanding  or
relationship between the Reporting Persons and any other person, with respect to
any securities of the Issuer.


                               Page 8 of 10 Pages



<PAGE>

ITEM 7. MATERIAL TO BE FILED AS EXHIBITS

         The  information  contained in Item 7 to the Schedule is hereby amended
and supplemented to read in its entirety as follows:

Exhibit A:    Agreement of Joint Filing of Schedule 13D dated as of July 9, 1997

Exhibit B:    List of executive officers and directors of Paramount Capital and
              information called for by Items 2-6 of this statement relating to
              said officers and directors.

Exhibit C:    List of executive  officers and  directors of Aries  Domestic and
              information called for by Items 2-6 of this statement relating to
              said officers and directors.

Exhibit D:    List of  executive  officers  and  directors  of Aries  Trust and
              information called for by Items 2-6 of this statement relating to
              said officers and directors.

Exhibit E:    Securities Purchase Agreement dated as of June 30, 1997.

Exhibit F:    Senior  Convertible  Note for  $70,000  issued to Aries  Domestic
              dated June 30, 1997.

Exhibit G:    Senior  Convertible Note for $130,000 issued to Aries Trust dated
              June 30, 1997.

Exhibit H:    Class A Warrant  for the  Purchase  of  959,944  shares of Common
              Stock issued to Aries Domestic dated June 30, 1997.

Exhibit I:    Class A Warrant for the  Purchase of  1,782,752  shares of Common
              Stock issued to Aries Trust dated June 30, 1997.

Exhibit J:    Class B Warrant for the  Purchase of  2,660,746  shares of Common
              Stock issued to Aries Domestic dated June, 1997.

Exhibit K:    Class B Warrant for the  Purchase of  4,941,386  shares of Common
              Stock issued to Aries Trust dated June 30, 1997.

Exhibit L:    Letter of Intent dated June 29, 1997.

Exhibit M:    Certificate of Designation for Series A Convertible Preferred 
              Stock of Procept, Inc.


                               Page 9 of 10 Pages

<PAGE>


                                   SIGNATURES

                  After reasonable  inquiry and to the best knowledge and belief
of the  undersigned,  the undersigned  certify that the information set forth in
this statement is true, complete and correct.

                    PARAMOUNT CAPITAL ASSET MANAGEMENT, INC.

Dated:   September 2, 1997
         New York, NY             By: /s/ Lindsay A. Rosenwald, M.D.
                                      --------------------------------
                                      Lindsay A. Rosenwald, M.D.
                                      President

                                  ARIES DOMESTIC FUND, L.P.
                                  By: Paramount Capital Asset Management, Inc.
                                      General Partner

Dated:   September 2, 1997
         New York, NY             By: /s/ Lindsay A. Rosenwald, M.D.
                                      --------------------------------
                                      Lindsay A. Rosenwald, M.D.
                                      President


                                  THE ARIES TRUST
                                  By: Paramount Capital Asset Management, Inc.
                                      Investment Manager

Dated:   September 2, 1997
         New York, NY             By: /s/ Lindsay A. Rosenwald, M.D.
                                      --------------------------------
                                      Lindsay A. Rosenwald, M.D.
                                      President


Dated:   September 2, 1997
         New York, NY                 /s/ Lindsay A. Rosenwald, M.D.
                                      --------------------------------
                                      Lindsay A. Rosenwald, M.D.


                              Page 10 of 10 Pages

<PAGE>

                                   EXHIBIT E

                                          SECURITIES  PURCHASE AGREEMENT


                                            PURCHASE       AGREEMENT       (this
                           "Agreement")  dated as of June 30, 1997, by and among
                           PROCEPT,    INC.,   a   Delaware   corporation   (the
                           "Company"),  THE ARIES FUND,  A CAYMAN  ISLAND  TRUST
                           (the "Trust"),  and THE ARIES DOMESTIC FUND,  L.P., a
                           Delaware  limited   partnership  (the  "Partnership")
                           (collectively with the Trust, the "Purchasers").

         The Company  desires to issue and sell to  Purchasers,  and  Purchasers
desire to  purchase  from the  Company,  30,000  shares of Series A  Convertible
Preferred Stock of the Company,  par value $.01 per share,  stated value $100.00
per share,  (the "Series A Preferred Stock") issued pursuant to a Certificate of
Designations  in the form  attached  hereto as  Exhibit A (the  "Certificate  of
Designations"),  2,742,696 Class A Warrants (the "Class A Warrants") to purchase
one share of the Common  Stock,  par value $.01 per share,  of the Company  (the
"Common Stock") in the form attached as Exhibit B hereto,  and 7,602,132 Class B
Warrants to purchase  one share of the Common Stock of the Company (the "Class B
Warrants," and  collectively  with the Class A Warrants,  the "Warrants") in the
form attached  hereto as Exhibit C, upon and subject to the terms and conditions
hereinafter set forth (the "Series A Offering"). Alternatively, in the event the
Company fails to obtain  approval from its  stockholders of the inclusion in the
Company's  Certificate of  Incorporation  of blank check  Preferred  Stock on or
before June 30, 1997,  then,  in lieu of Series A Preferred  Stock,  the Company
desires  to sell to  purchasers,  and  purchasers  desire to  purchase  from the
Company (i)  5,973,334  (the  "Alternate  Offering  Quantity")  shares of Common
Stock,  (ii) the contractual  rights contained in Article 9 hereof (the "Article
IX Rights") and (iii) $200,000 principal amount of 12% Convertible Notes (the "A
Notes") a form of which is attached  hereto as Exhibit D (the sale and  purchase
of the Warrants,  however,  remaining as above) (the "Alternate  Offering") (the
Common  Stock  to be  purchased  pursuant  to the  Alternate  Offering,  if any,
including the Common Stock issuable upon any Reset  Issuance,  Annual  Issuance,
Dilutive  Issuance  or Approval  Issuance  (as defined in Article 9), the Common
Stock  issuable upon  conversion of the Series A Preferred  Stock  issuable upon
exercise of the  Approval  Call (as defined in Article 9), and the Common  Stock
issuable  upon  conversion  of the A  Notes  being  referred  to  herein  as the
"Alternate Offering Common").

         Accordingly, in consideration of the premises and the mutual agreements
contained herein, Purchasers and the Company hereby agree as follows:

         1. Purchase of Company Securities.

         1.1.  Purchase  and  Sale  of the  Series  A  Preferred  Stock  and the
Warrants.  Subject to the terms and  conditions  set forth  herein,  the Company
hereby agrees to issue and sell to Purchasers, and Purchasers, severally and not
jointly, hereby agree to purchase from the Company, the Series A Preferred Stock
and the Warrants (allocated amongst the Trust and the


                                        1

<PAGE>

Partnership  as set forth on Exhibit E hereto),  at the Closing (as such term is
defined in  Section 2 hereof).  The  aggregate  purchase  price for the Series A
Preferred Stock and the Warrants sold pursuant to this Agreement  (including any
additional  shares of Common  Stock  issuable  pursuant to Section 8.6) shall be
$3,000,000  (the  "Purchase  Price")   (allocated  amongst  the  Trust  and  the
Partnership  as set forth on Exhibit E hereto).  "Operative  Documents"  as used
herein shall mean this Agreement, the Certificate of Designations, the Warrants,
the A Notes and the Letter of Intent between Paramount  Capital,  Inc.,  Procept
Inc. and the Purchasers (the "Letter of Intent").  In the event that the Company
fails to obtain approval from its stockholders of the inclusion in the Company's
Certificate of  Incorporation  of blank check  preferred stock on or before June
30, 1997, then the term "Series A Preferred Stock" as used herein shall mean the
Alternate  Offering  Common  and the A Notes as well as any  Series A  Preferred
Stock issued pursuant hereto (including any Series A Preferred Stock issued upon
exercise of the Approval Call).

         2.  Closing.  The  closing  of the  purchase  and sale of the  Series A
Preferred  Stock and the  Warrants  will take place at the offices of  Paramount
Capital Asset Management, Inc. at 787 Seventh Avenue, New York, New York, 10019.
Such closing (the "Closing")  will take place at 3:00 P.M.,  local time, on June
30, 1997;  provided that the Closing may take place at such other time, place or
later date as may be mutually  agreed upon by the  Company and  Purchasers.  The
date of the Closing is referred to herein as the "Closing Date." At the Closing,
the Company  will  deliver to  Purchasers  the Series A Preferred  Stock and the
Warrants  purchased  as set forth in  Section 1 hereof,  against  payment of the
Purchase  Price by  Purchasers,  by wire  transfer  payable to the Company.  The
Series A Preferred  Stock and the Warrants  shall be registered  in  Purchasers'
name or the  name of the  nominee(s)  of  Purchasers  in such  denominations  as
Purchasers shall request  pursuant to instructions  delivered to the Company not
less than one day prior to the Closing Date.

         3..  Conditions to the  Obligations  of Purchasers at the Closing.  The
obligation of  Purchasers  to purchase and pay for the Series A Preferred  Stock
and the Warrants to be purchased by  Purchasers at the Closing is subject to the
satisfaction on or prior to the Closing Date of the following conditions,  which
may only be waived by written consent of Purchasers:

         3.1 Opinion of Counsel to the Company.  Purchasers  shall have received
from Palmer & Dodge, LLP, counsel for the Company, its opinion dated the Closing
Date in the form of Exhibit F hereto.

         3.2  Representations  and Warranties.  All of the  representations  and
warranties of the Company  contained in this Agreement shall be true and correct
at and as of the  Closing  Date,  except to the extent of changes  caused by the
transactions contemplated hereby.

         3.3.  Performance of Covenants.  All of the covenants and agreements of
the Company contained in this Agreement and required to be performed on or prior
to the Closing Date shall have been  performed in a manner  satisfactory  in all
respects to Purchasers in their sole discretion.


                                        2

<PAGE>

         3.4. Legal Action. No injunction,  order, investigation,  claim, action
or  proceeding  before  any  court or  governmental  body  shall be  pending  or
threatened  wherein an  unfavorable  judgment,  decree or order would  restrain,
impair or prevent the carrying out of this Agreement or any of the  transactions
contemplated  hereby,  declare  unlawful the  transactions  contemplated by this
Agreement or cause any such transaction to be rescinded.

         3.5.  Consents.  The Company shall have obtained in writing or made all
consents, waivers,  approvals,  orders, permits, licenses and authorizations of,
and registrations,  declarations,  notices to and filings and applications with,
any  governmental  authority or any other person or entity  (including,  without
limitation,  securityholders  and  creditors  of  the  Company)  required  to be
obtained  or made in order to enable the  Company to observe and comply with all
its  obligations  under  this  Agreement  and  to  consummate  the  transactions
contemplated hereby.

         3.6. Closing Documents.  The Company shall have delivered to Purchasers
the following:

         (a) a certificate  executed by the President or Chief Executive Officer
of the Company dated the Closing Date stating that the  conditions  set forth in
Sections 3.2 through 3.5 have been satisfied;

         (b) an incumbency  certificate  dated the Closing Date for the officers
of the Company  executing this Agreement,  the shares  representing the Series A
Preferred  Stock  and  the  Warrants  and any  other  documents  or  instruments
delivered in connection with this Agreement at the Closing;

         (c) a  certificate  of the  Secretary  or  Assistant  Secretary  of the
Company,  dated the Closing Date, as to the continued and valid existence of the
Company,  certifying  the  attached  copy of the  By-laws  of the  Company,  the
authorization of the execution,  delivery and performance of this Agreement, and
the resolutions adopted by the Board of Directors of the Company authorizing the
actions to be taken by the Company under this Agreement;

         (d) a  certificate  of the Secretary of State of the State of Delaware,
dated a recent date,  to the effect that the Company is in good  standing in the
State of  Delaware  and that all  annual  reports,  if any,  have been  filed as
required and that all taxes and fees have been paid in connection therewith;

         (e) a certified copy of the Certificate of Incorporation of the Company
as filed with the Secretary of State of the State of Delaware and any amendments
thereto; and

         (f) such  certificates,  other  documents and instruments as Purchasers
and their counsel may reasonably  request in connection with, and to effect, the
transactions contemplated by this Agreement.


                                        3

<PAGE>

         3.7.  Proceedings.  All corporate and other  proceedings taken or to be
taken in connection with the transactions  contemplated hereby to be consummated
at the Closing and all documents  incident thereto shall be satisfactory in form
and substance to Purchasers.

         3.8. Due  Diligence.  Prior to the Closing Date,  Purchasers  and their
counsel shall have  completed  their due  diligence  and business  review of the
Company,  its  business,  assets,  liabilities,  corporate  and legal status and
intellectual property,  including patents, licenses and technical processes, all
of which shall be satisfactory in form and substance to each Purchaser and their
counsel in each Purchaser's sole discretion.

         3.9. Closing Financial Statements;  Absence of Changes. (a) The Company
shall have provided to Purchasers (i) the unaudited balance sheet of the Company
as of March 31, 1997, and the related unaudited  statement of operations for the
three-month  period then ended, as well as the related  unaudited  statements of
stockholders'  equity  (deficit) and cash flows for the three-month  period then
ended,  accompanied  by the  unqualified  certification  thereon  of  the  Chief
Financial Officer or Vice  President--Finance  of the Company (together with any
notes  thereto,  the "March 31 Financial  Statements")  and (ii) a  "bring-down"
certificate  of the  Chief  Executive  Officer  of the  Company  and  the  Chief
Financial Officer or Vice  President--Finance of the Company with respect to the
financial  position of the Company as of the Closing  Date and as to results for
the period  from the date of the March 31  Financial  Statements  to the Closing
Date, in form and substance satisfactory to Purchaser and its counsel.

         (b)  Except  as  set  forth  on the  schedules  hereto  of the  Company
delivered to Purchaser as of the date hereof,  there shall have been no material
adverse  change in the  financial  condition,  operating  results,  employee  or
customer  relations or prospects  of, or otherwise  with respect to, the Company
from the date of the March 31 Financial Statements to the Closing Date.

         3.10. Schedules.  The Company shall have provided to the Purchasers all
schedules  required  pursuant  to  this  Agreement,  which  schedules  shall  be
satisfactory to Purchasers in their sole discretion.

         4.  Conditions to the  Obligations  of the Company at the Closing.  The
obligation of the Company to issue and sell the Series A Preferred Stock and the
Warrants to Purchasers at the Closing is subject to the satisfaction on or prior
to the Closing Date of the following  conditions,  any of which may be waived by
the Company:

         4.1. Representations and Warranties. The representations and warranties
of Purchasers contained in this Agreement shall be true and correct at and as of
the Closing Date.

         4.2. Legal Action. No injunction,  order, investigation,  claim, action
or  proceeding  before  any  court or  governmental  body  shall be  pending  or
threatened  wherein an  unfavorable  judgment,  decree or order would  restrain,
impair or prevent the carrying out of this


                                        4

<PAGE>

Agreement or any of the transactions  contemplated hereby,  declare unlawful the
transactions  contemplated by this Agreement or cause any such transaction to be
rescinded.

         5.  Representations  and Warranties of the Company.  The Company hereby
represents and warrants to Purchasers as follows:

         5.1. Organization. The Company is a corporation duly organized, validly
existing  and in good  standing  under  the laws of the State of  Delaware.  The
Company has all requisite corporate power and authority, and holds all licenses,
permits  and  other  required  authorizations  from  governmental   authorities,
necessary to conduct its business as it is now being conducted or proposed to be
conducted  and to own or lease the  properties  and  assets it now owns or holds
under  lease  (except  that the  Company may in the future be required to obtain
certain  approvals of the U.S. Food and Drug  Administration  in connection with
its  business as proposed to be  conducted).  The Company is duly  qualified  or
licensed and in good standing as a foreign  corporation in Massachusetts  and in
each  jurisdiction  wherein the character of its properties or the nature of the
activities conducted by it makes such qualification or licensing necessary.

         5.2.  Charter  Documents.  The  Company  has  heretofore  delivered  to
Purchasers  true,  correct and complete  copies of the Company's  Certificate of
Incorporation and By-Laws as in full force and effect on the date hereof.

         5.3.  Capitalization.  As of the date hereof, the Company's  authorized
capitalization  consists solely of:  30,000,000 shares of Common Stock, of which
13,723,338 shares are presently issued and outstanding;  and 7,292,637 shares of
Common  Stock are  reserved  for  issuance  upon the  conversion  or exercise of
presently outstanding convertible securities,  options, warrants or other rights
to purchase  Common Stock.  As of the date hereof,  the Company has no shares of
treasury stock.  All  outstanding  securities of the Company are validly issued,
fully paid and  nonassessable.  No stockholder of the Company is entitled to any
preemptive  rights with respect to the purchase or sale of any securities by the
Company.  Except  as has been set forth in  Schedule  5.3  hereto,  there are no
outstanding  options,  warrants or other rights,  commitments  or  arrangements,
written or oral, to purchase or otherwise  acquire any  authorized  but unissued
shares of capital  stock of the Company or any security  directly or  indirectly
convertible  into or exchangeable  for any capital stock of the Company or under
which any such  option,  warrant or  convertible  security  may be issued in the
future, and there are no voting trusts or agreements,  stockholders' agreements,
pledge agreements,  buy-sell,  rights of first offer,  negotiation or refusal or
proxies or similar  arrangements  relating to any  securities  of the Company to
which the Company is a party, and to the best knowledge of the Company after due
investigation there are no such trusts,  agreement,  rights,  proxies or similar
arrangements  as to which  the  Company  is not a party.  Except as set forth on
Schedule 5.3 and as contemplated  herein, none of the shares of capital stock of
the Company is reserved for any purpose,  and the Company is neither  subject to
any obligation  (contingent  or otherwise),  nor has any option to repurchase or
otherwise  acquire or retire any shares of its capital stock.  Schedule 5.3 sets
forth (i) the number of shares of Common Stock authorized for issuance under any
stock


                                        5

<PAGE>

option  plan of the  Company;  (ii) the  number of shares of Common  Stock as to
which  options  under any such plan have been (a)  reserved for issuance and (b)
exercised;  and (iii) the exercise prices for all outstanding  options under any
such plan. Except as set forth on Schedule 5.3, no antidilution adjustments with
respect to the  outstanding  securities  of the Company will be triggered by the
issuance of the securities contemplated hereby.

         5.4 Due  Authorization,  Valid  Issuance,  Etc.. The Series A Preferred
Stock  has been  duly  authorized  and,  when  issued  in  accordance  with this
Agreement upon the Closing Date,  will be free and clear of all liens imposed by
or through the Company.  The Warrants have been duly authorized and, when issued
in accordance  with this Agreement upon the Closing Date, will be validly issued
and free and clear of all liens  imposed by or through the  Company.  The Common
Stock issuable upon the conversion of the Series A Preferred  Stock and upon the
exercise of the Warrants has been duly  authorized and reserved and, when issued
in accordance with the terms and conditions thereof and this Agreement,  will be
validly issued,  fully paid and nonassessable shares of Common Stock and will be
free and clear of all liens  imposed by or through the  Company.  The  issuance,
sale and delivery of the Series A Preferred  Stock,  the Warrants and the Common
Stock issuable upon the conversion of the Series A Preferred  Stock and upon the
exercise  of the  Warrants  will  not be  subject  to any  preemptive  right  of
stockholders  of the Company or to any right of first  refusal or other right in
favor of any person.

         5.5.  Subsidiaries.  The  Company  has no  wholly  or  partially  owned
Subsidiaries  (as  defined in Section  9.10) and does not  control,  directly or
indirectly,   any  other  corporation,   business  trust,   firm,   partnership,
association,  joint  venture,  entity  or  organization.  Except as set forth in
Schedule 5.5 the Company does not own any shares of stock, partnership interest,
joint venture  interest or any other  security,  equity or interest in any other
corporation or other organization or entity.

         5.6. Authorization; No Breach. The Company has the full corporate power
and authority to execute,  deliver and enter into this  Agreement and to perform
its obligations hereunder,  and the execution,  delivery and performance of this
Agreement,  the  Certificate  of  Designations,   the  Warrants  and  all  other
transactions  contemplated hereby have been duly authorized by the Company,  and
this Agreement constitutes a legal, valid and binding obligation of the Company,
enforceable in accordance with its terms except as the enforceability hereof may
be limited by (a) bankruptcy,  insolvency, moratorium and similar laws affecting
creditors'  rights  generally and (b) the availability of remedies under general
equitable  principles  and  (c) to the  extent  the  indemnification  provisions
contained  in section 8.5 hereof may be limited by  applicable  federal or state
securities laws.  Except as set forth on Schedule 5.6 hereto,  the execution and
delivery by the Company of this  Agreement,  the offering,  sale and issuance of
the Series A Preferred Stock and the Warrants  pursuant to this  Agreement,  and
the performance  and  fulfillment of the Company of its  obligations  under this
Agreement,  the Series A Preferred  Stock and the Warrants,  do not and will not
(i) conflict  with or result in a breach of the terms,  conditions or provisions
of, (ii)  constitute a default  under,  or event which,  with notice or lapse of
time or both, would constitute a breach of or default under, (iii) result in the
creation of any lien,  security interest,  adverse claim,  charge or encumbrance
upon the capital stock or assets of


                                        6

<PAGE>

the Company  pursuant to, (iv) give any third party the right to accelerate  any
obligation under or terminate,  (v) result in a violation of, (vi) result in the
loss of any license,  certificate,  legal  privilege  or legal right  enjoyed or
possessed by the Company  under,  or (vii) require any  authorization,  consent,
approval,  exemption or other action by or notice to any court or administrative
or  governmental  body  pursuant to or require  the consent of any other  person
under,  the Certificate of  Incorporation  or By-Laws of the Company or any law,
statute,  rule or  regulation to which the Company is subject or by which any of
its  properties  are bound,  or any agreement,  instrument,  order,  judgment or
decree to which the Company is subject or by which its properties are bound.

         5.7.  Financial  Statements and SEC Documents.  (a) Attached  hereto as
Schedule  5.7 are (i) the audited  financial  statements  of the Company for the
fiscal year ended  December 31, 1996,  including the balance sheet as at the end
of such fiscal  year and the related  statements  of  operations,  stockholders'
equity  (deficit)  and cash flows for such fiscal  year,  certified by Coopers &
Lybrand,  L.L.P.  and (ii) the  March 31  Financial  Statements  (the  financial
statements  referred  to  in  clauses  (i)  and  (ii)  are  referred  to  herein
collectively  as the "Financial  Statements").  For purposes of this  Agreement,
March 31, 1997,  shall be  hereinafter  referred to as the "Balance Sheet Date."
The Financial  Statements  have been  prepared in accordance  with the books and
records of the Company and generally  accepted  accounting  principles,  applied
consistently  with the past practices of the Company  (except as otherwise noted
in such Financial  Statements),  reflect all  liabilities and obligations of the
Company, as of their respective dates, and present fairly the financial position
of the  Company  and the  results of its  operations  as of the time and for the
periods indicated therein.

         (b) The Company has made  available  to  Purchasers a true and complete
copy of each report,  schedule,  registration  statement  and  definitive  proxy
statement filed by the Company with the Securities and Exchange Commission since
January  1, 1993 (as such  documents  have since the time of their  filing  been
amended,   the  "SEC  Documents")  which  are  all  the  documents  (other  than
preliminary  material) that the Company was required to file with the Securities
and Exchange  Commission since such date. As of their respective  dates, the SEC
Documents  complied in all respects with the  requirements of the Securities Act
(as defined in Section  9.7) and/or the Exchange Act (as defined in Section 9.8)
as the case may be, and the rules and regulations of the Securities and Exchange
Commission  thereunder  applicable  to such  SEC  Documents  and none of the SEC
Documents  contained  any  untrue  statement  of a  material  fact or omitted to
statement of material  fact  required to be stated  therein or necessary to make
the  statements  therein,  in light of the  circumstances  under which they were
made, not misleading.  The financial  statements of the Company  included in the
SEC  Documents  comply as to form in all  respects  with  applicable  accounting
requirements  and with the published rules and regulations of the Securities and
Exchange Commission with respect thereto,  have been prepared in accordance with
generally  accepted  accounting  principles applied on a consistent basis during
the periods involved (except as may be indicated in the notes thereto or, in the
case of the unaudited  statements,  as permitted by Form 10-Q of the  Securities
and  Exchange  Commission)  and  fairly  present  (subject,  in the  case of the
unaudited statements, to normal, recurring audit


                                        7

<PAGE>

adjustments)  the financial  position of the Company as at the dates thereof and
the consolidated results of their operations and cash flows for the periods then
ended.

         5.8. No Material Adverse  Changes.  Except as set forth on Schedule 5.8
hereto,  since the  Balance  Sheet  Date  there has not at any time been (a) any
material adverse change in the financial condition,  operating results, business
prospects, employee relations or customer relations of the Company, or (b) other
adverse  changes,  which in the aggregate  have been  materially  adverse to the
Company.

         5.9.  Absence of Certain  Developments.  Except as contemplated by this
Agreement,  and except as set forth in Schedule  5.9  hereto,  since the Balance
Sheet Date, the Company has not, nor will have prior to the Closing:  (a) issued
any  securities;  (b) borrowed  any amount or incurred or became  subject to any
liabilities  (absolute or contingent),  other than  liabilities  incurred in the
ordinary course of business and liabilities  under contracts entered into in the
ordinary  course of  business,  none of which are or shall be material and which
are less than $25,000;  (c)  discharged or satisfied any lien,  adverse claim or
encumbrance or paid any obligation or liability (absolute or contingent),  other
than current  liabilities paid in the ordinary course of business;  (d) declared
or  made  any  payment  or  distribution  of  cash  or  other  property  to  the
stockholders  of the Company  with  respect to the Common  Stock or purchased or
redeemed any shares of Common Stock; (e) mortgaged,  pledged or subjected to any
lien, adverse claim,  charge or any other encumbrance,  any of its properties or
assets,  except for liens for taxes not yet due and payable;  (f) sold, assigned
or transferred any of its assets, tangible or intangible, except in the ordinary
course of  business  and in an amount less than  $25,000,  or  disclosed  to any
person, firm or entity not party to a confidentiality agreement with the Company
any proprietary confidential information;  (g) suffered any extraordinary losses
or waived any rights of material  value;  (h) made any capital  expenditures  or
commitments  therefor;  (i) entered into any other transaction other than in the
ordinary  course of business in an amount less than  $25,000 or entered into any
material  transaction,  whether or not in the ordinary  course of business;  (j)
made any charitable contributions or pledges; (k) suffered damages,  destruction
or casualty  loss,  whether or not covered by  insurance,  affecting  any of the
properties  or assets of the  Company or any other  properties  or assets of the
Company which could have a material adverse effect on the business or operations
of the Company;  (l) made any change in the nature or operations of the business
of the Company;  or (m) resolved or entered into any agreement or  understanding
with respect to any of the foregoing.

         5.10.  Properties.  The Company has good and marketable title to all of
the real  property and good title to all of the personal  property and assets it
purports to own, including those reflected as owned on the Company Balance Sheet
or acquired thereafter,  and a good and valid leasehold interest in all property
indicated as leased on the Company Balance Sheet,  whether such property is real
or personal, free and clear of all liens, adverse claims, charges,  encumbrances
or  restrictions of any nature  whatsoever,  except (a) such as are reflected on
the Company  Balance  Sheet or  described  in  Schedule  5.10 hereto and (b) for
receivables and charges collected in the ordinary course of business.  Except as
disclosed  in  Schedule  5.10  hereto,  the  Company  owns or  leases  all  such
properties as are necessary to its operations as now conducted


                                        8

<PAGE>

and as presently  proposed to be conducted and all such  properties  are, in all
material respects, in good operating condition and repair.

         5.11. Taxes. Except as referred to in Schedule 5.11 hereto, the Company
has timely filed all federal,  state,  local and foreign tax returns and reports
required to be filed, and all taxes, fees,  assessments and governmental charges
of any nature  shown by such returns and reports to be due and payable have been
timely paid except for those amounts being contested in good faith and for which
appropriate  amounts have been reserved in accordance  with  generally  accepted
accounting  principles and are reflected on the Company Balance Sheet.  There is
no tax deficiency  which has been, or, to the knowledge of the Company might be,
asserted  against  the  Company  which would  adversely  affect the  business or
operations,  or proposed  business or operations,  of the Company.  All such tax
returns and reports were  prepared in  accordance  with the  relevant  rules and
regulations of each taxing  authority having  jurisdiction  over the Company and
are true and correct.  The Company has neither given nor been  requested to give
any waiver of any  statute of  limitations  relating  to the payment of federal,
state,  local or foreign  taxes.  The Company has not been, nor is it now being,
audited by any federal, state, local or foreign tax authorities. The Company has
made all required  deposits for taxes  applicable  to the current tax year.  The
Company is not, and has never been, a member of any  "affiliated  group"  within
the meaning of Section 1504 of the Internal Revenue Code, as in effect from time
to time.

         5.12.  Litigation.  Except as set forth on Schedule 5.12 hereto,  there
are no actions, suits, proceedings, orders, investigations or claims pending or,
to the Company's knowledge,  threatened against or affecting the Company, at law
or in equity or before or by any federal, state, municipal or other governmental
department,  commission, board, bureau, agency or instrumentality;  there are no
arbitration  proceedings  pending  under  collective  bargaining  agreements  or
otherwise;  and, to the  knowledge of the Company,  there is no basis for any of
the foregoing.

         5.13.  Compliance  with Law.  The Company has  complied in all respects
with all  applicable  statutes and  regulations  of the United States and of all
states,  municipalities  and applicable  agencies and foreign  jurisdictions  or
bodies in respect of the  conduct of its  business  and  operations  and benefit
plans,  and the failure,  if any, by the Company to have fully complied with any
such statute or regulation does not and will not materially adversely affect the
business, operations or financial condition of the Company.

         5.14.  Trademarks and Patents.  Schedule 5.14 annexed hereto contains a
true,  complete and correct  list of all  trademarks,  trade names,  patents and
copyrights (and applications  therefor) if any, heretofore or presently owned or
licensed or used or required  to be used by the Company in  connection  with its
business; and, except as set forth on Schedule 5.14, each such trademark,  trade
name, patent and copyright (and application therefor) listed in Schedule 5.14 as
being owned by the Company is not subject to any license,  royalty  arrangement,
option or dispute and is free and clear of all liens.  To the best  knowledge of
the Company, none of the trademarks,  trade names, patents or copyrights used by
the Company in connection with its


                                        9

<PAGE>

business  infringe any trademark,  trade name,  patent or copyright of others in
the United States or in any other country, in any way which adversely affects or
which in the future may  adversely  affect the  business  or  operations  of the
Company.  Except as set forth in  Schedule  5.14,  no  stockholder,  officer  or
director  of the  Company or any other  person  owns or has any  interest in any
trademark,  trade name, service mark, patent, copyright or application therefor,
or trade  secret,  licenses,  invention,  information  or  proprietary  right or
process,  if any,  used by the  Company in  connection  with its  business.  The
Company has no notice or knowledge of any  objection or claim being  asserted by
any person with respect to the ownership,  validity enforceability or use of any
such trademarks, trade names, patents and copyrights (and applications therefor)
listed  on  Schedule  5.14  or  challenging  or  questioning   the  validity  or
effectiveness of any license relating thereto. There are no unresolved conflicts
with,  or  pending  claims  of,  any other  person,  whether  in  litigation  or
otherwise,  involving the trademarks,  trade names,  patents and copyrights (and
applications therefor), and there are no liens, encumbrances, adverse claims, or
rights of any other person which would prevent the Company from  fulfilling  its
obligations  under this  Agreement.  To the best  knowledge of the Company,  the
business of the Company,  as presently conducted and as proposed to be conducted
does not and will not cause the  Company to violate any  trademark,  trade name,
patent,  copyright,  trade secret,  license or proprietary interest of any other
person or entity,  in any way which adversely affects or which in the future may
adversely affect the business or operations of the Company.  Except as disclosed
in Schedule  5.14  hereto,  the Company  possesses  all  proprietary  technology
necessary  for the  conduct  of  business  by the  Company,  both  as  presently
conducted and as presently proposed to be conducted.

         5.15.  Insurance.   Schedule  5.15  annexed  hereto  contains  a  brief
description of each insurance  policy  maintained by the Company with respect to
its  properties,  assets  and  business;  each such  policy is in full force and
effect;  and the Company is not in default with respect to its obligations under
any of such  insurance  policies.  The  insurance  coverage of the Company is in
amounts not less than is customarily  maintained by corporations  engaged in the
same or similar business and similarly situated,  including, without limitation,
insurance against loss, damage,  fire, theft,  public liability and other risks.
The  activities and operations of the Company have been conducted in a manner so
as to conform to all applicable  provisions of these insurance  policies and the
Company  has not taken or failed to take any action  which  would cause any such
insurance policy to lapse.

         5.16.  Agreements.  Except as set forth in Schedule  5.16  hereto,  the
Company is neither a party to nor bound by any agreement or commitment,  written
or oral,  which  obligates the Company to make payments to any person,  or which
obligates any person to make  payments to the Company,  in the case of each such
agreement in an amount exceeding $75,000 in the aggregate, or which is otherwise
material to the  conduct and  operation  of the  Company's  business or proposed
business or any of its properties or assets, including,  without limitation, all
shareholder, employment,  non-competition and consulting agreements and employee
benefit plans and arrangements and collective bargaining agreements to which the
Company is a party or by which it is bound. All such agreements are legal, valid
and  binding  obligations  of  the  Company,  in  full  force  and  effect,  and
enforceable in accordance with their respective terms,


                                       10

<PAGE>

except  as  the  enforceability  thereof  may  be  limited  by  (a)  bankruptcy,
insolvency,  moratorium,  and similar laws affecting creditors' rights generally
and (b) the  availability of remedies under general  equitable  principles.  The
Company has performed all obligations required to be performed by it, and is not
in default,  or in receipt of any claim, under any such agreement or commitment,
and the Company has no present  expectation or intention of not fully performing
all of such  obligations,  nor does the Company have any knowledge of any breach
or anticipated  breach by the other parties to any such agreement or commitment.
The  Company  is  not  a  party  to  any  contract,  agreement,   instrument  or
understanding  which  materially  adversely  affects the  business,  properties,
operations,  assets  or  condition  (financial  or  otherwise)  of the  Company.
Purchasers  have been furnished  with, or the Company has made available for the
Purchaser's  review, a true and correct copy of each written agreement  referred
to in Schedule  5.16,  together  with all  amendments,  waivers or other changes
thereto.

         5.17.  Undisclosed  Liabilities.  Except as set forth on Schedule  5.17
hereto, the Company has no obligation or liability  (whether accrued,  absolute,
contingent,  unliquidated,  or  otherwise,  whether or not known to the Company,
whether due or to become due)  arising out of  transactions  entered  into at or
prior to the Closing of this Agreement, or any action or inaction at or prior to
the Closing of this Agreement, or any state of facts existing at or prior to the
Closing of this  Agreement,  except (a)  liabilities  reflected  on the  Company
Balance Sheet;  (b)  liabilities in an amount less than $25,000  incurred in the
ordinary  course of business  since the  Balance  Sheet Date (none of which is a
liability  for breach of  contract,  breach of warranty,  torts,  infringements,
claims  or  lawsuits);  and (c)  liabilities  or  obligations  disclosed  in the
schedules hereto.

         5.18. Employees;  Conflicting  Agreements.  (a) The Company shall cause
all members of management and all professional  employees of and consultants and
advisors to the Company,  including all employees and  consultants  and advisors
involved in its  research  and  development,  to be subject to  agreements  with
respect to (i)  nondisclosure  of confidential  information,  (ii) assignment of
patents, trademarks,  copyrights and proprietary rights to the Company and (iii)
disclosure to the Company of inventions.

         (b) Except as set forth on Schedule  5.18, to the best of the Company's
knowledge, no stockholder, director, officer or key employee of the Company is a
party to or bound by any agreement,  contract or  commitment,  or subject to any
restrictions in connection  with any previous or current  employment of any such
person,  which adversely  affects,  or which in the future may adversely affect,
the business or the proposed business of the Company or the rights of Purchasers
under  this  Agreement  and in respect of its rights as a holder of the Series A
Preferred Stock and the Warrants.

         5.19.  Disclosure.  Neither this  Agreement  nor any of the  schedules,
exhibits, written statements,  documents or certificates prepared or supplied by
the Company with respect to the  transactions  contemplated  hereby  contain any
untrue  statement of a material fact or omit a material  fact  necessary to make
the  statements  contained  herein or  therein  not  misleading  in light of the
circumstances  under which made.  Except as disclosed  in Schedule  5.19 hereto,
there


                                       11

<PAGE>

exists no fact or  circumstance  which, to the knowledge of the Company upon due
inquiry,  materially adversely affects, or which could reasonably be anticipated
to have a material  adverse  effect  on,  the  existing  or  expected  financial
condition,  operating results, assets, customer relations, employee relations or
business prospects of the Company.

         5.20.  Compliance  with the  Securities  Laws.  Except  as set forth on
Schedule  5.20 hereto,  neither the Company nor anyone  acting on its behalf has
directly or indirectly  offered the Series A Preferred  Stock or the Warrants or
any part thereof or any similar security of the Company (or any other securities
convertible or exchangeable for the Series A Preferred Stock and the Warrants or
any similar security), for sale to, or solicited any offer to buy the same from,
anyone  other than  Purchasers.  Assuming  the accuracy and truth of each of the
Purchasers'  representations  set  forth in  Section  6 of this  Agreement,  all
securities of the Company heretofore sold and issued by it were sold and issued,
and the Series A Preferred  Stock and the Warrants were offered and will be sold
and issued, in compliance with all applicable federal and state securities laws.

         5.21.  Brokers.  Except  as set  forth on  Schedule  5.21,  no  finder,
investment  banker,  broker,  agent,  financial person or other intermediary has
acted on behalf of the Company in  connection  with the offering of the Series A
Preferred Stock and the Warrants or the consummation of this Agreement or any of
the transactions  contemplated  hereby and none of the foregoing are entitled to
any compensation or success fee in connection therewith.

         5.22.  Transactions  with  Affiliates.  Except as set forth in Schedule
5.22, no director,  officer,  employee,  consultant or agent of the Company,  or
member of the family of any such person or any corporation,  partnership,  trust
or other  entity in which any such  person,  or any  member of the family of any
such person, has a substantial interest in or is an officer, director,  trustee,
partner or holder of more than 5% of the outstanding capital stock thereof, is a
party to any transaction with the Company, including any contract,  agreement or
other arrangement  providing for the employment of, furnishing of services by or
requiring payments to any such person or firm.

         5.23.  Environmental  Matters (a) The Company and all properties owned,
operated or leased by the Company  have  obtained  and  currently  maintain  all
environmental  permits  required for their  business and  operations  and are in
compliance  with  all  such  environmental  permits;  (ii)  there  are no  legal
proceedings  pending nor, to the best  knowledge of the Company,  threatened  to
modify or revoke any such environmental  permits;  and (iii) neither Company nor
any  property  owned,  operated or leased by the Company has received any notice
from any source that there is lacking any environmental  permit required for the
current use or operation of the business of the Company,  or any property owned,
operated or leased by the Company.

         (b) Except as set forth in Schedule 5.23 hereto,  (i) all real property
owned,  operated or leased by the  Company,  and, to the best  knowledge  of the
Company,  all property adjacent to such properties,  are free from contamination
by any hazardous material; and the


                                       12

<PAGE>

Company is not subject to  environmental  costs and liabilities  with respect to
hazardous  materials,  and no facts or circumstances exist which could give rise
to environmental costs and liabilities with respect to hazardous materials.

         (c) Except as set forth in Schedule 5.23 hereto,  there is not now, nor
has there been in the past, on, in, or under any real property owned, leased, or
operated   by  the   Company,   or  by  any  of   its   predecessors   (i)   any
asbestos-containing   materials,  (ii)  any  underground  storage  tanks,  (iii)
above-ground storage tanks, (iv) impoundments, (v) poly-chlorinated biphenyls or
(vi) radioactive substances.


         (d) The Company has provided or made available to the Purchasers drafts
and final versions of all  environmental  site assessments  (including,  but not
limited to Phase I and Phase II reports),  risk management  studies and internal
environmental  audits  that have been  conducted  by or on behalf of the Company
("Environmental  Studies"), with respect to any real property that now or in the
past  has  been  owned,  operated  or  leased  by  the  Company,  or  any of its
predecessors.

         (e) Except as set forth in Schedule  5.23  hereto,  the Company and all
properties  owned,  operated  or leased by the Company  are in  compliance  with
environmental law.

         (f) Except as set forth in Schedule  5.23  hereto,  neither the Company
nor any property  owned,  leased or operated by the Company has received or been
issued any written  request for  information,  or has been notified that it is a
potentially  responsible party under the environmental  laws with respect to any
on-site or off-site for which environmental costs and liabilities are asserted.

         6.  Representations  and  Warranties of Purchasers.  Purchasers  hereby
severally and not jointly represent and warrant to the Company as follows:

         6.1.  Investment  Intent.  Each  of the  Purchasers  is an  "accredited
investor"  within the meaning of Regulation D under the Securities  Act. Each of
the  Purchasers  has  experience  in making  investments  in  development  stage
biotechnology  companies and is acquiring  the Series A Preferred  Stock and the
Warrants  for its own  account  and not with a  present  view to, or for sale in
connection  with,  any  distribution  thereof in violation  of the  registration
requirements  of the  Securities  Act.  Purchasers  consent to the  placing of a
legend on the  certificates  representing  the Series A Preferred  Stock and the
Warrants to the effect that the shares of Common Stock issuable upon exercise or
conversion,  as the case may be, of the  Warrants,  and the  Series A  Preferred
Stock  have  not  been  registered  under  the  Securities  Act  and  may not be
transferred except in accordance with applicable securities laws or an exception
therefrom.  Each  of  the  Purchasers  acknowledges  that  it has  reviewed  the
Company's Form 10-K for the year ended December 31, 1996.


                                       13

<PAGE>

         6.2. Authorization.  Each of the Purchasers has the power and authority
to execute and deliver this Agreement and to perform its obligations  hereunder,
having obtained all required consents, if any, and this Agreement, when executed
and  delivered,  will  constitute a legal valid and binding  obligation  of such
Purchaser.

         6.3.  Brokers.  No finder,  broker,  agent,  financial  person or other
intermediary  has acted on behalf of Purchasers in connection  with the offering
of the Series A Preferred  Stock and the  Warrants or the  consummation  of this
Agreement or any of the transactions contemplated hereby.

         7.  Covenants  of the  Company.  So long as the  Purchasers,  Paramount
Capital, Inc. and their affiliates,  in the aggregate,  beneficially own (taking
into account  shares  issuable upon  conversion or exercise of other  securities
held by them) at least five percent (5%) of the outstanding  shares of any class
or classes  (however  designated) of capital stock entitled to vote generally in
the election of members of the Board of Directors  (the  "Voting  Shares"),  the
Company covenants and agrees with Purchasers as follows:

         7.1.  Books and Accounts.  The Company  will:  (a) make and keep books,
records and accounts, which, in reasonable detail, accurately and fairly reflect
its transactions,  including without limitation, dispositions of its assets; and
(b) devise and maintain a system of internal  accounting  controls sufficient to
provide  reasonable  assurances that (i) transactions are executed in accordance
with  management's  general or specific  authorization,  (ii)  transactions  are
recorded  as  necessary  to  permit  preparation  of  financial   statements  in
conformity with generally accepted accounting  principles and in accordance with
the  Company's  past  practices  or  any  other  criteria   applicable  to  such
statements, and to maintain accountability for assets, (iii) access to assets is
permitted   only  in   accordance   with   management's   general  or   specific
authorization,  and (iv) the recorded accountability for assets is compared with
the existing assets at reasonable intervals and appropriate action is taken with
respect to any differences.

         7.2.  Periodic  Reports.  (a) The Company will furnish to Purchasers as
soon as  practicable,  and in any  event  within  90 days  after the end of each
fiscal year of the Company  (commencing  with the fiscal year ended December 31,
1997), an annual report of the Company,  including a balance sheet as at the end
of such fiscal year and statement of operations,  stockholders' equity (deficit)
and cash flows for such fiscal year,  together with the related  notes  thereto,
setting forth in each case in  comparative  form  corresponding  figures for the
preceding  fiscal  year,  all of which will be  correct  and  complete  and will
present  fairly the  financial  position  of the  Company and the results of its
operations  and  changes in its  financial  position  as of the time and for the
period  then  ended.  Such  financial  statements  shall  be  accompanied  by an
unqualified  report  (other than  qualifications  contingent  upon the Company's
ability  to  obtain  additional  financing),  in form and  substance  reasonably
satisfactory  to  Purchasers,   of  independent  public  accountants  reasonably
satisfactory  to Purchasers to the effect that such  financial  statements  have
been  prepared  in  accordance  with the books and  records of the  Company  and
generally  accepted  accounting  principles  applied on a basis  consistent with
prior years (except as otherwise  specified in such report),  and present fairly
the financial position of


                                       14

<PAGE>

the  Company and the results of its  operations  and changes in their  financial
position as of the time and for the period then ended.  The Company will use its
best  efforts to conduct its  business  so that such  report of the  independent
public  accountants will not contain any  qualifications  as to the scope of the
audit,  the  continuance  of the  Company,  or  with  respect  to the  Company's
compliance with generally accepted accounting  principles  consistently applied,
except for changes in methods of accounting in which such accountants concur.

         (b) The Company will furnish to Purchasers,  as soon as practicable and
in any event  within 45 days  after  the end of each of the first  three  fiscal
quarters of the  Company  during each  fiscal  year,  a quarterly  report of the
Company  consisting of an unaudited  balance sheet as at the end of such quarter
and an unaudited  statement of operations,  stockholders'  equity  (deficit) and
cash flows for such  quarter  and the  portion of the  fiscal  year then  ended,
setting forth in each case in  comparative  form  corresponding  figures for the
preceding  fiscal  year.  All such  reports  shall  be  certified  by the  Chief
Financial  Officer or Vice  President--Finance  of the Company to be correct and
complete,  to present  fairly the  financial  position  of the  Company  and the
consolidated  results of its operations and changes in its financial position as
of the  time  and  for the  period  then  ended  and to have  been  prepared  in
accordance with generally accepted accounting principles.


         (c) The Company shall furnish to  Purchasers,  within 30 days after the
end of each calendar month, an unaudited  balance sheet of the Company as of the
end  of  such  month  and  the  related   unaudited   statement  of  operations,
stockholders'  equity (deficit) and cash flows for such month and for the fiscal
year to date,  setting forth in each case in comparative form the  corresponding
figures  for the budget for the current  fiscal  year,  or such other  financial
information as otherwise  agreed to by the parties  hereto.  All such statements
shall be certified by the Chief Financial Officer or Vice  President--Finance of
the  Company to the effect that such  statements  fairly  present the  financial
condition of the Company as of the dates shown and the results of its operations
for the  periods  then  ended and that such  statements  have been  prepared  in
conformity with generally accepted accounting  principles  consistently  applied
except for normal,  recurring,  year-end  audit  adjustments  and the absence of
footnotes.

         (d) Commencing  with the Company's  fiscal year  commencing  January 1,
1997, the Company shall furnish to Purchasers, as soon as practicable and in any
event not less than sixty (60) days prior to the end of each  fiscal year of the
Company,  (i) an annual  operating  budget for the Company,  for the  succeeding
fiscal year,  containing  projections  of profit and loss,  cash flow and ending
balance  sheets for each month of such fiscal year and (ii) a business  plan for
the  Company  as  specified  in  Section  7.18.  The  Company  shall  furnish to
Purchasers at least thirty (30) days prior to the date the Board of Directors is
scheduled to approve the annual  operating  budget and business plan referred to
above, such operating budget and business plan as proposed to be approved by the
Board of Directors. Promptly upon preparation thereof, the Company shall furnish
to Purchasers any other operating budgets or business plans that the Company may
prepare and any revisions or modifications of such previously  furnished budgets
or business plans.


                                       15

<PAGE>

         (e) The annual statements and quarterly  statements  furnished pursuant
to Sections 7.2(a) and (b) shall include a narrative  discussion prepared by the
Company  describing  the business  operations  of the Company  during the period
covered by such statements. The monthly statements furnished pursuant to Section
7.02(c) shall be  accompanied  by a statement  describing  any material  events,
transactions or deviations  from the Company's  Business Plan (as defined below)
contemplated  by Section 7.18 and  containing an  explanation  of the causes and
circumstances thereof.

         7.3.  Certificates of Compliance.  The Company  covenants that promptly
after the occurrence of any default  hereunder or any default under or breach of
any material  agreement,  or any other  material  adverse event or  circumstance
affecting the Company,  it will deliver to  Purchasers an Officers'  Certificate
specifying in reasonable detail the nature and period of existence thereof,  and
what actions the Company has taken and proposes to take with respect thereto.

         7.4.  Other  Reports and  Inspection.  (a) The Company  will furnish to
Purchasers (a) as soon as practicable  after  issuance,  copies of any financial
statements  or reports  prepared by the Company for, or otherwise  furnished to,
its  stockholders  or the Securities  and Exchange  Commission and (b) promptly,
such other  documents,  reports and financial  data as Purchasers may reasonably
request.  In addition the Company  will,  upon prior notice,  make  available to
Purchasers or its  representatives  or designees (a) all assets,  properties and
business  records of the  Company  for  inspection  and/or  copying  and (b) the
directors,  officers and employees of the Company for interviews  concerning the
business, affairs and finances of the Company.

         7.5.  Insurance.  The Company will at all times maintain valid policies
of worker's compensation and such other insurance with respect to its properties
and business of the kinds and in amounts not less than is customarily maintained
by corporations  engaged in the same or similar business and similarly situated,
including,  without  limitation,  insurance against fire, loss,  damage,  theft,
public  liability and other risks.  The activities and operations of the Company
shall be conducted in a manner to as to conform in all material  respects to all
applicable provisions of such policies.

         7.6. Use of Proceeds;  Restriction  on Payments.  The Company shall use
the net proceeds  from the sale of the Series A Preferred  Stock and Warrants to
bridge its working  capital  needs  through  such time as it can  consummate  an
offering of its securities.  The Company  covenants and agrees that it will not,
without the prior written consents of the Purchasers, directly or indirectly use
any of the proceeds to (i) repay any indebtedness of the Company,  including but
not limited to any indebtedness to officers,  employees,  directors or principal
stockholders  of the Company,  but excluding  accounts  payable  incurred in the
ordinary course of business or (ii) redeem,  repurchase or otherwise acquire any
equity  security  of the  Company,  without  the prior  written  consents of the
Purchasers.  Notwithstanding  the  foregoing,  the  Company  shall  not make any
payments before August 15 to any parties that exceed $25,000


                                       16

<PAGE>

(or, after August 15, that exceed $50,000) without the prior written consents of
the Partnership and the Trust.

         7.7. Material  Changes.  The Company will promptly notify Purchasers of
any material  adverse change in the business,  properties,  assets or condition,
financial or otherwise,  of the Company,  or any other material adverse event or
circumstance  affecting  the  Company,  and of any  litigation  or  governmental
proceeding  pending or, to the knowledge of the Company,  threatened against the
Company or against any director or officer of the Company.

         7.8.  Transactions  with  Affiliates.  Except as disclosed as Schedules
5.16 and 5.22 and, for the  transactions  contemplated  by this  Agreement,  the
Company shall not (a) engage in any transaction with, (b) make any loans to, nor
(c) enter into any contract,  agreement or other  arrangement  (i) providing for
(x) the  employment  of, (y) the furnishing of services by, or (z) the rental of
real or personal  property  from, or (ii) otherwise  requiring  payments to, any
officer, director or key employee of the Company or any relative of such persons
or any other  "affiliate"  or  "associate"  of such  persons  (as such terms are
defined in the rules and  regulations  promulgated  under the  Securities  Act),
without the prior written approval of the Partnership and the Trust.

         7.9.  Corporate  Existence,   Licenses  and  Permits;   Maintenance  of
Properties;  New Businesses.  The Company will at all times conduct its business
in the  ordinary  course and cause to be done all things  necessary to maintain,
preserve and renew its existence and will preserve and keep in force and effect,
all  licenses,  permits and  authorizations  necessary to the conduct of its and
their  respective  businesses.  The  Company  will  also  maintain  and keep its
properties in good repair,  working order and condition,  and from time to time,
to make all needful and proper repairs,  renewals and replacements,  so that the
business  carried on in connection  therewith  may be properly  conducted at all
times.

         7.10. Other Material Obligations. The Company will comply with, (a) all
material  obligations which it is subject to, or becomes subject to, pursuant to
any contract or  agreement,  whether oral or written,  as such  obligations  are
required to be observed or performed, unless and to the extent that the same are
being contested in good faith and by appropriate proceedings and the Company has
set aside on its books  adequate  reserves  with  respect  thereto,  and (b) all
applicable laws,  rules, and regulations of all  governmental  authorities,  the
violation of which could have a material adverse effect upon the business of the
Company.

         7.11.  Amendment to the Certificate of  Incorporation  and the By-Laws.
The  Company  will  perform  and be in  compliance  with and  observe all of the
provisions  set forth in its  Certificate  of  Incorporation  and By-Laws to the
extent that the performance of such obligations is legally permissible; provided
that the fact that performance is not legally  permissible will not prevent such
nonperformance  from constituting an event of default under this Agreement.  The
Company  will not amend its  Certificate  of  Incorporation  or  By-Laws  or any
Certificate  of  Designations  for any other  series of  Preferred  Stock of the
Company so as


                                       17

<PAGE>

adversely  to  affect  the  rights  of  Purchasers  under  this  Agreement,  the
Certificate of  Incorporation,  the By-Laws,  the Warrants or the Certificate of
Designations.

         7.12.  Merger;  Sale of Assets.  The Company will not become a party to
any merger, consolidation or reorganization, or sell, lease, license, sublicense
or  otherwise  dispose of all or  substantially  all of its assets,  without the
prior approval of Purchasers.

         7.13.  Acquisition.  The Company  will not acquire any  interest in any
business  from any  person,  firm or entity  (whether  by a purchase  of assets,
purchase  of  stock,   merger  or  otherwise)  without  the  prior  approval  of
Purchasers.

         7.14. Dividends;  Distributions;  Repurchases of Common Stock; Treasury
Stock.  The Company shall not declare or pay any dividends on, or make any other
distribution  with  respect to, its  capital  stock,  whether  now or  hereafter
outstanding,  or purchase,  acquire,  redeem or retire any shares of its capital
stock, without the consent of Purchasers, provided, however, the foregoing shall
not prohibit the Company from  repurchasing  any shares of its Common Stock from
any present or former  officer,  Director  or  employee  of the  Company  upon a
termination or resignation of such person from the Company.

         7.15.  Consents and Waivers.  (a) Except as set forth on Schedule 7.15,
the Company has obtained all consents and waivers needed to enable it to perform
all of its obligations  under this Agreement and the  transactions  contemplated
hereby.

         (b) Except as set forth on Schedule 7.15, the Company has obtained from
all holders of options,  warrants and other securities of the Company having any
right  of  first  refusal,   offer,  sale,  negotiation  or  similar  rights  or
antidilution or other rights to have the terms (including,  without  limitation,
conversion or exercise prices or rates) of such  instruments  adjusted by virtue
of the purchase and sale of the Series A Preferred Stock and the Warrants or the
other transactions  contemplated by this Agreement, a written waiver in form and
substance satisfactory to Purchasers and their counsel.

         7.16.  Taxes and Liens.  The Company will duly pay and  discharge  when
payable, all taxes, assessments and governmental charges imposed upon or against
the Company or its properties, or any part thereof or upon the income or profits
therefrom,  in each case before the same become  delinquent and before penalties
accrue thereon, as well as all claims for labor,  materials or supplies which if
unpaid  might by law become a lien upon any of its  property,  unless and to the
extent  that the same are  being  contested  in good  faith  and by  appropriate
proceedings  and the Company has set aside on its books  adequate  reserves with
respect thereto.

         7.17.  Restrictive  Agreement.  The Company  covenants  and agrees that
subsequent to the Closing, it will not be a party to any agreement or instrument
which by its terms would restrict the Company's  performance of its  obligations
pursuant to this  Agreement,  the  Certificate of  Incorporation,  By-laws,  the
Warrants or the Series A Preferred Stock.


                                       18

<PAGE>

         7.18.  Business  Plan.   Commencing  with  the  Company's  fiscal  year
commencing  January 1,  1997,  the  Company's  Chief  Financial  Officer or Vice
President--Finance  shall  prepare or have  prepared  and submit to the Board of
Directors  not less than 60 days prior to the  beginning  of each fiscal year of
the Company,  an updated business plan (the "Business Plan") for such year which
shall set forth the  Company's  product  development,  marketing  and  servicing
plans,  capital expenditures and expense budgets and shall encompass a statement
of long range strategy over a five-year  period and  short-range  tactics over a
two-year  period.  The Business Plan shall specify  quantitative and qualitative
goals for the Company and relate the  attainment of those goals to the Company's
strategic objectives.

         7.19.  Director and Observer.  (a) For a period of five years after the
Closing  Date,  the  Partnership  and the Trust  shall be entitled to nominate a
majority  of the  voting  members  of the  Board  of  Directors  of the  Company
provided,  however,  that,  to the extent  such right would cause the Company to
violate  Rule  4460(i)  of  the  National  Association  of  Securities  Dealers'
Marketplace  Rules, the Partnership and the Trust shall not elect such number of
directors  as would  violate  such  rule  until the  earlier  of (1) the date of
approval by the  stockholders  of the Company of the  transactions  contemplated
herein  and in the Letter of  Intent,  (2) the date that Rule  4460(i) no longer
applies to such  transactions  and (3) September 30, 1997.  Notwithstanding  the
foregoing,  the Purchasers  shall  immediately,  and during the entirety of such
five (5) year period,  have the right to appoint at least three designees to the
Board of Directors.  If necessary,  the Directors of the Company will elect each
such person to the Board of  Directors of the Company by creating a new position
on the  Board of  Directors  promptly  following  such  person's  nomination  by
Purchasers  and shall  nominate such person for election in connection  with any
stockholder  vote for  Directors,  and the Company  will use its best efforts to
ensure that the stockholders of the Company vote all their voting  securities in
favor  of  such  person's  election.  The  Company  agrees  to vote  all  voting
securities for which the Company holds proxies,  granting it voting  discretion,
or is  otherwise  entitled to vote,  in favor of, and to use its best efforts in
all  respect to cause,  the  election  of each such  individual  proposed by the
Partnership  and the Trust.  In the event that a vacancy is created on the Board
of Directors at any time by the death, disability,  resignation or removal (with
or  without  cause)  of  any  such  individual  proposed  and  nominated  by the
Partnership  and the Trust,  pursuant to this  Agreement,  the Company will, and
will use its best efforts to ensure that the  stockholders of the Company,  vote
all voting  securities to elect each individual  proposed by the Partnership and
the  Trust and  approved  by the  Company  and  nominated  for  election  by the
Partnership and the Trusts to fill such vacancy and serve as a voting Director.

         (b) In  addition to the rights set forth in Section  7.19(a),  from and
after the Closing Date,  until such time as Purchasers or their affiliates shall
not  beneficially  own any securities of the Company,  the  Partnership  and the
Trust shall be entitled to designate  nonvoting  observers who shall be entitled
to attend all meetings of the Board of Directors and any of its  committees  and
who shall be provided (i)  reasonable  prior notice of all meetings of the Board
of Directors  and any of its  committees,  (ii)  reasonable  prior notice of any
action that the Board of Directors or any of its  committees may take by written
consent,  (iii)  promptly  delivered  copies of all minutes and other records of
action by, and all written information furnished to,


                                       19

<PAGE>

the Board of Directors or any of its committees  and (iv) any other  information
requested by such  observer  which a member of the Board of  Directors  would be
entitled to request to  discharge  his or her duties.  Such  observers  shall be
entitled to the same rights to  reimbursement  for the expense of  attendance at
meeting as any outside Director.

         (c) If the  Partnership  and the Trust give notice to the Company  that
the  Partnership  and the  Trust  desire to remove a  Director  proposed  by the
Partnership  and the Trust pursuant to this  Agreement,  the Company shall,  and
shall use its best efforts to ensure that the stockholders of the Company shall,
vote all voting  securities  in favor of  removing  such  Director  if a vote of
holders of such  securities  shall be required to remove the  Director,  and the
Company agrees to take any action necessary to facilitate such removal.

         (d) Each Director  nominated by the  Partnership and the Trust shall be
entitled  to the same type and an amount of  compensation  at least equal to the
highest amount payable to any other Director for serving in such capacity.

         (e) The Company shall take all steps necessary to limit the size of the
Board to no greater than seven members or such fewer number as designated by the
Partnership, and the Trust.

         (f) Concurrently with the Closing Date, if requested by the Partnership
and the Trust,  the Company  shall have voted to appoint  the initial  Directors
nominated by the Partnership  and the Trust,  to its Board of Directors  subject
only to such individuals'  acceptance of such appointment in accordance with the
provisions  of this Section  7.19,  which  individuals  shall be  identified  in
writing to the Company by such time.

         (g) At any time that a designee or designees of the Partnership and the
Trust serve on the Company's  Board of Directors,  the Partnership and the Trust
shall be entitled to  representation  on any committee of the Board of Directors
proportionate with their representation on the Board as a whole.

         7.20. Board of Directors. (a) The Company shall promptly reimburse each
director or observer of the Company  designated by the Partnership and the Trust
who  is not an  employee  of the  Company  for  all of his  reasonable  expenses
incurred in  attending  each meeting of the Board of Directors of the Company or
any committee thereof.

         (b) The Company shall at all times  maintain  provisions in its By-laws
and/or Certificate of Incorporation indemnifying all directors against liability
and absolving all directors from  liability to the Company and its  stockholders
to the maximum extent permitted under the laws of the State of Delaware.

         (c)  The  By-laws  of  the  Company  shall  always  contain  provisions
consistent  with the  provisions  of this Section 7.20 except to the extent this
Section 7.20 deals with the possible observer.


                                       20

<PAGE>

         (d) For so long as any  designee  of  Purchasers  is a director  of the
Company,  the Company shall procure and maintain  Director and Officer Liability
Insurance  covering  such  designees  with a  coverage  amount  and other  terms
acceptable to each of the  Purchasers  with a reputable  insurance  carrier.  In
addition, the Company shall enter into an indemnification agreement, in form and
substance satisfactory to the Purchasers, with each such designee.

         7.21.  No  Subsidiaries.  The  Company  will not create or acquire  any
entity  that would be a  Subsidiary  (as defined in Section  10.10)  without the
Purchasers' prior written consents.

         7.22.  Publicity.  (a) The Company  shall not issue any press  release,
make any  other  public  announcement  with  respect  to this  Agreement  or the
transactions  contemplated  hereby,  hold any press conference nor engage in any
other  publicity  without  obtaining the prior written  approval of  Purchasers,
except as may be required by law or the  regulations of any securities  exchange
or the Nasdaq Stock Market.

         (b)  The  Company  shall  not  disclose  or use  the  names,  identity,
addresses or any other  information  regarding  each of the Purchasers or any of
its officers,  directors,  employees,  shareholders,  nominees and/or  designees
without such Purchaser's prior written consent;  provided,  however, each of the
names of  Purchasers  (but not its  addresses)  may be  disclosed  in the  Shelf
Registration Statement.

         (c) After the Closing  Date,  upon request of the  Partnership  and the
Trust, the Company shall cause, at its sole expense,  the immediate  publication
of a "tombstone"  advertisement  in the Wall Street Journal  (National  Edition)
announcing the consummation of this Agreement and the transactions  contemplated
herein,  the exact form and substance of which shall be mutually  agreed upon by
the Company and the Partnership and the Trust.

         7.23. Restriction on Securities. (a) During the 18 months following the
Closing  Date,  the  Company  shall not  without  prior  written  consent of the
Partnership  and the  Trust,  issue,  offer  or sell any of its  equity  or debt
securities  (including,  without limitation,  any securities convertible into or
exercisable for such securities);  provided that the Company may issue shares of
Common Stock upon conversion or exercise of the Company's outstanding securities
and  pursuant to exercise of options  under any stock option plan of the Company
in accordance  with the terms of such plan (it being agreed that the issuance of
any  additional  options  under  such plan may be  effected  only with the prior
written consent of the Purchasers);  provided,  further,  that the Company, with
the  consents of the  Partnership  and the Trust,  may issue  options  under the
Company's  Non-Employee  Director  Stock  Option Plan and shares of Common Stock
under the Company's  1993 Stock  Purchase  Plan in accordance  with the terms of
such plans which will not be amended  without the consent of the Partnership and
the Trust);  provided,  further,  that this  Section 7.23 shall not apply to the
offerings to be conducted by the Company with Paramount Capital,  Inc. acting as
placement  agent as  contemplated  in the Letter of Intent  (all such  exccepted
Common Stock, the "7.23 Exceptions"). During the 36-months following the Closing
Date, the Company shall not, without the prior written consents of the


                                       21

<PAGE>

Purchasers,  offer or sell any of its debt or equity  securities  in reliance on
Regulation S of the Securities  Act.  During the 36-month  period  following the
Closing  Date,  the Company  will not extend the  expiration  date nor lower the
exercise  price of any  options or  warrants,  or take any  similar  action with
respect to any convertible securities of the Company,  without the prior written
consent of the Partnership and the Trust.

         (b) Prior to the Closing  Date,  the Company  shall  obtain the written
agreement of all executive  officers and directors of the Company (and shall use
its  best  efforts  to  obtain  a  written  agreement  from  all  5% or  greater
stockholders  of  the  Company,   calculated  without  including  any  issuances
contemplated  by this  Agreement) to "lock-up" all of the shares of Common Stock
owned by each of them at any time until 24 months  following  the Closing  Date,
and to agree not to directly or indirectly, issue, agree or offer to sell, grant
an option for the purchase or sale, assign, sell, contract to sell, sell "short"
or "short  against the box" (as those terms are generally  understood),  pledge,
hypothecate,  distribute  or  otherwise  encumber or dispose of, any such shares
(including  options,  rights,  warrants or other  securities  convertible  into,
exchangeable,  exercisable  for or evidencing any right to purchase or subscribe
for shares of capital stock of the Company (whether or not beneficially owned by
the undersigned) or any beneficial  interest therein of any shares of the Common
Stock,  all in form and substance  satisfactory to the Partnership and the Trust
and their counsel.

         (c) The Company shall not, directly or indirectly, through any officer,
director, agent or otherwise, initiate, solicit, encourage, negotiate or discuss
with any third party  (including  by way of  furnishing  non-public  information
concerning the Company or its businesses,  assets or  properties),  nor take any
other  action to  facilitate  any  inquiries  with respect to the making of, any
proposal that  constitutes or may reasonably be expected to lead to, a Competing
Transaction  (as  defined  below),   provided,   however,   that  the  foregoing
prohibitions  shall terminate  either (x) on the date that is 210 days after the
Closing  Date if the Company  does not proceed with the Series B Offering or (y)
upon the final closing date of the Series B Offering if the Company does proceed
with the Series B Offering. "Competing Transaction" shall mean any proposal with
respect  to (a) a  possible  public or  private  offering  or  placement  of its
securities,  (b)  a  recapitalization,  merger  or  other  business  combination
involving the Company or any of its  subsidiaries  or (c) the  acquisition  of a
substantial portion of the assets of the Company. Notwithstanding the foregoing,
nothing shall prohibit the Board of Directors of the Company from (i) furnishing
information to, or entering into discussions or negotiations  with any person or
entity  that  makes  an  unsolicited   proposal  with  respect  to  a  Competing
Transaction,  if, and only to the extent that, (A) the Board of the Directors of
the  Company,  after  consultation  with and based  upon the  written  advice of
independent  legal  counsel,  determines  in good  faith  that  such  action  is
necessary for the Board of Directors of the Company to comply with its fiduciary
duties to stockholders  under applicable law, but only in response to a written,
bona fide  proposal  with respect to a Competing  Transaction  that the Board of
Directors  of the  Company,  after  consultation  with its  financial  advisors,
determines is financially superior to the Company,  than the Series A and Series
B  Offerings  and  related  transactions  (considered  together  as  a  complete
transaction),  taking into account the ability of the party making such proposal
to finance  such  proposal  and such  party's  ability  to obtain  any  required
regulatory and third party


                                       22

<PAGE>

approvals for such  Competing  Transaction  (a "Superior  Proposal") and (B) the
Company,  prior to furnishing such  information to, or entering into discussions
or  negotiations  with,  such person or entity (x) provides  notice to Paramount
Capital, Inc. and the Purchasers to the effect that it is furnishing information
to, or entering into discussions or negotiations with, such person or entity and
(y) receives from such person or entity an executed confidentiality agreement in
reasonably customary form; or (ii) complying with its obligations, if any, under
applicable  law to  disclose  the  existence  and  terms of any  proposal  for a
Competing Transaction.

         7.24.  Restriction on Liens. The Company shall not create or permit the
imposition  of any liens on any of its assets  from and after the  Closing  Date
without the prior written consents of the Purchasers.

         7.25. Restrictions on Indebtedness.  The Company shall not, without the
prior written consent of the  Purchasers,  incur,  create,  assume nor suffer to
exist any indebtedness (including but not limited to any indebtedness to current
executive  officers,  employees,  directors  or  principal  stockholders  of the
Company,  but excluding (x) accounts payable incurred in the ordinary course and
paid in  accordance  with roman  numeral  (iv) of  paragraph 14 of the Letter of
Intent  and (y)  indebtedness  existing  on the  date  hereof  reflected  in the
Company's March 31, 1997 Financial Statement.

         7.26 Blank Check Preferred.  (a) In the event that the Company fails to
obtain approval from its stockholders of the inclusion in the Company's  Charter
of blank check  Preferred  Stock in connection with the Proxy Statement prior to
June 30, 1997,  then,  with the consent of the  Partnership  and the Trust,  the
Company (i) shall amend its current proxy  statement (the "Proxy  Statement") by
no later than July 3, 1997,  and (ii) with the  assistance of a proxy  solicitor
acceptable  to the Trust and the  Partnership,  shall use best efforts to obtain
approval of the inclusion of blank check  Preferred  Stock in its Certificate of
Incorporation  by no later than July 15,  1997.  In the event  that the  Company
fails to obtain approval from its stockholders of the inclusion in the Company's
Charter of blank check Preferred  Stock in connection with the Proxy  Statement,
the Company shall obtain such approval as set forth in Subsection 7.26(b) below.

         (b) The Company shall obtain the Required Shareholder Approvals as soon
as possible following the Closing and, in any event,  before September 30, 1997.
The Company  shall,  as promptly as  possible,  engage a  nationally  recognized
independent  investment  banking  firm  to  render  a  fairness  opinion  on the
transactions contemplated herein and in the Letter of Intent.

         7.27.  Put  Exercisable  Upon  Certain  Events.  In the event  that the
Company  does not  obtain  the  Required  Shareholder  Approvals  (as  hereafter
defined) by  September  30, 1997,  each  Purchaser  shall have the right,  for a
period of 10 years, at such Purchaser's election (the "Non-Approval Put") (i) to
require the Company to  repurchase  with cash,  within two  business  days after
request is made therefor, all or any portion of the shares of Series A Preferred
Stock  then  owned  by such  Purchaser  for  $140 per  share  tendered  for such
repurchase (or in the case


                                       23

<PAGE>

of the  Alternate  Offering,  140% of the aggregate  Dilution  Value (as defined
below) of the number of shares of Alternate  Offering  Common  tendered for such
repurchase),  (ii) to require the Company to issue A Notes,  within two business
days after request is made  therefor,  in exchange for all or any portion of the
shares of Series A Preferred Stock then owned by such Purchaser,  in a principal
amount of $140 per share  tendered  for such  repurchase  (or in the case of the
Alternate  Offering,  in a principal  amount of 140% of the  aggregate  Dilution
Value of the number of shares of  Alternate  Offering  Common  tendered for such
exchange) or (iii) any combination of the above.

         The "Required  Shareholder  Approvals" shall mean any required approval
by the holders of Common Stock of the Company necessary (whether pursuant to law
or the  rules  of The  Nasdaq  Stock  Market)  to  consummate  the  transactions
contemplated  hereby and to provide  the  Purchasers  with all of the rights set
forth in this  Agreement  and the  instruments  referred  to herein,  including,
without limitation,  approvals of (a) the amendment of the Company's Certificate
of  Incorporation  to authorize  "blank check" preferred stock, (b) the issuance
pursuant to this Agreement of Series A Preferred Stock, the Warrants and the New
Warrants  (as defined in the  Warrants) or any Common  Stock  issuable  upon the
conversion or exercise of any of the  foregoing,  (c) the Approval  Issuance and
(d) the  appointment by the  Purchasers of a majority of the Company's  Board of
Directors.

         7.28 Break-up Fee. If, by September 30, 1997,  the Series A Offering is
not completed on the terms contained  herein and in the Letter of Intent,  or if
the required  adjustments to the Conversion Price (as defined in the Certificate
of Designation for the Series A Preferred Stock) of the Series A Preferred Stock
or the  conversion of the Class A and Class B Warrants into New Warrants has not
been approved or has not occurred or, in the case of the Alternate Offering, the
Approval  Issuance (as defined below) has not been approved or has otherwise not
occurred, or if Paramount Capital,  Inc., the Partnership and the Trust have not
appointed a majority of the Company's  Board of Directors,  or if the Purchasers
have not acquired  capital  stock of the Company  representing  in excess in the
aggregate of 51% of the Voting Shares, as a result of the failure of the Company
to obtain the Required  Shareholder  Approval or for any other reason,  then, in
addition to any other rights of the  Purchasers  or Paramount  Capital,  Inc. or
obligations of the Company hereunder and under the Letter of Intent, the Company
shall  pay  to  the   Purchasers  a  fee  of   $500,000.   In  addition  to  and
notwithstanding  the  foregoing,  whether  or not the  proposed  financings  are
completed and  irrespective  of the reason that the proposed  financings are not
completed  (including a  determination  by Paramount  Capital,  Inc.,  the Trust
and/or the  Partnership  not to proceed with the transaction for any reason) the
Company  shall be  responsible  for,  and  shall  reimburse  the  Trust  and the
Partnership  for, all costs incurred in connection with the Series A Transaction
(as defined in the Letter of Intent) and the  transactions  contemplated  by the
Letter of Intent (including, without, limitation,  attorney's fees, expenses and
disbursements).

         7.29  Class  Covenant.  In the  event  of the  Alternate  Offering,  in
addition to any other covenants  contained herein, the Company covenants that it
shall not,  without the prior written  consent of the Rights Holders (as defined
below) having at least 50% of all outstanding


                                       24

<PAGE>

Article IX Rights,  (i) incur or voluntarily repay prior to the maturity thereof
any  indebtedness  in excess of $100,000 or (ii) authorize or issue, or increase
the authorized  amount of, any equity security  ranking prior to, or on a parity
with, the Common Stock (other than  additional  Common Stock approved in writing
by the  Partnership  and  the  Trust  or any  Article  IX  Issuances,  any  7.23
Exceptions) (A) upon a Liquidation Event (as defined below), (B) with respect to
the payment of any  dividends  or  distributions  or (C) with  respect to voting
rights (except for class voting rights required by law).

         7.30 Listing. The Company shall,  concurrently with the issuance of any
Alternate  Offering  Common,  take all  actions  necessary  so that  the  shares
comprising  any such  issuance  are listed on any stock  exchange  or  quotation
system on which the Common Stock trades.

         7.31 Reservation of Shares;  Transfer Taxes,  Etc. The Company shall at
all times reserve and keep available,  out of its authorized and unissued shares
of Common Stock, solely for the purpose of effecting any conversions of Series A
Preferred Stock or A Notes,  any exercises of Class A and Class B Warrants,  and
any Reset  Issuance (as defined  below),  Annual  Issuance  (as defined  below),
Dilution  Issuance (as defined  below) and Approval  Issuance (as defined  below
and,  together with Reset Issuances,  Annual  Issuances and Dilution  Issuances,
referred  to herein as  "Article  IX  Issuances"),  such number of shares of its
Common Stock free of  preemptive  rights as shall be  sufficient  to effect such
conversions,  exercises  and Article IX Issuances  from time to time required or
reasonably  anticipated.  The Company  shall use its best  efforts  from time to
time,  in  accordance  with the laws of the State of Delaware  to  increase  the
authorized  number of shares of Common Stock if at any time the number of shares
of authorized,  unissued and unreserved  Common Stock shall not be sufficient to
permit any required or reasonably anticipated  conversions of Series A Preferred
Stock and A Notes,  exercises  of Class A and Class B  Warrants  and  Article IX
Issuance.  In the  event,  and to the  extent,  that the  company  does not have
sufficient  authorized  but  unissued  shares  of  Common  Stock to  effect  any
conversion of Series A Preferred Stock or A Notes, any exercise of Warrants, any
Article IX  Issuance  or any other  issuance  of Common  Stock  pursuant to this
Agreement  (collectively a "Common Issuance Event"),  the Company shall pay each
Purchaser cash or A Notes in an amount per share of Common Stock that would have
been issued to such Purchaser pursuant to such Common Issuance Event but for the
lack of sufficient  authorized but unissued Common Stock equal to the greater of
(i) 1.40 times the Dilution  Value (as defined below) (or, in the case of shares
of Common Stock  issuable upon  conversion of the Series A Preferred  Stock,  or
exercise of the Warrants, 1.40 times the respective Conversion Price or exercise
price) and (ii) the Market  Price,  in either case  determined as of the date of
the event giving rise to such Common Issuance Event.

         The  Company  shall  pay any and all issue or other  taxes  that may be
payable in respect to any Article IX Issuance.

         7.32 D&O Insurance.  The Company shall obtain, by July 10, 1997, at the
latest, a waiver (the "D&O Insurance  Waiver") from the provider of its Director
and Officer


                                       25

<PAGE>

Liability  Insurance Policy of any provisions  thereof that allow or require any
termination, reduction, limitation or other impairment of coverage upon a change
of control  with  respect  to the  transactions  contemplated  herein and in the
Letter of Intent.

         8. Registration of Common Stock.

         8.1.  Registration.  The Company will, as soon as practicable,  but not
later than the earlier of (a) 30 days after the final closing date of the Series
B Offering or a Qualified Offering (as defined below) and (b) 210 days after the
Closing  Date  (each a  "Filing  Target  Date"),  (i) file a shelf  registration
statement (the "Shelf Registration Statement") with respect to (x) the resale of
the shares of Common Stock issuable upon conversion of the Series A and Series B
Preferred  Stock  or,  in the  case of the  Alternate  Offering,  the  Alternate
Offering  Common  and any  Common  Stock to be issued  pursuant  to the Series B
Offering (including any Common Stock issuable upon the exercise of the Placement
Warrants  and  Advisory  Warrants  (as  defined in the Letter of Intent) and any
Common Stock  issuable  pursuant to  contractual  rights created in the Series B
Offering analogous to the Article IX Rights herein, (y) the Class C Warrants and
(z) the shares of Common Stock  issuable  upon  exercise of the Class A, Class B
and Class C Warrants (including the New Warrants, as the case may be) (together,
the "Registrable Securities") with the SEC and use its best efforts to have such
Shelf  Registration  Statement  declared  effective by the SEC prior to the date
which is 75 days after the final  closing date of the Series B Offering or other
applicable  Filing  Target Date (subject to penalties for failure to effect such
registration  in the time frames required as set forth in Section 8.6 below) and
(b) cause such Shelf Registration  Statement to remain effective until such date
as the holders of the  Registrable  Securities  have completed the  distribution
described in the Shelf  Registration  Statement or at such time that such shares
are no longer,  by reason of Rule 144(k) under the  Securities  Act of 1933,  as
amended,  required to be registered  for the sale thereof by such  holders,  but
this  sentence  shall not relieve the Company of any  obligation  to comply with
this Article 8 as to any Registrable  Securities thereafter issued. If requested
by the Purchasers,  and in accordance with applicable securities laws, the Shelf
Registration   Statement  shall  cover  the  direct  sale  of  such  Registrable
Securities to the holders of such  securities.  A "Qualified  Offering" means an
equity  offering  (other than the Series A Offering) or series of offerings with
gross proceeds to the Company in excess of $2,000,000.

         8.2.  Registration  Procedures.  In connection with the registration of
any Registrable  Securities under the Securities Act as provided in this Section
8, the Company will use its best efforts, as expeditiously as possible:

         (a) To prepare and file with the Securities and Exchange Commission the
Shelf Registration Statement with respect to such Registrable Securities and use
its best efforts to cause such Shelf Registration Statement to become effective;

         (b) To prepare and file with the  Securities  and  Exchange  Commission
such  amendments and  supplements to such Shelf  Registration  Statement and the
prospectus  used in connection  therewith as may be necessary to keep such Shelf
Registration Statement effective


                                       26

<PAGE>

until the disposition of all securities in accordance with the intended  methods
of  disposition  by the  seller  or  sellers  thereof  set  forth in such  Shelf
Registration Statement shall be completed,  and to comply with the provisions of
the  Securities  Act (to the extent  applicable  to the Company) with respect to
such dispositions;

         (c) To  furnish  to each  seller of such  Registrable  Securities  such
number of copies of such Shelf Registration Statement and of each such amendment
and supplement  thereto (in each case  including all  exhibits),  such number of
copies  of  the  prospectus  included  in  such  Shelf  Registration   Statement
(including each preliminary prospectus),  in conformity with the requirements of
the  Securities  Act, and such other  documents,  as such seller may  reasonably
request,  in order to facilitate the disposition of the  Registrable  Securities
owned by such seller;

         (d) To use its best  efforts to  register or qualify  such  Registrable
Securities  covered  by such  Shelf  Registration  Statement  under  such  other
securities  or blue  sky laws of such  jurisdictions  as any  seller  reasonably
requests,  and do any and all other  acts and  things  which  may be  reasonably
necessary or advisable to enable such seller to consummate  the  disposition  in
such  jurisdictions of the Registrable  Securities owned by such seller,  except
that the Company will not for any such purpose be required to qualify  generally
to do business as a foreign  corporation  in any  jurisdiction  wherein it would
not,  but for the  requirements  of  this  Section  8.2(d)  be  obligated  to be
qualified, to subject itself to taxation in any such jurisdiction, or to consent
to general service of process in any such jurisdiction;

         (e) To provide a transfer agent and registrar for all such  Registrable
Securities  covered  by such  Shelf  Registration  Statement  not later than the
effective date of such Shelf Registration Statement;

         (f) To notify each seller of such  Registrable  Securities  at any time
when a  prospectus  relating  thereto  is  required  to be  delivered  under the
Securities  Act,  of the  happening  of any  event  as a  result  of  which  the
prospectus  included  in such Shelf  Registration  Statement  contains an untrue
statement of a material fact or omits any fact  necessary to make the statements
therein not misleading, and, at the request of any such seller, the Company will
prepare a supplement  or amendment to such  prospectus  so that,  as  thereafter
delivered to the purchasers of such Registrable Securities, such prospectus will
not  contain an untrue  statement  of a material  fact or omit to state any fact
necessary to make the statements therein not misleading;

         (g) To cause  all such  Registrable  Securities  to be  listed  on each
securities  exchange  or  automated  over-the-counter  trading  system  on which
similar securities issued by the Company are then listed;

         (h) To enter  into such  customary  agreements  and take all such other
actions  as  reasonably   required  in  order  to  expedite  or  facilitate  the
disposition of such Registrable Securities; and


                                       27

<PAGE>

         (i) To make  available  for  inspection  by any  seller of  Registrable
Securities, all financial and other records, pertinent corporation documents and
properties  of the Company,  and cause the  Company's  officers,  directors  and
employees to supply all information  reasonably  requested by any such seller in
connection with the Shelf Registration Statement pursuant to Section 8.1.

         8.3 Registration and Selling Expenses. (a) All expenses incurred by the
Company in connection with the Company's  performance of or compliance with this
Section 8, including,  without  limitation (i) all  registration and filing fees
(including  all  expenses  incident to filing with the National  Association  of
Securities Dealers, Inc.), (ii) blue sky fees and expenses,  (iii) all necessary
printing and duplicating expenses and (iv) all fees and disbursements of counsel
and  accountants  for the  Company  (including  the  expenses  of any  audit  of
financial  statements),  retained by the Company (all such expenses being herein
called "Registration Expenses"), will be paid by the Company except as otherwise
expressly provided in this Section 8.3.

         (b) The Company will, in any event, in connection with any registration
statement,  pay  its  internal  expenses  (including,  without  limitation,  all
salaries and expenses of its officers and employees performing legal, accounting
or other  duties in  connection  therewith  and  expenses  of audits of year-end
financial  statements),  the expense of liability insurance and the expenses and
fees for listing  the  securities  to be  registered  on one or more  securities
exchanges  or  automated  over-the-counter  trading  systems  on  which  similar
securities issued by the Company are then listed.

         (c) Nothing  herein shall be construed to prevent any holder or holders
of  Registrable  Securities  from  retaining  such  counsel  (the  Trust and the
Partnership  to be limited to one counsel  representing  them both and any other
purchasers to be  represented by one counsel  separately  from the Trust and the
Partnership)  as they shall choose,  the expenses of which shall be borne by the
Company.

         8.4. Other Public Sales and  Registrations.  The Company agrees that it
will  not,  on its own  behalf,  file or cause to  become  effective  any  other
registration  of any of its  securities  under the  Securities  Act or otherwise
effect a public  sale or  distribution  of its  securities  (except  pursuant to
registration on Form S-8 or any successor form relating to a special offering to
the employees or security  holders of the Company)  until at least 180 days have
elapsed  after  the  effective  date of the  Shelf  Registration  Statement.  In
addition,  the Company  agrees that it will use its best efforts to obtain prior
to the  filing of the Shelf  Registration  Statement  an  agreement  in form and
substance  satisfactory  to  Purchasers  and  their  counsel  in their  sole and
absolute discretion from each person that has the right to have the Company file
or cause to become  effective any other  registration  of any of its  securities
under the Securities Act or otherwise  effect a public sale or  distribution  of
its securities  (except  pursuant to  registration  on Form S-8 or any successor
form relating to a special  offering to the employees or security holders of the
Company),  pursuant  to which each such person will agree for the benefit of the
Company and


                                       28

<PAGE>

Purchasers to waive any and all such rights until at least 180 days have elapsed
after the effective date of the Shelf Registration Statement.

         8.5.  Indemnification.  (a) The Company hereby agrees to indemnify,  to
the maximum extent permitted by law, each holder of Registrable Securities,  its
officers  and  directors,  if any, and each  person,  if any, who controls  such
holder  within the  meaning of the  Securities  Act,  against,  and  promptly to
reimburse them for, all losses, claims, damages, liabilities and expenses (under
the Securities Act or common law or otherwise) caused by any untrue statement or
alleged  untrue  statement  of a material  fact  contained  in any  registration
statement  or  prospectus  (and as amended or  supplemented  if the  Company has
furnished any amendments or supplements thereto) or any preliminary  prospectus,
which  registration  statement,  prospectus or preliminary  prospectus  shall be
prepared in connection with the registration  contemplated by this Section 8, or
caused by any  omission  or alleged  omission to state  therein a material  fact
required to be stated  therein or necessary to make the  statements  therein not
misleading,  except  insofar as such losses,  claims,  damages,  liabilities  or
expenses  are  caused  by any  untrue  statement  or  alleged  untrue  statement
contained in or by any omission or alleged omission from  information  furnished
in writing by such holder to the  Company in  connection  with the  registration
contemplated by this Section 8, provided the Company will not be liable pursuant
to this Section 8.5 if such losses,  claims,  damages,  liabilities  or expenses
have been caused by any selling  security  holder's failure to deliver a copy of
the  registration  statement or  prospectus,  or any  amendments or  supplements
thereto,  after the Company has furnished  such holder with the number of copies
required by Section 8.2(c).

         (b) In connection with any registration  statement in which a holder of
Registrable  Securities is participating,  each such holder shall furnish to the
Company in writing such  information  as is reasonably  requested by the Company
for use in any such  registration  statement or prospectus and shall  severally,
but not jointly,  indemnify,  to the extent  permitted by law, the Company,  its
directors and officers and each person,  if any, who controls the Company within
the  meaning  of the  Securities  Act,  against  any  losses,  claims,  damages,
liabilities and expenses  resulting from any untrue  statement or alleged untrue
statement of a material  fact or any omission or alleged  omission of a material
fact  required to be stated in the  registration  statement or prospectus or any
amendment  thereof or  supplement  thereto or necessary  to make the  statements
therein not  misleading,  but only to the extent such losses,  claims,  damages,
liabilities  or expenses  are caused by an untrue  statement  or alleged  untrue
statement contained in or by an omission or alleged omission from information so
furnished  in  writing  by such  holder  in  connection  with  the  registration
contemplated  by  this  Section  8.  If  the  offering   pursuant  to  any  such
registration is made through underwriters, each such holder agrees to enter into
an  underwriting  agreement  in  customary  form with such  underwriters  and to
indemnify such  underwriters,  their  officers and  directors,  if any, and each
person who controls such  underwriters  within the meaning of the Securities Act
to the same extent as hereinabove  provided with respect to  indemnification  by
such holder of the Company. Notwithstanding the foregoing or any other provision
of this  Agreement,  in no event  shall a holder of  Registrable  Securities  be
liable for any such losses, claims,  damages,  liabilities or expenses in excess
of the lesser of (a) the net proceeds received by such holder in the offering or
(b) $1,000,000.


                                       29

<PAGE>

         (c) Promptly  after receipt by an  indemnified  party under Section 8.5
(a) or (b) of notice of the  commencement  of any  action  or  proceeding,  such
indemnified  party  will,  if a claim in  respect  thereof is made  against  the
indemnifying party under such Section,  notify the indemnifying party in writing
of the  commencement  thereof;  but the  omission so to notify the  indemnifying
party  will  not  relieve  it  from  any  liability  which  it may  have  to any
indemnified party otherwise than under such Section.  In case any such action or
proceeding  is brought  against  any  indemnified  party,  and it  notifies  the
indemnifying party of the commencement  thereof,  the indemnifying party will be
entitled to participate therein, and, to the extent that it wishes, jointly with
any other indemnifying party similarly notified,  to assume the defense thereof,
with  counsel  approved by such  indemnified  party,  and after  notice from the
indemnifying  party to such  indemnified  party of its election so to assume the
defense thereof,  the indemnifying  party will not be liable to such indemnified
party  under  such  Section  for any  legal or any other  expenses  subsequently
incurred by such indemnified party in connection with the defense thereof (other
than reasonable costs of  investigation)  unless incurred at the written request
of the indemnifying party. Notwithstanding the above, the indemnified party will
have the  right to  employ  counsel  of its own  choice  in any such  action  or
proceeding if the indemnified  party has reasonably  concluded that there may be
defenses  available to it which are different from or additional to those of the
indemnifying  party, or counsel to the indemnified  party is of the opinion that
it  would  not  be  desirable  for  the  same  counsel  to  represent  both  the
indemnifying party and the indemnified party because such  representation  might
result in a conflict  of  interest  (in either of which  cases the  indemnifying
party  will not have the  right to  assume  the  defense  of any such  action or
proceeding  on behalf of the  indemnified  party or  parties  and such legal and
other expenses will be borne by the indemnifying  party). An indemnifying  party
will not be  liable to any  indemnified  party  for any  settlement  of any such
action or proceeding effected without the consent of such indemnifying party.

         (d) If the  indemnification  provided  for in Section  8.5(a) or (b) is
unavailable  under  applicable  law to an  indemnified  party in  respect of any
losses, claims, damages or liabilities referred to therein, then each applicable
indemnifying  party,  in lieu of  indemnifying  such  indemnified  party,  shall
contribute to the amount paid or payable by such  indemnified  party as a result
of  such  losses,  claims,  damages  or  liabilities  in such  proportion  as is
appropriate  to reflect the relative fault of the Company on the one hand and of
the  holders  of  Registrable  Securities  on the other in  connection  with the
statements  or omissions  which  resulted in such losses,  claims,  damages,  or
liabilities,  as  well  as any  other  relevant  equitable  considerations.  The
relative  fault of the Company on the one hand and of the holders of Registrable
Securities on the other shall be determined by reference to, among other things,
whether  the  untrue or  alleged  untrue  statement  of a  material  fact or the
omission to state a material fact relates to information supplied by the Company
or by the holders of Registrable  Securities and the parties'  relative  intent,
knowledge,  access to  information  and  opportunity  to correct or prevent such
statement or omission.  The amount paid or payable by a party as a result of the
losses,  claims,  damages and  liabilities  referred to above shall be deemed to
include,  subject to the limitations  set forth in Section 8.5(c),  any legal or
other fees or  expenses  reasonably  incurred by such party in  connection  with
investigating  or defending any action or claim.  No person guilty of fraudulent
misrepresentation  (within the meaning of Section 11(f) of the  Securities  Act)
will be entitled to

                                       30

<PAGE>

contribution   from  any   person   who  is  not   guilty  of  such   fraudulent
misrepresentation.  Notwithstanding the foregoing or any other provision of this
Agreement,  in no event shall a holder of  Registrable  Securities be liable for
any such  losses,  claims,  damages,  liabilities  or  expenses in excess of the
lesser of (a) the net  proceeds  received by such holder in the  offering or (b)
$1,000,000.

         (e) Promptly  after  receipt by the Company or any holder of Securities
of notice of the commencement of any action or proceeding, such party will, if a
claim for  contribution  in respect  thereof is to be made against another party
(the  "contributing  party"),  notify the contributing party of the commencement
thereof;  but the omission so to notify the contributing  party will not relieve
it from any  liability  which  it may have to any  other  party  other  than for
contribution  hereunder. In case any such action, suit, or proceeding is brought
against  any  party,  and  such  party  notifies  a  contributing  party  of the
commencement  thereof,  the  contributing  party will be entitled to participate
therein with the  notifying  party and any other  contributing  party  similarly
notified.

         8.6.  Additional Common Stock Issuable Upon Delay of Registration.  (a)
Except to the extent any delay is due to the  failure of a holder to  reasonably
cooperate in providing to the Company such  information  as shall be  reasonably
requested by the Company in writing for use in the Shelf Registration Statement,
if the  Shelf  Registration  Statement  is not  filed  with the  Securities  and
Exchange  Commission  within the target dates set forth in the first sentence of
Section 8.1 (the "Outside  Target Date"),  the Company shall declare and pay for
no additional  consideration  to  Purchasers  of  additional  shares of Series A
Preferred Stock and Warrants or New Warrants, as the case may be, equal to 0.25%
of the  shares of Series A  Preferred  Stock (or,  in the case of the  Alternate
Offering,  Common Stock,  Article IX Rights and principal amount of A Notes) and
the Warrants or the New  Warrants,  as the case may be, then held by  Purchasers
for each day after the  Outside  Target  Date  that the  Registration  Statement
remains unfiled.

         (b) If the Shelf  Registration  Statement is not declared  effective by
the  Securities  and Exchange  Commission  within 210 days following the Closing
Date (the "Targeted  Effective Date"),  the Company shall declare and pay for no
additional  consideration to Purchasers  additional shares of Series A Preferred
Stock (or,  in the case of the  Alternate  Offering,  Common  Stock,  Article IX
Rights and A Notes) and Warrants or New  Warrants,  as the case may be, equal to
0.25% of the shares of the  Series A  Preferred  Stock  (or,  in the case of the
Alternate  Offering,  Common Stock,  Article IX Rights and principal amount of A
Notes) and the  Warrants or the New  Warrants,  as the case may be, then held by
Purchasers  for  each  day the  Shelf  Registration  Statement  is not  declared
effective by the Securities and Exchange Commission  following the occurrence of
the Targeted Effective Date.

         (c) All shares of Common Stock issuable  pursuant to Section 8.6(a) and
(b) shall be duly  authorized,  fully  paid and  nonassessable  shares of Common
Stock and shall be included in the Shelf Registration  Statement contemplated by
Section 8.1. Such shares shall be registered


                                       31

<PAGE>

in  Purchasers'  names  or the  name of the  nominee(s)  of  Purchasers  in such
denominations as Purchasers shall request pursuant to instructions  delivered to
the Company.

         9. Article IX Rights.

         In the event of the Alternate  Offering,  the Purchasers shall have the
additional contractual rights contained in this Article 9.

         9.1 Definitions.  As used in this Agreement,  the following terms shall
have the following meanings, unless the context otherwise requires:

               (a)  "Article  IX Rights"  shall  mean the rights to receive  all
Reset Issuances,  Annual Issuances,  Dilution Issuances and Approval  Issuances,
the right to exercise the  Liquidation  Put and Approval  Call, the other rights
provided  in this  Article 9, and the right to give or  withhold  consent  under
Section 7.29.

               (b) "Change of Shares" shall mean any event that  necessitates an
adjustment  to the  Dilution  Value (as defined  below)  pursuant to Section 9.7
below.

               (c) The "Closing Bid Price" of any security,  for any trading day
(as defined below),  shall be the reported per share closing bid price,  regular
way, of such  security on the relevant  Stock Market (as defined  below) on such
trading day or, if there were no  transactions  on such trading day, the average
of the reported  closing bid and asked prices,  regular way, of such security on
the relevant Stock Market on such trading day.

               (d) "Dilution  Event" shall mean any event that  necessitates  an
adjustment  to the  Dilution  Value (as defined  below)  pursuant to Section 9.6
below.

               (e)  The  "Dilution  Value"  initially  shall  be  $0.46875.  The
Dilution Value is further  subject to adjustment  pursuant to Sections 9.2, 9.6,
9.7, 9.16 and 9.17.

               (f) "Fair Market  Value" of any asset  (including  any  security)
means the fair market value  thereof as mutually  determined  by the Company and
the  Partnership  and the Trust If the Company and the Partnership and the Trust
are unable to reach agreement on any valuation  matter,  such valuation shall be
submitted to and determined by a nationally  recognized  independent  investment
bank selected by the Board of Directors of the Company and the  Partnership  and
the Trust (or, if such selection cannot be agreed upon promptly, or in any event
within ten days,  then such valuation  shall be made by a nationally  recognized
independent  investment  banking  firm  selected  by  the  American  Arbitration
Association in New York City in accordance  with its rules),  the costs of which
valuation shall be paid for by the Company.

               (g) The "Issuance Base Amount" for each  Purchaser,  at any time,
means the sum of (i) the portion of the Alternate Offering Quantity allocated to
such  Purchaser  pursuant to Exhibit E hereof,  (ii) the number of shares of any
Reset Issuances (as defined below)


                                       32

<PAGE>

made to such Purchaser occurring before such time, (iii) the number of shares of
any Annual Issuances (as defined below) made to such Purchaser  occurring before
such  time,  (iv) the number of shares of any  Dilution  Issuances  (as  defined
below) made to such  Purchaser  occurring  before  such time,  (v) the number of
shares of Common Stock issued to such  Purchaser  upon  conversion of all or any
portion  of the  principal  and  interest  of the A Notes and (vi) the number of
shares of Common Stock  issued to such  Purchaser  upon any  Approval  Issuances
(with appropriate  adjustments for any Change of Shares and subject to reduction
pursuant to Section 9.10). For any transferee  Rights Holder,  the Issuance Base
Amount,  at any time,  shall be the number of shares of Common Stock  related to
such Article IX Rights as were transferred to such Rights Holder plus the number
of shares of any Reset Issuance,  Annual Issuance,  Dilution Issuance,  Approval
Issuance  and any  issuance  pursuant  to  conversion  of any  principal  and/or
interest  of A Notes made to such Rights  Holder  occurring  subsequent  to such
transfer but before such time.  The Issuance Base Amount shall include  Dilution
Issuances  which would have been  required  but for the  operation  of Paragraph
9.6(b)(i).

               (h)   "Liquidation   Event"  shall  mean  any  (i)   liquidation,
dissolution or winding up of the Company, whether voluntary or involuntary, (ii)
sale or other  disposition  of all or  substantially  all of the  assets  of the
Company or (iii) any consolidation, merger, combination, reorganization or other
transaction in which the Company is not the surviving entity or shares of Common
Stock  constituting  more  than  50% of the  voting  power  of the  Company  are
exchanged for or changed into stock or securities of another entity, cash and/or
any other  property  (clause  (iii) of this  Subsection  being  referred to as a
"Merger  Transaction").  Notwithstanding  the above, any consolidation,  merger,
combination, reorganization or other transaction in which the Company is not the
surviving entity but the stockholders of the Company  immediately  prior to such
transaction  own  in  excess  of  50% of the  voting  power  of the  corporation
surviving  such  transaction  and own such  interest in  substantially  the same
proportions as prior to such transaction,  shall not be considered a Liquidation
Event or a Merger Transaction,  provided that the surviving corporation has made
appropriate  provisions  acceptable  to the Rights  Holders  to ensure  that the
Article IX Rights survive any such transaction.

               (i)  "Market  Price"  shall mean the  average  Closing  Bid Price
(adjusted,  where  appropriate,  for any  Change  of  Shares)  for  twenty  (20)
consecutive  trading  days,  ending with the trading day prior to the date as of
which the Market Price is being determined, provided that if the prices referred
to in the  definition of Closing Bid Price cannot be determined for such period,
"Market Price" shall mean Fair Market Value.

               (j) The "Post-Dilution Common Quantity" means the quotient of the
Pre-Dilution  Common  Value (as defined  below)  divided by the  Dilution  Value
immediately following the relevant Dilution Event or Reset Event.

               (k) The  "Pre-Dilution  Common  Value"  means the  product of the
Issuance Base Amount times the Dilution Value immediately preceding the relevant
Dilution Event or Reset Event.


                                       33

<PAGE>

               (l) "Rights  Holder" shall mean the  Purchasers or any Person who
succeeds  to any such  Purchaser's  respective  Article  IX Rights  pursuant  to
Section 9.9.

               (m) The "Stock Market" shall mean,  with respect to any security,
the principal national  securities  exchange on which such security is listed or
admitted to trading or, if such security is not listed or admitted to trading on
any national securities  exchange,  shall mean The Nasdaq National Market System
or The Nasdaq SmallCap Market  (collectively,  "Nasdaq") or, if such security is
not quoted on Nasdaq,  shall mean the OTC Bulletin Board or, if such security is
not quoted on the OTC Bulletin Board, shall mean the over-the-counter  market as
furnished by any NASD member firm  selected from time to time by the Company for
that purpose.

               (n) A "trading day" shall mean a day on which the Stock Market is
open for the transaction of business.

               (o) The  "Transfer  Agent"shall  mean American  Stock  Transfer &
Trust Company or the duly appointed  successor  thereto  serving as the transfer
agent for the Common Stock.

         9.2 Reset.  (a) The Dilution Value in effect  immediately  prior to the
date that is 12 months  after the  Closing  Date  (the  "Reset  Date")  shall be
adjusted  and reset  effective  as of the Reset Date if the Market  Price of the
Common Stock as of the Reset Date (the  "12-Month  Trading  Price") is less than
140%  of the  then  applicable  Dilution  Value  (a  "Reset  Event").  Upon  the
occurrence of a Reset Event,  the Dilution Value shall be reduced to be equal to
the greater of (A) the 12-Month  Trading Price  divided by 1.40,  and (B) 25% of
the then applicable Dilution Value.

               (b) Within 15 days of the Reset Date, the Company shall prepare a
certificate  signed by the principal  financial  officer of the Company  setting
forth the Dilution Value as of the Reset Date,  showing in reasonable detail the
facts  upon which  such  Dilution  Value is based,  and such  certificate  shall
forthwith be filed with the Transfer  Agent.  A notice stating that the Dilution
Value has been  adjusted  pursuant to this  paragraph,  or that no adjustment is
necessary,  and setting forth the Dilution  Value in effect as of the Reset Date
shall be mailed as promptly as  practicable  after the Reset Date by the Company
to all  Rights  Holders  at their last  addresses  as they  shall  appear in the
Transfer Agent's record books.

         9.3 Reset  Issuance.  If there is any change in the Dilution Value as a
result of Subsection 9.2(a), then, on such date, the Company shall issue to each
Rights Holder a number of shares of Common Stock (the "Reset Issuance") equal to
the difference  between such Rights  Holder's  respective  Post-Dilution  Common
Quantity minus such Rights Holder's respective Issuance Base Amount.

         9.4 Annual  Issuances.  On each  anniversary  of the Reset Date (or the
next  succeeding  business  day),  the  Company  shall  issue  (each  a  "Annual
Issuance") to each Rights


                                       34

<PAGE>

Holder a number of shares of Common Stock having an aggregate Market Price equal
to 10% of the  product of (i) such  Rights  Holder's  respective  Issuance  Base
Amount on the applicable  anniversary date times (ii) 140% of the Dilution Value
immediately prior to such Annual Issuance.

         9.5 Dilution Issuances.  Upon the occurrence of any Dilution Event, the
Company shall issue (each a "Dilution  Issuance") to each Rights Holder a number
of  shares of Common  Stock  equal to the  difference  of such  Rights  Holder's
respective  Post-Dilution  Common Quantity minus such Rights Holder's respective
Issuance Base Amount.

         9.6 Anti-Dilution Adjustments.

               (a) Except as otherwise  provided in  Subsection  9.6(c),  in the
event the Company shall, at any time or from time to time after the date hereof,
sell or issue any shares of Common Stock for a consideration per share less than
either (i) the Dilution  Value in effect on the date of such sale or issuance or
(ii) the Market Price of the Common Stock as of the date of the sale or issuance
(any such sale or issuance a "Dilutive  Issuance"),  then, and  thereafter  upon
each further Dilutive  Issuance,  the Dilution Value in effect immediately prior
to such Dilutive  Issuance  shall be changed to a price  (rounded to the nearest
cent) determined by multiplying the Dilution Value in effect  immediately  prior
thereto by a fraction,  the numerator of which shall be the sum of the number of
shares of Common Stock  outstanding  immediately  prior to the Dilutive Issuance
and the  number  of shares of Common  Stock  which the  aggregate  consideration
received  (determined as provided in Paragraph 9.6(b)(v) below) for the issuance
of such  additional  shares  would  purchase at the greater of (x) the  Dilution
Value in  effect on the date of such  issuance  or (y) the  Market  Price of the
Common Stock as of such date,  and the  denominator of which shall be the number
of shares of Common Stock outstanding  immediately after the Dilutive  Issuance.
Such adjustment shall be made successively whenever such an issuance is made.

               (b) For purposes of Subsection 9.6(a),  the following  Paragraphs
(i) to (v) shall also be applicable:

                    (i) No adjustment of the Dilution Value shall be made unless
such  adjustment  would  require a decrease of at least $.01;  provided that any
adjustments  which by reason of this Paragraph  9.6(b)(i) are not required to be
made shall be carried forward and shall be made at the time of and together with
the next  subsequent  adjustment  which,  together with  adjustments  so carried
forward, shall require a decrease of at least $.01 in the Dilution Value then in
effect hereunder.

                    (ii)  In  case of (A) the  sale  or  other  issuance  by the
Company  (including  as a  component  of a unit) of any  rights or  warrants  to
subscribe  for or purchase,  or any options for the purchase of, Common Stock or
any  securities   convertible  into  or  exchangeable  for  Common  Stock  (such
securities  convertible,  exercisable  or  exchangeable  into Common Stock being
herein called "Convertible Securities"), or (B) the issuance by the


                                       35

<PAGE>

Company,  without the receipt by the Company of any consideration  therefor,  of
any rights or  warrants to  subscribe  for or  purchase,  or any options for the
purchase of, Common Stock or Convertible Securities, whether or not such rights,
warrants  or  options,  or the right to convert  or  exchange  such  Convertible
Securities,  are immediately  exercisable,  and the  consideration per share for
which  Common Stock is issuable  upon the  exercise of such rights,  warrants or
options  or upon the  conversion  or  exchange  of such  Convertible  Securities
(determined by dividing (x) the minimum aggregate consideration, as set forth in
the instrument  relating  thereto without regard to any  antidilution or similar
provisions contained therein for a subsequent adjustment of such amount, payable
to the Company upon the exercise of such rights,  warrants or options,  plus the
consideration  received by the Company for the  issuance or sale of such rights,
warrants or  options,  plus,  in the case of such  Convertible  Securities,  the
minimum  aggregate  amount,  as set  forth in the  instrument  relating  thereto
without regard to any antidilution or similar provisions contained therein for a
subsequent adjustment of such amount, of additional consideration, if any, other
than such  Convertible  Securities,  payable  upon the  conversion  or  exchange
thereof,  by (y) the  total  maximum  number,  as set  forth  in the  instrument
relating  thereto  without  regard to any  antidilution  or  similar  provisions
contained  therein for a  subsequent  adjustment  of such  amount,  of shares of
Common Stock  issuable upon the exercise of such rights,  warrants or options or
upon the conversion or exchange of such Convertible Securities issuable upon the
exercise of such  rights,  warrants or options) is less than either the Dilution
Value or the Market  Price of the Common Stock as of the date of the issuance or
sale of such  rights,  warrants or options,  then such total  maximum  number of
shares of Common Stock  issuable  upon the exercise of such rights,  warrants or
options or upon the conversion or exchange of such Convertible Securities (as of
the date of the issuance or sale of such rights,  warrants or options)  shall be
deemed to be  "Common  Stock" for  purposes  of  Subsection  9.6(a) and shall be
deemed to have been sold for an amount equal to such consideration per share and
shall cause an adjustment to be made in accordance with Subsection 9.6(a).

                    (iii) In case of the sale or other  issuance  by the Company
of any  Convertible  Securities,  whether  or not the  right  of  conversion  or
exchange  thereunder  is  immediately  exercisable,  and the price per share for
which  Common  Stock  is  issuable  upon  the  conversion  or  exchange  of such
Convertible   Securities  (determined  by  dividing  (x)  the  total  amount  of
consideration  received  by  the  Company  for  the  sale  of  such  Convertible
Securities,  plus the minimum  aggregate  amount, as set forth in the instrument
relating  thereto  without  regard to any  antidilution  or  similar  provisions
contained  therein for a subsequent  adjustment  of such amount,  of  additional
consideration,  if any, other than such Convertible Securities, payable upon the
conversion or exchange thereof, by (y) the total maximum number, as set forth in
the instrument  relating  thereto without regard to any  antidilution or similar
provisions  contained  therein for a subsequent  adjustment  of such amount,  of
shares  of  Common  Stock  issuable  upon the  conversion  or  exchange  of such
Convertible  Securities)  is less than either the  Dilution  Value or the Market
Price  of the  Common  Stock  as of the  date of the  sale  of such  Convertible
Securities,  then such total maximum  number of shares of Common Stock  issuable
upon the conversion or exchange of such  Convertible  Securities (as of the date
of the sale of such Convertible Securities) shall be deemed to be "Common Stock"
for purposes of Subsection


                                       36

<PAGE>

9.6(a)  and  shall be  deemed  to have  been  sold for an  amount  equal to such
consideration  per share and shall cause an  adjustment to be made in accordance
with Subsection 9.6(a).

                    (iv)  In  case  the  Company  shall  modify  the  rights  of
conversion,  exchange  or  exercise  of  any of the  securities  referred  to in
Paragraphs  (ii) or (iii) of this Subsection  9.6(b) or any other  securities of
the Company convertible, exchangeable or exercisable for shares of Common Stock,
for any reason  other than an event that  would  require  adjustment  to prevent
dilution, so that the consideration per share received by the Company after such
modification  is less than either the Dilution  Value or the Market Price of the
Common Stock as of the date prior to such modification, then such securities, to
the extent not theretofore exercised, converted or exchanged, shall be deemed to
have expired or terminated  immediately  prior to the date of such  modification
and the Company  shall be deemed for  purposes of  calculating  any  adjustments
pursuant to this  Section 9.6 to have issued such new  securities  upon such new
terms on the date of modification.  Such adjustment shall become effective as of
the date upon which such  modification  shall take effect.  On the expiration or
cancellation  of any  such  right,  warrant  or  option  or the  termination  or
cancellation  of any such  right to  convert or  exchange  any such  Convertible
Securities,  the  Dilution  Value then in effect  hereunder  shall  forthwith be
readjusted to such Dilution Value as would have obtained (A) had the adjustments
made upon the issuance or sale of such rights, warrants,  options or Convertible
Securities been made upon the basis of the issuance of only the number of shares
of Common Stock  theretofore  actually  delivered  (and the total  consideration
received therefor) upon the exercise of such rights, warrants or options or upon
the  conversion  or  exchange  of  such  Convertible   Securities  and  (B)  had
adjustments  been  made on the basis of the  Dilution  Value as  adjusted  under
clause (A) of this sentence for all transactions (which would have affected such
adjusted  Dilution  Value)  made  after  the  issuance  or sale of such  rights,
warrants, options or Convertible Securities.

                    (v) In case of the sale of any shares of Common  Stock,  any
Convertible Securities,  any rights or warrants to subscribe for or purchase, or
any options for the purchase of,  Common Stock or  Convertible  Securities,  the
consideration  received by the Company  therefor shall be deemed to be the gross
sales price therefor without deducting therefrom any expense paid or incurred by
the Company or any underwriting  discounts or commissions or concessions paid or
allowed by the Company in connection therewith. In the event that any securities
shall be issued in connection with any other securities of the Company, together
comprising  one  integral  transaction  in which no  specific  consideration  is
allocated among the securities,  then each of such securities shall be deemed to
have been issued for such consideration as the Board of Directors of the Company
determines in good faith; provided, however that if the Partnership or the Trust
disagrees with such determination, the Company shall retain, at its own expense,
an independent  investment  banking firm  acceptable to the  Partnership and the
Trust for the purpose of obtaining an appraisal.

               (c)  Notwithstanding any other provision hereof, no adjustment to
the Dilution Value will be made:


                                       37

<PAGE>

                    (i) upon the  exercise  of any of the  options  or  warrants
outstanding on the date hereof under the Company's  existing stock option plans;
or

                    (ii) upon the  issuance  or  exercise  of options  which may
hereafter be granted with the approval of the Board of Directors,  or exercised,
under  any  employee  benefit  plan  of  the  Company  to  officers,  directors,
consultants  or  employees,  but  only  with  respect  to  such  options  as are
exercisable  at prices no lower than the  Closing  Bid Price (or,  if the prices
referenced in the definition of Closing Bid Price cannot be determined, the Fair
Market Value) of the Common Stock as of the date of grant thereof; or

                    (iii) upon the  issuance  of stock  which may  hereafter  be
purchased  or sold with the approval of the Board of  Directors,  under the 1993
Employee Stock Purchase Plan of the Company to officers, directors,  consultants
or employees,  but only with respect to such shares as are purchased and/or sold
in  accordance  with the  current  plan and at prices  no lower  than 85% of the
Closing Bid Price (or, if the prices referenced in the definition of Closing Bid
Price cannot be determined, 85% of the Fair Market Value) of the Common Stock as
of the date of purchase and/or sale thereof; or

                    (iv) upon the  issuance  of Common  Stock to Rights  Holders
pursuant to any Reset  Issuance,  Annual  Issuance or  Dilution  Issuance,  upon
issuance or exercise of the Placement  Warrants or Advisory Warrants (as defined
in the Letter of Intent), or upon the issuance or exercise of the Class A, Class
B or Class C Warrants  issued (A) on or prior to the Closing Date or pursuant to
the Series B Offering or (B) pursuant to the exercise of the Placement  Warrants
or Advisory Warrants (as defined in the Letter of Intent),  or upon the issuance
or  exercise  of any  Class A,  Class B and  Class C  Warrants  approved  by the
Partnership and the Trust; or

                    (v) upon the issuance or sale of Common Stock or Convertible
Securities  pursuant  to the  exercise  of any  rights,  options or  warrants to
receive,  subscribe for or purchase,  or any options for the purchase of, Common
Stock or Convertible Securities, whether or not such rights, warrants or options
were outstanding on the Closing Date or were thereafter issued or sold, provided
that an adjustment was either made or not required to be made in accordance with
Subsection  9.6(a) in connection with the issuance or sale of such securities or
any modification of the terms thereof; or

                    (vi)  upon  the  issuance  or  sale  of  Common  Stock  upon
conversion  or  exchange  of  any  Convertible  Securities,  provided  that  any
adjustments  required to be made upon the  issuance or sale of such  Convertible
Securities or any modification of the terms thereof were so made, and whether or
not such  Convertible  Securities  were  outstanding on the Closing Date or were
thereafter issued or sold.

               Paragraph 9.6(b)(iv) shall nevertheless apply to any modification
of the rights of  conversion,  exchange  or  exercise  of any of the  securities
referred  to in  Paragraphs  (i),  (ii),  (iii),  (v),  (vi) and,  to the extent
effected with respect to fewer than all of the outstanding


                                       38

<PAGE>

Class A, Class B and Class C  Warrants,  as the case may be,  Paragraph  (iv) of
this Subsection 9.6(c).

               (d) As used in this Section  9.6,  the term "Common  Stock" shall
mean and include the  Company's  Common Stock  authorized on the date hereof and
shall also  include  any capital  stock of any class of the  Company  thereafter
authorized which shall not be limited to a fixed sum or percentage in respect of
the  rights of the  holders  thereof  to  participate  in  dividends  and in the
distribution of assets upon the voluntary liquidation, dissolution or winding up
of the Company.

               (e) The Company from time to time may decrease the Dilution Value
by any  amount  for any  period of time if the period is at least 20 days and if
the decrease is irrevocable during the period. Whenever the Dilution Value is so
decreased, the Company shall mail to the Rights Holders a notice of the decrease
at least 15 days before the date the decreased  Dilution Value takes effect, and
such notice shall state the decreased  Dilution  Value and the period it will be
in effect.

               The Company may make such  decreases  in the Dilution  Value,  in
addition to those required or allowed by this Article IX, as shall be determined
by it, as evidenced by a resolution of the Board of  Directors,  to be advisable
in  order to avoid or  diminish  any  income  tax to  holders  of  Common  Stock
resulting  from any dividend or  distribution  of stock or issuance of rights or
warrants to purchase or  subscribe  for stock or from any event  treated as such
for income tax purposes.

         9.7 Change of Shares  Adjustments.  In the event the Company shall,  at
any time or from time to time  after  the date  hereof  (i) issue any  shares of
Common  Stock  as a stock  dividend  to the  holders  of  Common  Stock  or (ii)
subdivide  or combine the  outstanding  shares of Common Stock into a greater or
lesser number of shares (any such issuance,  subdivision  or  combination  being
herein called a "Change of Shares"), then the Dilution Value shall be changed to
a price  (rounded to the nearest cent)  determined by  multiplying  the Dilution
Value in effect  immediately  prior to such Change of Shares by a fraction,  the
numerator  of which  shall be the number of shares of Common  Stock  outstanding
immediately  prior to the Change of Shares and the denominator of which shall be
the  number of shares of Common  Stock  outstanding  immediately  following  the
Change of Shares.

         9.8  Liquidation  Put. (a) The Rights Holder may require the Company to
repurchase  with cash any number (not to exceed such  Rights  Holder's  Issuance
Base Amount) of shares of Common Stock then owned by such Rights Holder for 140%
of the aggregate Dilution Value of such shares; provided,  however, in the event
of a Merger Transaction, any repurchase pursuant to this Section 9.8 may be paid
in cash,  property (valued as provided in Subsection 9.8 (d)) and/or  securities
(valued as provided in Subsection  9.8 (d)) of the entity  surviving such Merger
Transaction.


                                       39

<PAGE>

               (b) The Rights Holder  covenants not to exercise the  Liquidation
Put unless a  Liquidation  Event has  occurred  (it being  understood  that this
Section 9.8 shall not affect any rights under Section 7.27).

               (c) The Rights Holder's  Article IX Rights shall be terminated to
the pro rata extent of any exercise of such Rights Holder's Liquidation Put.

               (d) Any  securities  or other  property  to be  delivered  to the
Rights Holder pursuant to this Section 9.8 shall be valued as follows:

                    (i) Securities not subject to an investment  letter or other
similar restriction on free marketability:

                    (A)       If actively traded on the Stock Market,  the value
                              shall be  deemed  to be the  Market  Price of such
                              securities  as of the  third day prior to the date
                              of valuation.

                    (B)       If not actively  traded on the Stock  Market,  the
                              value  shall  be the  Fair  Market  Value  of such
                              securities.

                    (ii) For  securities  for which  there is an  active  public
market but which are subject to an investment  letter or other  restrictions  on
free marketability, the value shall be the Fair Market Value thereof, determined
by discounting appropriately the Market Price thereof.

                    (iii) For all other securities,  the value shall be the Fair
Market Value thereof.

         9.9  Transfer  of  Article IX Rights.  The Rights  Holders'  Article IX
Rights are transferrable  along with the Common Stock to which they relate.  Any
such  transferee  of Article IX Rights shall provide his or her name and address
to the Company. Any transfer of Common Stock and related Article IX Rights shall
be performed in accordance with applicable securities laws and regulations.

         9.10  Adjustments to Issuance Base Amount.  Upon the termination of any
of the Rights Holder's  Article IX Rights,  such Rights  Holder's  Issuance Base
Amount shall be proportionally reduced.

         9.11 Notices.

               (a) After each  adjustment  of the  Dilution  Value  pursuant  to
Sections 9.2, 9.6, 9.7 and 9.16 the Company will promptly  prepare a certificate
signed by the Chief Executive  Officer or President,  and by the Treasurer or an
Assistant Treasurer or the Secretary or an Assistant  Secretary,  of the Company
setting forth: (i) the Dilution Value as so adjusted


                                       40

<PAGE>

and (ii) a brief  statement of the facts  accounting  for such  adjustment.  The
Company will promptly file such  certificate with the Transfer Agent and cause a
brief  summary  thereof to be sent by  ordinary  first class mail to each Rights
Holder at his or her last  address as it shall  appear on the  Transfer  Agent's
record  books.  No failure to mail such notice nor any defect  therein or in the
mailing thereof shall affect the validity of such  adjustment.  The affidavit of
an officer of the Transfer  Agent or the Secretary or an Assistant  Secretary of
the Company that such notice has been mailed shall,  in the absence of fraud, be
prima facie evidence of the facts therein stated. The Transfer Agent may rely on
the  information  in the  certificate  as true and  correct  and has no duty nor
obligation  independently  to verify the  amounts or  calculations  therein  set
forth.

               (b) After any  adjustment in the Issuance  Base Amount  resulting
from (i) any Reset Issuance,  Annual Issuances or Dilution  Issuances,  (ii) any
Change in Shares or (iii) any termination of Article IX Rights, the Company will
promptly  prepare  a  certificate  signed  by the  Chief  Executive  Officer  or
President, and by the Treasurer or an Assistant Treasurer or the Secretary or an
Assistant Secretary,  of the Company setting forth: (x) the Issuance Base Amount
immediately  preceding and succeeding  such adjustment and (y) a brief statement
of the facts accounting for such adjustment. The Company will promptly file such
certificate with the Transfer Agent and cause a brief summary thereof to be sent
by ordinary first class mail to each Rights Holder at his or her last address as
it shall appear on the Transfer  Agent's  record books.  No failure to mail such
notice  nor any  defect  therein  or in the  mailing  thereof  shall  affect the
validity of such  adjustment.  The affidavit of an officer of the Transfer Agent
or the  Secretary or an Assistant  Secretary of the Company that such notice has
been mailed shall, in the absence of fraud, be prima facie evidence of the facts
therein  stated.  The  Transfer  Agent  may  rely  on  the  information  in  the
certificate as true and correct and has no duty nor obligation  independently to
verify the amounts or calculations therein set forth.

         9.12 Treasury Stock.  Any Reset  Issuance,  Annual  Issuance,  Dilution
Issuance or Approval Issuance shall be made with duly authorized, fully-paid and
non-assessable  shares of Common  Stock,  in  accordance  with Delaware Law, and
shall be drawn from the treasury  stock of the Company to the extent  available.
The  Company  shall  promptly  furnish to the  Partnership  and the Trust,  upon
request,  an opinion of counsel  reasonably  satisfactory to the Partnership and
the Trust that the  requirements  of this  Section  9.12 have been met as to any
issuance referred to herein. The Company shall not otherwise sell, issue, cancel
or otherwise  impair any of its treasury stock without the  Partnership  and the
Trust's prior written consent.


         9.13  Mandatory  Termination  of Article  IX Rights.  At any time on or
after the Reset Date, provided that the Required Shareholder Approvals have been
obtained,  the  Company  may cause the Rights  Holder's  Article IX Rights to be
terminated if the Closing Bid Price of the Common Stock shall have exceeded 300%
of the then applicable Dilution Value for the 20 consecutive trading days ending
on the third business day prior to the date of notice of termination. No greater
than  60 nor  fewer  than 20  days  prior  to the  date  of any  such  mandatory
termination,  notice by first class mail, postage prepaid, shall be given to the
Rights Holders, addressed to such Rights Holders at their last addresses as they
shall appear in the Transfer


                                       41

<PAGE>

Agent's  record  books.  Each  such  notice  shall  specify  the date  fixed for
termination. Any notice which is mailed as herein provided shall be conclusively
presumed  to have been duly given by the  Company on the date  deposited  in the
mail,  whether  or not the Rights  Holder  receives  such  notice;  and  failure
properly  to give such  notice by mail,  or any  defect in such  notice,  to any
Rights  Holders  shall  not  affect  the  validity  of the  proceedings  for the
termination of any other Rights Holders' Article IX Rights.

         9.14 With the written  consent of the  Company  and the Rights  Holders
holding at least a majority of the issued and  outstanding  Common Stock subject
to Article IX Rights,  any  provision of this  Article IX may be waived  (either
generally or in a particular instance, either retroactively or prospectively and
either for a specified  period of time or  indefinitely)  or  amended.  Upon the
effectuation  of each such waiver or amendment,  the Company shall promptly give
written  notice thereof to the Rights  Holders,  if any, who have not previously
received notice thereof or consented thereto in writing.

         9.15 Approval Call. (a) Upon, and within five (5) years following,  the
Company's  obtaining  the approval of its  stockholders  of the inclusion in the
Company's  Certificate of  Incorporation  of blank check preferred  stock,  each
Rights  Holder may require the Company to authorize  and  designate the Series A
Preferred  Stock and each Rights  Holder may require (the  "Approval  Call") the
Company  to sell an  amount  Series  A  Preferred  Stock to such  Rights  Holder
determined  by dividing the product of (a) such Rights  Holder's  Issuance  Base
Amount times the  Dilution  Value at such time by (b) the per share stated value
of the Series A Preferred  Stock,  at an exercise  price equal to the  aggregate
stated value of any shares of Series A Preferred  Stock so called.  The Approval
Call may be  exercised  with  respect  to all or any  portion  of the  permitted
quantity of Series A Preferred  Stock,  and shall survive any  exercise,  to the
extent of any portion of such  permitted  quantity  of Series A Preferred  Stock
with respect to which it has not yet been exercised.

               (b) The Rights Holder's  Article IX Rights shall be terminated to
the pro rata extent of any exercise of such Rights Holder's Approval Call.

               (c) The exercise  price of the Approval Call shall be paid by the
Rights  Holders in shares of Common  Stock  valued at their  aggregate  Dilution
Value at such time.

               (d) The Registration Rights contained in Article 8 shall apply to
the Common Stock  issuable upon the  conversion of the Series A Preferred  Stock
issuable upon exercise of the Approval Call.


         9.16.  Approval Issuance.  (a) Immediately upon the earliest of (i) the
approval by the holders of Common Stock of the Company of the provisions of this
Section 9.16, to the extent such approval is necessary  pursuant to Rule 4460(i)
of the National  Association of Securities Dealers'  Marketplace Rules, (ii) any
event which renders such stockholder approval


                                       42

<PAGE>

unnecessary or which renders such Rule inapplicable and (iii) September 30, 1997
(such earliest date, the "Approval Date"),  the Dilution Value shall be adjusted
as provided in Subsection  9.16(b) the Company shall issue to each Rights Holder
a number  of fully  paid and  non-assessable  shares of  Common  Stock,  free of
preemptive  rights,  (the  "Approval  Issuance")  equal to such Rights  Holder's
respective  Post-Dilution  Common Quantity minus such Rights Holders  respective
Issuance Base Amount at such time.

               (b) Upon the Approval  Date, the Dilution Value shall be adjusted
to equal the lesser of (x) $.29 and (y) 50% of the average Closing Bid Price for
either  (A) the thirty  consecutive  trading  days  immediately  preceeding  the
Approval Date, (B) the five consecutive  trading days immediately  preceding the
Approval Date or (C) the five consecutive  trading days  immediately  succeeding
the Approval Date, whichever is lowest.

         9.17. (a) The Dilution Value is subject to reduction as described below
upon each  closing of the Series B Offering or any other  Qualified  Offering in
the event  that the  quotient  of (a) the  price  per unit sold in the  Series B
Offering or other Qualified Offering divided by (b) the quantity of Common Stock
included in each unit sold in such Series B Offering or other Qualified Offering
(such  quotient,  the  "Qualified  Offering  Dilution  Value")  is less than the
Dilution Value at such time (or, in the event that securities  other than Common
Stock are sold in any such Series B Offering or other  Qualified  Offering,  the
"Qualified  Offering  Dilution  Value" shall mean the lowest  exercise  price or
conversion price of any such  securities).  In the event of any such adjustment,
the  Dilution  Value  shall be reduced to equal the  lowest  Qualified  Offering
Dilution  Value at any such closing of the Series B Offering or other  Qualified
Offering.

         (b) Upon any  adjustment to the Dilution Value pursuant to this Section
9.17, the Company shall issue to each Rights Holder a number of shares of Common
Stock equal to the difference of such Rights Holder's  respective  Post-Dilution
Common Quantity minus such Rights Holder's respective Issuance Base Amount.

         10.  Certain  Definitions.  For  the  purposes  of this  Agreement  the
following terms have the respective meanings set forth below:

         10.1. "Affiliate" means any person,  corporation,  firm or entity which
directly or indirectly  controls,  is controlled  by, or is under common control
with the indicated person, corporation, firm or entity.

         10.2. "Common Stock" means the Company's Common Stock.

         10.3.  "Generally  Accepted  Accounting   Principles"  means  generally
accepted accounting principles consistently applied.


                                       43

<PAGE>

         10.4. "Officers' Certificate" means a certificate executed on behalf of
the Company by its President,  Chairman of the Board,  Chief Executive  Officer,
Chief Financial Officer,  Vice  President--Finance,  Secretary and/or one of its
other Vice- Presidents.

         10.5. "Registrable Securities" means (i) the Common Stock issuable upon
conversion of the Series A Preferred  Stock and exercise of the Warrants (or the
New  Warrants)  purchased  pursuant  to  Section  1.1  (or,  in the  case of the
Alternate  Offering,  all  Alternate  Offering  Common) (ii) any other shares of
Common Stock now owned or hereafter acquired by Purchasers (whether Common Stock
owned  directly  or  underlying  convertible  securities  of the  Company).  For
purposes  of this  Agreement,  any shares of Common  Stock  issued  pursuant  to
Section 8.6 shall be deemed to be  Registrable  Securities and shall be included
in the Shelf Registration Statement contemplated by Section 8.1.

         10.6.  "Securities" means the Series A Preferred Stock (or, in the case
of the Alternate  Offering,  the Alternate Offering Common and the A Notes), the
Warrants (or the New Warrants) and any Common Stock issuable upon  conversion or
exercise of the foregoing whether issued at the Closing or thereafter.

         10.7.  "Securities Act" means, as of any given time, the Securities Act
of 1933, as amended, or any similar federal law then in force.

         10.8.  "Securities  Exchange  Act"  means,  as of any given  time,  the
Securities  Exchange Act of 1934, as amended, or any similar federal law then in
force.

         10.9.  "Securities and Exchange  Commission"  includes any governmental
body or agency succeeding to the functions thereof.

         10.10.  "Subsidiary" means any person,  corporation,  firm or entity at
least the majority of the equity  securities (or  equivalent  interest) of which
are, at the time as of which any determination is being made, owned of record or
beneficially by the Company,  directly or indirectly,  through any Subsidiary or
otherwise.

         11. Company  Indemnities.  (a) The Company agrees to indemnify and hold
harmless  the  Partnership,  the  Trust and  Paramount  Capital,  Inc.  and each
selected  dealer  selected  by  Paramount  Capital,  Inc.,  if  any,  and  their
respective partners,  affiliates,  shareholders,  directors,  officers,  agents,
advisors, representatives, employees, counsel and controlling persons within the
meaning of the Securities Act of 1933, as amended,  and each person serving as a
Director of the Company as a designee of the Purchasers (a "Director  Designee")
(any of the  foregoing,  a "Paramount  Indemnified  Party")  against any and all
losses, liabilities, claims, damages and expenses whatsoever (and all actions in
respect thereof) (including,  without limitation,  any shareholder lawsuits) and
promptly to reimburse any such  Paramount  Indemnified  Party for legal fees and
related expenses as incurred (including,  but not limited to the costs of giving
testimony or furnishing  documents in response to a subpoena or  otherwise,  the
costs of  investigating,  preparing,  pursuing or  defending  any such action or
claim whether or not pending


                                       44

<PAGE>

or  threatened  and  whether or not  Paramount  Capital  Inc.  or any  Paramount
Indemnified  Party is a party  thereto),  insofar as such  losses,  liabilities,
claims,  damages  or  expenses  arise out of,  relate  to,  are in  incurred  in
connection  with, or are in any way a result of, (i) the engagement of Paramount
Capital,  Inc. pursuant to the Letter of Intent,  the Placement Agency Agreement
(as  defined in the Letter of  Intent),  Advisory  Agreement  (as defined in the
Letter  of  Intent),  or other  offering  documents  or any of the  transactions
contemplated   by  this  Agreement  and  the  other   offering   documents  (the
"Engagement"),   including  any   modifications  or  future  additions  to  such
engagement  and related  activities  prior to the date  hereof,  (ii) any act by
Paramount  Capital,  Inc.  the  Partnership,  the Trust or any  other  Paramount
Indemnified  Party taken in connection  with the Engagement or the  transactions
contemplated  herein or taken by a Director  Designee in accordance  with, or to
ensure compliance by the Company with, the provisions of this Agreement, (iii) a
breach of any representation,  warranty,  covenant,  or agreement of the Company
contained in this  Agreement,  the  Placement  Agency  Agreement,  the Letter of
Intent  or any of the  other  offering  documents,  (iv) the  employment  by the
Company of any device,  scheme or artifice  to defraud,  or the  engaging by the
Company in any act,  practice  or course of  business  which  operates  or would
operate  as a fraud or  deceit,  or any  conspiracy  with  respect  thereto,  in
connection  with the sale of the Units,  or (v) any untrue  statement or alleged
untrue  statement of a material fact contained  herein or in any of the Series A
or Series B offering  documents or the omission or alleged omission therefrom of
a material fact necessary in order to make the statements  therein,  in light of
the  circumstances  under which they were made,  not  misleading,  except to the
extent any of the  foregoing  are  finally and fully  adjudicated  by a court of
competent  jurisdiction to be a direct result of the  intentional  misconduct of
any Paramount Indemnified Party.

               (b) The Company agrees to indemnify and hold harmless a Paramount
Indemnified Party to the same extent as the foregoing indemnity,  and subject to
the limitations set forth therein,  against any and all loss, liability,  claim,
damage and expense whatsoever directly arising out of the exercise by any person
of any right under the Securities Act of 1933, as amended, or the Securities and
Exchange  Act of 1934,  as amended,  or the  securities  or Blue Sky laws of any
state on account of violations of the representations,  warranties or agreements
set forth herein and in any documents related hereto.

         12. Miscellaneous.

         12.1.   Termination;   Survival  of  Representations,   Warranties  and
Covenants.   Except  as   otherwise   provided   for  in  this   Agreement   all
representations,   warranties,   covenants  and  agreements  contained  in  this
Agreement,  or in any document,  exhibit,  schedule or  certificate by any party
delivered in  connection  herewith  shall  survive the execution and delivery of
this  Agreement and the Closing Date and the  consummation  of the  transactions
contemplated  hereby,  regardless of any investigation  made by Purchasers or on
their behalf.

         12.2.  Expenses.  The  Company  shall  pay  all  its  own  expenses  in
connection with this Agreement and the  transactions  contemplated  herein.  The
Company agrees to pay promptly and save the  Partnership  and the Trust harmless
against liability for the payment all expenses


                                       45

<PAGE>

incurred by the Company and the Partnership and the Trust in connection with the
preparation and consummation of the Agreement and the transactions  contemplated
herein,  including  but not limited to: all costs and expenses  under Section 8,
including without limitation,  the costs of preparing,  printing and filing with
the Securities  and Exchange  Commission  the Shelf  Registration  Statement and
amendments,  post-effective  amendments,  and  supplements  thereto;  preparing,
printing and delivering  exhibits thereto and copies of the  preliminary,  final
and supplemental  prospectuses;  preparing,  printing and delivering all selling
documents,  including but not limited to the subscription agreement, the warrant
agreement and stock and warrant  certificates;  legal fees and  disbursements of
the  Partnership  and the Trusts'  counsel (which amount shall be offset against
payment of the  purchase  price for legal fees that have been accrued up to such
date and the  remainder of which shall be paid within 30 days of  submission  of
any statements  therefor) in connection with the preparation and consummation of
this Agreement and the  transactions  contemplated  herein,  including the legal
fees and costs of  negotiating  and  drafting  any  transaction  documents,  due
diligence and any necessary  regulatory filings (including,  without limitation,
the Shelf Registration  Statement,  Forms 3, 4 and 5 and Schedule 13-D filings);
the cost of a total of two sets of bound closing volumes for the Partnership and
the Trust and their counsel; and the cost of the tombstone  advertisement in the
Wall Street Journal (National Edition) pursuant to Section 7.22(c).

         12.3. Amendments and Waivers. Except for the Operative Documents,  this
Agreement and all exhibits and schedules  hereto set forth the entire  agreement
and  understanding  among the parties as to the subject matter hereof and merges
and supersedes all prior  discussions,  agreements and understandings of any and
every nature among them.  This  Agreement may be amended only by mutual  written
agreement of the Company and the holders of a majority of the outstanding shares
of  Series A  Preferred  Stock,  and the  Company  may take  any  action  herein
prohibited or omit to take any action herein required to be performed by it, and
any breach of any covenant, agreement, warranty or representation may be waived,
only if the Company has obtained the written consent or waiver of the holders of
a majority of the outstanding  shares of Series A Preferred  Stock. No course of
dealing  between or among any persons having any interest in this Agreement will
be deemed effective to modify,  amend or discharge any part of this Agreement or
any rights or obligations of any person under or by reason of this Agreement.

         12.4. Successors and Assigns. This Agreement may not be assigned by the
Company  except with the prior  written  consent of the holders of a majority of
the  outstanding  shares of Series A Preferred  Stock.  This Agreement  shall be
binding  upon  and  inure  to the  benefit  of the  Company  and  its  permitted
successors  and assigns and Purchasers  and their  successors  and assigns.  The
provisions hereof which are for Purchasers'  benefit as purchasers or holders of
the Series A Preferred  Stock and the  Warrants are also for the benefit of, and
enforceable  by, any  subsequent  holder of such  Series A  Preferred  Stock and
Warrants.

         12.5.  Notices.  All notices,  demands and other  communications  to be
given or delivered  under or by reason of the provisions of this Agreement shall
be in writing and shall be deemed to have been given  personally  or when mailed
by certified or registered mail, return


                                       46

<PAGE>

receipt  requested  and postage  prepaid,  and addressed to the addresses of the
respective  parties set forth below or to such changed addresses as such parties
may have  fixed by  notice;  provided,  however,  that any  notice  of change of
address shall be effective only upon receipt:


                           If to the Company:
                           Procept, Inc.
                           840 Memorial Drive
                           Cambridge, MA  02139
                           Attn:  Stanley C. Erck

                           With a Copy to:
                           Palmer & Dodge LLP
                           One Beacon Street
                           Boston, MA  02108
                           Attn:  Lynnette C. Fallon

                           If to the Partnership or the Trust:
                           Paramount Capital Asset Management, Inc.
                           787 Seventh Avenue
                           New York, NY 10019
                           Attn: David R. Walner

                           With a Copy to:
                           Kramer, Levin, Naftalis & Frankel
                           919 Third Avenue
                           New York, New York 10022
                           Attention: Monica C. Lord

         12.6. Governing Law. The validity, performance, construction and effect
of this  Agreement  shall be governed by the  internal  laws of the State of New
York without giving effect to such State's principles of conflict of laws.

         12.7.  Counterparts.  This  Agreement  may be executed in any number of
counterparts  and,  notwithstanding  that any of the parties did not execute the
same counterpart,  each of such counterparts shall, for all purposes,  be deemed
an  original,  and all  such  counterparts  shall  constitute  one and the  same
instrument binding on all of the parties thereto.

         12.8.  Headings.  The headings of the Sections hereof are inserted as a
matter of  convenience  and for  reference  only and in no way define,  limit or
describe the scope of this Agreement or the meaning of any provision hereof.

         12.9.  Severability.  In the event that any provision of this Agreement
or the application of any provision hereof is declared to be illegal, invalid or
otherwise unenforceable


                                       47

<PAGE>

by a court of competent jurisdiction,  the remainder of this Agreement shall not
be affected  except to the extent  necessary to delete such illegal,  invalid or
unenforceable  provision  unless the provision held invalid shall  substantially
impair the benefit of the remaining portion of this Agreement.

         12.10.  Freedom of Action.  (a) The Partnership and the Trust and their
affiliates shall not have any obligation to the Company not to (i) engage in the
same or similar  activities  or lines of  business  as the Company or develop or
market any  products,  services or  technologies  that does or may in the future
compete,  directly or indirectly,  with those of the Company, (ii) invest or own
any interest publicly or privately in, or develop a business  relationship with,
any  corporation,  partnership  or other person or entity engaged in the same or
similar  activities or lines or business as, or otherwise in  competition  with,
the  Company  or (iii) do  business  with any  client,  collaborator,  licensor,
consultant, vendor or customer of the Company. The Partnership and the Trust and
its officers, directors,  employees or former employees and affiliates shall not
have any  obligation,  or be  liable,  to the  Company  solely on account of the
conduct  described in the  preceding  sentence.  In the event that either of the
Partnership or the Trust and any officer, director,  employee or former employee
or affiliate thereof acquires knowledge of a potential  transaction,  agreement,
arrangement  or other matter which may be a corporate  opportunity  for both the
Partnership  and the Trust and the Company,  neither of the  Partnership and the
Trust nor their officers, directors, employees or former employees or affiliates
shall have any duty to communicate  or offer such  corporate  opportunity to the
Company  and  neither  of the  Partnership  and the Trust  nor  their  officers,
directors,  employees or former  employees or affiliates  shall be liable to the
Company for breach of any fiduciary duty, as a stockholder or otherwise,  solely
by reason of the fact that  Partnership  and the Trust or any of their officers,
directors,  employees or former  employees or affiliates  pursue or acquire such
corporate  opportunity for either of the  Partnership or the Trust,  direct such
corporate  opportunity  to another  person or entity or  communicate  or fail to
communicate such corporate opportunity or entity to the Company. As used in this
Section,  the  Partnership  and the  Trust  shall  mean  either  and both of the
Partnership  and the Trust and their  affiliates  (excluding  the  Company as an
affiliate of the Partnership and the Trust).

         (b) The  provisions of this Section 12.10 shall be  enforceable  to the
fullest extent permitted by law.

         12.11.  Rights of Purchasers  Inter Se. Each  Purchaser  shall have the
absolute right to exercise or refrain from  exercising any right or rights which
such Purchaser may have by reason of this  Agreement or any security  including,
without limitation,  the right to consent to the waiver of any obligation of the
Company under this Agreement and to enter into an agreement with the Company for
the  purpose  of  modifying  this  Agreement  or any  agreement  effecting  such
modification,  and such  Purchaser  shall not incur any  liability  to any other
Purchaser or Purchasers with respect to exercising or refraining from exercising
any such right or rights. Each Purchaser and Paramount Capital,  Inc. may assign
to an affiliate any of their respective rights under this Agreement.


                                       48

<PAGE>

         12.12. Consent to Jurisdiction.  The parties hereto irrevocably consent
to the  jurisdiction  of the courts of the State of New York and of any  federal
court located in such State in connection with any action or proceeding  arising
out of or relating to this  Agreement,  any  document  or  instrument  delivered
pursuant to, in connection  with or  simultaneously  with this  Agreement,  or a
breach of this Agreement or any such document or instrument.  In any such action
or  proceeding,  each party  hereto  waives  personal  service  of any  summons,
complaint  or other  process  and agrees  that  service  thereof  may be made in
accordance with this Section 12.12.  Within 30 days after such service,  or such
other time as may be mutually  agreed upon in writing by the  attorneys  for the
parties to such action or proceeding, the party so served shall appear or answer
such summons, complaint or other process.


                                       49

<PAGE>


         IN WITNESS WHEREOF,  the parties hereto have executed this Agreement as
of the day and year first above written.


                                     PROCEPT INC.


                                     By:   /s/ Lindsay A. Rosenwald, M.D.
                                        ------------------------------------
                                           Name:
                                           Title:


                                     THE ARIES FUND, A CAYMAN ISLAND
                                     TRUST

                                     By:  its Investment Manager, PARAMOUNT
                                     CAPITAL ASSET MANAGEMENT, INC.


                                     By:    /s/ Lindsay A. Rosenwald, M.D.
                                        ------------------------------------
                                           Name:  Lindsay A. Rosenwald, M.D.
                                           Title:  President


                                     THE ARIES DOMESTIC FUND, L.P.


                                     By:  its General Partner, PARAMOUNT
                                     CAPITAL ASSET MANAGEMENT, INC..


                                     By:    /s/ Lindsay A. Rosenwald, M.D.
                                        ------------------------------------
                                           Name:  Lindsay A. Rosenwald, M.D.
                                           Title:  President

<PAGE>
                                   EXHIBIT F

THE  SECURITIES  REPRESENTED  BY THIS  NOTE HAVE NOT BEEN  REGISTERED  UNDER THE
SECURITIES ACT OF 1933 OR ANY APPLICABLE  STATE  SECURITIES LAWS, AND MAY NOT BE
SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED OR OTHERWISE  TRANSFERRED IN THE
ABSENCE OF A  REGISTRATION  STATEMENT IN EFFECT WITH  RESPECT TO THE  SECURITIES
UNDER SUCH ACT OR AN EXEMPTION THEREFROM.  ANY SUCH TRANSFER MAY ALSO BE SUBJECT
TO APPLICABLE STATE SECURITIES LAWS.


                                  PROCEPT, INC.

                                                                         No. A-2
                             SENIOR CONVERTIBLE NOTE

$70,000.00                                                 New York, New York
                                                           June 30, 1997

                  Procept,  Inc., a Delaware corporation,  (the "Company"),  for
value  received,  hereby  promises to pay to the Aries Domestic Fund,  L.P. (the
"Holder"),  or registered assigns, the principal sum of seventy thousand dollars
($70,000.00),  with interest  from the date of original  issuance of this Senior
Convertible  Note on the  unpaid  principal  balance  at a rate  equal to twelve
percent (12%) per annum,  on the earlier of (a) September 30, 1997, (b) five (5)
business  days  following  the  completion  of any equity  offering or series of
equity offerings with gross proceeds to the Company in excess of $1,000,000 (the
"Maturity  Date"),  and (c) the  failure of the  Company to obtain the  Required
Shareholder  Approval (as defined in the Purchase  Agreement).  Payment shall be
made at such place as  designated  by the Holder upon  surrender  of this Senior
Convertible  Note, and shall be in such coin or currency of the United States of
America  as at the time of  payment  shall be legal  tender  for the  payment of
public and private  debts.  Interest shall be computed on the basis of a 360-day
year of twelve  30-day  months.  This Senior  Convertible  Note is one of a duly
authorized issue of Procept,  Inc. 12% Senior  Convertible Notes in an aggregate
principal amount of $200,000.00,  subject to increase  pursuant to Sections 7.27
and 8.6 of the Purchase Agreement (as defined below)  (individually a "Note" and
collectively  the "Notes")  issued pursuant to a Securities  Purchase  Agreement
dated June 30,  1997 (the  "Purchase  Agreement")  between  the  Company and the
Holders of the Notes (the "Noteholders"). The Notes shall be senior to all other
indebtedness of the Company ("Other  Indebtedness")  and all Other  Indebtedness
shall be subordinated to the Notes.




SECTION 1.        PREPAYMENT.

                  This Note (including interest accrued on the principal hereof)
may be prepaid by the Company,  at any time without penalty or premium  provided
that the  Company  shall  provide the holders of the Notes with at least 30 days
prior written notice of prepayment, and prior to


<PAGE>

such prepayment, the holders of the Notes shall have the opportunity to exercise
their optional conversion rights pursuant to Section 2 hereof.

SECTION 2.         OPTIONAL CONVERSION.

                  (a) Right of Conversion. (i) Immediately or, (ii) if the rules
of any securities  exchange or automated quotation system on which the Company's
common  stock,  par value  $.01 per  share,  (the  "Common  Stock") is traded or
quoted, or any other law or regulation, require the approval of the shareholders
of the Company to permit  convertibility of the Notes, then (x) upon the receipt
of such  approvals but (y) in no event later than  September 30, 1997, the Notes
shall  be  convertible,  in  whole  or in part,  at the  option  (the  "Optional
Conversion  Right") of the holders thereof and upon notice to the Company as set
forth in paragraph  2(b) below,  into either,  at the election of the holder (A)
shares of Series A Preferred Stock of the Company (the "Preferred Stock") or (B)
Common  Stock of the  Company . In the event that the  holders  elect to receive
Common  Stock,  the  number of shares  shall be equal to the  Conversion  Amount
divided by the then current  Conversion Price (as defined below). The Conversion
Amount shall be the Liquidation  Amount (as defined below),  or in the case of a
partial  conversion,  such lesser amount as designated by the converting holder.
The  Liquidation  Amount shall mean the aggregate  principal  value of the Notes
held by such Holder plus any accrued and unpaid  interest.  The Conversion Price
shall   initially  be  $.46875,   subject  to  adjustment  as  provided   below,
representing an initial conversion rate (subject to adjustment) of 21,333 shares
of Common Stock per $10,000 of Conversion Amount.

                  In the  event  that the  holders  elect to  receive  Preferred
Stock,  then the  number of  shares of  Preferred  Stock to be  received  by the
holders shall be the  Liquidation  Amount divided by the then current  Preferred
Conversion Price (as defined below).  The Preferred Stock Conversion Price shall
initially be $100.00,  subject to adjustment as provided  below,  representing a
Preferred Stock initial conversion rate (subject to adjustment) of 100 shares of
Preferred Stock per $10,000 of Conversion  Amount. In the event that the holders
elect to receive  Preferred  Stock in connection  with any conversion  hereunder
rather than Common Stock,  any  reference to the to the terms "Common  Stock" or
the  "Conversion  Price",  shall be read to mean the " Preferred  Stock" and the
"Preferred  Conversion Price", with all the provisions applicable to the "Common
Stock" and the "Conversion  Price" being applied to the terms "Preferred  Stock"
and the "Preferred  Stock  Conversion  Price",  respectively,  on a proportional
basis .

                  The Conversion Price is subject to adjustment, upon the Series
B Final Closing Date (as defined in the Letter of Intent between the Corporation
and Paramount Capital,  Inc., dated June 30, 1997 (the "Letter of Intent")),  if
the  conversion  price of the preferred  stock (the "Series B Preferred  Stock")
sold in the Series B Offering (as defined in the Letter of Intent), or the price
per share of any Common  Stock sold in such Series B Offering,  or the  exercise
price of any warrants sold in such Series B Offering is less than the Conversion
Price. In such event,  the Conversion Price shall be reduced to equal the lesser
of any such conversion price, purchase price or exercise price of any securities
sold in such  Series B Offering  as in effect on any of the  respective  closing
dates of such  Series B  Offering.  In the event that there is no Series B Final
Closing Date, or the above  referenced  Series B Offering is not commenced or is
otherwise


                                        2

<PAGE>

terminated,  if the price per share of  Common  Stock (or the  effective  price,
conversion  price or exercise  price per share of Common Stock,  as the case may
be, of a security  convertible into or exchangeable for Common Stock) offered to
investors  in the next  offering  or  series  of  related  offerings  of  equity
securities of the Corporation (or any securities convertible into or exercisable
for equity securities)  following the date hereof which yields gross proceeds to
the  Corporation  in  excess  of  $2,000,000  in  the  aggregate  (a  "Qualified
Offering")  shall  be  less  than  the  Conversion  Price  then in  effect,  the
Conversion  Price shall be reduced to equal the lowest such  offering  price (or
effective  price,  conversion  price or exercise  price, as the case may be) per
share of Common Stock to investors in such Qualified Offering.

                  The  Conversion  Price  is  subject  to  adjustment,  upon any
Approval  Issuance (as defined in the Purchase  Agreement).  In the event of any
such  Approval  Issuance,  the  Conversion  Price shall be adjusted to equal the
Dilution Value (as defined in the Purchase Agreement) immediately following such
Approval Issuance.

                  (b)  Conversion  Procedures.  Any holder of Notes  desiring to
convert such Notes into Common Stock shall surrender the Notes at the offices of
the Company,  which Notes shall be accompanied by irrevocable  written notice to
the Company that the holder elects so to convert such Notes and  specifying  the
name or names (with address) in which a certificate or  certificates  evidencing
shares of Common Stock are to be issued. The Company will make a notation of the
date that a notice of conversion  is received,  which date shall be deemed to be
the date of receipt for purposes hereof.

                  The Company shall deliver to the holder  converting the Notes,
or to the nominee or nominees of such person, certificates evidencing the number
of full  shares  of Common  Stock to which  such  person  shall be  entitled  as
aforesaid,  together  with a cash  adjustment  of any  fraction  of a  share  as
hereinafter  provided.  Subject to the following  provisions of this  paragraph,
such  conversion  shall  be  deemed  to have  been  made as of the  date of such
surrender of the Notes and the person or persons  entitled to receive the Common
Stock  deliverable  upon  conversion  of such  Notes  shall be  treated  for all
purposes  as the record  holder or holders  of such  Common  Stock on such date;
provided,  however,  that the Company shall not be required to convert any Notes
while the stock  transfer  books of the Company are closed for any purpose,  but
the surrender of Notes for conversion  during any period while such books are so
closed shall become  effective for conversion  immediately upon the reopening of
such books as if the surrender had been made on the date of such reopening,  and
the conversion shall be at the conversion rate in effect on such date.

                  All  notices of  conversion  shall be  irrevocable;  provided,
however,  that if the Company has sent notice of an event  pursuant to paragraph
2(e) hereof,  a holder of Notes may, at its  election,  provide in its notice of
conversion  that  the  conversion  of its  Notes  shall be  contingent  upon the
occurrence  of the record date or  effectiveness  of such event (as specified by
such holder), provided that such notice of conversion is received by the Company
prior to such record date or effective date, as the case may be.


                                        3

<PAGE>

                  (c)      Protection From Dilution.

                    (i) Except as otherwise  provided  herein,  in the event the
Company shall, at any time or from time to time after the date hereof,  (A) sell
or issue any  shares of Common  Stock for a  consideration  per share  less than
either (I) the  Conversion  Price in effect on the date of such sale or issuance
or (II) the Market  Price (as defined in the Purchase  Agreement)  of the Common
Stock as of the date of the sale or  issuance,  (B) issue  any  shares of Common
Stock as a stock  dividend to the holders of Common  Stock,  or (C) subdivide or
combine the  outstanding  shares of Common Stock into a greater or lesser number
of shares (any such sale,  issuance,  subdivision  or  combination  being herein
called a "Change of Shares"),  then, and thereafter  upon each further Change of
Shares,  the  Conversion  Price in effect  immediately  prior to such  Change of
Shares shall be changed to a price  (rounded to the nearest cent)  determined by
multiplying  the  Conversion  Price in effect  immediately  prior  thereto  by a
fraction,  the  numerator  of which  shall be the sum of the number of shares of
Common  Stock  outstanding  immediately  prior to the sale or  issuance  of such
additional shares or such subdivision or combination and the number of shares of
Common Stock which the aggregate  consideration received (determined as provided
in Subparagraph  2(c)(v)(E))  for the issuance of such  additional  shares would
purchase  at the  greater of (x) the  Conversion  Price in effect on the date of
such issuance, and (y) the Market Price of the Common Stock as of such date, and
the  denominator  of  which  shall be the  number  of  shares  of  Common  Stock
outstanding  immediately after the sale or issuance of such additional shares or
such  subdivision or  combination.  Such adjustment  shall be made  successively
whenever such an issuance is made.

                    (ii) In case of any reclassification, capital reorganization
or other  change  of  outstanding  shares  of  Common  Stock,  or in case of any
consolidation or merger of the Company with or into another entity (other than a
consolidation or merger in which the Company is the continuing  entity and which
does not result in any reclassification,  capital reorganization or other change
of outstanding shares of Common Stock other than the number thereof), or in case
of any sale or conveyance  to another  entity of the property of the Company as,
or substantially as, an entirety (other than a sale/leaseback, mortgage or other
financing  transaction),  the Company shall cause effective provision to be made
so that the Holder shall be entitled to receive,  upon  conversion of this Note,
the  kind and  number  of  shares  of stock  or  other  securities  or  property
(including cash) receivable upon such  reclassification,  capital reorganization
or other change,  consolidation,  merger,  sale or conveyance by a holder of the
number  of  shares  of  Common  Stock  into  which  such  Note  was  convertible
immediately  prior to such  reclassification,  capital  reorganization  or other
change,  consolidation,  merger,  sale or conveyance.  Any such provision  shall
include  provision for adjustments that shall be as nearly  equivalent as may be
practicable to the adjustments provided for in this Subsection 2(c). The Company
shall not  effect any such  consolidation,  merger or sale  unless  prior to, or
simultaneously  with, the consummation  thereof the successor (if other than the
Company)  resulting from such  consolidation or merger or the entity  purchasing
assets or other appropriate entity shall assume, by written instrument  executed
and  delivered  to the  Company,  the  obligation  to deliver to the Holder such
shares of stock,  securities  or assets  as, in  accordance  with the  foregoing
provisions,  such Holder may be  entitled  to receive and the other  obligations
under this Note. The foregoing  provisions  shall  similarly apply to successive
reclassifications,  capital  reorganizations  and other  changes of  outstanding
shares  of Common  Stock and to  successive  consolidations,  mergers,  sales or
conveyances.


                                        4

<PAGE>

                    (iii)  If,  at any time or from  time to time,  the  Company
shall issue or distribute  to the holders of shares of Common Stock  evidence of
its indebtedness,  any other securities of the Company or any cash,  property or
other assets (any such event being herein called a "Special Dividend"),  then in
each case the Holder  shall be  entitled  to a  proportionate  share of any such
Special  Dividend as though it were the holder of the number of shares of Common
Stock of the Company into which this Note is  convertible  as of the record date
fixed  for the  determination  of the  holders  of Common  Stock of the  Company
entitled to receive such Special Dividend.

                    (iv) After each adjustment of the Conversion  Price pursuant
to this Subsection 2(c), the Company will promptly prepare a certificate  signed
by the Chairman or President,  and by the Treasurer or an Assistant Treasurer or
the Secretary or an Assistant  Secretary,  of the Company setting forth: (A) the
Conversion Price as so adjusted,  (B) the conversion rate  corresponding to such
Conversion  Price and (C) a brief  statement  of the facts  accounting  for such
adjustment. The Company will promptly file such certificate in the Note Register
(as defined  below) and send such  certificate  by ordinary  first class mail to
each registered holder of Notes at his or her last address as it shall appear in
the Note  Register.  No failure to mail such notice nor any defect therein or in
the mailing thereof shall affect the validity of such adjustment.  The affidavit
of an authorized  officer of the Company that such notice has been mailed shall,
in the absence of fraud,  be prima facie  evidence of the facts stated  therein.
The Transfer Agent may rely on the  information  in the  certificate as true and
correct  and has no duty or  obligation  independently  to verify the amounts or
calculations set forth therein.

                    (v) For purposes of Subsection 2(c)(i) hereof, the following
provisions (A) to (E) shall also be applicable:

                              (A) No adjustment of the Conversion Price shall be
                    made unless  such  adjustment  would  require an increase or
                    decrease of at least $.01 in such price;  provided  that any
                    adjustments which by reason of this Subparagraph (A) are not
                    required  to be made shall be carried  forward  and shall be
                    made at the time of, and together with, the next  subsequent
                    adjustment  which,  together  with  adjustments  so  carried
                    forward,  shall  require an increase or decrease of at least
                    $.01 in the Conversion Price then in effect hereunder.

                              (B) In case of (I) the sale or other  issuance  by
                    the  Company  (including  as a  component  of a unit) of any
                    rights or  warrants to  subscribe  for or  purchase,  or any
                    options for the purchase of, Common Stock or any  securities
                    convertible  into or  exchangeable  for Common  Stock  (such
                    securities  convertible,  exercisable or  exchangeable  into
                    Common Stock being herein called "Convertible  Securities"),
                    or (II) the issuance by the Company,  without the receipt by
                    the Company of any consideration  therefor, of any rights or
                    warrants to subscribe  for or  purchase,  or any options for
                    the purchase of,  Common  Stock or  Convertible  Securities,
                    whether or not such  rights,  warrants  or  options,  or the
                    right to convert or exchange  such  Convertible  Securities,
                    are immediately exercisable, and the consideration per share
                    for which Common Stock is issuable upon the exercise of such
                    rights,  warrants  or  options  or upon  the  conversion  or
                    exchange  of  such  Convertible  Securities  (determined  by
                    dividing


                                        5

<PAGE>

                    (x) the minimum aggregate consideration, as set forth in the
                    instrument   relating   thereto   without   regard   to  any
                    antidilution or similar  provisions  contained therein for a
                    subsequent adjustment of such amount, payable to the Company
                    upon the exercise of such rights,  warrants or options, plus
                    the  consideration  received by the Company for the issuance
                    or sale of such rights,  warrants or options,  plus,  in the
                    case of such Convertible  Securities,  the minimum aggregate
                    amount,  as set  forth in the  instrument  relating  thereto
                    without  regard to any  antidilution  or similar  provisions
                    contained  therein  for  a  subsequent  adjustment  of  such
                    amount, of additional consideration, if any, other than such
                    Convertible  Securities,  payable  upon  the  conversion  or
                    exchange  thereof,  by (y) the total maximum number,  as set
                    forth in the instrument  relating  thereto without regard to
                    any antidilution or similar provisions contained therein for
                    a subsequent  adjustment of such amount, of shares of Common
                    Stock issuable upon the exercise of such rights, warrants or
                    options  or  upon  the   conversion   or  exchange  of  such
                    Convertible  Securities  issuable  upon the exercise of such
                    rights,  warrants  or  options)  is  less  than  either  the
                    Conversion  Price or the Market Price of the Common Stock as
                    of the date of the issuance or sale of such rights, warrants
                    or  options,  then such  total  maximum  number of shares of
                    Common  Stock  issuable  upon the  exercise of such  rights,
                    warrants  or options or upon the  conversion  or exchange of
                    such Convertible  Securities (as of the date of the issuance
                    or sale of such rights, warrants or options) shall be deemed
                    to be "Common Stock" for purposes of Subsection  2(c)(i) and
                    shall be deemed  to have  been  sold for an amount  equal to
                    such  consideration  per share and shall cause an adjustment
                    to be made in accordance with Subsection 2(c)(i).

                              (C) In case  of the  sale  by the  Company  of any
                    Convertible   Securities,   whether  or  not  the  right  of
                    conversion   or   exchange    thereunder   is    immediately
                    exercisable,  and the price per share for which Common Stock
                    is  issuable  upon  the   conversion  or  exchange  of  such
                    Convertible Securities (determined by dividing (x) the total
                    amount of consideration received by the Company for the sale
                    of such Convertible  Securities,  plus the minimum aggregate
                    amount,  as set  forth in the  instrument  relating  thereto
                    without  regard to any  antidilution  or similar  provisions
                    contained  therein  for  a  subsequent  adjustment  of  such
                    amount, of additional consideration, if any, other than such
                    Convertible  Securities,  payable  upon  the  conversion  or
                    exchange  thereof,  by (y) the total maximum number,  as set
                    forth in the instrument  relating  thereto without regard to
                    any antidilution or similar provisions contained therein for
                    a subsequent  adjustment of such amount, of shares of Common
                    Stock  issuable  upon the  conversion  or  exchange  of such
                    Convertible  Securities)  is less than either the Conversion
                    Price or the Market Price of the Common Stock as of the date
                    of the sale of such Convertible Securities,  then such total
                    maximum  number of shares of Common Stock  issuable upon the
                    conversion or exchange of such Convertible Securities (as of
                    the date of the sale of such Convertible  Securities)  shall
                    be deemed to be "Common  Stock" for  purposes of  Subsection
                    2(c)(i)  and shall be deemed to have been sold for an amount
                    equal to such consideration


                                        6

<PAGE>


                    per  share  and  shall  cause  an  adjustment  to be made in
                    accordance with Subsection 2(c)(i).

                              (D) In case the Company shall modify the rights of
                    conversion,  exchange or  exercise of any of the  securities
                    referred to in (B) and (C) above or any other  securities of
                    the Company  convertible,  exchangeable  or exercisable  for
                    shares of Common  Stock,  for any reason other than an event
                    that would require  adjustment to prevent dilution  pursuant
                    to  the  terms  of any  such  convertible,  exchangeable  or
                    exercisable instrument,  so that the consideration per share
                    received by the Company after such modification is less than
                    either the  Conversion  Price or the Market  Price as of the
                    date prior to such  modification,  then such securities,  to
                    the  extent  not   theretofore   exercised,   converted   or
                    exchanged,  shall be deemed to have  expired  or  terminated
                    immediately  prior to the date of such  modification and the
                    Company  shall be deemed for  purposes  of  calculating  any
                    adjustments  pursuant to this Subsection 2(c) to have issued
                    such  new  securities  upon  such  new  terms on the date of
                    modification.  Such adjustment  shall become effective as of
                    the date upon which such modification  shall take effect. On
                    the expiration or cancellation of any such right, warrant or
                    option or the  termination or cancellation of any such right
                    to convert or exchange any such Convertible Securities,  the
                    Conversion Price then in effect hereunder shall forthwith be
                    readjusted to such  Conversion  Price as would have obtained
                    (a) had the  adjustments  made upon the  issuance or sale of
                    such rights,  warrants,  options or  Convertible  Securities
                    been made upon the basis of the  issuance of only the number
                    of shares of Common  Stock  theretofore  actually  delivered
                    (and the total  consideration  received  therefor)  upon the
                    exercise  of such  rights,  warrants  or options or upon the
                    conversion or exchange of such  Convertible  Securities  and
                    (b) had adjustments been made on the basis of the Conversion
                    Price as adjusted  under clause (a) of this sentence for all
                    transactions   (which  would  have  affected  such  adjusted
                    Conversion  Price)  made after the  issuance or sale of such
                    rights, warrants, options or Convertible Securities.

                              (E) In case of the sale of any  shares  of  Common
                    Stock, any Convertible Securities, any rights or warrants to
                    subscribe  for or purchase,  or any options for the purchase
                    of,   Common   Stock   or   Convertible   Securities,    the
                    consideration  received  by the  Company  therefor  shall be
                    deemed  to  be  the  gross  sales  price  therefor   without
                    deducting  therefrom  any  expense  paid or  incurred by the
                    Company or any  underwriting  discounts  or  commissions  or
                    concessions  paid or  allowed by the  Company in  connection
                    therewith.  In the event that any securities shall be issued
                    in  connection  with any other  securities  of the  Company,
                    together  comprising  one integral  transaction  in which no
                    specific  consideration  is allocated  among the securities,
                    then  each of such  securities  shall be deemed to have been
                    issued for such  consideration  as the Board of Directors of
                    the Company determines in good faith; provided, however that
                    if the holders of in excess of ten percent (10%) of the then
                    outstanding  principal  amount of Notes  disagree  with such
                    determination, the Company shall retain, at its own


                                        7

<PAGE>

                    expense,  an  independent  investment  banking  firm for the
                    purpose of rendering an appraisal.

                    (vi)   Notwithstanding   any  other  provision   hereof,  no
adjustment to the Conversion Price will be made:

                              (A) upon the  exercise  of (i) any of the  options
                    outstanding on the date hereof under the Company's  existing
                    stock option plans, or (ii) any warrants  outstanding on the
                    date  hereof   listed  on  schedule   5.3  to  the  Purchase
                    Agreement,  copies of which have been provided to the Holder
                    prior to the date hereof; or

                              (B) upon the  issuance  or  exercise of options or
                    stock which may hereafter be granted, purchased or sold with
                    the approval of the Board of Directors, or exercised,  under
                    any  employee  benefit  plan  or  the  1993  Employee  Stock
                    Purchase  Plan  of  the  Company  to  officers,   directors,
                    consultants  or  employees,  but only with  respect  to such
                    options  as  are   exercisable  at,  and  shares  which  are
                    purchased  and/or sold at,  prices no lower than the Closing
                    Bid Price (as defined in the Purchase Agreement) (or, if the
                    Closing  Bid Price  cannot be  determined,  the Fair  Market
                    Value (as defined in the Purchase  Agreement)) of the Common
                    Stock as of the date of grant thereof; or

                              (C) upon  issuance or  exercise  of the  Placement
                    Warrants,  or the  Advisory  Warrants,  (as  defined  in the
                    Letter of Intent) (collectively,  the "Paramount Warrants"),
                    upon  the  issuance  of any  Common  Stock  pursuant  to the
                    Purchase  Agreement  (including any Article IX Issuances (as
                    defined  therein)),  upon the  exercise  of the  Class A and
                    Class B  Warrants  (as  defined  in the Letter of Intent) or
                    upon the  issuance,  conversion  or exercise of the Series B
                    Preferred Stock or Common Stock  (including any common stock
                    issuable  pursuant to  contractual  rights  analogous to the
                    Article IX  Issuances)  or the Class C Warrants to be issued
                    (i) on or  prior  to the  Series  B Final  Closing  Date (as
                    defined in the Letter of  Intent)  or (ii)  pursuant  to the
                    exercise of the  Paramount  Warrants,  or upon the issuance,
                    conversion or exercise of any Series A or Series B Preferred
                    Stock or Class A,  Class B or Class C Warrants  approved  in
                    writing by the Placement  Agent, or upon the issuance of any
                    other  equity  securities  of the Company to the extent that
                    such issuance  causes an adjustment to the Conversion  Price
                    pursuant to the second paragraph of Subsection 2(a); or

                              (D) upon the  issuance or sale of Common  Stock or
                    Convertible  Securities  pursuant  to  the  exercise  of any
                    rights,  options or warrants to  receive,  subscribe  for or
                    purchase,  or any options for the purchase of,  Common Stock
                    or  Convertible  Securities,  whether  or not  such  rights,
                    warrants  or  options  were  outstanding  on the date of the
                    original  issuance of the Notes or were thereafter issued or
                    sold,  provided  that an  adjustment  was either made or not
                    required to


                                        8

<PAGE>

                    be made in accordance with Subsection  2(c)(i) in connection
                    with  the  issuance  or  sale  of  such  securities  or  any
                    modification of the terms thereof; or

                              (E) upon the issuance or sale of Common Stock upon
                    conversion  or  exchange  of  any  Convertible   Securities,
                    provided that any  adjustments  required to be made upon the
                    issuance  or  sale  of such  Convertible  Securities  or any
                    modification  of the terms thereof were so made, and whether
                    or not such  Convertible  Securities were outstanding on the
                    date  of  the  original   issuance  of  the  Notes  or  were
                    thereafter issued or sold.

Subparagraph  2(c)(v)(D)  shall  nevertheless  apply to any  modification of the
rights of conversion,  exchange or exercise of any of the securities referred to
in  Subparagraphs  (A), (B), (D) and (E), or to the extent effected with respect
to  fewer  than  all of such  securities,  Subparagraph  (C) of this  Subsection
2(c)(vi).

                    (vii) As used in this  Subsection  2(c),  the  term  "Common
Stock" shall mean and include the Company's  Common Stock authorized on the date
of the original  issue of the Notes and shall also include any capital  stock of
any class of the Company  thereafter  authorized which shall not be limited to a
fixed sum or  percentage  in  respect of the  rights of the  holders  thereof to
participate  in dividends and in the  distribution  of assets upon the voluntary
liquidation,  dissolution or winding up of the Company; provided,  however, that
the shares  issuable  upon  conversion of the Notes shall include only shares of
such class designated in the Certificate of Incorporation as Common Stock on the
date  of  the  original  issue  of  the  Notes  or  (i),  in  the  case  of  any
reclassification,  change,  consolidation,  merger,  sale or  conveyance  of the
character referred to in Subsection  2(c)(ii) hereof,  the stock,  securities or
property   provided  for  in  such   section  or  (ii),   in  the  case  of  any
reclassification  or change in the  outstanding  shares of Common Stock issuable
upon  conversion of the Notes as a result of a  subdivision  or  combination  or
consisting of a change in par value,  or from par value to no par value, or from
no par value to par value,  such shares of Common  Stock as so  reclassified  or
changed.

                    (viii) Any  determination as to whether an adjustment in the
Conversion Price in effect hereunder is required  pursuant to Subsection 2(a) or
2(c), or as to the amount of any such adjustment,  if required, shall be binding
upon the holders of the Notes and the Company if made in good faith by the Board
of Directors of the Company.

                  (d) Reservation of Shares;  Transfer  Taxes;  Etc. The Company
shall  at all  times  reserve  and keep  available,  out of its  authorized  and
unissued  shares of Common  Stock,  solely  for the  purpose  of  effecting  the
conversion  of  the  Notes,  including,  without  limitation  upon  any  Default
Conversion,  such number of shares of its Common Stock free of preemptive rights
as shall be sufficient  to effect the  conversion of all Notes from time to time
outstanding.  The  Company  shall use its best  efforts  from  time to time,  in
accordance  with the laws of the State of Delaware,  to increase the  authorized
number of shares of Common  Stock if at any time the  number of shares of Common
Stock not  outstanding  shall not be sufficient to permit the  conversion of all
the then-outstanding Notes.


                                        9

<PAGE>

                  The  Company  shall pay any and all issue or other  taxes that
may be payable in respect of any issue or delivery of shares of Common  Stock on
conversion of the Notes. The Company shall not, however,  be required to pay any
tax which may be payable in respect  of any  transfer  involved  in the issue or
delivery of Common  Stock (or other  securities  or assets) in a name other than
that in which the  Notes so  converted  were  registered,  and no such  issue or
delivery  shall be made  unless and until the person  requesting  such issue has
paid  to  the  Company  the  amount  of  such  tax or  has  established,  to the
satisfaction of the Company,  that such tax has been paid. The Company covenants
that all shares of Common  Stock  issuable  upon  exercise of the  Optional  and
Default Conversion Rights shall be validly issued, fully paid and nonassessable.

                  (e) Prior Notice of Certain Events. In case:

                    (i) the Company  shall  declare any  dividend  (or any other
          distribution); or

                    (ii) the Company shall authorize the granting to the holders
          of Common Stock of rights or warrants to subscribe for or purchase any
          shares of stock of any class or of any other rights or warrants; or

                    (iii) of any  reclassification of Common Stock (other than a
         subdivision or combination of the outstanding Common Stock, or a change
         in par value,  or from par value to no par value,  or from no par value
         to par value); or

                    (iv) of any  consolidation or merger to which the Company is
          a party and for which  approval  of any  stockholders  of the  Company
          shall be required,  or of the sale or transfer of all or substantially
          all of the assets of the Company or of any  compulsory  share exchange
          whereby the Common Stock is converted into other  securities,  cash or
          other property; or

                    (v) of the voluntary or involuntary dissolution, liquidation
          or winding up of the Company;

then the Company shall cause to be mailed to the holders of Notes, at their last
addresses as they shall  appear upon the books of the Company,  at least 20 days
prior to the applicable record date hereinafter  specified, a notice stating (x)
the date on which a record  (if  any) is to be  taken  for the  purpose  of such
dividend,  distribution or granting of rights or warrants or, if a record is not
to be taken,  the date as of which the  holders of Common  Stock of record to be
entitled to such dividend, distribution, rights or warrants are to be determined
and a description  of the cash,  securities or other  property to be received by
such holders upon such dividend,  distribution or granting of rights or warrants
or (y) the date on which such  reclassification,  consolidation,  merger,  sale,
transfer,  share  exchange,  dissolution,  liquidation  or  winding  up or other
liquidation  event is expected to become  effective,  the date as of which it is
expected  that  holders of Common  Stock of record shall be entitled to exchange
their shares of Common Stock for securities or other property  deliverable  upon
such exchange, dissolution, liquidation or winding up or other liquidation event
and the consideration, including securities or other property, to be received by
such holders upon such exchange; provided, however, that no failure to mail such


                                       10

<PAGE>

notice or any defect therein or in the mailing thereof shall affect the validity
of the corporate action required to be specified in such notice.

                    (f) Other Changes in Conversion  Rate. The Company from time
to time may increase the Conversion Rate by any amount for any period of time if
the period is at least 20 days and if the  increase  is  irrevocable  during the
period. Whenever the Conversion Rate is so increased,  the Company shall mail to
holders of record of Notes a notice of the  increase at least 15 days before the
date the increased Conversion Rate takes effect, and such notice shall state the
increased Conversion Rate and the period it will be in effect.

                    The Company may make such increases in the Conversion  Rate,
in  addition  to those  required  or  allowed by this  paragraph  4, as shall be
determined by it, as evidenced by a resolution of the Board of Directors,  to be
advisable  in order to avoid or  diminish  any  income  tax to holders of Common
Stock resulting from any dividend or distribution of stock or issuance of rights
or warrants to purchase or subscribe for stock or from any event treated as such
for income tax purposes.

SECTION 3.          DEFAULT CONVERSION.

                    (a) If this  Note and all  accrued  interest  shall not have
been paid in full on or before the Maturity  Date or upon the  occurrence  of an
Event of Default  (as  defined in Section 7 hereof),  the Holder  shall have the
right (the  "Default  Conversion  Right"),  in addition  to any other  available
remedies  set forth in Section 8 hereof or at law or in equity,  to convert  ten
percent  (10%) of the  principal  amount of the Notes (the  "Default  Conversion
Amount")  into a number  of  shares of  Common  Stock of the  Company  ("Default
Conversion Share Amount") which, when added to the Voting Securities (as defined
below) then owned by the  Noteholders,  equals  fifty-one  percent  (51%) of the
outstanding  shares of Common Stock of the Company for a purchase  price of $.01
per share (the  "Default  Conversion  Price").  For  purposes of this Section 3,
Voting Securities shall mean the Alternate Offering Common Stock and/or Series A
Preferred Stock (both as defined in the Purchase  Agreement)).  Upon conversion,
the Company shall pay all accrued and unpaid interest on the Default  Conversion
Amount.

                    (b) To exercise the Default Conversion Right, the Holder, on
or before the twentieth day after the Maturity  Date, but before payment in full
of the then outstanding principal and interest under this Note, shall deliver to
the Company, at its office at as set forth in Section 11, or at such other place
as is designated in writing by the Company,  a notice (the "Conversion  Notice")
stating that the Holder is exercising the Default  Conversion Right, the Default
Conversion  Amount  and the  name or  names  in  which  the  Holder  wishes  the
certificates for shares of Common Stock to be issued.

                    (c) To the extent permitted by applicable law, upon exercise
of the Default  Conversion Right, the Holder shall be deemed to be the holder of
record  of  the  shares  of  Common  Stock  issuable  upon  such  exercise  (the
"Conversion  Shares"),  notwithstanding  that the transfer  books of the Company
shall then be closed or certificates  representing  such Conversion Shares shall
not then have been actually  delivered to the Holder. As soon as practicable and
in any event  within  five (5) days after  exercise  of the  Default  Conversion
Right, the Company shall


                                       11

<PAGE>

issue and deliver to the Holder a certificate  or  certificates  evidencing  the
Conversion Shares registered in the name of the Holder or its designee, provided
that the Company may require the holder,  by notice given to the Holder promptly
after receipt of the Conversion  Notice,  as a condition to the delivery of such
certificate  or  certificates,  to  present  this  Note to the  Company  for the
placement  hereon of a legend  indicating that the Default  Conversion Right has
been  exercised to the extent of the Default  Conversion  Amount,  and this Note
(unless thereby paid in full) shall be immediately returned to the Holder.

                    (d) The issuance of any shares or other  securities upon the
exercise of the Default  Conversion  Right,  and the delivery of certificates or
other instruments  representing  such shares or other securities,  shall be made
without  charge to the  Holder  for any tax or other  charge in  respect of such
issuance.  The Company shall not, however,  be required to pay any tax which may
be payable in respect of any transfer  involved in the issue and delivery of any
certificate in a name other than that of the Holder and the Company shall not be
required to issue or deliver any such certificate unless and until the person or
persons  requesting  the issue thereof shall have paid to the Company the amount
of such tax or shall have  established to the  satisfaction  of the Company that
such tax has been paid.

                    (e) The  Holder  shall not have,  solely on  account of such
status as a Holder of this Note,  any rights of a  stockholder  of the  Company,
either at law or in equity,  or any notice of meetings of stockholders or of any
other proceedings of the Company except as provided in this Note.

SECTION 4.          FRACTIONAL SHARES.

                    The  Company  shall not be required  to issue  fractions  of
shares of Common Stock or other  capital  stock of the Company upon the exercise
of the Optional and Default  Conversion  Right. If any fraction of a share would
be issuable  on any  exercise of the  Optional or Default  Conversion  Right (or
specified  portions  thereof),  the Company shall  purchase such fraction for an
amount in cash equal to the same  fraction of the  closing  price for the Common
Stock on the trading  date  immediately  preceding  the date of exercise of such
Option or Default Conversion Right.

SECTION 5.          AFFIRMATIVE COVENANTS OF THE COMPANY.

                    The Company  covenants  and agrees that until the payment in
full of this Note, the Company shall:

                    (a)  Existence;  Business.  (i) Preserve,  renew and keep in
full force and effect its legal  existence  and (ii)  obtain,  preserve,  renew,
extend and keep in full force and effect the licenses, permits,  authorizations,
patents, trademarks and trade names material to its business.

                    (b) Use of  Proceeds.  Use the proceeds of the Notes of this
issue solely as set forth in Section 7.6 of the Purchase Agreement.


                                       12

<PAGE>

                    (c) Reports. Furnish to the Holder, at the time furnished to
the  Company's  stockholders,  reports  furnished  generally  to  the  Company's
stockholders, and copies of Current Reports on Form 8-K.

                    (d)  Notice of  Events of  Default.  Furnish  to the  Holder
prompt written notice of any Event of Default,  specifying the nature and extent
thereof  and  corrective  action,  if any,  proposed  to be taken  with  respect
thereto.

                    (e)   Authorization   of  Stock  Issuable  Upon  Conversion.
Authorize  and  reserve a  sufficient  number of its shares for  exercise of the
Optional and Default Conversion Rights.

SECTION 6.          NEGATIVE COVENANTS OF THE COMPANY.

                    The Company  covenants and agrees with the Holder that until
the payment in full of this Note, the Company shall not:

                    (a)  Indebtedness.  Without the prior written consent of the
Holders,  incur, create,  assume, nor suffer to exist any indebtedness including
but not limited to any indebtedness to current  executive  officers,  employees,
directors or principal  stockholders of the Company,  but excluding (i) accounts
payable  incurred  in the  ordinary  course  and paid in  accordance  with roman
numeral  (iv) of  paragraph  14 of the Letter of Intent  dated June 30, 1997 and
(ii)  indebtedness  existing on the date hereof reflected in the Company's March
31, 1997 Financial Statement.

                    (b) Liens. Create, incur, assume or permit to exist any lien
on any property or assets  (including  stock or other  securities of any person)
now owned or hereafter  acquired by the Company,  except (i) liens for taxes not
yet due or which are being contested by appropriate proceedings; (ii) carriers',
warehousemen's,  mechanic's,  materialmen's,  repairmen's  or other  like  liens
arising in the ordinary course of business and securing obligations that are not
due or which are being  contested;  or (iii) liens of attachments,  judgments or
awards against the Company (X) which could not reasonably be expected to have an
adverse material effect on the Company or (Y) with respect to which an appeal or
proceeding  for review shall be pending or a stay of  execution  shall have been
obtained,  or  which  are  otherwise  being  contested  in  good  faith  and  by
appropriate  proceedings,  or (iv) purchase  money liens,  equipment  leases and
financings incurred in the ordinary course of business.

                    (c)  Sale  and  Lease-Back  Transactions.   Enter  into  any
arrangement,  directly or  indirectly,  with any person whereby it shall sell or
transfer any property, real or personal, used or useful in its business, whether
now owned or hereafter  acquired,  and thereafter rent  (including  intellectual
property),  lease or license such property or other property which it intends to
use for substantially the same purpose or purposes as the property being sold or
transferred.

                    (d)   Mergers,   Consolidations,   Sales   of   Assets   and
Acquisitions.  Merge into or  consolidate  with any other person,  or permit any
other person to merge into or consolidate with it, or sell,  transfer,  lease or
otherwise  dispose of (in one transaction or in a series of transactions) all or
a substantial part of its assets (whether now owned or hereafter acquired) or

                                       13

<PAGE>

purchase,  lease  or  otherwise  acquire  (in one  transaction  or a  series  of
transactions) all or a substantial part of the assets of any other person.

                    (e) Dividends and Distributions. Declare or pay, directly or
indirectly, any dividend or make any other distribution (by reduction of capital
or otherwise),  whether in cash, property,  securities or a combination thereof,
with  respect to any  shares of its  capital  stock or  directly  or  indirectly
redeem, purchase,  retire or otherwise acquire for value any shares of any class
of its  capital  stock or set aside any amount for any such  purpose,  except as
permitted by Section 7.14 of the Purchase Agreement.

                    (f) No  Impairment.  By  amendment of its charter or through
reorganization,  consolidation, merger, dissolution, sale of assets or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the  terms of this  Note,  but will at all  times in good  faith  assist  in the
carrying  out of all such terms and in the  taking of all such  action as may be
necessary  or  appropriate  in order to protect the rights of the Holder of this
Note against impairment.

SECTION 7.          EVENTS OF DEFAULT DEFINED.

                    The  following  shall each  constitute an "Event of Default"
hereunder:

                    (a) the  failure  of the  Company  to make  any  payment  of
principal of, or interest on, this Note when due and payable;

                    (b) the  failure of the  Company  to observe or perform  any
covenant in this Note or in the Purchase Agreement,  and such failure shall have
continued unremedied for a period of five (5) days;

                    (c) if the Company shall:

                              (1)       admit in writing  its  inability  to pay
                                        its debts generally as they become due,

                              (2)       file  a  petition  in  bankruptcy  or  a
                                        petition  to  take   advantage   of  any
                                        insolvency act,

                              (3)       make an  assignment  for the  benefit of
                                        its creditors,

                              (4)       consent to the appointment of a receiver
                                        of   itself  or  of  the  whole  or  any
                                        substantial part of its property,

                              (5)       on  a  petition  in   bankruptcy   filed
                                        against, be adjudicated a bankrupt, or


                                       14

<PAGE>

                              (6)       file  a  petition   or  answer   seeking
                                        reorganization  or arrangement under the
                                        federal  bankruptcy  laws  or any  other
                                        applicable  law or statute of the United
                                        States of America or any state thereof;

                    (d) if a court  of  competent  jurisdiction  shall  enter an
order,  judgment or decree  appointing,  without the consent of the  Company,  a
receiver of the Company or of the whole or any substantial part of its property,
or approving a petition filed against it seeking  reorganization  or arrangement
of the Company under the federal  bankruptcy laws or any other applicable law or
statute of the United  States of America or any State  thereof,  and such order,
judgment  or decree  shall not be vacated or set aside or stayed  within  thirty
(30) days from the date of entry thereof;

                    (e) if, under the provisions of any other law for the relief
or aid of debtors,  any court of competent  jurisdiction shall assume custody or
control of the Company or the whole or any substantial  part of its property and
such custody or control  shall not be  terminated  or stayed  within thirty (30)
days from the date of assumption of such custody or control;

                    (f)  the  liquidation,  dissolution  or  winding  up of  the
Company;

                    (g) the failure to comply  with any section of the  Purchase
Agreement; or

                    (h) a final  judgment or judgments  for the payment of money
in  excess of  $1,000,000  in the  aggregate  shall be  rendered  by one or more
courts, administrative or arbitral tribunals or other bodies having jurisdiction
against the Company and the same shall not be discharged (or provision shall not
be made  for  such  discharge),  or a stay of  execution  thereof  shall  not be
procured,  within 30 days from the date of entry  thereof and the Company  shall
not, within such 30-day period,  or such longer period during which execution of
the same  shall  have been  stayed,  appeal  therefrom  and cause the  execution
thereof to be stayed during such appeal.

SECTION 8.          REMEDIES UPON EVENT OF DEFAULT.

                    (i) Upon the  occurrence  of an  Event of  Default,  (i) the
entire  principal  amount of, and all accrued and unpaid  interest on, this Note
shall  automatically  become  immediately due and payable  without  presentment,
demand,  protest  or other  formalities  of any kind,  all of which  are  hereby
expressly  waived by the Company  and (ii)  additional  interest  shall begin to
accrue,  and shall be  considered  immediately  due and  payable,  on the unpaid
principal  amount of this Note at the rate of eighteen  percent  (18%) per annum
and shall continue to accrue until the initial interest and additional  interest
is paid. In addition,  the Holder may take any action  available to it under the
Purchase Agreement or at law or in equity or by statute or otherwise.

                    (j) No remedy herein  conferred upon the Holder of this Note
is intended to be  exclusive  of any other remedy and each and every such remedy
shall be  cumulative  and  shall be in  addition  to every  other  remedy  given
hereunder  or now or  hereafter  existing  at law or in equity or by  statute or
otherwise.


                                       15

<PAGE>

SECTION 9.          NOTE REGISTER.

                    (a) The Company shall keep at its principal executive office
a register  (herein  sometimes  referred to as the "Note  Register"),  in which,
subject to such reasonable  regulations as it may prescribe,  but at its expense
(other than transfer taxes, if any), the Company shall provide for  registration
and transfer of this Note.

                    (b) Whenever this Note shall be surrendered at the principal
executive  office of the Company  for  transfer or  exchange,  accompanied  by a
written  instrument of transfer in form  reasonably  satisfactory to the Company
duly executed by the Holder  hereof or his attorney duly  authorized in writing,
the Company shall execute and deliver in exchange  therefor a new Note or Notes,
as may be requested  by such  Holder,  in the same  aggregate  unpaid  principal
amount and payable on the same date as the principal amount of the Note or Notes
so  surrendered;  each  such  new  Note  shall  be dated as of the date to which
interest  has been paid on the unpaid  principal  amount of the Note or Notes so
surrendered and shall be in such principal amount and registered in such name or
names as such Holder may designate in writing.

                    (c) Upon  receipt  by the  Company  of  evidence  reasonably
satisfactory  to it of the loss,  theft,  destruction or mutilation of this Note
and of indemnity  reasonably  satisfactory to it, and upon  reimbursement to the
Company of all reasonable expenses  incidental  thereto,  and upon surrender and
cancellation  of this Note (in case of  mutilation)  the  Company  will make and
deliver  in lieu of this  Note a new Note of like  tenor  and  unpaid  principal
amount  and dated as of the date to which  interest  has been paid on the unpaid
principal  amount  of this  Note in lieu of  which  such  new  Note is made  and
delivered.


SECTION 10.         REGISTRATION UNDER SECURITIES ACT OF 1933.

                    The Holder of this Note shall  have  registration  rights as
provided in Section 8 of the Purchase  Agreement,  with respect to the shares of
Common Stock issuable upon  conversion of the Notes pursuant to the Optional and
Default  Conversion  Right.  If the  Holder  is  not a  party  to  the  Purchase
Agreement,  by  acceptance  of this  Note,  the  Holder  agrees to  comply  with
provisions  of Section 8 of the  Purchase  Agreement to the same extent as if it
were a party thereto.

SECTION 11.         MISCELLANEOUS.

                    (a)  Amendments  and Waivers.  The holders of sixty-six  and
two-thirds percent (66 2/3%) or more in principal amount of outstanding Notes of
this  issue  may  waive or  otherwise  consent  to the  amendment  of any of the
provisions  hereof,  provided  that no such waiver or  amendment  may reduce the
principal  amount of or interest on any of the Notes of this issue or change the
stated maturity of the principal or reduce the percentage of holders of Notes of
this issue necessary to waive or amend the provisions of this Note,  without the
consent of each holder of any Note affected thereby.


                                       16

<PAGE>

                    (b)  Restrictions  on  Transferability.  In  addition to the
restrictions set forth in Section 6(a) of this Note, the securities  represented
by this Note have been  acquired  for  investment  and have not been  registered
under the  Securities  Act of 1933, as amended,  or the  securities  laws of any
state or other jurisdiction.  Without such registration, such securities may not
be sold,  pledged,  hypothecated  or otherwise  transferred,  except pursuant to
exemptions from the Securities Act of 1933, and the securities laws of any state
or other  jurisdiction.  Notwithstanding  the above, the holder of this Note has
been  provided the  registration  rights  contained in Section 8 of the Purchase
Agreement with respect to the shares of the Company's  Common Stock which may be
acquired upon exercise of the Optional and Default Conversion Right.

                    (c) Forbearance  from Suit. No holder of Notes of this issue
shall  institute any suit or proceeding  for the  enforcement  of the payment of
principal or interest unless the holders of at least fifty-one  percent (51%) in
principal amount of all of the outstanding Notes of this issue join in such suit
or proceeding.

                    (d)  Governing  Law.  This  Note  shall be  governed  by and
construed in  accordance  with the laws of the State of New York,  excluding the
body of law  relating  to  conflict  of laws.  Notwithstanding  anything  to the
contrary  contained  herein,  in no event  may the  effective  rate of  interest
collected or received by the Holder exceed that which may be charged,  collected
or received by the Holder under applicable law.

                    (e)  Interpretation.  If any term or  provision of this Note
shall be held invalid, illegal or unenforceable, the validity of all other terms
and provisions hereof shall in no way be affected thereby.

                    (f) Successors and Assigns.  This Note shall be binding upon
the Company and its successors and assigns and shall inure to the benefit of the
Holder and its successors and assigns.

                    (g)  Notices.  All notices,  requests,  consents and demands
shall be made in writing and shall be mailed  postage  prepaid,  or delivered by
hand, to the Company or to the Holder thereof at their respective  addresses set
forth below or to such other address as may be furnished in writing to the other
party hereto:

     If to the Holder:      At the address shown on Schedule A attached hereto.

     with a copy to:        Paramount Capital Asset Management, Inc.
                            787 Seventh Avenue
                            New York, NY  10019
                            Attn:  David R. Walner

     If to the Company:     Procept, Inc.
                            840 Memorial Drive
                            Cambridge, MA
                            Attention: Stanley C. Erck



                                       17

<PAGE>


      with a copy to:           Paramount Capital Asset Management, Inc.
                                787 Seventh Avenue
                                New York, NY  10019
                                Attn:  Michael S. Weiss

                    (h) Saturdays,  Sundays,  Holidays.  If any date that may at
any time be  specified  in this Note as a date for the making of any  payment of
principal or interest under this Note shall fall on Saturday, Sunday or on a day
which in New York shall be a legal holiday, then the date for the making of that
payment  shall be the next  subsequent  day which is not a  Saturday,  Sunday or
legal holiday.

                    (i)  Purchase  Agreement.  This Note is subject to the terms
contained in the Purchase  Agreement and the Operative  Documents (as defined in
Purchase  Agreement)  dated the date  hereof  between  the  Company  and certain
purchasers  of the Notes and the holder of this Note is entitled to the benefits
of such Purchase  Agreement and the Operative  Documents and may, in addition to
any rights  hereunder,  enforce the agreements of the Company  contained therein
and exercise the remedies provided for thereby or otherwise available in respect
thereof.


                                       18

<PAGE>

         IN WITNESS  WHEREOF,  this Note has been  executed and delivered on the
date first above written by the duly authorized representative of the Company.


ATTEST:                             PROCEPT, INC.


/s/ Lynnette C. Fallon              By:   /s/ Stanley C. Erck
- -----------------------                   --------------------------------
                                    Name:   Stanley C. Erck
                                    Its:    President


                                       19

<PAGE>
                                   EXHIBIT G

THE  SECURITIES  REPRESENTED  BY THIS  NOTE HAVE NOT BEEN  REGISTERED  UNDER THE
SECURITIES ACT OF 1933 OR ANY APPLICABLE  STATE  SECURITIES LAWS, AND MAY NOT BE
SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED OR OTHERWISE  TRANSFERRED IN THE
ABSENCE OF A  REGISTRATION  STATEMENT IN EFFECT WITH  RESPECT TO THE  SECURITIES
UNDER SUCH ACT OR AN EXEMPTION THEREFROM.  ANY SUCH TRANSFER MAY ALSO BE SUBJECT
TO APPLICABLE STATE SECURITIES LAWS.


                                  PROCEPT, INC.
                                                                         No. A-1
                             SENIOR CONVERTIBLE NOTE

$130,000.00                                                   New York, New York
                                                              June 30, 1997

                  Procept,  Inc., a Delaware corporation,  (the "Company"),  for
value received,  hereby promises to pay to The Aries Fund, a Cayman Island Trust
(the "Holder"),  or registered assigns,  the principal sum of one hundred thirty
thousand dollars ($130,000.00), with interest from the date of original issuance
of this Senior  Convertible Note on the unpaid principal balance at a rate equal
to twelve percent (12%) per annum, on the earlier of (a) September 30, 1997, (b)
five (5) business days following the completion of any equity offering or series
of equity  offerings  with gross proceeds to the Company in excess of $1,000,000
(the "Maturity Date"), and (c) the failure of the Company to obtain the Required
Shareholder  Approval (as defined in the Purchase  Agreement).  Payment shall be
made at such place as  designated  by the Holder upon  surrender  of this Senior
Convertible  Note, and shall be in such coin or currency of the United States of
America  as at the time of  payment  shall be legal  tender  for the  payment of
public and private  debts.  Interest shall be computed on the basis of a 360-day
year of twelve  30-day  months.  This Senior  Convertible  Note is one of a duly
authorized issue of Procept,  Inc. 12% Senior  Convertible Notes in an aggregate
principal amount of $200,000.00,  subject to increase  pursuant to Sections 7.27
and 8.6 of the Purchase Agreement (as defined below)  (individually a "Note" and
collectively  the "Notes")  issued pursuant to a Securities  Purchase  Agreement
dated June 30,  1997 (the  "Purchase  Agreement")  between  the  Company and the
Holders of the Notes (the "Noteholders"). The Notes shall be senior to all other
indebtedness of the Company ("Other  Indebtedness")  and all Other  Indebtedness
shall be subordinated to the Notes.




SECTION 1.         PREPAYMENT.

                  This Note (including interest accrued on the principal hereof)
may be prepaid by the Company,  at any time without penalty or premium  provided
that the Company shall provide


<PAGE>

the  holders  of the  Notes  with at  least  30 days  prior  written  notice  of
prepayment,  and prior to such  prepayment,  the holders of the Notes shall have
the opportunity to exercise their optional conversion rights pursuant to Section
2 hereof.

SECTION 2.         OPTIONAL CONVERSION.

                  (a) Right of Conversion. (i) Immediately or, (ii) if the rules
of any securities  exchange or automated quotation system on which the Company's
common  stock,  par value  $.01 per  share,  (the  "Common  Stock") is traded or
quoted, or any other law or regulation, require the approval of the shareholders
of the Company to permit  convertibility of the Notes, then (x) upon the receipt
of such  approvals but (y) in no event later than  September 30, 1997, the Notes
shall  be  convertible,  in  whole  or in part,  at the  option  (the  "Optional
Conversion  Right") of the holders thereof and upon notice to the Company as set
forth in paragraph  2(b) below,  into either,  at the election of the holder (A)
shares of Series A Preferred Stock of the Company (the "Preferred Stock") or (B)
Common  Stock of the  Company . In the event that the  holders  elect to receive
Common  Stock,  the  number of shares  shall be equal to the  Conversion  Amount
divided by the then current  Conversion Price (as defined below). The Conversion
Amount shall be the Liquidation  Amount (as defined below),  or in the case of a
partial  conversion,  such lesser amount as designated by the converting holder.
The  Liquidation  Amount shall mean the aggregate  principal  value of the Notes
held by such Holder plus any accrued and unpaid  interest.  The Conversion Price
shall   initially  be  $.46875,   subject  to  adjustment  as  provided   below,
representing an initial conversion rate (subject to adjustment) of 21,333 shares
of Common Stock per $10,000 of Conversion Amount.

                  In the  event  that the  holders  elect to  receive  Preferred
Stock,  then the  number of  shares of  Preferred  Stock to be  received  by the
holders shall be the  Liquidation  Amount divided by the then current  Preferred
Conversion Price (as defined below).  The Preferred Stock Conversion Price shall
initially be $100.00,  subject to adjustment as provided  below,  representing a
Preferred Stock initial conversion rate (subject to adjustment) of 100 shares of
Preferred Stock per $10,000 of Conversion  Amount. In the event that the holders
elect to receive  Preferred  Stock in connection  with any conversion  hereunder
rather than Common Stock,  any  reference to the to the terms "Common  Stock" or
the  "Conversion  Price",  shall be read to mean the " Preferred  Stock" and the
"Preferred  Conversion Price", with all the provisions applicable to the "Common
Stock" and the "Conversion  Price" being applied to the terms "Preferred  Stock"
and the "Preferred  Stock  Conversion  Price",  respectively,  on a proportional
basis .

                  The Conversion Price is subject to adjustment, upon the Series
B Final Closing Date (as defined in the Letter of Intent between the Corporation
and Paramount Capital,  Inc., dated June 30, 1997 (the "Letter of Intent")),  if
the  conversion  price of the preferred  stock (the "Series B Preferred  Stock")
sold in the Series B Offering (as defined in the Letter of Intent), or the price
per share of any Common  Stock sold in such Series B Offering,  or the  exercise
price of any warrants sold in such Series B Offering is less than the Conversion
Price. In such event,  the Conversion Price shall be reduced to equal the lesser
of any such conversion price, purchase price or exercise price of any securities
sold in such  Series B Offering  as in effect on any of the  respective  closing
dates of such Series B Offering. In the event that there is no Series B Final


                                        2

<PAGE>

Closing Date, or the above  referenced  Series B Offering is not commenced or is
otherwise  terminated,  if the price per share of Common Stock (or the effective
price, conversion price or exercise price per share of Common Stock, as the case
may be, of a security convertible into or exchangeable for Common Stock) offered
to  investors  in the next  offering  or series of related  offerings  of equity
securities of the Corporation (or any securities convertible into or exercisable
for equity securities)  following the date hereof which yields gross proceeds to
the  Corporation  in  excess  of  $2,000,000  in  the  aggregate  (a  "Qualified
Offering")  shall  be  less  than  the  Conversion  Price  then in  effect,  the
Conversion  Price shall be reduced to equal the lowest such  offering  price (or
effective  price,  conversion  price or exercise  price, as the case may be) per
share of Common Stock to investors in such Qualified Offering.

                  The  Conversion  Price  is  subject  to  adjustment,  upon any
Approval  Issuance (as defined in the Purchase  Agreement).  In the event of any
such  Approval  Issuance,  the  Conversion  Price shall be adjusted to equal the
Dilution Value (as defined in the Purchase Agreement) immediately following such
Approval Issuance.

                  (b)  Conversion  Procedures.  Any holder of Notes  desiring to
convert such Notes into Common Stock shall surrender the Notes at the offices of
the Company,  which Notes shall be accompanied by irrevocable  written notice to
the Company that the holder elects so to convert such Notes and  specifying  the
name or names (with address) in which a certificate or  certificates  evidencing
shares of Common Stock are to be issued. The Company will make a notation of the
date that a notice of conversion  is received,  which date shall be deemed to be
the date of receipt for purposes hereof.

                  The Company shall deliver to the holder  converting the Notes,
or to the nominee or nominees of such person, certificates evidencing the number
of full  shares  of Common  Stock to which  such  person  shall be  entitled  as
aforesaid,  together  with a cash  adjustment  of any  fraction  of a  share  as
hereinafter  provided.  Subject to the following  provisions of this  paragraph,
such  conversion  shall  be  deemed  to have  been  made as of the  date of such
surrender of the Notes and the person or persons  entitled to receive the Common
Stock  deliverable  upon  conversion  of such  Notes  shall be  treated  for all
purposes  as the record  holder or holders  of such  Common  Stock on such date;
provided,  however,  that the Company shall not be required to convert any Notes
while the stock  transfer  books of the Company are closed for any purpose,  but
the surrender of Notes for conversion  during any period while such books are so
closed shall become  effective for conversion  immediately upon the reopening of
such books as if the surrender had been made on the date of such reopening,  and
the conversion shall be at the conversion rate in effect on such date.

                  All  notices of  conversion  shall be  irrevocable;  provided,
however,  that if the Company has sent notice of an event  pursuant to paragraph
2(e) hereof,  a holder of Notes may, at its  election,  provide in its notice of
conversion  that  the  conversion  of its  Notes  shall be  contingent  upon the
occurrence  of the record date or  effectiveness  of such event (as specified by
such holder), provided that such notice of conversion is received by the Company
prior to such record date or effective date, as the case may be.


                                        3

<PAGE>

                  (c)      Protection From Dilution.

                    (i) Except as otherwise  provided  herein,  in the event the
Company shall, at any time or from time to time after the date hereof,  (A) sell
or issue any  shares of Common  Stock for a  consideration  per share  less than
either (I) the  Conversion  Price in effect on the date of such sale or issuance
or (II) the Market  Price (as defined in the Purchase  Agreement)  of the Common
Stock as of the date of the sale or  issuance,  (B) issue  any  shares of Common
Stock as a stock  dividend to the holders of Common  Stock,  or (C) subdivide or
combine the  outstanding  shares of Common Stock into a greater or lesser number
of shares (any such sale,  issuance,  subdivision  or  combination  being herein
called a "Change of Shares"),  then, and thereafter  upon each further Change of
Shares,  the  Conversion  Price in effect  immediately  prior to such  Change of
Shares shall be changed to a price  (rounded to the nearest cent)  determined by
multiplying  the  Conversion  Price in effect  immediately  prior  thereto  by a
fraction,  the  numerator  of which  shall be the sum of the number of shares of
Common  Stock  outstanding  immediately  prior to the sale or  issuance  of such
additional shares or such subdivision or combination and the number of shares of
Common Stock which the aggregate  consideration received (determined as provided
in Subparagraph  2(c)(v)(E))  for the issuance of such  additional  shares would
purchase  at the  greater of (x) the  Conversion  Price in effect on the date of
such issuance, and (y) the Market Price of the Common Stock as of such date, and
the  denominator  of  which  shall be the  number  of  shares  of  Common  Stock
outstanding  immediately after the sale or issuance of such additional shares or
such  subdivision or  combination.  Such adjustment  shall be made  successively
whenever such an issuance is made.

                    (ii) In case of any reclassification, capital reorganization
or other  change  of  outstanding  shares  of  Common  Stock,  or in case of any
consolidation or merger of the Company with or into another entity (other than a
consolidation or merger in which the Company is the continuing  entity and which
does not result in any reclassification,  capital reorganization or other change
of outstanding shares of Common Stock other than the number thereof), or in case
of any sale or conveyance  to another  entity of the property of the Company as,
or substantially as, an entirety (other than a sale/leaseback, mortgage or other
financing  transaction),  the Company shall cause effective provision to be made
so that the Holder shall be entitled to receive,  upon  conversion of this Note,
the  kind and  number  of  shares  of stock  or  other  securities  or  property
(including cash) receivable upon such  reclassification,  capital reorganization
or other change,  consolidation,  merger,  sale or conveyance by a holder of the
number  of  shares  of  Common  Stock  into  which  such  Note  was  convertible
immediately  prior to such  reclassification,  capital  reorganization  or other
change,  consolidation,  merger,  sale or conveyance.  Any such provision  shall
include  provision for adjustments that shall be as nearly  equivalent as may be
practicable to the adjustments provided for in this Subsection 2(c). The Company
shall not  effect any such  consolidation,  merger or sale  unless  prior to, or
simultaneously  with, the consummation  thereof the successor (if other than the
Company)  resulting from such  consolidation or merger or the entity  purchasing
assets or other appropriate entity shall assume, by written instrument  executed
and  delivered  to the  Company,  the  obligation  to deliver to the Holder such
shares of stock,  securities  or assets  as, in  accordance  with the  foregoing
provisions,  such Holder may be  entitled  to receive and the other  obligations
under this Note. The foregoing  provisions  shall  similarly apply to successive
reclassifications,  capital  reorganizations  and other  changes of  outstanding
shares  of Common  Stock and to  successive  consolidations,  mergers,  sales or
conveyances.


                                        4

<PAGE>

                    (iii)  If,  at any time or from  time to time,  the  Company
shall issue or distribute  to the holders of shares of Common Stock  evidence of
its indebtedness,  any other securities of the Company or any cash,  property or
other assets (any such event being herein called a "Special Dividend"),  then in
each case the Holder  shall be  entitled  to a  proportionate  share of any such
Special  Dividend as though it were the holder of the number of shares of Common
Stock of the Company into which this Note is  convertible  as of the record date
fixed  for the  determination  of the  holders  of Common  Stock of the  Company
entitled to receive such Special Dividend.

                    (iv) After each adjustment of the Conversion  Price pursuant
to this Subsection 2(c), the Company will promptly prepare a certificate  signed
by the Chairman or President,  and by the Treasurer or an Assistant Treasurer or
the Secretary or an Assistant  Secretary,  of the Company setting forth: (A) the
Conversion Price as so adjusted,  (B) the conversion rate  corresponding to such
Conversion  Price and (C) a brief  statement  of the facts  accounting  for such
adjustment. The Company will promptly file such certificate in the Note Register
(as defined  below) and send such  certificate  by ordinary  first class mail to
each registered holder of Notes at his or her last address as it shall appear in
the Note  Register.  No failure to mail such notice nor any defect therein or in
the mailing thereof shall affect the validity of such adjustment.  The affidavit
of an authorized  officer of the Company that such notice has been mailed shall,
in the absence of fraud,  be prima facie  evidence of the facts stated  therein.
The Transfer Agent may rely on the  information  in the  certificate as true and
correct  and has no duty or  obligation  independently  to verify the amounts or
calculations set forth therein.

                    (v) For purposes of Subsection 2(c)(i) hereof, the following
provisions (A) to (E) shall also be applicable:

                           (A) No  adjustment of the  Conversion  Price shall be
                    made unless  such  adjustment  would  require an increase or
                    decrease of at least $.01 in such price;  provided  that any
                    adjustments which by reason of this Subparagraph (A) are not
                    required  to be made shall be carried  forward  and shall be
                    made at the time of, and together with, the next  subsequent
                    adjustment  which,  together  with  adjustments  so  carried
                    forward,  shall  require an increase or decrease of at least
                    $.01 in the Conversion Price then in effect hereunder.

                           (B) In case of (I) the sale or other  issuance by the
                    Company  (including  as a component of a unit) of any rights
                    or warrants to subscribe for or purchase, or any options for
                    the purchase of, Common Stock or any securities  convertible
                    into or  exchangeable  for  Common  Stock  (such  securities
                    convertible,  exercisable or exchangeable  into Common Stock
                    being herein called "Convertible  Securities"),  or (II) the
                    issuance by the Company,  without the receipt by the Company
                    of any consideration  therefor, of any rights or warrants to
                    subscribe  for or purchase,  or any options for the purchase
                    of, Common Stock or Convertible  Securities,  whether or not
                    such rights, warrants or options, or the right to convert or
                    exchange  such  Convertible   Securities,   are  immediately
                    exercisable,  and the  consideration  per  share  for  which
                    Common  Stock is issuable  upon the exercise of such rights,
                    warrants  or options or upon the  conversion  or exchange of
                    such Convertible Securities (determined by dividing


                                        5

<PAGE>

                    (x) the minimum aggregate consideration, as set forth in the
                    instrument   relating   thereto   without   regard   to  any
                    antidilution or similar  provisions  contained therein for a
                    subsequent adjustment of such amount, payable to the Company
                    upon the exercise of such rights,  warrants or options, plus
                    the  consideration  received by the Company for the issuance
                    or sale of such rights,  warrants or options,  plus,  in the
                    case of such Convertible  Securities,  the minimum aggregate
                    amount,  as set  forth in the  instrument  relating  thereto
                    without  regard to any  antidilution  or similar  provisions
                    contained  therein  for  a  subsequent  adjustment  of  such
                    amount, of additional consideration, if any, other than such
                    Convertible  Securities,  payable  upon  the  conversion  or
                    exchange  thereof,  by (y) the total maximum number,  as set
                    forth in the instrument  relating  thereto without regard to
                    any antidilution or similar provisions contained therein for
                    a subsequent  adjustment of such amount, of shares of Common
                    Stock issuable upon the exercise of such rights, warrants or
                    options  or  upon  the   conversion   or  exchange  of  such
                    Convertible  Securities  issuable  upon the exercise of such
                    rights,  warrants  or  options)  is  less  than  either  the
                    Conversion  Price or the Market Price of the Common Stock as
                    of the date of the issuance or sale of such rights, warrants
                    or  options,  then such  total  maximum  number of shares of
                    Common  Stock  issuable  upon the  exercise of such  rights,
                    warrants  or options or upon the  conversion  or exchange of
                    such Convertible  Securities (as of the date of the issuance
                    or sale of such rights, warrants or options) shall be deemed
                    to be "Common Stock" for purposes of Subsection  2(c)(i) and
                    shall be deemed  to have  been  sold for an amount  equal to
                    such  consideration  per share and shall cause an adjustment
                    to be made in accordance with Subsection 2(c)(i).

                           (C)  In  case  of the  sale  by  the  Company  of any
                    Convertible   Securities,   whether  or  not  the  right  of
                    conversion   or   exchange    thereunder   is    immediately
                    exercisable,  and the price per share for which Common Stock
                    is  issuable  upon  the   conversion  or  exchange  of  such
                    Convertible Securities (determined by dividing (x) the total
                    amount of consideration received by the Company for the sale
                    of such Convertible  Securities,  plus the minimum aggregate
                    amount,  as set  forth in the  instrument  relating  thereto
                    without  regard to any  antidilution  or similar  provisions
                    contained  therein  for  a  subsequent  adjustment  of  such
                    amount, of additional consideration, if any, other than such
                    Convertible  Securities,  payable  upon  the  conversion  or
                    exchange  thereof,  by (y) the total maximum number,  as set
                    forth in the instrument  relating  thereto without regard to
                    any antidilution or similar provisions contained therein for
                    a subsequent  adjustment of such amount, of shares of Common
                    Stock  issuable  upon the  conversion  or  exchange  of such
                    Convertible  Securities)  is less than either the Conversion
                    Price or the Market Price of the Common Stock as of the date
                    of the sale of such Convertible Securities,  then such total
                    maximum  number of shares of Common Stock  issuable upon the
                    conversion or exchange of such Convertible Securities (as of
                    the date of the sale of such Convertible  Securities)  shall
                    be deemed to be "Common  Stock" for  purposes of  Subsection
                    2(c)(i)  and shall be deemed to have been sold for an amount
                    equal to such consideration


                                        6

<PAGE>

                    per  share  and  shall  cause  an  adjustment  to be made in
                    accordance with Subsection 2(c)(i).

                           (D) In case the  Company  shall  modify the rights of
                    conversion,  exchange or  exercise of any of the  securities
                    referred to in (B) and (C) above or any other  securities of
                    the Company  convertible,  exchangeable  or exercisable  for
                    shares of Common  Stock,  for any reason other than an event
                    that would require  adjustment to prevent dilution  pursuant
                    to  the  terms  of any  such  convertible,  exchangeable  or
                    exercisable instrument,  so that the consideration per share
                    received by the Company after such modification is less than
                    either the  Conversion  Price or the Market  Price as of the
                    date prior to such  modification,  then such securities,  to
                    the  extent  not   theretofore   exercised,   converted   or
                    exchanged,  shall be deemed to have  expired  or  terminated
                    immediately  prior to the date of such  modification and the
                    Company  shall be deemed for  purposes  of  calculating  any
                    adjustments  pursuant to this Subsection 2(c) to have issued
                    such  new  securities  upon  such  new  terms on the date of
                    modification.  Such adjustment  shall become effective as of
                    the date upon which such modification  shall take effect. On
                    the expiration or cancellation of any such right, warrant or
                    option or the  termination or cancellation of any such right
                    to convert or exchange any such Convertible Securities,  the
                    Conversion Price then in effect hereunder shall forthwith be
                    readjusted to such  Conversion  Price as would have obtained
                    (a) had the  adjustments  made upon the  issuance or sale of
                    such rights,  warrants,  options or  Convertible  Securities
                    been made upon the basis of the  issuance of only the number
                    of shares of Common  Stock  theretofore  actually  delivered
                    (and the total  consideration  received  therefor)  upon the
                    exercise  of such  rights,  warrants  or options or upon the
                    conversion or exchange of such  Convertible  Securities  and
                    (b) had adjustments been made on the basis of the Conversion
                    Price as adjusted  under clause (a) of this sentence for all
                    transactions   (which  would  have  affected  such  adjusted
                    Conversion  Price)  made after the  issuance or sale of such
                    rights, warrants, options or Convertible Securities.

                           (E) In  case  of the  sale of any  shares  of  Common
                    Stock, any Convertible Securities, any rights or warrants to
                    subscribe  for or purchase,  or any options for the purchase
                    of,   Common   Stock   or   Convertible   Securities,    the
                    consideration  received  by the  Company  therefor  shall be
                    deemed  to  be  the  gross  sales  price  therefor   without
                    deducting  therefrom  any  expense  paid or  incurred by the
                    Company or any  underwriting  discounts  or  commissions  or
                    concessions  paid or  allowed by the  Company in  connection
                    therewith.  In the event that any securities shall be issued
                    in  connection  with any other  securities  of the  Company,
                    together  comprising  one integral  transaction  in which no
                    specific  consideration  is allocated  among the securities,
                    then  each of such  securities  shall be deemed to have been
                    issued for such  consideration  as the Board of Directors of
                    the Company determines in good faith; provided, however that
                    if the holders of in excess of ten percent (10%) of the then
                    outstanding  principal  amount of Notes  disagree  with such
                    determination, the Company shall retain, at its own


                                        7

<PAGE>

                    expense,  an  independent  investment  banking  firm for the
                    purpose of rendering an appraisal.

                    (vi)   Notwithstanding   any  other  provision   hereof,  no
adjustment to the Conversion Price will be made:

                           (A)  upon  the  exercise  of (i)  any of the  options
                    outstanding on the date hereof under the Company's  existing
                    stock option plans, or (ii) any warrants  outstanding on the
                    date  hereof   listed  on  schedule   5.3  to  the  Purchase
                    Agreement,  copies of which have been provided to the Holder
                    prior to the date hereof; or

                           (B) upon the issuance or exercise of options or stock
                    which may  hereafter be granted,  purchased or sold with the
                    approval of the Board of Directors, or exercised,  under any
                    employee  benefit plan or the 1993 Employee  Stock  Purchase
                    Plan of the Company to officers,  directors,  consultants or
                    employees,  but only with  respect  to such  options  as are
                    exercisable  at, and shares which are purchased  and/or sold
                    at,  prices no lower than the  Closing Bid Price (as defined
                    in the  Purchase  Agreement)  (or,  if the Closing Bid Price
                    cannot be  determined,  the Fair Market Value (as defined in
                    the Purchase  Agreement)) of the Common Stock as of the date
                    of grant thereof; or

                           (C)  upon  issuance  or  exercise  of  the  Placement
                    Warrants,  or the  Advisory  Warrants,  (as  defined  in the
                    Letter of Intent) (collectively,  the "Paramount Warrants"),
                    upon  the  issuance  of any  Common  Stock  pursuant  to the
                    Purchase  Agreement  (including any Article IX Issuances (as
                    defined  therein)),  upon the  exercise  of the  Class A and
                    Class B  Warrants  (as  defined  in the Letter of Intent) or
                    upon the  issuance,  conversion  or exercise of the Series B
                    Preferred Stock or Common Stock  (including any common stock
                    issuable  pursuant to  contractual  rights  analogous to the
                    Article IX  Issuances)  or the Class C Warrants to be issued
                    (i) on or  prior  to the  Series  B Final  Closing  Date (as
                    defined in the Letter of  Intent)  or (ii)  pursuant  to the
                    exercise of the  Paramount  Warrants,  or upon the issuance,
                    conversion or exercise of any Series A or Series B Preferred
                    Stock or Class A,  Class B or Class C Warrants  approved  in
                    writing by the Placement  Agent, or upon the issuance of any
                    other  equity  securities  of the Company to the extent that
                    such issuance  causes an adjustment to the Conversion  Price
                    pursuant to the second paragraph of Subsection 2(a); or

                           (D)  upon the  issuance  or sale of  Common  Stock or
                    Convertible  Securities  pursuant  to  the  exercise  of any
                    rights,  options or warrants to  receive,  subscribe  for or
                    purchase,  or any options for the purchase of,  Common Stock
                    or  Convertible  Securities,  whether  or not  such  rights,
                    warrants  or  options  were  outstanding  on the date of the
                    original  issuance of the Notes or were thereafter issued or
                    sold,  provided  that an  adjustment  was either made or not
                    required to


                                        8

<PAGE>

                    be made in accordance with Subsection  2(c)(i) in connection
                    with  the  issuance  or  sale  of  such  securities  or  any
                    modification of the terms thereof; or

                           (E) upon the  issuance  or sale of Common  Stock upon
                    conversion  or  exchange  of  any  Convertible   Securities,
                    provided that any  adjustments  required to be made upon the
                    issuance  or  sale  of such  Convertible  Securities  or any
                    modification  of the terms thereof were so made, and whether
                    or not such  Convertible  Securities were outstanding on the
                    date  of  the  original   issuance  of  the  Notes  or  were
                    thereafter issued or sold.

Subparagraph  2(c)(v)(D)  shall  nevertheless  apply to any  modification of the
rights of conversion,  exchange or exercise of any of the securities referred to
in  Subparagraphs  (A), (B), (D) and (E), or to the extent effected with respect
to  fewer  than  all of such  securities,  Subparagraph  (C) of this  Subsection
2(c)(vi).

                    (vii) As used in this  Subsection  2(c),  the  term  "Common
Stock" shall mean and include the Company's  Common Stock authorized on the date
of the original  issue of the Notes and shall also include any capital  stock of
any class of the Company  thereafter  authorized which shall not be limited to a
fixed sum or  percentage  in  respect of the  rights of the  holders  thereof to
participate  in dividends and in the  distribution  of assets upon the voluntary
liquidation,  dissolution or winding up of the Company; provided,  however, that
the shares  issuable  upon  conversion of the Notes shall include only shares of
such class designated in the Certificate of Incorporation as Common Stock on the
date  of  the  original  issue  of  the  Notes  or  (i),  in  the  case  of  any
reclassification,  change,  consolidation,  merger,  sale or  conveyance  of the
character referred to in Subsection  2(c)(ii) hereof,  the stock,  securities or
property   provided  for  in  such   section  or  (ii),   in  the  case  of  any
reclassification  or change in the  outstanding  shares of Common Stock issuable
upon  conversion of the Notes as a result of a  subdivision  or  combination  or
consisting of a change in par value,  or from par value to no par value, or from
no par value to par value,  such shares of Common  Stock as so  reclassified  or
changed.

                    (viii) Any  determination as to whether an adjustment in the
Conversion Price in effect hereunder is required  pursuant to Subsection 2(a) or
2(c), or as to the amount of any such adjustment,  if required, shall be binding
upon the holders of the Notes and the Company if made in good faith by the Board
of Directors of the Company.

                  (d) Reservation of Shares;  Transfer  Taxes;  Etc. The Company
shall  at all  times  reserve  and keep  available,  out of its  authorized  and
unissued  shares of Common  Stock,  solely  for the  purpose  of  effecting  the
conversion  of  the  Notes,  including,  without  limitation  upon  any  Default
Conversion,  such number of shares of its Common Stock free of preemptive rights
as shall be sufficient  to effect the  conversion of all Notes from time to time
outstanding.  The  Company  shall use its best  efforts  from  time to time,  in
accordance  with the laws of the State of Delaware,  to increase the  authorized
number of shares of Common  Stock if at any time the  number of shares of Common
Stock not  outstanding  shall not be sufficient to permit the  conversion of all
the then-outstanding Notes.


                                        9

<PAGE>

                  The  Company  shall pay any and all issue or other  taxes that
may be payable in respect of any issue or delivery of shares of Common  Stock on
conversion of the Notes. The Company shall not, however,  be required to pay any
tax which may be payable in respect  of any  transfer  involved  in the issue or
delivery of Common  Stock (or other  securities  or assets) in a name other than
that in which the  Notes so  converted  were  registered,  and no such  issue or
delivery  shall be made  unless and until the person  requesting  such issue has
paid  to  the  Company  the  amount  of  such  tax or  has  established,  to the
satisfaction of the Company,  that such tax has been paid. The Company covenants
that all shares of Common  Stock  issuable  upon  exercise of the  Optional  and
Default Conversion Rights shall be validly issued, fully paid and nonassessable.

                  (e) Prior Notice of Certain Events.  In case:

                    (i) the Company  shall  declare any  dividend  (or any other
          distribution); or

                    (ii) the Company shall authorize the granting to the holders
         of Common Stock of rights or warrants to subscribe  for or purchase any
         shares of stock of any class or of any other rights or warrants; or

                    (iii) of any  reclassification of Common Stock (other than a
         subdivision or combination of the outstanding Common Stock, or a change
         in par value,  or from par value to no par value,  or from no par value
         to par value); or

                    (iv) of any  consolidation or merger to which the Company is
         a party and for which approval of any stockholders of the Company shall
         be required,  or of the sale or transfer of all or substantially all of
         the assets of the Company or of any compulsory  share exchange  whereby
         the Common  Stock is  converted  into other  securities,  cash or other
         property; or

                    (v) of the voluntary or involuntary dissolution, liquidation
          or winding up of the Company;

then the Company shall cause to be mailed to the holders of Notes, at their last
addresses as they shall  appear upon the books of the Company,  at least 20 days
prior to the applicable record date hereinafter  specified, a notice stating (x)
the date on which a record  (if  any) is to be  taken  for the  purpose  of such
dividend,  distribution or granting of rights or warrants or, if a record is not
to be taken,  the date as of which the  holders of Common  Stock of record to be
entitled to such dividend, distribution, rights or warrants are to be determined
and a description  of the cash,  securities or other  property to be received by
such holders upon such dividend,  distribution or granting of rights or warrants
or (y) the date on which such  reclassification,  consolidation,  merger,  sale,
transfer,  share  exchange,  dissolution,  liquidation  or  winding  up or other
liquidation  event is expected to become  effective,  the date as of which it is
expected  that  holders of Common  Stock of record shall be entitled to exchange
their shares of Common Stock for securities or other property  deliverable  upon
such exchange, dissolution, liquidation or winding up or other liquidation event
and the consideration, including securities or other property, to be received by
such holders upon such exchange; provided, however, that no failure to mail such


                                       10

<PAGE>

notice or any defect therein or in the mailing thereof shall affect the validity
of the corporate action required to be specified in such notice.

                  (f) Other Changes in Conversion Rate. The Company from time to
time may  increase the  Conversion  Rate by any amount for any period of time if
the period is at least 20 days and if the  increase  is  irrevocable  during the
period. Whenever the Conversion Rate is so increased,  the Company shall mail to
holders of record of Notes a notice of the  increase at least 15 days before the
date the increased Conversion Rate takes effect, and such notice shall state the
increased Conversion Rate and the period it will be in effect.

                  The Company may make such increases in the Conversion Rate, in
addition  to  those  required  or  allowed  by this  paragraph  4, as  shall  be
determined by it, as evidenced by a resolution of the Board of Directors,  to be
advisable  in order to avoid or  diminish  any  income  tax to holders of Common
Stock resulting from any dividend or distribution of stock or issuance of rights
or warrants to purchase or subscribe for stock or from any event treated as such
for income tax purposes.

SECTION 3.         DEFAULT CONVERSION.

                  (a) If this Note and all accrued  interest shall not have been
paid in full on or before the Maturity  Date or upon the  occurrence of an Event
of Default  (as  defined in Section 7 hereof),  the Holder  shall have the right
(the "Default  Conversion  Right"),  in addition to any other available remedies
set forth in Section 8 hereof or at law or in equity,  to  convert  ten  percent
(10%) of the  principal  amount of the Notes (the "Default  Conversion  Amount")
into a number  of shares of Common  Stock of the  Company  ("Default  Conversion
Share  Amount")  which,  when added to the Voting  Securities (as defined below)
then owned by the Noteholders, equals fifty-one percent (51%) of the outstanding
shares of Common  Stock of the  Company  for a purchase  price of $.01 per share
(the  "Default  Conversion  Price").  For  purposes  of this  Section 3,  Voting
Securities  shall mean the  Alternate  Offering  Common  Stock  and/or  Series A
Preferred Stock (both as defined in the Purchase  Agreement)).  Upon conversion,
the Company shall pay all accrued and unpaid interest on the Default  Conversion
Amount.

                  (b) To exercise the Default  Conversion  Right, the Holder, on
or before the twentieth day after the Maturity  Date, but before payment in full
of the then outstanding principal and interest under this Note, shall deliver to
the Company, at its office at as set forth in Section 11, or at such other place
as is designated in writing by the Company,  a notice (the "Conversion  Notice")
stating that the Holder is exercising the Default  Conversion Right, the Default
Conversion  Amount  and the  name or  names  in  which  the  Holder  wishes  the
certificates for shares of Common Stock to be issued.

                  (c) To the extent  permitted by applicable  law, upon exercise
of the Default  Conversion Right, the Holder shall be deemed to be the holder of
record  of  the  shares  of  Common  Stock  issuable  upon  such  exercise  (the
"Conversion  Shares"),  notwithstanding  that the transfer  books of the Company
shall then be closed or certificates  representing  such Conversion Shares shall
not then have been actually  delivered to the Holder. As soon as practicable and
in any event  within  five (5) days after  exercise  of the  Default  Conversion
Right, the Company shall


                                       11

<PAGE>

issue and deliver to the Holder a certificate  or  certificates  evidencing  the
Conversion Shares registered in the name of the Holder or its designee, provided
that the Company may require the holder,  by notice given to the Holder promptly
after receipt of the Conversion  Notice,  as a condition to the delivery of such
certificate  or  certificates,  to  present  this  Note to the  Company  for the
placement  hereon of a legend  indicating that the Default  Conversion Right has
been  exercised to the extent of the Default  Conversion  Amount,  and this Note
(unless thereby paid in full) shall be immediately returned to the Holder.

                  (d) The  issuance of any shares or other  securities  upon the
exercise of the Default  Conversion  Right,  and the delivery of certificates or
other instruments  representing  such shares or other securities,  shall be made
without  charge to the  Holder  for any tax or other  charge in  respect of such
issuance.  The Company shall not, however,  be required to pay any tax which may
be payable in respect of any transfer  involved in the issue and delivery of any
certificate in a name other than that of the Holder and the Company shall not be
required to issue or deliver any such certificate unless and until the person or
persons  requesting  the issue thereof shall have paid to the Company the amount
of such tax or shall have  established to the  satisfaction  of the Company that
such tax has been paid.

                  (e) The  Holder  shall not have,  solely  on  account  of such
status as a Holder of this Note,  any rights of a  stockholder  of the  Company,
either at law or in equity,  or any notice of meetings of stockholders or of any
other proceedings of the Company except as provided in this Note.

SECTION 4.        FRACTIONAL SHARES.

                  The Company shall not be required to issue fractions of shares
of Common Stock or other  capital  stock of the Company upon the exercise of the
Optional  and  Default  Conversion  Right.  If any  fraction of a share would be
issuable  on any  exercise  of the  Optional  or  Default  Conversion  Right (or
specified  portions  thereof),  the Company shall  purchase such fraction for an
amount in cash equal to the same  fraction of the  closing  price for the Common
Stock on the trading  date  immediately  preceding  the date of exercise of such
Option or Default Conversion Right.

SECTION 5.        AFFIRMATIVE COVENANTS OF THE COMPANY.

                  The  Company  covenants  and agrees  that until the payment in
full of this Note, the Company shall:

                  (a) Existence;  Business. (i) Preserve, renew and keep in full
force and effect its legal existence and (ii) obtain,  preserve,  renew,  extend
and  keep in full  force  and  effect  the  licenses,  permits,  authorizations,
patents, trademarks and trade names material to its business.

                  (b) Use of  Proceeds.  Use the  proceeds  of the Notes of this
issue solely as set forth in Section 7.6 of the Purchase Agreement.


                                       12

<PAGE>

                  (c) Reports.  Furnish to the Holder,  at the time furnished to
the  Company's  stockholders,  reports  furnished  generally  to  the  Company's
stockholders, and copies of Current Reports on Form 8-K.

                  (d) Notice of Events of Default.  Furnish to the Holder prompt
written notice of any Event of Default, specifying the nature and extent thereof
and corrective action, if any, proposed to be taken with respect thereto.

                  (e) Authorization of Stock Issuable Upon Conversion. Authorize
and reserve a  sufficient  number of its shares for exercise of the Optional and
Default Conversion Rights.

SECTION 6.        NEGATIVE COVENANTS OF THE COMPANY.

                  The  Company  covenants  and agrees with the Holder that until
the payment in full of this Note, the Company shall not:

                  (a)  Indebtedness.  Without the prior  written  consent of the
Holders,  incur, create,  assume, nor suffer to exist any indebtedness including
but not limited to any indebtedness to current  executive  officers,  employees,
directors or principal  stockholders of the Company,  but excluding (i) accounts
payable  incurred  in the  ordinary  course  and paid in  accordance  with roman
numeral  (iv) of  paragraph  14 of the Letter of Intent  dated June 30, 1997 and
(ii)  indebtedness  existing on the date hereof reflected in the Company's March
31, 1997 Financial Statement.

                  (b) Liens.  Create,  incur, assume or permit to exist any lien
on any property or assets  (including  stock or other  securities of any person)
now owned or hereafter  acquired by the Company,  except (i) liens for taxes not
yet due or which are being contested by appropriate proceedings; (ii) carriers',
warehousemen's,  mechanic's,  materialmen's,  repairmen's  or other  like  liens
arising in the ordinary course of business and securing obligations that are not
due or which are being  contested;  or (iii) liens of attachments,  judgments or
awards against the Company (X) which could not reasonably be expected to have an
adverse material effect on the Company or (Y) with respect to which an appeal or
proceeding  for review shall be pending or a stay of  execution  shall have been
obtained,  or  which  are  otherwise  being  contested  in  good  faith  and  by
appropriate  proceedings,  or (iv) purchase  money liens,  equipment  leases and
financings incurred in the ordinary course of business.

                  (c)  Sale  and   Lease-Back   Transactions.   Enter  into  any
arrangement,  directly or  indirectly,  with any person whereby it shall sell or
transfer any property, real or personal, used or useful in its business, whether
now owned or hereafter  acquired,  and thereafter rent  (including  intellectual
property),  lease or license such property or other property which it intends to
use for substantially the same purpose or purposes as the property being sold or
transferred.

                  (d) Mergers, Consolidations, Sales of Assets and Acquisitions.
Merge into or consolidate  with any other person,  or permit any other person to
merge into or consolidate with it, or sell, transfer, lease or otherwise dispose
of (in one transaction or in a series of transactions) all or a substantial part
of its assets (whether now owned or hereafter acquired) or


                                       13

<PAGE>

purchase,  lease  or  otherwise  acquire  (in one  transaction  or a  series  of
transactions) all or a substantial part of the assets of any other person.

                  (e) Dividends and  Distributions.  Declare or pay, directly or
indirectly, any dividend or make any other distribution (by reduction of capital
or otherwise),  whether in cash, property,  securities or a combination thereof,
with  respect to any  shares of its  capital  stock or  directly  or  indirectly
redeem, purchase,  retire or otherwise acquire for value any shares of any class
of its  capital  stock or set aside any amount for any such  purpose,  except as
permitted by Section 7.14 of the Purchase Agreement.

                  (f) No  Impairment.  By  amendment  of its  charter or through
reorganization,  consolidation, merger, dissolution, sale of assets or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the  terms of this  Note,  but will at all  times in good  faith  assist  in the
carrying  out of all such terms and in the  taking of all such  action as may be
necessary  or  appropriate  in order to protect the rights of the Holder of this
Note against impairment.

SECTION 7.          EVENTS OF DEFAULT DEFINED.

                  The  following  shall each  constitute  an "Event of  Default"
hereunder:

                  (a)  the  failure  of the  Company  to  make  any  payment  of
principal of, or interest on, this Note when due and payable;

                  (b) the  failure of the  Company  to  observe  or perform  any
covenant in this Note or in the Purchase Agreement,  and such failure shall have
continued unremedied for a period of five (5) days;

                  (c)      if the Company shall:

                              (1)       admit in writing  its  inability  to pay
                                        its debts generally as they become due,

                              (2)       file  a  petition  in  bankruptcy  or  a
                                        petition  to  take   advantage   of  any
                                        insolvency act,

                              (3)       make an  assignment  for the  benefit of
                                        its creditors,

                              (4)       consent to the appointment of a receiver
                                        of   itself  or  of  the  whole  or  any
                                        substantial part of its property,

                              (5)       on  a  petition  in   bankruptcy   filed
                                        against, be adjudicated a bankrupt, or


                                       14

<PAGE>

                              (6)       file  a  petition   or  answer   seeking
                                        reorganization  or arrangement under the
                                        federal  bankruptcy  laws  or any  other
                                        applicable  law or statute of the United
                                        States of America or any state thereof;

                  (d) if a court of competent jurisdiction shall enter an order,
judgment or decree appointing, without the consent of the Company, a receiver of
the  Company  or of the  whole  or any  substantial  part  of its  property,  or
approving a petition filed against it seeking  reorganization  or arrangement of
the Company under the federal  bankruptcy  laws or any other  applicable  law or
statute of the United  States of America or any State  thereof,  and such order,
judgment  or decree  shall not be vacated or set aside or stayed  within  thirty
(30) days from the date of entry thereof;

                  (e) if, under the  provisions  of any other law for the relief
or aid of debtors,  any court of competent  jurisdiction shall assume custody or
control of the Company or the whole or any substantial  part of its property and
such custody or control  shall not be  terminated  or stayed  within thirty (30)
days from the date of assumption of such custody or control;

                  (f) the liquidation, dissolution or winding up of the Company;

                  (g) the  failure to comply  with any  section of the  Purchase
Agreement; or

                  (h) a final  judgment or judgments for the payment of money in
excess of $1,000,000  in the aggregate  shall be rendered by one or more courts,
administrative or arbitral tribunals or other bodies having jurisdiction against
the Company and the same shall not be discharged (or provision shall not be made
for such  discharge),  or a stay of  execution  thereof  shall not be  procured,
within 30 days from the date of entry thereof and the Company shall not,  within
such 30-day  period,  or such longer period  during which  execution of the same
shall have been stayed,  appeal therefrom and cause the execution  thereof to be
stayed during such appeal.

SECTION 8.        REMEDIES UPON EVENT OF DEFAULT.

                  (i) Upon the occurrence of an Event of Default, (i) the entire
principal  amount of, and all  accrued and unpaid  interest  on, this Note shall
automatically  become immediately due and payable without  presentment,  demand,
protest or other  formalities  of any kind,  all of which are  hereby  expressly
waived by the Company and (ii)  additional  interest shall begin to accrue,  and
shall be considered  immediately due and payable, on the unpaid principal amount
of this Note at the rate of eighteen  percent (18%) per annum and shall continue
to accrue  until the  initial  interest  and  additional  interest  is paid.  In
addition,  the  Holder may take any action  available  to it under the  Purchase
Agreement or at law or in equity or by statute or otherwise.

                  (j) No remedy herein conferred upon the Holder of this Note is
intended  to be  exclusive  of any other  remedy and each and every such  remedy
shall be  cumulative  and  shall be in  addition  to every  other  remedy  given
hereunder  or now or  hereafter  existing  at law or in equity or by  statute or
otherwise.


                                       15

<PAGE>

SECTION 9.        NOTE REGISTER.

                  (a) The Company shall keep at its principal executive office a
register  (herein  sometimes  referred  to as the  "Note  Register"),  in which,
subject to such reasonable  regulations as it may prescribe,  but at its expense
(other than transfer taxes, if any), the Company shall provide for  registration
and transfer of this Note.

                  (b) Whenever this Note shall be  surrendered  at the principal
executive  office of the Company  for  transfer or  exchange,  accompanied  by a
written  instrument of transfer in form  reasonably  satisfactory to the Company
duly executed by the Holder  hereof or his attorney duly  authorized in writing,
the Company shall execute and deliver in exchange  therefor a new Note or Notes,
as may be requested  by such  Holder,  in the same  aggregate  unpaid  principal
amount and payable on the same date as the principal amount of the Note or Notes
so  surrendered;  each  such  new  Note  shall  be dated as of the date to which
interest  has been paid on the unpaid  principal  amount of the Note or Notes so
surrendered and shall be in such principal amount and registered in such name or
names as such Holder may designate in writing.

                  (c)  Upon  receipt  by  the  Company  of  evidence  reasonably
satisfactory  to it of the loss,  theft,  destruction or mutilation of this Note
and of indemnity  reasonably  satisfactory to it, and upon  reimbursement to the
Company of all reasonable expenses  incidental  thereto,  and upon surrender and
cancellation  of this Note (in case of  mutilation)  the  Company  will make and
deliver  in lieu of this  Note a new Note of like  tenor  and  unpaid  principal
amount  and dated as of the date to which  interest  has been paid on the unpaid
principal  amount  of this  Note in lieu of  which  such  new  Note is made  and
delivered.


SECTION 10.       REGISTRATION UNDER SECURITIES ACT OF 1933.

                  The  Holder of this Note  shall  have  registration  rights as
provided in Section 8 of the Purchase  Agreement,  with respect to the shares of
Common Stock issuable upon  conversion of the Notes pursuant to the Optional and
Default  Conversion  Right.  If the  Holder  is  not a  party  to  the  Purchase
Agreement,  by  acceptance  of this  Note,  the  Holder  agrees to  comply  with
provisions  of Section 8 of the  Purchase  Agreement to the same extent as if it
were a party thereto.

SECTION 11.       MISCELLANEOUS.

                    (a)  Amendments  and Waivers.  The holders of sixty-six  and
two-thirds percent (66 2/3%) or more in principal amount of outstanding Notes of
this  issue  may  waive or  otherwise  consent  to the  amendment  of any of the
provisions  hereof,  provided  that no such waiver or  amendment  may reduce the
principal  amount of or interest on any of the Notes of this issue or change the
stated maturity of the principal or reduce the percentage of holders of Notes of
this issue necessary to waive or amend the provisions of this Note,  without the
consent of each holder of any Note affected thereby.


                                       16

<PAGE>

                    (b)  Restrictions  on  Transferability.  In  addition to the
restrictions set forth in Section 6(a) of this Note, the securities  represented
by this Note have been  acquired  for  investment  and have not been  registered
under the  Securities  Act of 1933, as amended,  or the  securities  laws of any
state or other jurisdiction.  Without such registration, such securities may not
be sold,  pledged,  hypothecated  or otherwise  transferred,  except pursuant to
exemptions from the Securities Act of 1933, and the securities laws of any state
or other  jurisdiction.  Notwithstanding  the above, the holder of this Note has
been  provided the  registration  rights  contained in Section 8 of the Purchase
Agreement with respect to the shares of the Company's  Common Stock which may be
acquired upon exercise of the Optional and Default Conversion Right.

                    (c) Forbearance  from Suit. No holder of Notes of this issue
shall  institute any suit or proceeding  for the  enforcement  of the payment of
principal or interest unless the holders of at least fifty-one  percent (51%) in
principal amount of all of the outstanding Notes of this issue join in such suit
or proceeding.

                  (d)  Governing  Law.  This  Note  shall  be  governed  by  and
construed in  accordance  with the laws of the State of New York,  excluding the
body of law  relating  to  conflict  of laws.  Notwithstanding  anything  to the
contrary  contained  herein,  in no event  may the  effective  rate of  interest
collected or received by the Holder exceed that which may be charged,  collected
or received by the Holder under applicable law.

                  (e)  Interpretation.  If any term or  provision  of this  Note
shall be held invalid, illegal or unenforceable, the validity of all other terms
and provisions hereof shall in no way be affected thereby.

                  (f)  Successors  and Assigns.  This Note shall be binding upon
the Company and its successors and assigns and shall inure to the benefit of the
Holder and its successors and assigns.

                  (g) Notices. All notices, requests, consents and demands shall
be made in writing and shall be mailed postage prepaid, or delivered by hand, to
the Company or to the Holder  thereof at their  respective  addresses  set forth
below or to such other address as may be furnished in writing to the other party
hereto:

    If to the Holder:      At the address shown on Schedule A attached hereto.

    with a copy to:        Paramount Capital Asset Management, Inc.
                           787 Seventh Avenue
                           New York, NY  10019
                           Attn:  David R. Walner

    If to the Company:     Procept, Inc.
                           840 Memorial Drive
                           Cambridge, MA
                           Attention: Stanley C. Erck


                                       17

<PAGE>

    with a copy to:        Paramount Capital Asset Management, Inc.
                           787 Seventh Avenue
                           New York, NY  10019
                           Attn:  Michael S. Weiss

                  (h) Saturdays,  Sundays, Holidays. If any date that may at any
time be  specified  in this  Note as a date for the  making  of any  payment  of
principal or interest under this Note shall fall on Saturday, Sunday or on a day
which in New York shall be a legal holiday, then the date for the making of that
payment  shall be the next  subsequent  day which is not a  Saturday,  Sunday or
legal holiday.

                  (i)  Purchase  Agreement.  This Note is  subject  to the terms
contained in the Purchase  Agreement and the Operative  Documents (as defined in
Purchase  Agreement)  dated the date  hereof  between  the  Company  and certain
purchasers  of the Notes and the holder of this Note is entitled to the benefits
of such Purchase  Agreement and the Operative  Documents and may, in addition to
any rights  hereunder,  enforce the agreements of the Company  contained therein
and exercise the remedies provided for thereby or otherwise available in respect
thereof.


                                       18

<PAGE>

         IN WITNESS  WHEREOF,  this Note has been  executed and delivered on the
date first above written by the duly authorized representative of the Company.


ATTEST:                             PROCEPT, INC.


/s/ Lynnette C. Fallon              By: /s/ Stanley C. Erck
- -------------------                    -------------------------------
                                    Name:  Stanley C. Erck
                                    Its:   President


                                       19
<PAGE>

                                   EXHIBIT H



THESE  SECURITIES HAVE NOT BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933 OR
ANY APPLICABLE STATE  SECURITIES  LAWS. THEY MAY NOT BE SOLD,  OFFERED FOR SALE,
PLEDGED  OR  HYPOTHECATED   OR  OTHERWISE   TRANSFERRED  IN  THE  ABSENCE  OF  A
REGISTRATION  STATEMENT IN EFFECT WITH RESPECT TO THE SECURITIES  UNDER SUCH ACT
OR AN EXEMPTION  THEREFROM.  ANY SUCH TRANSFER MAY ALSO BE SUBJECT TO APPLICABLE
STATE SECURITIES LAWS.



                                  PROCEPT, INC.


                  Class A Warrant for the Purchase of Shares of
                                  Common Stock


No. CA-1                                                          959,944 Shares


                  FOR VALUE RECEIVED, PROCEPT, INC., a Delaware corporation (the
"COMPANY"),  hereby certifies that THE ARIES DOMESTIC FUND, LP or its registered
assigns (the "Holder") is entitled to purchase from the Company,  subject to the
provisions of this Warrant (the "Warrant"), at any time commencing upon the date
hereof (the  "INITIAL  EXERCISE  DATE"),  and prior to 5:00 P.M.,  New York City
time, on the date which is five (5) years from the date hereof (the "TERMINATION
DATE"), June 30, 2002 fully paid and non-assessable  shares of the Common Stock,
$.01 par value, of the Company  ("Common  Stock"),  at an exercise price of $.01
per share of Common Stock for an aggregate  exercise price of NINE THOUSAND FIVE
HUNDRED  NINETY-NINE  DOLLARS AND FORTY-FOUR  CENTS  ($9,599.44)  (the aggregate
purchase price payable for the Warrant Shares hereunder is hereinafter sometimes
referred to as the "AGGREGATE  EXERCISE PRICE").  The number of shares of Common
Stock to be received  upon exercise of this Warrant and the price to be paid for
each share of Common Stock are subject to possible  adjustment from time to time
as  hereinafter  set forth.  The shares of Common Stock or other  securities  or
property  deliverable  upon  such  exercise  as  adjusted  from  time to time is
hereinafter sometimes referred to as the "WARRANT SHARES." The exercise price of
a share of Common Stock in effect at any time and as adjusted  from time to time
is hereinafter  sometimes referred to as the "PER SHARE EXERCISE PRICE." The Per
Share Exercise Price is subject to adjustment as  hereinafter  provided;  in the
event of any such adjustment,  the number of Warrant Shares shall be adjusted by
dividing the Aggregate  Exercise Price by the Per Share Exercise Price in effect
immediately after such adjustment.  The Aggregate  Exercise Price is not subject
to adjustment.


<PAGE>

                  1.       EXERCISE OF WARRANT.

                  (a) This Warrant may be exercised in whole or in part,  at any
time by the Holder  commencing  on the  Initial  Exercise  Date and prior to the
Termination  Date, by presentation and surrender of this Warrant,  together with
the duly executed  subscription  form attached at the end hereof, at the address
set forth in subsection  8(a) hereof,  together  with  payment,  by certified or
official bank check or wire transfer payable to the order of the Company, of the
Aggregate Exercise Price or the proportionate part thereof if exercised in part.

                  (b) If this  Warrant is  exercised  in part only,  the Company
shall, upon presentation of this Warrant upon such exercise, execute and deliver
(along with the  certificate  for the Warrant  Shares  purchased)  a new Warrant
evidencing  the  rights of the  Holder  hereof to  purchase  the  balance of the
Warrant  Shares  purchasable  hereunder  upon the same terms and  conditions  as
herein set forth.  Upon proper  exercise of this Warrant,  the Company  promptly
shall deliver certificates for the Warrant Shares to the Holder duly legended as
authorized by the subscription  form. No fractional shares or scrip representing
fractional  shares shall be issued upon exercise of this Warrant;  provided that
the  Company  shall  pay to the  holders  of the  Warrant  cash  in lieu of such
fractional shares.

                  2.  RESERVATION OF WARRANT SHARES;  FULLY PAID SHARES;  TAXES.
The Company hereby  represents that it has, and until expiration of this Warrant
agrees that it shall,  reserve for  issuance or delivery  upon  exercise of this
Warrant,  such  number of shares of the Common  Stock as shall be  required  for
issuance  and/or delivery upon exercise of this Warrant in full, and agrees that
all Warrant Shares so issued and/or delivered will be validly issued, fully paid
and non-assessable,  and further agrees to pay all taxes and charges that may be
imposed upon such issuance and/or delivery.

                  3.       PROTECTION AGAINST DILUTION.

                  (a) In the event the Company  shall,  at any time or from time
to time after the date of issuance of this  Warrant,  issue or distribute to all
of the holders of its shares of Common Stock evidence of its  indebtedness,  any
other securities of the Company or any cash,  property or other assets (any such
event being herein called a "SPECIAL  DIVIDEND"),  the Per Share  Exercise Price
shall be adjusted by multiplying  the Per Share Exercise Price then in effect by
a fraction,  the  numerator of which shall be the then Current  Market Price (as
defined in paragraph  3(k) below) of the Common Stock,  less the Current  Market
Price of the Special  Dividend  issued or distributed in respect of one share of
Common Stock,  and the denominator of which shall be the Current Market Price of
the Common Stock.  Such adjustment  shall be made  successively  whenever such a
record  date  is  fixed.  Such  adjustment  shall  be  made  whenever  any  such
distribution  is made and shall become  effective  immediately  after the record
date for the determination of shareholders entitled to receive such distribution
unless such distribution is not ultimately made.

                  (b) In case the Company shall  hereafter (i) pay a dividend or
make a  distribution  on its  capital  stock in  shares of  Common  Stock,  (ii)
subdivide  its  outstanding  shares of  Common  Stock  into a greater  number of
shares, (iii) combine its outstanding shares of


                                        2

<PAGE>

Common Stock into a smaller  number of shares or (iv) issue by  reclassification
of its Common Stock any shares of capital  stock of the  Company,  the Per Share
Exercise  Price shall be adjusted to be equal to a fraction,  the  numerator  of
which shall be the Aggregate  Exercise Price and the  denominator of which shall
be the number of shares of Common  Stock or other  capital  stock of the Company
issuable upon exercise of this Warrant  assuming this Warrant had been exercised
immediately prior to such action. An adjustment made pursuant to this subsection
3(b) shall become effective  immediately  after the record date in the case of a
dividend  or  distribution  and shall  become  effective  immediately  after the
effective date in the case of a subdivision, combination or reclassification.

                  (c)(i) Except as provided in subsections 3(a) and 3(b)(i),  in
the event the  Company  shall  hereafter  issue or sell any  Common  Stock,  any
securities  convertible into Common Stock or any rights,  options or warrants to
purchase Common Stock or securities  convertible into Common Stock, in each case
for a price per share or entitling the holders  thereof to purchase Common Stock
at a price per share  (determined  by  dividing  (i) the total  amount,  if any,
received or receivable by the Company in  consideration  of the issuance or sale
of such securities plus the  consideration,  if any, payable to the Company upon
exercise or conversion thereof (collectively, the "TOTAL CONSIDERATION") by (ii)
the number of additional  shares of Common Stock  issued,  sold or issuable upon
exercise or conversion of such  securities)  which is less than the then Current
Market  Price of the Common  Stock (as defined  below) but not below the current
Per Share Exercise Price (which event is governed by subsection  3(c)(ii)),  the
Per Share  Exercise  Price shall be adjusted as of the date of such  issuance or
sale by  multiplying  the Per Share Exercise Price then in effect by a fraction,
the  numerator  of which  shall be (x) the sum of (A) the  number  of  shares of
Common Stock  outstanding  on the record date of such  issuance or sale plus (B)
the Total Consideration divided by the Current Market Price of the Common Stock,
and the  denominator  of which shall be (y) the number of shares of Common Stock
outstanding  on the record date of such issuance or sale plus the maximum number
of additional  shares of Common Stock issued,  sold or issuable upon exercise or
conversion of such securities.

                  (ii) Except as provided in subsection 3(a) and 3(b)(i), in the
event the Company shall hereafter issue or sell any Common Stock, any securities
convertible  into Common  Stock or any  rights,  options or warrants to purchase
Common Stock or securities  convertible  into Common  Stock,  in each case for a
price per share or entitling the holders  thereof to purchase  Common Stock at a
price per share (the  "ISSUE  PRICE"),  (determined  by  dividing  (i) the Total
Consideration  by (ii) the number of additional  shares of Common Stock issuable
upon  exercise or  conversion  of such  securities)  which is less than the then
current Per Share  Exercise Price in effect on the record date of such issuance,
the Per Share Exercise Price shall be adjusted to equal the Issue Price.

                  (d)  In  the   event   of  any   capital   reorganization   or
reclassification, or any consolidation or merger to which the Company is a party
other than a merger or  consolidation  in which the  Company  is the  continuing
corporation,  or in case of any sale or  conveyance  to  another  entity  of the
property of the Company as an entirety or  substantially  as an entirety,  or in
the case of any  statutory  exchange  of  securities  with  another  corporation
(including  any  exchange  effected  in  connection  with a  merger  of a  third
corporation into the Company), the


                                        3

<PAGE>

Holder  of this  Warrant  shall  have the right  thereafter  to  receive  on the
exercise  of this  Warrant  the kind and  amount  of  securities,  cash or other
property  which the Holder  would have  owned or have been  entitled  to receive
immediately after such reorganization, reclassification,  consolidation, merger,
statutory  exchange,   sale  or  conveyance  had  this  Warrant  been  exercised
immediately   prior   to   the   effective   date   of   such    reorganization,
reclassification,  consolidation, merger, statutory exchange, sale or conveyance
and in any such case, if necessary,  appropriate adjustment shall be made in the
application  of the  provisions  set forth in this Section 3 with respect to the
rights and  interests  thereafter  of the Holder of this Warrant to the end that
the provisions set forth in this Section 3 shall thereafter  correspondingly  be
made  applicable,  as nearly as may  reasonably be, in relation to any shares of
stock or other securities or property thereafter  deliverable on the exercise of
this Warrant. The above provisions of this subsection 3(e) shall similarly apply
to  successive  reorganizations,  reclassifications,   consolidations,  mergers,
statutory exchanges, sales or conveyances.  The issuer of any shares of stock or
other  securities  or property  thereafter  deliverable  on the exercise of this
Warrant shall be responsible  for all of the  agreements and  obligations of the
Company  hereunder.   Notice  of  any  such  reorganization,   reclassification,
consolidation,  merger,  statutory  exchange,  sale  or  conveyance  and of said
provisions  so  proposed  to be made,  shall be  mailed  to the  Holders  of the
Warrants  not  less  than  30  days  prior  to  such  event.  A  sale  of all or
substantially  all of the assets of the Company for a  consideration  consisting
primarily  of  securities  shall be deemed a  consolidation  or  merger  for the
foregoing purposes.

                  (e) In case  any  event  shall  occur as to  which  the  other
provisions  of this  Section 3 are not strictly  applicable  but as to which the
failure to make any  adjustment  would not fairly  protect the  purchase  rights
represented  by this  Warrant  in  accordance  with  the  essential  intent  and
principles hereof then, in each such case, the Holders of Warrants  representing
the  right  to  purchase  a  majority  of  the  Warrant  Shares  subject  to all
outstanding  Warrants may appoint a firm of  independent  public  accountants of
recognized national standing reasonably  acceptable to the Company,  which shall
give their opinion as to the adjustment,  if any, on a basis consistent with the
essential intent and principles  established  herein,  necessary to preserve the
purchase rights represented by the Warrants.  Upon receipt of such opinion,  the
Company  will  promptly  mail a copy  thereof to the Holder of this  Warrant and
shall make the  adjustments  described  therein.  The fees and  expenses of such
independent public accountants shall be borne by the Company.

                  (f)  Whenever  the  Per  Share  Exercise  Price  payable  upon
exercise of each  Warrant is adjusted  pursuant to this Section 3, the number of
shares of Common Stock underlying a Warrant shall  simultaneously be adjusted to
equal the number  obtained  by  dividing  the  Aggregate  Exercise  Price by the
adjusted Per Share Exercise Price.

                  (g) No  adjustment  in the Per Share  Exercise  Price shall be
required  unless  such  adjustment  would  require an increase or decrease of at
least $0.01 per share of Common Stock;  provided,  however, that any adjustments
which by reason of this  subsection  3(g) are not  required  to be made shall be
carried  forward  and taken  into  account  in any  subsequent  adjustment.  All
calculations  under this  Section 3 shall be made to the nearest  cent or to the
nearest  1/100th of a share,  as the case may be.  Anything in this Section 3 to
the  contrary  notwithstanding,  the  Company  shall be  entitled  to make  such
reductions in the Per Share


                                        4

<PAGE>

Exercise  Price,  in addition to those  required by this Section 3, as it in its
discretion  shall  deem to be  advisable  in  order  that  any  stock  dividend,
subdivision of shares or  distribution of rights to purchase stock or securities
convertible  or  exchangeable  for stock  hereafter  made by the  Company to its
stockholders shall not be taxable.

                  (h)  Whenever  the Per Share  Exercise  Price is  adjusted  as
provided in this Section 3 and upon any  modification  of the rights of a Holder
of Warrants  in  accordance  with this  Section 3, the  Company  shall  promptly
obtain,  at  its  expense,  a  certificate  of  a  firm  of  independent  public
accountants of recognized  standing  selected by the Board of Directors (who may
be the regular  auditors of the Company)  setting  forth the Per Share  Exercise
Price and the number of Warrant  Shares after such  adjustment  or the effect of
such  modification,  a brief statement of the facts requiring such adjustment or
modification  and the  manner of  computing  the same and  cause  copies of such
certificate to be mailed to the Holders of the Warrants.

                  (i) If the Board of Directors of the Company shall declare any
dividend or other  distribution  with respect to the Common  Stock,  the Company
shall mail notice  thereof to the Holders of the  Warrants not less than 30 days
prior  to the  record  date  fixed  for  determining  stockholders  entitled  to
participate in such dividend or other distribution.

                  (j) If, as a result of an  adjustment  made  pursuant  to this
Section 3, the Holder of any Warrant  thereafter  surrendered for exercise shall
become  entitled to receive  shares of two or more  classes of capital  stock or
shares of Common  Stock and other  capital  stock of the  Company,  the Board of
Directors (whose  determination  shall be conclusive and shall be described in a
written  notice to the Holder of any  Warrant  promptly  after such  adjustment)
shall  determine the allocation of the adjusted Per Share Exercise Price between
or among shares or such  classes of capital  stock or shares of Common Stock and
other capital stock.

                  (k) For the purpose of any computation  under Section 3 above,
the then Current  Market Price per share (the "CURRENT  MARKET  PRICE") shall be
deemed to be the last sale price of the Common Stock on the trading day prior to
such date or, in case no such reported sales take place on such day, the average
of the last  reported  bid and asked  prices of the Common Stock on such day, in
either case on the principal  national  securities  exchange on which the Common
Stock is admitted to trading or listed,  or if not listed or admitted to trading
on any such exchange,  the representative  closing bid price of the Common Stock
as reported by the National  Association of Securities  Dealers,  Inc. Automated
Quotations  System  ("NASDAQ"),  or other similar  organization  if NASDAQ is no
longer  reporting such  information,  or, if the Common Stock is not reported on
NASDAQ,   the  high  per  share  bid   price  for  the   Common   Stock  in  the
over-the-counter  market as reported by the National Quotation Bureau or similar
organization,  or if not so available, the fair market value of the Common Stock
as determined by agreement between the Company's Board of Directors,  on the one
part, and the Holders of Warrants  representing the right to purchase a majority
of the Warrant Shares subject to all outstanding  Warrants,  on the second part.
If the Board of Directors  and such Holders fail to agree on the Current  Market
Price  within 60 days of the date of the action  giving  rise to any  adjustment
pursuant to this Section 3, such Holders  shall be entitled to appoint a firm of
independent  public  accountants or appraisers of recognized  national  standing
reasonably acceptable to the Company,  which shall give their opinion as to such
Current Market Price on


                                        5

<PAGE>

a basis consistent with the essential intent and principles  established herein.
Upon receipt of such  opinion,  the Company will promptly mail a copy thereof to
the Holder of this Warrant and shall make the adjustments described therein. The
fees and expenses of such independent  public accountants or appraisers shall be
borne by the Company.

                  4.  REGISTRATION  UNDER SECURITIES ACT OF 1933 . The resale of
the Warrant Shares shall be registered on the Shelf  Registration  Statement (as
defined  in  Article  8 of the  Securities  Purchase  Agreement  (the  "Purchase
Agreement") dated as of June 30, 1997, by and among the Company, The Aries Fund,
a Cayman Island Trust,  and The Aries  Domestic Fund,  L.P., a Delaware  limited
partnership)  and certain  purchasers  and the Holder of this Warrant shall have
the registration rights as provided in Article 8 of the Purchase  Agreement.  If
the  Holder is not a party to the  Purchase  Agreement,  by  acceptance  of this
Warrant the Holder agrees to comply with provisions of Article 8 of the Purchase
Agreement to the same extent as if it were a party thereto.

                  5.  LIMITED  TRANSFERABILITY.  This  Warrant  may not be sold,
transferred,  assigned or  hypothecated  by the Holder except in compliance with
the  provisions  of the  Securities  Act of 1933 (the "Act") and the  applicable
state securities "blue sky" laws, and is so transferable  only upon the books of
the Company which it shall cause to be maintained for such purpose.  The Company
may treat the  registered  Holder of this  Warrant  as he or it  appears  on the
Company's  books at any time as the Holder for all  purposes.  The Company shall
permit any Holder of a Warrant or his duly  authorized  attorney,  upon  written
request during  ordinary  business  hours,  to inspect and copy or make extracts
from its books showing the registered  holders of Warrants.  All Warrants issued
upon the transfer or  assignment  of this Warrant will be dated the same date as
this Warrant,  and all rights of the holder  thereof shall be identical to those
of the Holder.

                  6.  LOSS,   ETC.,   OF  WARRANT.   Upon  receipt  of  evidence
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant, and of indemnity reasonably  satisfactory to the Company, if lost,
stolen or destroyed,  and upon surrender and  cancellation  of this Warrant,  if
mutilated,  the Company shall execute and deliver to the Holder a new Warrant of
like date, tenor and denomination.

                  7.  STATUS OF HOLDER.  This  Warrant  does not confer upon the
Holder any right to vote or to consent to or receive  notice as a stockholder of
the Company, as such, in respect of any matters whatsoever,  or any other rights
or liabilities as a stockholder, prior to the exercise hereof.

                  8.  NOTICES.  No  notice  or other  communication  under  this
Warrant shall be effective unless, but any notice or other  communication  shall
be  effective  and shall be deemed to have been given if, the same is in writing
and is mailed by first-class mail, postage prepaid, addressed to:

                  (a)  the    Company   at  840   Memorial   Drive,   Cambridge,
          Massachusetts,  Attention:  Stanley C. Erck,  or such other address as
          the Company has designated in writing to the Holder; or



                                        6

<PAGE>

                  (b)  the  Holder  at  the  address  indicated  in  the  notice
         provisions  to the  Purchase  Agreement,  or other such  address as the
         Holder has designated in writing to the Company.

                  9. OPTIONAL  CONVERSION.  This Warrant shall be converted (the
"New Warrant  Conversion")  into a New Warrant (as hereinafter  defined) with an
adjusted  exercise  price as set forth in this Section 9. "New  Warrants"  shall
mean a new class of warrants  entitling the holders thereof to purchase,  at any
time on or before  the date which is five (5) years  from the date  hereof,  one
share of Common Stock at an exercise price, subject to adjustment,  equal to the
lesser of (a) $.29 and (b) fifty percent (50%) of the average  closing bid price
of the Common  Stock for either (i) the thirty  (30)  consecutive  trading  days
preceding the date of the Required  Shareholder  Approval (the "Approval Date"),
if any, or  September  30,  1997,  (ii) the five (5)  consecutive  trading  days
preceding the Approval Date, if any, or September 30, 1997 or (iii) the five (5)
consecutive  trading days  immediately  succeeding the Approval Date, if any, or
September  30,  1997  whichever  is lowest.  Other  than the per share  exercise
prices, the New Warrants shall have the same terms as the Class A and B Warrants
held by such Holder respectively  (including,  without limitation,  an Aggregate
Exercise  Price equal to the Aggregate  Exercise Price of the sum of the Class A
and B Warrants  Aggregate  Exercise Prices prior to the New Warrant  Conversion)
and all adjustments required upon an adjustment to the exercise price of the New
Warrants  pursuant to the terms thereof shall be made in connection with the New
Warrant Conversion. To the extent that there is no Required Shareholder Approval
(as defined in the Purchase Agreement) necessary,  the Initial Warrants shall be
converted  into New Warrants on September  30, 1997,  with an adjusted  exercise
price equal to the lesser of (a) $.29 and (b) fifty percent (50%) of the average
closing bid price of the Common Stock for either (i) the thirty (30) consecutive
trading days preceding September 30, 1997, (ii) the five (5) consecutive trading
days preceding September 30, 1997 or (iii) the five (5) consecutive trading days
immediately succeeding September 30, 1997, whichever is lowest.

                  Notwithstanding  the  foregoing,  the New  Warrants' per share
exercise  price shall be adjusted at the time of the Series B Final Closing Date
or the closing of the  Company's  next  Qualified  Offering  (as these terms are
defined in the Letter of Intent between the Company and Paramount  Capital Inc.,
dated  June  30,  1997) if (i) the per  share  exercise  price  of the  Offering
Warrants (as defined  below) or (ii) the quotient of (a) the price per unit sold
in the Series B Offering or other Qualified Offering divided by (b) the quantity
of Common  Stock (or any  securities  other than Common Stock viewed on a Common
Stock equivalent basis,  collectively,  the "Other Securities") included in each
unit sold in such Series B Offering or other  Qualified  Offering,  is less than
twice the per share  exercise  price of the New Warrants.  In such event the New
Warrants  per share  exercise  price  shall be  reduced to equal 50% of the then
current per share exercise price of the Offering Warrants (as hereafter defined)
or per share  exercise or offering  price of the Other  Securities  (viewed on a
Common Stock  equivalent  basis).  "Offering  Warrants"  shall mean the warrants
described  in  paragraph  8 of the  Letter of Intent  between  the  Company  the
Holders, and Paramount Capital, Inc. dated June 30, 1997.

                  10. HEADINGS.  The headings of this Warrant have been inserted
as a matter of convenience and shall not affect the construction hereof.


                                        7

<PAGE>

                  11.  APPLICABLE  LAW.  This  Warrant  shall be governed by and
construed in  accordance  with the law of the State of New York  without  giving
effect to principles of conflicts of law thereof.

                  IN WITNESS WHEREOF,  the Company has caused this Warrant to be
signed by its  President  and its  corporate  seal to be  hereunto  affixed  and
attested by its Secretary this June 30, 1997.


                                  PROCEPT, INC.



                                  By: /s/ Stanley C. Erck
                                     --------------------------
                                       Name:  Stanley C. Erck
                                       Title: President


ATTEST:


/s/ Lynnette C. Fallon
- -----------------------
       Secretary



[Corporate Seal]




                                        8

<PAGE>

                                  SUBSCRIPTION

                  The undersigned, ____________________________, pursuant to the
provisions  of the  foregoing  Warrant,  hereby  elects to  exercise  the within
Warrant to the extent of purchasing _____________________ shares of Common Stock
thereunder and hereby makes payment of $_______________ by certified or official
bank check in payment of the per share exercise price therefor.

Dated:                                 Signature:
      ------------                               --------------------------

                                       Address:
                                                 --------------------------


                                   ASSIGNMENT

                  FOR  VALUE  RECEIVED   _______________________________________
hereby sells,  assigns and transfers unto  _____________________________________
the foregoing  Warrant and all rights  evidenced  thereby,  and does irrevocably
constitute and appoint _____________________________, attorney, to transfer said
Warrant on the books of Procept, Inc.


Dated:                                 Signature:
      ------------                               --------------------------

                                       Address:
                                                 --------------------------

                               PARTIAL ASSIGNMENT

                  FOR VALUE RECEIVED  __________________________  hereby assigns
and transfers unto  _________________________  the right to purchase  __________
shares of the Common Stock, no par value per share,  of Procept Inc.  covered by
the foregoing  Warrant,  and a proportionate part of said Warrant and the rights
evidenced    thereby,    and   does    irrevocably    constitute   and   appoint
__________________________,  attorney,  to transfer that part of said Warrant on
the books of Procept, Inc.


Dated:                                 Signature:
      ------------                               --------------------------

                                       Address:
                                                 --------------------------


                                        9


<PAGE>
                                   EXHIBIT I

THESE  SECURITIES HAVE NOT BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933 OR
ANY APPLICABLE STATE  SECURITIES  LAWS. THEY MAY NOT BE SOLD,  OFFERED FOR SALE,
PLEDGED  OR  HYPOTHECATED   OR  OTHERWISE   TRANSFERRED  IN  THE  ABSENCE  OF  A
REGISTRATION  STATEMENT IN EFFECT WITH RESPECT TO THE SECURITIES  UNDER SUCH ACT
OR AN EXEMPTION  THEREFROM.  ANY SUCH TRANSFER MAY ALSO BE SUBJECT TO APPLICABLE
STATE SECURITIES LAWS.



                                  PROCEPT, INC.


                  Class A Warrant for the Purchase of Shares of
                                  Common Stock


No. CA-2                                                        1,782,752 Shares


                  FOR VALUE RECEIVED, PROCEPT, INC., a Delaware corporation (the
"COMPANY"),  hereby certifies that THE ARIES FUND, A CAYMAN ISLANDS TRUST or its
registered  assigns  (the  "Holder")  is entitled to purchase  from the Company,
subject  to the  provisions  of  this  Warrant  (the  "Warrant"),  at  any  time
commencing upon the date hereof (the "INITIAL EXERCISE DATE"), and prior to 5:00
P.M.,  New York City  time,  on the date  which is five (5) years  from the date
hereof (the  "TERMINATION  DATE"),  June 30, 2002 fully paid and  non-assessable
shares of the Common Stock, $.01 par value, of the Company ("Common Stock"),  at
an exercise  price of $.01 per share of Common Stock for an  aggregate  exercise
price of SEVENTEEN  THOUSAND  EIGHT HUNDRED  TWENTY-SEVEN  DOLLARS AND FIFTY-TWO
CENTS  ($17,827.52) (the aggregate purchase price payable for the Warrant Shares
hereunder  is  hereinafter  sometimes  referred  to as the  "AGGREGATE  EXERCISE
PRICE").  The number of shares of Common Stock to be received  upon  exercise of
this Warrant and the price to be paid for each share of Common Stock are subject
to possible adjustment from time to time as hereinafter set forth. The shares of
Common Stock or other  securities or property  deliverable upon such exercise as
adjusted from time to time is hereinafter  sometimes referred to as the "WARRANT
SHARES." The exercise price of a share of Common Stock in effect at any time and
as adjusted from time to time is hereinafter  sometimes  referred to as the "PER
SHARE EXERCISE  PRICE." The Per Share Exercise Price is subject to adjustment as
hereinafter provided; in the event of any such adjustment, the number of Warrant
Shares shall be adjusted by dividing  the  Aggregate  Exercise  Price by the Per
Share Exercise Price in effect immediately after such adjustment.  The Aggregate
Exercise Price is not subject to adjustment.


<PAGE>

                  1.       EXERCISE OF WARRANT.

                  (a) This Warrant may be exercised in whole or in part,  at any
time by the Holder  commencing  on the  Initial  Exercise  Date and prior to the
Termination  Date, by presentation and surrender of this Warrant,  together with
the duly executed  subscription  form attached at the end hereof, at the address
set forth in subsection  8(a) hereof,  together  with  payment,  by certified or
official bank check or wire transfer payable to the order of the Company, of the
Aggregate Exercise Price or the proportionate part thereof if exercised in part.

                  (b) If this  Warrant is  exercised  in part only,  the Company
shall, upon presentation of this Warrant upon such exercise, execute and deliver
(along with the  certificate  for the Warrant  Shares  purchased)  a new Warrant
evidencing  the  rights of the  Holder  hereof to  purchase  the  balance of the
Warrant  Shares  purchasable  hereunder  upon the same terms and  conditions  as
herein set forth.  Upon proper  exercise of this Warrant,  the Company  promptly
shall deliver certificates for the Warrant Shares to the Holder duly legended as
authorized by the subscription  form. No fractional shares or scrip representing
fractional  shares shall be issued upon exercise of this Warrant;  provided that
the  Company  shall  pay to the  holders  of the  Warrant  cash  in lieu of such
fractional shares.

                  2.  RESERVATION OF WARRANT SHARES;  FULLY PAID SHARES;  TAXES.
The Company hereby  represents that it has, and until expiration of this Warrant
agrees that it shall,  reserve for  issuance or delivery  upon  exercise of this
Warrant,  such  number of shares of the Common  Stock as shall be  required  for
issuance  and/or delivery upon exercise of this Warrant in full, and agrees that
all Warrant Shares so issued and/or delivered will be validly issued, fully paid
and non-assessable,  and further agrees to pay all taxes and charges that may be
imposed upon such issuance and/or delivery.

                  3.       PROTECTION AGAINST DILUTION.

                  (a) In the event the Company  shall,  at any time or from time
to time after the date of issuance of this  Warrant,  issue or distribute to all
of the holders of its shares of Common Stock evidence of its  indebtedness,  any
other securities of the Company or any cash,  property or other assets (any such
event being herein called a "SPECIAL  DIVIDEND"),  the Per Share  Exercise Price
shall be adjusted by multiplying  the Per Share Exercise Price then in effect by
a fraction,  the  numerator of which shall be the then Current  Market Price (as
defined in paragraph  3(k) below) of the Common Stock,  less the Current  Market
Price of the Special  Dividend  issued or distributed in respect of one share of
Common Stock,  and the denominator of which shall be the Current Market Price of
the Common Stock.  Such adjustment  shall be made  successively  whenever such a
record  date  is  fixed.  Such  adjustment  shall  be  made  whenever  any  such
distribution  is made and shall become  effective  immediately  after the record
date for the determination of shareholders entitled to receive such distribution
unless such distribution is not ultimately made.

                  (b) In case the Company shall  hereafter (i) pay a dividend or
make a  distribution  on its  capital  stock in  shares of  Common  Stock,  (ii)
subdivide  its  outstanding  shares of  Common  Stock  into a greater  number of
shares, (iii) combine its outstanding shares of


                                        2

<PAGE>

Common Stock into a smaller  number of shares or (iv) issue by  reclassification
of its Common Stock any shares of capital  stock of the  Company,  the Per Share
Exercise  Price shall be adjusted to be equal to a fraction,  the  numerator  of
which shall be the Aggregate  Exercise Price and the  denominator of which shall
be the number of shares of Common  Stock or other  capital  stock of the Company
issuable upon exercise of this Warrant  assuming this Warrant had been exercised
immediately prior to such action. An adjustment made pursuant to this subsection
3(b) shall become effective  immediately  after the record date in the case of a
dividend  or  distribution  and shall  become  effective  immediately  after the
effective date in the case of a subdivision, combination or reclassification.

                  (c)(i) Except as provided in subsections 3(a) and 3(b)(i),  in
the event the  Company  shall  hereafter  issue or sell any  Common  Stock,  any
securities  convertible into Common Stock or any rights,  options or warrants to
purchase Common Stock or securities  convertible into Common Stock, in each case
for a price per share or entitling the holders  thereof to purchase Common Stock
at a price per share  (determined  by  dividing  (i) the total  amount,  if any,
received or receivable by the Company in  consideration  of the issuance or sale
of such securities plus the  consideration,  if any, payable to the Company upon
exercise or conversion thereof (collectively, the "TOTAL CONSIDERATION") by (ii)
the number of additional  shares of Common Stock  issued,  sold or issuable upon
exercise or conversion of such  securities)  which is less than the then Current
Market  Price of the Common  Stock (as defined  below) but not below the current
Per Share Exercise Price (which event is governed by subsection  3(c)(ii)),  the
Per Share  Exercise  Price shall be adjusted as of the date of such  issuance or
sale by  multiplying  the Per Share Exercise Price then in effect by a fraction,
the  numerator  of which  shall be (x) the sum of (A) the  number  of  shares of
Common Stock  outstanding  on the record date of such  issuance or sale plus (B)
the Total Consideration divided by the Current Market Price of the Common Stock,
and the  denominator  of which shall be (y) the number of shares of Common Stock
outstanding  on the record date of such issuance or sale plus the maximum number
of additional  shares of Common Stock issued,  sold or issuable upon exercise or
conversion of such securities.

                  (ii) Except as provided in subsection 3(a) and 3(b)(i), in the
event the Company shall hereafter issue or sell any Common Stock, any securities
convertible  into Common  Stock or any  rights,  options or warrants to purchase
Common Stock or securities  convertible  into Common  Stock,  in each case for a
price per share or entitling the holders  thereof to purchase  Common Stock at a
price per share (the  "ISSUE  PRICE"),  (determined  by  dividing  (i) the Total
Consideration  by (ii) the number of additional  shares of Common Stock issuable
upon  exercise or  conversion  of such  securities)  which is less than the then
current Per Share  Exercise Price in effect on the record date of such issuance,
the Per Share Exercise Price shall be adjusted to equal the Issue Price.

                  (d)  In  the   event   of  any   capital   reorganization   or
reclassification, or any consolidation or merger to which the Company is a party
other than a merger or  consolidation  in which the  Company  is the  continuing
corporation,  or in case of any sale or  conveyance  to  another  entity  of the
property of the Company as an entirety or  substantially  as an entirety,  or in
the case of any  statutory  exchange  of  securities  with  another  corporation
(including  any  exchange  effected  in  connection  with a  merger  of a  third
corporation into the Company), the


                                        3

<PAGE>

Holder  of this  Warrant  shall  have the right  thereafter  to  receive  on the
exercise  of this  Warrant  the kind and  amount  of  securities,  cash or other
property  which the Holder  would have  owned or have been  entitled  to receive
immediately after such reorganization, reclassification,  consolidation, merger,
statutory  exchange,   sale  or  conveyance  had  this  Warrant  been  exercised
immediately   prior   to   the   effective   date   of   such    reorganization,
reclassification,  consolidation, merger, statutory exchange, sale or conveyance
and in any such case, if necessary,  appropriate adjustment shall be made in the
application  of the  provisions  set forth in this Section 3 with respect to the
rights and  interests  thereafter  of the Holder of this Warrant to the end that
the provisions set forth in this Section 3 shall thereafter  correspondingly  be
made  applicable,  as nearly as may  reasonably be, in relation to any shares of
stock or other securities or property thereafter  deliverable on the exercise of
this Warrant. The above provisions of this subsection 3(e) shall similarly apply
to  successive  reorganizations,  reclassifications,   consolidations,  mergers,
statutory exchanges, sales or conveyances.  The issuer of any shares of stock or
other  securities  or property  thereafter  deliverable  on the exercise of this
Warrant shall be responsible  for all of the  agreements and  obligations of the
Company  hereunder.   Notice  of  any  such  reorganization,   reclassification,
consolidation,  merger,  statutory  exchange,  sale  or  conveyance  and of said
provisions  so  proposed  to be made,  shall be  mailed  to the  Holders  of the
Warrants  not  less  than  30  days  prior  to  such  event.  A  sale  of all or
substantially  all of the assets of the Company for a  consideration  consisting
primarily  of  securities  shall be deemed a  consolidation  or  merger  for the
foregoing purposes.

                  (e) In case  any  event  shall  occur as to  which  the  other
provisions  of this  Section 3 are not strictly  applicable  but as to which the
failure to make any  adjustment  would not fairly  protect the  purchase  rights
represented  by this  Warrant  in  accordance  with  the  essential  intent  and
principles hereof then, in each such case, the Holders of Warrants  representing
the  right  to  purchase  a  majority  of  the  Warrant  Shares  subject  to all
outstanding  Warrants may appoint a firm of  independent  public  accountants of
recognized national standing reasonably  acceptable to the Company,  which shall
give their opinion as to the adjustment,  if any, on a basis consistent with the
essential intent and principles  established  herein,  necessary to preserve the
purchase rights represented by the Warrants.  Upon receipt of such opinion,  the
Company  will  promptly  mail a copy  thereof to the Holder of this  Warrant and
shall make the  adjustments  described  therein.  The fees and  expenses of such
independent public accountants shall be borne by the Company.

                  (f)  Whenever  the  Per  Share  Exercise  Price  payable  upon
exercise of each  Warrant is adjusted  pursuant to this Section 3, the number of
shares of Common Stock underlying a Warrant shall  simultaneously be adjusted to
equal the number  obtained  by  dividing  the  Aggregate  Exercise  Price by the
adjusted Per Share Exercise Price.

                  (g) No  adjustment  in the Per Share  Exercise  Price shall be
required  unless  such  adjustment  would  require an increase or decrease of at
least $0.01 per share of Common Stock;  provided,  however, that any adjustments
which by reason of this  subsection  3(g) are not  required  to be made shall be
carried  forward  and taken  into  account  in any  subsequent  adjustment.  All
calculations  under this  Section 3 shall be made to the nearest  cent or to the
nearest  1/100th of a share,  as the case may be.  Anything in this Section 3 to
the  contrary  notwithstanding,  the  Company  shall be  entitled  to make  such
reductions in the Per Share


                                        4

<PAGE>

Exercise  Price,  in addition to those  required by this Section 3, as it in its
discretion  shall  deem to be  advisable  in  order  that  any  stock  dividend,
subdivision of shares or  distribution of rights to purchase stock or securities
convertible  or  exchangeable  for stock  hereafter  made by the  Company to its
stockholders shall not be taxable.

                  (h)  Whenever  the Per Share  Exercise  Price is  adjusted  as
provided in this Section 3 and upon any  modification  of the rights of a Holder
of Warrants  in  accordance  with this  Section 3, the  Company  shall  promptly
obtain,  at  its  expense,  a  certificate  of  a  firm  of  independent  public
accountants of recognized  standing  selected by the Board of Directors (who may
be the regular  auditors of the Company)  setting  forth the Per Share  Exercise
Price and the number of Warrant  Shares after such  adjustment  or the effect of
such  modification,  a brief statement of the facts requiring such adjustment or
modification  and the  manner of  computing  the same and  cause  copies of such
certificate to be mailed to the Holders of the Warrants.

                  (i) If the Board of Directors of the Company shall declare any
dividend or other  distribution  with respect to the Common  Stock,  the Company
shall mail notice  thereof to the Holders of the  Warrants not less than 30 days
prior  to the  record  date  fixed  for  determining  stockholders  entitled  to
participate in such dividend or other distribution.

                  (j) If, as a result of an  adjustment  made  pursuant  to this
Section 3, the Holder of any Warrant  thereafter  surrendered for exercise shall
become  entitled to receive  shares of two or more  classes of capital  stock or
shares of Common  Stock and other  capital  stock of the  Company,  the Board of
Directors (whose  determination  shall be conclusive and shall be described in a
written  notice to the Holder of any  Warrant  promptly  after such  adjustment)
shall  determine the allocation of the adjusted Per Share Exercise Price between
or among shares or such  classes of capital  stock or shares of Common Stock and
other capital stock.

                  (k) For the purpose of any computation  under Section 3 above,
the then Current  Market Price per share (the "CURRENT  MARKET  PRICE") shall be
deemed to be the last sale price of the Common Stock on the trading day prior to
such date or, in case no such reported sales take place on such day, the average
of the last  reported  bid and asked  prices of the Common Stock on such day, in
either case on the principal  national  securities  exchange on which the Common
Stock is admitted to trading or listed,  or if not listed or admitted to trading
on any such exchange,  the representative  closing bid price of the Common Stock
as reported by the National  Association of Securities  Dealers,  Inc. Automated
Quotations  System  ("NASDAQ"),  or other similar  organization  if NASDAQ is no
longer  reporting such  information,  or, if the Common Stock is not reported on
NASDAQ,   the  high  per  share  bid   price  for  the   Common   Stock  in  the
over-the-counter  market as reported by the National Quotation Bureau or similar
organization,  or if not so available, the fair market value of the Common Stock
as determined by agreement between the Company's Board of Directors,  on the one
part, and the Holders of Warrants  representing the right to purchase a majority
of the Warrant Shares subject to all outstanding  Warrants,  on the second part.
If the Board of Directors  and such Holders fail to agree on the Current  Market
Price  within 60 days of the date of the action  giving  rise to any  adjustment
pursuant to this Section 3, such Holders  shall be entitled to appoint a firm of
independent  public  accountants or appraisers of recognized  national  standing
reasonably acceptable to the Company,  which shall give their opinion as to such
Current Market Price on


                                        5

<PAGE>

a basis consistent with the essential intent and principles  established herein.
Upon receipt of such  opinion,  the Company will promptly mail a copy thereof to
the Holder of this Warrant and shall make the adjustments described therein. The
fees and expenses of such independent  public accountants or appraisers shall be
borne by the Company.

                  4.  REGISTRATION  UNDER SECURITIES ACT OF 1933 . The resale of
the Warrant Shares shall be registered on the Shelf  Registration  Statement (as
defined  in  Article  8 of the  Securities  Purchase  Agreement  (the  "Purchase
Agreement") dated as of June 30, 1997, by and among the Company, The Aries Fund,
a Cayman Island Trust,  and The Aries  Domestic Fund,  L.P., a Delaware  limited
partnership)  and certain  purchasers  and the Holder of this Warrant shall have
the registration rights as provided in Article 8 of the Purchase  Agreement.  If
the  Holder is not a party to the  Purchase  Agreement,  by  acceptance  of this
Warrant the Holder agrees to comply with provisions of Article 8 of the Purchase
Agreement to the same extent as if it were a party thereto.

                  5.  LIMITED  TRANSFERABILITY.  This  Warrant  may not be sold,
transferred,  assigned or  hypothecated  by the Holder except in compliance with
the  provisions  of the  Securities  Act of 1933 (the "Act") and the  applicable
state securities "blue sky" laws, and is so transferable  only upon the books of
the Company which it shall cause to be maintained for such purpose.  The Company
may treat the  registered  Holder of this  Warrant  as he or it  appears  on the
Company's  books at any time as the Holder for all  purposes.  The Company shall
permit any Holder of a Warrant or his duly  authorized  attorney,  upon  written
request during  ordinary  business  hours,  to inspect and copy or make extracts
from its books showing the registered  holders of Warrants.  All Warrants issued
upon the transfer or  assignment  of this Warrant will be dated the same date as
this Warrant,  and all rights of the holder  thereof shall be identical to those
of the Holder.

                  6.  LOSS,   ETC.,   OF  WARRANT.   Upon  receipt  of  evidence
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant, and of indemnity reasonably  satisfactory to the Company, if lost,
stolen or destroyed,  and upon surrender and  cancellation  of this Warrant,  if
mutilated,  the Company shall execute and deliver to the Holder a new Warrant of
like date, tenor and denomination.

                  7.  STATUS OF HOLDER.  This  Warrant  does not confer upon the
Holder any right to vote or to consent to or receive  notice as a stockholder of
the Company, as such, in respect of any matters whatsoever,  or any other rights
or liabilities as a stockholder, prior to the exercise hereof.

                  8.  NOTICES.  No  notice  or other  communication  under  this
Warrant shall be effective unless, but any notice or other  communication  shall
be  effective  and shall be deemed to have been given if, the same is in writing
and is mailed by first-class mail, postage prepaid, addressed to:

                    (a)  the   Company  at  840   Memorial   Drive,   Cambridge,
          Massachusetts,  Attention:  Stanley C. Erck,  or such other address as
          the Company has designated in writing to the Holder; or


                                        6

<PAGE>




                  (b)  the  Holder  at  the  address  indicated  in  the  notice
         provisions  to the  Purchase  Agreement,  or other such  address as the
         Holder has designated in writing to the Company.

                  9. OPTIONAL  CONVERSION.  This Warrant shall be converted (the
"New Warrant  Conversion")  into a New Warrant (as hereinafter  defined) with an
adjusted  exercise  price as set forth in this Section 9. "New  Warrants"  shall
mean a new class of warrants  entitling the holders thereof to purchase,  at any
time on or before  the date which is five (5) years  from the date  hereof,  one
share of Common Stock at an exercise price, subject to adjustment,  equal to the
lesser of (a) $.29 and (b) fifty percent (50%) of the average  closing bid price
of the Common  Stock for either (i) the thirty  (30)  consecutive  trading  days
preceding the date of the Required  Shareholder  Approval (the "Approval Date"),
if any, or  September  30,  1997,  (ii) the five (5)  consecutive  trading  days
preceding the Approval Date, if any, or September 30, 1997 or (iii) the five (5)
consecutive  trading days  immediately  succeeding the Approval Date, if any, or
September  30,  1997  whichever  is lowest.  Other  than the per share  exercise
prices, the New Warrants shall have the same terms as the Class A and B Warrants
held by such Holder respectively  (including,  without limitation,  an Aggregate
Exercise  Price equal to the Aggregate  Exercise Price of the sum of the Class A
and B Warrants  Aggregate  Exercise Prices prior to the New Warrant  Conversion)
and all adjustments required upon an adjustment to the exercise price of the New
Warrants  pursuant to the terms thereof shall be made in connection with the New
Warrant Conversion. To the extent that there is no Required Shareholder Approval
(as defined in the Purchase Agreement) necessary,  the Initial Warrants shall be
converted  into New Warrants on September  30, 1997,  with an adjusted  exercise
price equal to the lesser of (a) $.29 and (b) fifty percent (50%) of the average
closing bid price of the Common Stock for either (i) the thirty (30) consecutive
trading days preceding September 30, 1997, (ii) the five (5) consecutive trading
days preceding September 30, 1997 or (iii) the five (5) consecutive trading days
immediately succeeding September 30, 1997, whichever is lowest.

                  Notwithstanding  the  foregoing,  the New  Warrants' per share
exercise  price shall be adjusted at the time of the Series B Final Closing Date
or the closing of the  Company's  next  Qualified  Offering  (as these terms are
defined in the Letter of Intent between the Company and Paramount  Capital Inc.,
dated  June  30,  1997) if (i) the per  share  exercise  price  of the  Offering
Warrants (as defined  below) or (ii) the quotient of (a) the price per unit sold
in the Series B Offering or other Qualified Offering divided by (b) the quantity
of Common  Stock (or any  securities  other than Common Stock viewed on a Common
Stock equivalent basis,  collectively,  the "Other Securities") included in each
unit sold in such Series B Offering or other  Qualified  Offering,  is less than
twice the per share  exercise  price of the New Warrants.  In such event the New
Warrants  per share  exercise  price  shall be  reduced to equal 50% of the then
current per share exercise price of the Offering Warrants (as hereafter defined)
or per share  exercise or offering  price of the Other  Securities  (viewed on a
Common Stock  equivalent  basis).  "Offering  Warrants"  shall mean the warrants
described  in  paragraph  8 of the  Letter of Intent  between  the  Company  the
Holders, and Paramount Capital, Inc. dated June 30, 1997.

                  10. HEADINGS.  The headings of this Warrant have been inserted
as a matter of convenience and shall not affect the construction hereof.


                                        7

<PAGE>

                  11.  APPLICABLE  LAW.  This  Warrant  shall be governed by and
construed in  accordance  with the law of the State of New York  without  giving
effect to principles of conflicts of law thereof.

                  IN WITNESS WHEREOF,  the Company has caused this Warrant to be
signed by its  President  and its  corporate  seal to be  hereunto  affixed  and
attested by its Secretary this June 30, 1997.


                                      PROCEPT, INC.



                                      By: /s/ Stanley C. Erck
                                         -------------------------
                                             Name:  Stanley C. Erck
                                             Title: President


ATTEST:


/s/ Lynette C. Fallon
- ---------------------
      Secretary



[Corporate Seal]




                                        8

<PAGE>


                                 SUBSCRIPTION

                  The undersigned, ____________________________, pursuant to the
provisions  of the  foregoing  Warrant,  hereby  elects to  exercise  the within
Warrant to the extent of purchasing _____________________ shares of Common Stock
thereunder and hereby makes payment of $_______________ by certified or official
bank check in payment of the per share exercise price therefor.

Dated:                                 Signature:
      ------------                               --------------------------

                                       Address:
                                                 --------------------------

                                   ASSIGNMENT

                  FOR  VALUE  RECEIVED   _______________________________________
hereby sells,  assigns and transfers unto  _____________________________________
the foregoing  Warrant and all rights  evidenced  thereby,  and does irrevocably
constitute and appoint _____________________________, attorney, to transfer said
Warrant on the books of Procept, Inc.


Dated:                                 Signature:
      ------------                               --------------------------

                                       Address:
                                                 --------------------------


                               PARTIAL ASSIGNMENT

                  FOR VALUE RECEIVED  __________________________  hereby assigns
and transfers unto  _________________________  the right to purchase  __________
shares of the Common Stock, no par value per share,  of Procept Inc.  covered by
the foregoing  Warrant,  and a proportionate part of said Warrant and the rights
evidenced    thereby,    and   does    irrevocably    constitute   and   appoint
__________________________,  attorney,  to transfer that part of said Warrant on
the books of Procept, Inc.

Dated:                                 Signature:
      ------------                               --------------------------

                                       Address:
                                                 --------------------------



                                        9

<PAGE>
                                   EXHIBIT J

THESE  SECURITIES HAVE NOT BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933 OR
ANY APPLICABLE STATE  SECURITIES  LAWS. THEY MAY NOT BE SOLD,  OFFERED FOR SALE,
PLEDGED  OR  HYPOTHECATED   OR  OTHERWISE   TRANSFERRED  IN  THE  ABSENCE  OF  A
REGISTRATION  STATEMENT IN EFFECT WITH RESPECT TO THE SECURITIES  UNDER SUCH ACT
OR AN EXEMPTION  THEREFROM.  ANY SUCH TRANSFER MAY ALSO BE SUBJECT TO APPLICABLE
STATE SECURITIES LAWS.



                                  PROCEPT, INC.


                  Class B Warrant for the Purchase of Shares of
                                  Common Stock


No. CB-1                                                        2,660,746 Shares


         FOR  VALUE  RECEIVED,   PROCEPT,  INC.,  a  Delaware  corporation  (the
"COMPANY"),  hereby  certifies  that THE ARIES  DOMESTIC FUND or its  registered
assigns (the "Holder") is entitled to purchase from the Company,  subject to the
provisions of this Warrant (the "Warrant"), at any time commencing upon the date
hereof (the  "INITIAL  EXERCISE  DATE"),  and prior to 5:00 P.M.,  New York City
time, on the date which is five (5) years from the date hereof (the "TERMINATION
DATE"), June 30, 2002 fully paid and non-assessable  shares of the Common Stock,
$.01 par value, of the Company ("Common Stock"),  at an exercise price of $.5859
per share of Common  Stock for an aggregate  exercise  price of ONE MILLION FIVE
HUNDRED  FIFTY-EIGHT  THOUSAND  NINE HUNDRED  THIRTY ONE DOLLARS AND EIGHT CENTS
($1,558,931.08)  (the  aggregate  purchase  price payable for the Warrant Shares
hereunder  is  hereinafter  sometimes  referred  to as the  "AGGREGATE  EXERCISE
PRICE").  The number of shares of Common Stock to be received  upon  exercise of
this Warrant and the price to be paid for each share of Common Stock are subject
to possible adjustment from time to time as hereinafter set forth. The shares of
Common Stock or other  securities or property  deliverable upon such exercise as
adjusted from time to time is hereinafter  sometimes referred to as the "WARRANT
SHARES." The exercise price of a share of Common Stock in effect at any time and
as adjusted from time to time is hereinafter  sometimes  referred to as the "PER
SHARE EXERCISE  PRICE." The Per Share Exercise Price is subject to adjustment as
hereinafter provided; in the event of any such adjustment, the number of Warrant
Shares shall be adjusted by dividing  the  Aggregate  Exercise  Price by the Per
Share Exercise Price in effect immediately after such adjustment.  The Aggregate
Exercise Price is not subject to adjustment.



<PAGE>

         1. EXERCISE OF WARRANT.

         (a) This Warrant may be  exercised in whole or in part,  at any time by
the Holder  commencing on the Initial Exercise Date and prior to the Termination
Date, by  presentation  and  surrender of this  Warrant,  together with the duly
executed  subscription form attached at the end hereof, at the address set forth
in subsection 8(a) hereof,  together with payment, by certified or official bank
check or wire  transfer  payable to the order of the Company,  of the  Aggregate
Exercise Price or the proportionate part thereof if exercised in part.

         (b) If this Warrant is exercised in part only, the Company shall,  upon
presentation of this Warrant upon such exercise, execute and deliver (along with
the certificate for the Warrant Shares  purchased) a new Warrant  evidencing the
rights of the  Holder  hereof to  purchase  the  balance of the  Warrant  Shares
purchasable  hereunder  upon the same terms and  conditions as herein set forth.
Upon  proper  exercise  of this  Warrant,  the Company  promptly  shall  deliver
certificates for the Warrant Shares to the Holder duly legended as authorized by
the subscription  form. No fractional  shares or scrip  representing  fractional
shares shall be issued upon exercise of this Warrant;  provided that the Company
shall pay to the holders of the Warrant cash in lieu of such fractional shares.

         2. RESERVATION OF WARRANT SHARES; FULLY PAID SHARES; TAXES. The Company
hereby  represents that it has, and until expiration of this Warrant agrees that
it shall,  reserve for issuance or delivery upon exercise of this Warrant,  such
number of shares of the Common Stock as shall be required  for  issuance  and/or
delivery  upon  exercise  of this  Warrant in full,  and agrees that all Warrant
Shares so  issued  and/or  delivered  will be  validly  issued,  fully  paid and
non-assessable,  and  further  agrees to pay all taxes and  charges  that may be
imposed upon such issuance and/or delivery.

         3. PROTECTION AGAINST DILUTION.

         (a) In the event the  Company  shall,  at any time or from time to time
after the date of issuance of this  Warrant,  issue or  distribute to all of the
holders of its shares of Common Stock  evidence of its  indebtedness,  any other
securities of the Company or any cash,  property or other assets (any such event
being herein called a "SPECIAL DIVIDEND"), the Per Share Exercise Price shall be
adjusted  by  multiplying  the Per  Share  Exercise  Price  then in  effect by a
fraction,  the  numerator  of which shall be the then  Current  Market Price (as
defined in paragraph  3(k) below) of the Common Stock,  less the Current  Market
Price of the Special  Dividend  issued or distributed in respect of one share of
Common Stock,  and the denominator of which shall be the Current Market Price of
the Common Stock.  Such adjustment  shall be made  successively  whenever such a
record  date  is  fixed.  Such  adjustment  shall  be  made  whenever  any  such
distribution  is made and shall become  effective  immediately  after the record
date for the determination of shareholders entitled to receive such distribution
unless such distribution is not ultimately made.

         (b) In case the Company  shall  hereafter  (i) pay a dividend or make a
distribution on its capital stock in shares of Common Stock,  (ii) subdivide its
outstanding  shares  of Common  Stock  into a greater  number of  shares,  (iii)
combine its outstanding shares of


                                        2

<PAGE>

Common Stock into a smaller  number of shares or (iv) issue by  reclassification
of its Common Stock any shares of capital  stock of the  Company,  the Per Share
Exercise  Price shall be adjusted to be equal to a fraction,  the  numerator  of
which shall be the Aggregate  Exercise Price and the  denominator of which shall
be the number of shares of Common  Stock or other  capital  stock of the Company
issuable upon exercise of this Warrant  assuming this Warrant had been exercised
immediately prior to such action. An adjustment made pursuant to this subsection
3(b) shall become effective  immediately  after the record date in the case of a
dividend  or  distribution  and shall  become  effective  immediately  after the
effective date in the case of a subdivision, combination or reclassification.

         (c)(i) Except as provided in subsections 3(a) and 3(b)(i), in the event
the Company  shall  hereafter  issue or sell any Common  Stock,  any  securities
convertible  into Common  Stock or any  rights,  options or warrants to purchase
Common Stock or securities  convertible  into Common  Stock,  in each case for a
price per share or entitling the holders  thereof to purchase  Common Stock at a
price per share  (determined by dividing (i) the total amount,  if any, received
or  receivable by the Company in  consideration  of the issuance or sale of such
securities plus the consideration,  if any, payable to the Company upon exercise
or conversion  thereof  (collectively,  the "TOTAL  CONSIDERATION")  by (ii) the
number of  additional  shares of Common  Stock  issued,  sold or  issuable  upon
exercise or conversion of such  securities)  which is less than the then Current
Market  Price of the Common  Stock (as defined  below) but not below the current
Per Share Exercise Price (which event is governed by subsection  3(c)(ii)),  the
Per Share  Exercise  Price shall be adjusted as of the date of such  issuance or
sale by  multiplying  the Per Share Exercise Price then in effect by a fraction,
the  numerator  of which  shall be (x) the sum of (A) the  number  of  shares of
Common Stock  outstanding  on the record date of such  issuance or sale plus (B)
the Total Consideration divided by the Current Market Price of the Common Stock,
and the  denominator  of which shall be (y) the number of shares of Common Stock
outstanding  on the record date of such issuance or sale plus the maximum number
of additional  shares of Common Stock issued,  sold or issuable upon exercise or
conversion of such securities.

         (ii) Except as provided in  subsection  3(a) and 3(b)(i),  in the event
the Company  shall  hereafter  issue or sell any Common  Stock,  any  securities
convertible  into Common  Stock or any  rights,  options or warrants to purchase
Common Stock or securities  convertible  into Common  Stock,  in each case for a
price per share or entitling the holders  thereof to purchase  Common Stock at a
price per share (the  "ISSUE  PRICE"),  (determined  by  dividing  (i) the Total
Consideration  by (ii) the number of additional  shares of Common Stock issuable
upon  exercise or  conversion  of such  securities)  which is less than the then
current Per Share  Exercise Price in effect on the record date of such issuance,
the Per Share Exercise Price shall be adjusted to equal the Issue Price.

         (d) In the event of any capital reorganization or reclassification,  or
any  consolidation or merger to which the Company is a party other than a merger
or consolidation in which the Company is the continuing corporation,  or in case
of any sale or conveyance to another entity of the property of the Company as an
entirety  or  substantially  as an  entirety,  or in the  case of any  statutory
exchange of securities with another corporation (including any exchange effected
in connection with a merger of a third corporation into the Company), the


                                        3

<PAGE>

Holder  of this  Warrant  shall  have the right  thereafter  to  receive  on the
exercise  of this  Warrant  the kind and  amount  of  securities,  cash or other
property  which the Holder  would have  owned or have been  entitled  to receive
immediately after such reorganization, reclassification,  consolidation, merger,
statutory  exchange,   sale  or  conveyance  had  this  Warrant  been  exercised
immediately   prior   to   the   effective   date   of   such    reorganization,
reclassification,  consolidation, merger, statutory exchange, sale or conveyance
and in any such case, if necessary,  appropriate adjustment shall be made in the
application  of the  provisions  set forth in this Section 3 with respect to the
rights and  interests  thereafter  of the Holder of this Warrant to the end that
the provisions set forth in this Section 3 shall thereafter  correspondingly  be
made  applicable,  as nearly as may  reasonably be, in relation to any shares of
stock or other securities or property thereafter  deliverable on the exercise of
this Warrant. The above provisions of this subsection 3(e) shall similarly apply
to  successive  reorganizations,  reclassifications,   consolidations,  mergers,
statutory exchanges, sales or conveyances.  The issuer of any shares of stock or
other  securities  or property  thereafter  deliverable  on the exercise of this
Warrant shall be responsible  for all of the  agreements and  obligations of the
Company  hereunder.   Notice  of  any  such  reorganization,   reclassification,
consolidation,  merger,  statutory  exchange,  sale  or  conveyance  and of said
provisions  so  proposed  to be made,  shall be  mailed  to the  Holders  of the
Warrants  not  less  than  30  days  prior  to  such  event.  A  sale  of all or
substantially  all of the assets of the Company for a  consideration  consisting
primarily  of  securities  shall be deemed a  consolidation  or  merger  for the
foregoing purposes.

         (e) In case any event shall occur as to which the other  provisions  of
this Section 3 are not strictly  applicable  but as to which the failure to make
any adjustment would not fairly protect the purchase rights  represented by this
Warrant in accordance with the essential  intent and principles  hereof then, in
each such case,  the  Holders of Warrants  representing  the right to purchase a
majority of the Warrant Shares subject to all outstanding Warrants may appoint a
firm  of  independent  public   accountants  of  recognized   national  standing
reasonably  acceptable to the Company,  which shall give their opinion as to the
adjustment,  if  any,  on a basis  consistent  with  the  essential  intent  and
principles  established  herein,  necessary  to  preserve  the  purchase  rights
represented  by the  Warrants.  Upon receipt of such  opinion,  the Company will
promptly  mail a copy  thereof to the Holder of this  Warrant and shall make the
adjustments  described therein. The fees and expenses of such independent public
accountants shall be borne by the Company.

         (f) Whenever the Per Share Exercise Price payable upon exercise of each
Warrant is adjusted  pursuant to this  Section 3, the number of shares of Common
Stock underlying a Warrant shall  simultaneously be adjusted to equal the number
obtained by dividing  the  Aggregate  Exercise  Price by the  adjusted Per Share
Exercise Price.

         (g) No  adjustment  in the Per Share  Exercise  Price shall be required
unless such  adjustment  would require an increase or decrease of at least $0.01
per share of Common Stock;  provided,  however,  that any  adjustments  which by
reason of this  subsection  3(g) are not  required  to be made  shall be carried
forward and taken into account in any subsequent  adjustment.  All  calculations
under this Section 3 shall be made to the nearest cent or to the nearest 1/100th
of a share,  as the case may be.  Anything  in this  Section  3 to the  contrary
notwithstanding,  the Company  shall be entitled to make such  reductions in the
Per Share


                                        4

<PAGE>

Exercise  Price,  in addition to those  required by this Section 3, as it in its
discretion  shall  deem to be  advisable  in  order  that  any  stock  dividend,
subdivision of shares or  distribution of rights to purchase stock or securities
convertible  or  exchangeable  for stock  hereafter  made by the  Company to its
stockholders shall not be taxable.

         (h)  Whenever the Per Share  Exercise  Price is adjusted as provided in
this Section 3 and upon any  modification  of the rights of a Holder of Warrants
in accordance  with this Section 3, the Company shall  promptly  obtain,  at its
expense, a certificate of a firm of independent public accountants of recognized
standing  selected by the Board of Directors (who may be the regular auditors of
the  Company)  setting  forth the Per  Share  Exercise  Price and the  number of
Warrant Shares after such adjustment or the effect of such modification, a brief
statement of the facts requiring such adjustment or modification  and the manner
of computing the same and cause copies of such  certificate  to be mailed to the
Holders of the Warrants.

         (i) If the Board of Directors of the Company shall declare any dividend
or other  distribution  with respect to the Common Stock, the Company shall mail
notice thereof to the Holders of the Warrants not less than 30 days prior to the
record date fixed for determining  stockholders  entitled to participate in such
dividend or other distribution.

         (j) If, as a result of an  adjustment  made pursuant to this Section 3,
the Holder of any Warrant  thereafter  surrendered  for  exercise  shall  become
entitled to receive  shares of two or more classes of capital stock or shares of
Common  Stock and other  capital  stock of the  Company,  the Board of Directors
(whose  determination  shall be  conclusive  and shall be described in a written
notice to the  Holder of any  Warrant  promptly  after  such  adjustment)  shall
determine  the  allocation of the adjusted Per Share  Exercise  Price between or
among  shares or such  classes  of capital  stock or shares of Common  Stock and
other capital stock.

         (k) For the purpose of any computation  under Section 3 above, the then
Current  Market Price per share (the "CURRENT  MARKET PRICE") shall be deemed to
be the last sale price of the Common Stock on the trading day prior to such date
or, in case no such  reported  sales take place on such day,  the average of the
last  reported  bid and asked  prices of the Common Stock on such day, in either
case on the principal national  securities exchange on which the Common Stock is
admitted  to trading or listed,  or if not listed or  admitted to trading on any
such  exchange,  the  representative  closing  bid price of the Common  Stock as
reported by the National  Association  of  Securities  Dealers,  Inc.  Automated
Quotations  System  ("NASDAQ"),  or other similar  organization  if NASDAQ is no
longer  reporting such  information,  or, if the Common Stock is not reported on
NASDAQ,   the  high  per  share  bid   price  for  the   Common   Stock  in  the
over-the-counter  market as reported by the National Quotation Bureau or similar
organization,  or if not so available, the fair market value of the Common Stock
as determined by agreement between the Company's Board of Directors,  on the one
part, and the Holders of Warrants  representing the right to purchase a majority
of the Warrant Shares subject to all outstanding  Warrants,  on the second part.
If the Board of Directors  and such Holders fail to agree on the Current  Market
Price  within 60 days of the date of the action  giving  rise to any  adjustment
pursuant to this Section 3, such Holders  shall be entitled to appoint a firm of
independent  public  accountants or appraisers of recognized  national  standing
reasonably acceptable to the Company,  which shall give their opinion as to such
Current Market Price on


                                        5

<PAGE>

a basis consistent with the essential intent and principles  established herein.
Upon receipt of such  opinion,  the Company will promptly mail a copy thereof to
the Holder of this Warrant and shall make the adjustments described therein. The
fees and expenses of such independent  public accountants or appraisers shall be
borne by the Company.

         4.  REGISTRATION  UNDER  SECURITIES  ACT OF  1933 . The  resale  of the
Warrant  Shares shall be  registered  on the Shelf  Registration  Statement  (as
defined  in  Article  8 of the  Securities  Purchase  Agreement  (the  "Purchase
Agreement") dated as of June 30, 1997, by and among the Company, The Aries Fund,
a Cayman Island Trust,  and The Aries  Domestic Fund,  L.P., a Delaware  limited
partnership)  and certain  purchasers  and the Holder of this Warrant shall have
the registration rights as provided in Article 8 of the Purchase  Agreement.  If
the  Holder is not a party to the  Purchase  Agreement,  by  acceptance  of this
Warrant the Holder agrees to comply with provisions of Article 8 of the Purchase
Agreement to the same extent as if it were a party thereto.

         5. LIMITED TRANSFERABILITY.  This Warrant may not be sold, transferred,
assigned or  hypothecated by the Holder except in compliance with the provisions
of the Securities Act of 1933 (the "Act") and the  applicable  state  securities
"blue sky" laws, and is so transferable only upon the books of the Company which
it shall  cause to be  maintained  for such  purpose.  The Company may treat the
registered  Holder of this Warrant as he or it appears on the Company's books at
any time as the Holder for all purposes.  The Company shall permit any Holder of
a Warrant or his duly authorized attorney,  upon written request during ordinary
business  hours, to inspect and copy or make extracts from its books showing the
registered  holders of  Warrants.  All  Warrants  issued  upon the  transfer  or
assignment of this Warrant will be dated the same date as this Warrant,  and all
rights of the holder thereof shall be identical to those of the Holder.

         6. LOSS, ETC., OF WARRANT. Upon receipt of evidence satisfactory to the
Company of the loss,  theft,  destruction or mutilation of this Warrant,  and of
indemnity reasonably  satisfactory to the Company, if lost, stolen or destroyed,
and upon surrender and cancellation of this Warrant,  if mutilated,  the Company
shall  execute and  deliver to the Holder a new Warrant of like date,  tenor and
denomination.

         7. STATUS OF HOLDER.  This  Warrant does not confer upon the Holder any
right  to vote or to  consent  to or  receive  notice  as a  stockholder  of the
Company, as such, in respect of any matters  whatsoever,  or any other rights or
liabilities as a stockholder, prior to the exercise hereof.

         8. NOTICES.  No notice or other  communication under this Warrant shall
be effective unless,  but any notice or other  communication  shall be effective
and shall be deemed to have been given if, the same is in writing  and is mailed
by first-class mail, postage prepaid, addressed to:

                    (a)  the   Company  at  840   Memorial   Drive,   Cambridge,
          Massachusetts,  Attention:  Stanley C. Erck,  or such other address as
          the Company has designated in writing to the Holder; or


                                        6

<PAGE>

                  (b)  the  Holder  at  the  address  indicated  in  the  notice
         provisions  to the  Purchase  Agreement,  or other such  address as the
         Holder has designated in writing to the Company.

         9.  OPTIONAL  CONVERSION.  This Warrant  shall be  converted  (the "New
Warrant  Conversion")  into a New  Warrant  (as  hereinafter  defined)  with  an
adjusted  exercise  price as set forth in this Section 9. "New  Warrants"  shall
mean a new class of warrants  entitling the holders thereof to purchase,  at any
time on or before  the date which is five (5) years  from the date  hereof,  one
share of Common Stock at an exercise price, subject to adjustment,  equal to the
lesser of (a) $.29 and (b) fifty percent (50%) of the average  closing bid price
of the Common  Stock for either (i) the thirty  (30)  consecutive  trading  days
preceding the date of the Required  Shareholder  Approval (the "Approval Date"),
if any, or  September  30,  1997,  (ii) the five (5)  consecutive  trading  days
preceding the Approval Date, if any, or September 30, 1997 or (iii) the five (5)
consecutive  trading days  immediately  succeeding the Approval Date, if any, or
September  30,  1997  whichever  is lowest.  Other  than the per share  exercise
prices, the New Warrants shall have the same terms as the Class A and B Warrants
held by such Holder respectively  (including,  without limitation,  an Aggregate
Exercise  Price equal to the Aggregate  Exercise Price of the sum of the Class A
and B Warrants  Aggregate  Exercise Prices prior to the New Warrant  Conversion)
and all adjustments required upon an adjustment to the exercise price of the New
Warrants  pursuant to the terms thereof shall be made in connection with the New
Warrant Conversion. To the extent that there is no Required Shareholder Approval
(as defined in the Purchase Agreement) necessary,  the Initial Warrants shall be
converted  into New Warrants on September  30, 1997,  with an adjusted  exercise
price equal to the lesser of (a) $.29 and (b) fifty percent (50%) of the average
closing bid price of the Common Stock for either (i) the thirty (30) consecutive
trading days preceding September 30, 1997, (ii) the five (5) consecutive trading
days preceding September 30, 1997 or (iii) the five (5) consecutive trading days
immediately succeeding September 30, 1997, whichever is lowest.

         Notwithstanding  the  foregoing,  the New Warrants' per share  exercise
price shall be adjusted  at the time of the Series B Final  Closing  Date or the
closing of the Company's next Qualified  Offering (as these terms are defined in
the Letter of Intent between the Company and Paramount  Capital Inc., dated June
30,  1997) if (i) the per share  exercise  price of the  Offering  Warrants  (as
defined below) or (ii) the quotient of (a) the price per unit sold in the Series
B Offering or other  Qualified  Offering  divided by (b) the  quantity of Common
Stock (or any  securities  other  than  Common  Stock  viewed on a Common  Stock
equivalent basis,  collectively,  the "Other Securities")  included in each unit
sold in such Series B Offering or other Qualified  Offering,  is less than twice
the per share exercise price of the New Warrants. In such event the New Warrants
per share  exercise  price shall be reduced to equal 50% of the then current per
share  exercise  price of the Offering  Warrants (as  hereafter  defined) or per
share  exercise or offering  price of the Other  Securities  (viewed on a Common
Stock equivalent basis).  "Offering  Warrants" shall mean the warrants described
in  paragraph 8 of the Letter of Intent  between the  Company the  Holders,  and
Paramount Capital, Inc. dated June 30, 1997.

         10.  HEADINGS.  The headings of this  Warrant  have been  inserted as a
matter of convenience and shall not affect the construction hereof.


                                        7

<PAGE>

         11.  APPLICABLE LAW. This Warrant shall be governed by and construed in
accordance  with the law of the  State  of New York  without  giving  effect  to
principles of conflicts of law thereof.

         IN WITNESS WHEREOF, the Company has caused this Warrant to be signed by
its President and its corporate seal to be hereunto  affixed and attested by its
Secretary this June 30, 1997.



                                      By: /s/ Stanley C. Erck
                                         -------------------------
                                             Name:  Stanley C. Erck
                                             Title: President


ATTEST:


/s/ Lynette C. Fallon
- ---------------------
      Secretary



[Corporate Seal]



                                        8

<PAGE>



                                  SUBSCRIPTION

                  The undersigned, ____________________________, pursuant to the
provisions  of the  foregoing  Warrant,  hereby  elects to  exercise  the within
Warrant to the extent of purchasing _____________________ shares of Common Stock
thereunder and hereby makes payment of $_______________ by certified or official
bank check in payment of the per share exercise price therefor.

Dated:                       Signature:
      ------------                     -----------------------------------

                             Address:
                                       -----------------------------------


                             ASSIGNMENT

                  FOR  VALUE  RECEIVED   _______________________________________
hereby sells,  assigns and transfers unto  _____________________________________
the foregoing  Warrant and all rights  evidenced  thereby,  and does irrevocably
constitute and appoint _____________________________, attorney, to transfer said
Warrant on the books of Procept, Inc.

Dated:                       Signature:
      ------------                     -----------------------------------

                             Address:
                                       -----------------------------------


                               PARTIAL ASSIGNMENT

                  FOR VALUE RECEIVED  __________________________  hereby assigns
and transfers unto  _________________________  the right to purchase  __________
shares of the Common Stock, no par value per share,  of Procept Inc.  covered by
the foregoing  Warrant,  and a proportionate part of said Warrant and the rights
evidenced    thereby,    and   does    irrevocably    constitute   and   appoint
__________________________,  attorney,  to transfer that part of said Warrant on
the books of Procept, Inc.


Dated:                       Signature:
      ------------                     -----------------------------------

                             Address:
                                       -----------------------------------



                                        9

<PAGE>
                                   EXHIBIT K

THESE  SECURITIES HAVE NOT BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933 OR
ANY APPLICABLE STATE  SECURITIES  LAWS. THEY MAY NOT BE SOLD,  OFFERED FOR SALE,
PLEDGED  OR  HYPOTHECATED   OR  OTHERWISE   TRANSFERRED  IN  THE  ABSENCE  OF  A
REGISTRATION  STATEMENT IN EFFECT WITH RESPECT TO THE SECURITIES  UNDER SUCH ACT
OR AN EXEMPTION  THEREFROM.  ANY SUCH TRANSFER MAY ALSO BE SUBJECT TO APPLICABLE
STATE SECURITIES LAWS.



                                  PROCEPT, INC.


                  Class B Warrant for the Purchase of Shares of
                                  Common Stock


No. CB-2                                                        4,941,386 Shares


                  FOR VALUE RECEIVED, PROCEPT, INC., a Delaware corporation (the
"COMPANY"),  hereby certifies that THE ARIES FUND, A CAYMAN ISLANDS TRUST or its
registered  assigns  (the  "Holder")  is entitled to purchase  from the Company,
subject  to the  provisions  of  this  Warrant  (the  "Warrant"),  at  any  time
commencing upon the date hereof (the "INITIAL EXERCISE DATE"), and prior to 5:00
P.M.,  New York City  time,  on the date  which is five (5) years  from the date
hereof (the  "TERMINATION  DATE"),  June 30, 2002 fully paid and  non-assessable
shares of the Common Stock, $.01 par value, of the Company ("Common Stock"),  at
an exercise price of $.5859 per share of Common Stock for an aggregate  exercise
price of TWO MILLION EIGHT-HUNDRED NINETY-FIVE THOUSAND ONE HUNDRED FIFTY-EIGHT
DOLLARS AND SIX CENTS  ($2,895,158.06) (the aggregate purchase price payable for
the  Warrant  Shares  hereunder  is  hereinafter  sometimes  referred  to as the
"AGGREGATE EXERCISE PRICE"). The number of shares of Common Stock to be received
upon  exercise of this Warrant and the price to be paid for each share of Common
Stock are subject to possible  adjustment  from time to time as hereinafter  set
forth.  The shares of Common Stock or other  securities or property  deliverable
upon  such  exercise  as  adjusted  from time to time is  hereinafter  sometimes
referred to as the "WARRANT  SHARES."  The  exercise  price of a share of Common
Stock in effect  at any time and as  adjusted  from time to time is  hereinafter
sometimes  referred to as the "PER SHARE EXERCISE PRICE." The Per Share Exercise
Price is subject to adjustment as hereinafter provided; in the event of any such
adjustment,  the number of Warrant  Shares  shall be adjusted  by  dividing  the
Aggregate  Exercise Price by the Per Share Exercise Price in effect  immediately
after  such  adjustment.   The  Aggregate  Exercise  Price  is  not  subject  to
adjustment.





<PAGE>



                  1.       EXERCISE OF WARRANT.

                  (a) This Warrant may be exercised in whole or in part,  at any
time by the Holder  commencing  on the  Initial  Exercise  Date and prior to the
Termination  Date, by presentation and surrender of this Warrant,  together with
the duly executed  subscription  form attached at the end hereof, at the address
set forth in subsection  8(a) hereof,  together  with  payment,  by certified or
official bank check or wire transfer payable to the order of the Company, of the
Aggregate Exercise Price or the proportionate part thereof if exercised in part.

                  (b) If this  Warrant is  exercised  in part only,  the Company
shall, upon presentation of this Warrant upon such exercise, execute and deliver
(along with the  certificate  for the Warrant  Shares  purchased)  a new Warrant
evidencing  the  rights of the  Holder  hereof to  purchase  the  balance of the
Warrant  Shares  purchasable  hereunder  upon the same terms and  conditions  as
herein set forth.  Upon proper  exercise of this Warrant,  the Company  promptly
shall deliver certificates for the Warrant Shares to the Holder duly legended as
authorized by the subscription  form. No fractional shares or scrip representing
fractional  shares shall be issued upon exercise of this Warrant;  provided that
the  Company  shall  pay to the  holders  of the  Warrant  cash  in lieu of such
fractional shares.

                  2.  RESERVATION OF WARRANT SHARES;  FULLY PAID SHARES;  TAXES.
The Company hereby  represents that it has, and until expiration of this Warrant
agrees that it shall,  reserve for  issuance or delivery  upon  exercise of this
Warrant,  such  number of shares of the Common  Stock as shall be  required  for
issuance  and/or delivery upon exercise of this Warrant in full, and agrees that
all Warrant Shares so issued and/or delivered will be validly issued, fully paid
and non-assessable,  and further agrees to pay all taxes and charges that may be
imposed upon such issuance and/or delivery.

                  3.  PROTECTION AGAINST DILUTION.

                  (a) In the event the Company  shall,  at any time or from time
to time after the date of issuance of this  Warrant,  issue or distribute to all
of the holders of its shares of Common Stock evidence of its  indebtedness,  any
other securities of the Company or any cash,  property or other assets (any such
event being herein called a "SPECIAL  DIVIDEND"),  the Per Share  Exercise Price
shall be adjusted by multiplying  the Per Share Exercise Price then in effect by
a fraction,  the  numerator of which shall be the then Current  Market Price (as
defined in paragraph  3(k) below) of the Common Stock,  less the Current  Market
Price of the Special  Dividend  issued or distributed in respect of one share of
Common Stock,  and the denominator of which shall be the Current Market Price of
the Common Stock.  Such adjustment  shall be made  successively  whenever such a
record  date  is  fixed.  Such  adjustment  shall  be  made  whenever  any  such
distribution  is made and shall become  effective  immediately  after the record
date for the determination of shareholders entitled to receive such distribution
unless such distribution is not ultimately made.

                  (b) In case the Company shall  hereafter (i) pay a dividend or
make a  distribution  on its  capital  stock in  shares of  Common  Stock,  (ii)
subdivide  its  outstanding  shares of  Common  Stock  into a greater  number of
shares, (iii) combine its outstanding shares of



                                        2

<PAGE>



Common Stock into a smaller  number of shares or (iv) issue by  reclassification
of its Common Stock any shares of capital  stock of the  Company,  the Per Share
Exercise  Price shall be adjusted to be equal to a fraction,  the  numerator  of
which shall be the Aggregate  Exercise Price and the  denominator of which shall
be the number of shares of Common  Stock or other  capital  stock of the Company
issuable upon exercise of this Warrant  assuming this Warrant had been exercised
immediately prior to such action. An adjustment made pursuant to this subsection
3(b) shall become effective  immediately  after the record date in the case of a
dividend  or  distribution  and shall  become  effective  immediately  after the
effective date in the case of a subdivision, combination or reclassification.

                  (c)(i) Except as provided in subsections 3(a) and 3(b)(i),  in
the event the  Company  shall  hereafter  issue or sell any  Common  Stock,  any
securities  convertible into Common Stock or any rights,  options or warrants to
purchase Common Stock or securities  convertible into Common Stock, in each case
for a price per share or entitling the holders  thereof to purchase Common Stock
at a price per share  (determined  by  dividing  (i) the total  amount,  if any,
received or receivable by the Company in  consideration  of the issuance or sale
of such securities plus the  consideration,  if any, payable to the Company upon
exercise or conversion thereof (collectively, the "TOTAL CONSIDERATION") by (ii)
the number of additional  shares of Common Stock  issued,  sold or issuable upon
exercise or conversion of such  securities)  which is less than the then Current
Market  Price of the Common  Stock (as defined  below) but not below the current
Per Share Exercise Price (which event is governed by subsection  3(c)(ii)),  the
Per Share  Exercise  Price shall be adjusted as of the date of such  issuance or
sale by  multiplying  the Per Share Exercise Price then in effect by a fraction,
the  numerator  of which  shall be (x) the sum of (A) the  number  of  shares of
Common Stock  outstanding  on the record date of such  issuance or sale plus (B)
the Total Consideration divided by the Current Market Price of the Common Stock,
and the  denominator  of which shall be (y) the number of shares of Common Stock
outstanding  on the record date of such issuance or sale plus the maximum number
of additional  shares of Common Stock issued,  sold or issuable upon exercise or
conversion of such securities.

                  (ii) Except as provided in subsection 3(a) and 3(b)(i), in the
event the Company shall hereafter issue or sell any Common Stock, any securities
convertible  into Common  Stock or any  rights,  options or warrants to purchase
Common Stock or securities  convertible  into Common  Stock,  in each case for a
price per share or entitling the holders  thereof to purchase  Common Stock at a
price per share (the  "ISSUE  PRICE"),  (determined  by  dividing  (i) the Total
Consideration  by (ii) the number of additional  shares of Common Stock issuable
upon  exercise or  conversion  of such  securities)  which is less than the then
current Per Share  Exercise Price in effect on the record date of such issuance,
the Per Share Exercise Price shall be adjusted to equal the Issue Price.

                  (d)  In  the   event   of  any   capital   reorganization   or
reclassification, or any consolidation or merger to which the Company is a party
other than a merger or  consolidation  in which the  Company  is the  continuing
corporation,  or in case of any sale or  conveyance  to  another  entity  of the
property of the Company as an entirety or  substantially  as an entirety,  or in
the case of any  statutory  exchange  of  securities  with  another  corporation
(including  any  exchange  effected  in  connection  with a  merger  of a  third
corporation into the Company), the



                                        3

<PAGE>



Holder  of this  Warrant  shall  have the right  thereafter  to  receive  on the
exercise  of this  Warrant  the kind and  amount  of  securities,  cash or other
property  which the Holder  would have  owned or have been  entitled  to receive
immediately after such reorganization, reclassification,  consolidation, merger,
statutory  exchange,   sale  or  conveyance  had  this  Warrant  been  exercised
immediately   prior   to   the   effective   date   of   such    reorganization,
reclassification,  consolidation, merger, statutory exchange, sale or conveyance
and in any such case, if necessary,  appropriate adjustment shall be made in the
application  of the  provisions  set forth in this Section 3 with respect to the
rights and  interests  thereafter  of the Holder of this Warrant to the end that
the provisions set forth in this Section 3 shall thereafter  correspondingly  be
made  applicable,  as nearly as may  reasonably be, in relation to any shares of
stock or other securities or property thereafter  deliverable on the exercise of
this Warrant. The above provisions of this subsection 3(e) shall similarly apply
to  successive  reorganizations,  reclassifications,   consolidations,  mergers,
statutory exchanges, sales or conveyances.  The issuer of any shares of stock or
other  securities  or property  thereafter  deliverable  on the exercise of this
Warrant shall be responsible  for all of the  agreements and  obligations of the
Company  hereunder.   Notice  of  any  such  reorganization,   reclassification,
consolidation,  merger,  statutory  exchange,  sale  or  conveyance  and of said
provisions  so  proposed  to be made,  shall be  mailed  to the  Holders  of the
Warrants  not  less  than  30  days  prior  to  such  event.  A  sale  of all or
substantially  all of the assets of the Company for a  consideration  consisting
primarily  of  securities  shall be deemed a  consolidation  or  merger  for the
foregoing purposes.

                  (e) In case  any  event  shall  occur as to  which  the  other
provisions  of this  Section 3 are not strictly  applicable  but as to which the
failure to make any  adjustment  would not fairly  protect the  purchase  rights
represented  by this  Warrant  in  accordance  with  the  essential  intent  and
principles hereof then, in each such case, the Holders of Warrants  representing
the  right  to  purchase  a  majority  of  the  Warrant  Shares  subject  to all
outstanding  Warrants may appoint a firm of  independent  public  accountants of
recognized national standing reasonably  acceptable to the Company,  which shall
give their opinion as to the adjustment,  if any, on a basis consistent with the
essential intent and principles  established  herein,  necessary to preserve the
purchase rights represented by the Warrants.  Upon receipt of such opinion,  the
Company  will  promptly  mail a copy  thereof to the Holder of this  Warrant and
shall make the  adjustments  described  therein.  The fees and  expenses of such
independent public accountants shall be borne by the Company.

                  (f)  Whenever  the  Per  Share  Exercise  Price  payable  upon
exercise of each  Warrant is adjusted  pursuant to this Section 3, the number of
shares of Common Stock underlying a Warrant shall  simultaneously be adjusted to
equal the number  obtained  by  dividing  the  Aggregate  Exercise  Price by the
adjusted Per Share Exercise Price.

                  (g) No  adjustment  in the Per Share  Exercise  Price shall be
required  unless  such  adjustment  would  require an increase or decrease of at
least $0.01 per share of Common Stock;  provided,  however, that any adjustments
which by reason of this  subsection  3(g) are not  required  to be made shall be
carried  forward  and taken  into  account  in any  subsequent  adjustment.  All
calculations  under this  Section 3 shall be made to the nearest  cent or to the
nearest  1/100th of a share,  as the case may be.  Anything in this Section 3 to
the  contrary  notwithstanding,  the  Company  shall be  entitled  to make  such
reductions in the Per Share



                                        4

<PAGE>



Exercise  Price,  in addition to those  required by this Section 3, as it in its
discretion  shall  deem to be  advisable  in  order  that  any  stock  dividend,
subdivision of shares or  distribution of rights to purchase stock or securities
convertible  or  exchangeable  for stock  hereafter  made by the  Company to its
stockholders shall not be taxable.

                  (h)  Whenever  the Per Share  Exercise  Price is  adjusted  as
provided in this Section 3 and upon any  modification  of the rights of a Holder
of Warrants  in  accordance  with this  Section 3, the  Company  shall  promptly
obtain,  at  its  expense,  a  certificate  of  a  firm  of  independent  public
accountants of recognized  standing  selected by the Board of Directors (who may
be the regular  auditors of the Company)  setting  forth the Per Share  Exercise
Price and the number of Warrant  Shares after such  adjustment  or the effect of
such  modification,  a brief statement of the facts requiring such adjustment or
modification  and the  manner of  computing  the same and  cause  copies of such
certificate to be mailed to the Holders of the Warrants.

                  (i) If the Board of Directors of the Company shall declare any
dividend or other  distribution  with respect to the Common  Stock,  the Company
shall mail notice  thereof to the Holders of the  Warrants not less than 30 days
prior  to the  record  date  fixed  for  determining  stockholders  entitled  to
participate in such dividend or other distribution.

                  (j) If, as a result of an  adjustment  made  pursuant  to this
Section 3, the Holder of any Warrant  thereafter  surrendered for exercise shall
become  entitled to receive  shares of two or more  classes of capital  stock or
shares of Common  Stock and other  capital  stock of the  Company,  the Board of
Directors (whose  determination  shall be conclusive and shall be described in a
written  notice to the Holder of any  Warrant  promptly  after such  adjustment)
shall  determine the allocation of the adjusted Per Share Exercise Price between
or among shares or such  classes of capital  stock or shares of Common Stock and
other capital stock.

                  (k) For the purpose of any computation  under Section 3 above,
the then Current  Market Price per share (the "CURRENT  MARKET  PRICE") shall be
deemed to be the last sale price of the Common Stock on the trading day prior to
such date or, in case no such reported sales take place on such day, the average
of the last  reported  bid and asked  prices of the Common Stock on such day, in
either case on the principal  national  securities  exchange on which the Common
Stock is admitted to trading or listed,  or if not listed or admitted to trading
on any such exchange,  the representative  closing bid price of the Common Stock
as reported by the National  Association of Securities  Dealers,  Inc. Automated
Quotations  System  ("NASDAQ"),  or other similar  organization  if NASDAQ is no
longer  reporting such  information,  or, if the Common Stock is not reported on
NASDAQ,   the  high  per  share  bid   price  for  the   Common   Stock  in  the
over-the-counter  market as reported by the National Quotation Bureau or similar
organization,  or if not so available, the fair market value of the Common Stock
as determined by agreement between the Company's Board of Directors,  on the one
part, and the Holders of Warrants  representing the right to purchase a majority
of the Warrant Shares subject to all outstanding  Warrants,  on the second part.
If the Board of Directors  and such Holders fail to agree on the Current  Market
Price  within 60 days of the date of the action  giving  rise to any  adjustment
pursuant to this Section 3, such Holders  shall be entitled to appoint a firm of
independent  public  accountants or appraisers of recognized  national  standing
reasonably acceptable to the Company,  which shall give their opinion as to such
Current Market Price on



                                        5

<PAGE>



a basis consistent with the essential intent and principles  established herein.
Upon receipt of such  opinion,  the Company will promptly mail a copy thereof to
the Holder of this Warrant and shall make the adjustments described therein. The
fees and expenses of such independent  public accountants or appraisers shall be
borne by the Company.

                  4.  REGISTRATION  UNDER SECURITIES ACT OF 1933 . The resale of
the Warrant Shares shall be registered on the Shelf  Registration  Statement (as
defined  in  Article  8 of the  Securities  Purchase  Agreement  (the  "Purchase
Agreement") dated as of June 30, 1997, by and among the Company, The Aries Fund,
a Cayman Island Trust,  and The Aries  Domestic Fund,  L.P., a Delaware  limited
partnership)  and certain  purchasers  and the Holder of this Warrant shall have
the registration rights as provided in Article 8 of the Purchase  Agreement.  If
the  Holder is not a party to the  Purchase  Agreement,  by  acceptance  of this
Warrant the Holder agrees to comply with provisions of Article 8 of the Purchase
Agreement to the same extent as if it were a party thereto.

                  5.  LIMITED  TRANSFERABILITY.  This  Warrant  may not be sold,
transferred,  assigned or  hypothecated  by the Holder except in compliance with
the  provisions  of the  Securities  Act of 1933 (the "Act") and the  applicable
state securities "blue sky" laws, and is so transferable  only upon the books of
the Company which it shall cause to be maintained for such purpose.  The Company
may treat the  registered  Holder of this  Warrant  as he or it  appears  on the
Company's  books at any time as the Holder for all  purposes.  The Company shall
permit any Holder of a Warrant or his duly  authorized  attorney,  upon  written
request during  ordinary  business  hours,  to inspect and copy or make extracts
from its books showing the registered  holders of Warrants.  All Warrants issued
upon the transfer or  assignment  of this Warrant will be dated the same date as
this Warrant,  and all rights of the holder  thereof shall be identical to those
of the Holder.

                  6.  LOSS,   ETC.,   OF  WARRANT.   Upon  receipt  of  evidence
satisfactory  to the Company of the loss,  theft,  destruction  or mutilation of
this Warrant, and of indemnity reasonably  satisfactory to the Company, if lost,
stolen or destroyed,  and upon surrender and  cancellation  of this Warrant,  if
mutilated,  the Company shall execute and deliver to the Holder a new Warrant of
like date, tenor and denomination.

                  7.  STATUS OF HOLDER.  This Warrant does not confer upon the 
Holder any right to vote or to consent to or receive  notice as a stockholder of
the Company, as such, in respect of any matters whatsoever,  or any other rights
or liabilities as a stockholder, prior to the exercise hereof.

                  8.  NOTICES.  No notice or other communication under this 
Warrant shall be effective unless, but any notice or other  communication  shall
be  effective  and shall be deemed to have been given if, the same is in writing
and is mailed by first-class mail, postage prepaid, addressed to:

                  (a) the Company at 840 Memorial Drive, Cambridge, 
         Massachusetts, Attention: Stanley C. Erck, or such other address as the
         Company has designated in writing to the Holder; or



                                        6

<PAGE>




                  (b)  the  Holder  at  the  address  indicated  in  the  notice
         provisions  to the  Purchase  Agreement,  or other such  address as the
         Holder has designated in writing to the Company.

                  9. OPTIONAL  CONVERSION.  This Warrant shall be converted (the
"New Warrant  Conversion")  into a New Warrant (as hereinafter  defined) with an
adjusted  exercise  price as set forth in this Section 9. "New  Warrants"  shall
mean a new class of warrants  entitling the holders thereof to purchase,  at any
time on or before  the date which is five (5) years  from the date  hereof,  one
share of Common Stock at an exercise price, subject to adjustment,  equal to the
lesser of (a) $.29 and (b) fifty percent (50%) of the average  closing bid price
of the Common  Stock for either (i) the thirty  (30)  consecutive  trading  days
preceding the date of the Required  Shareholder  Approval (the "Approval Date"),
if any, or  September  30,  1997,  (ii) the five (5)  consecutive  trading  days
preceding the Approval Date, if any, or September 30, 1997 or (iii) the five (5)
consecutive  trading days  immediately  succeeding the Approval Date, if any, or
September  30,  1997  whichever  is lowest.  Other  than the per share  exercise
prices, the New Warrants shall have the same terms as the Class A and B Warrants
held by such Holder respectively  (including,  without limitation,  an Aggregate
Exercise  Price equal to the Aggregate  Exercise Price of the sum of the Class A
and B Warrants  Aggregate  Exercise Prices prior to the New Warrant  Conversion)
and all adjustments required upon an adjustment to the exercise price of the New
Warrants  pursuant to the terms thereof shall be made in connection with the New
Warrant Conversion. To the extent that there is no Required Shareholder Approval
(as defined in the Purchase Agreement) necessary,  the Initial Warrants shall be
converted  into New Warrants on September  30, 1997,  with an adjusted  exercise
price equal to the lesser of (a) $.29 and (b) fifty percent (50%) of the average
closing bid price of the Common Stock for either (i) the thirty (30) consecutive
trading days preceding September 30, 1997, (ii) the five (5) consecutive trading
days preceding September 30, 1997 or (iii) the five (5) consecutive trading days
immediately succeeding September 30, 1997, whichever is lowest.

                  Notwithstanding  the  foregoing,  the New  Warrants' per share
exercise  price shall be adjusted at the time of the Series B Final Closing Date
or the closing of the  Company's  next  Qualified  Offering  (as these terms are
defined in the Letter of Intent between the Company and Paramount  Capital Inc.,
dated  June  30,  1997) if (i) the per  share  exercise  price  of the  Offering
Warrants (as defined  below) or (ii) the quotient of (a) the price per unit sold
in the Series B Offering or other Qualified Offering divided by (b) the quantity
of Common  Stock (or any  securities  other than Common Stock viewed on a Common
Stock equivalent basis,  collectively,  the "Other Securities") included in each
unit sold in such Series B Offering or other  Qualified  Offering,  is less than
twice the per share  exercise  price of the New Warrants.  In such event the New
Warrants  per share  exercise  price  shall be  reduced to equal 50% of the then
current per share exercise price of the Offering Warrants (as hereafter defined)
or per share  exercise or offering  price of the Other  Securities  (viewed on a
Common Stock  equivalent  basis).  "Offering  Warrants"  shall mean the warrants
described  in  paragraph  8 of the  Letter of Intent  between  the  Company  the
Holders, and Paramount Capital, Inc. dated June 30, 1997.

                  10. HEADINGS.  The headings of this Warrant have been inserted
as a matter of convenience and shall not affect the construction hereof.




                                        7

<PAGE>

                  11.      APPLICABLE LAW.  This Warrant shall be governed by 
and construed in accordance with the law of the State of New York without giving
effect to principles of conflicts of law thereof.

                  IN WITNESS WHEREOF,  the Company has caused this Warrant to be
signed by its  _______________________  and its  corporate  seal to be  hereunto
affixed and attested by its Secretary this June 30, 1997.


                                  PROCEPT, INC.



                                  By: /s/ Stanley C. Erck
                                      ------------------------------
                                         Name:  Stanley C. Erck
                                         Title: President


ATTEST:


/s/ Lynette C. Fallon
- --------------------
      Secretary



[Corporate Seal]




                                        8

<PAGE>



                                  SUBSCRIPTION

                  The undersigned, ____________________________, pursuant to the
provisions  of the  foregoing  Warrant,  hereby  elects to  exercise  the within
Warrant to the extent of purchasing _____________________ shares of Common Stock
thereunder and hereby makes payment of $_______________ by certified or official
bank check in payment of the per share exercise price therefor.

Dated:                              Signature:
      --------------                           ---------------------------

                                    Address:
                                               ---------------------------


                                   ASSIGNMENT

                  FOR  VALUE  RECEIVED   _______________________________________
hereby sells,  assigns and transfers unto  _____________________________________
the foregoing  Warrant and all rights  evidenced  thereby,  and does irrevocably
constitute and appoint _____________________________, attorney, to transfer said
Warrant on the books of Procept, Inc.


Dated:                              Signature:
      --------------                           ---------------------------

                                    Address:
                                               ---------------------------



                               PARTIAL ASSIGNMENT

                  FOR VALUE RECEIVED  __________________________  hereby assigns
and transfers unto  _________________________  the right to purchase  __________
shares of the Common Stock, no par value per share,  of Procept Inc.  covered by
the foregoing  Warrant,  and a proportionate part of said Warrant and the rights
evidenced    thereby,    and   does    irrevocably    constitute   and   appoint
__________________________,  attorney,  to transfer that part of said Warrant on
the books of Procept, Inc.


Dated:                              Signature:
      --------------                           ---------------------------

                                    Address:
                                               ---------------------------


                                        9

<PAGE>
                                   EXHIBIT L


                                                           June 29, 1997


VIA FACSIMILE
(617) 491-1521

Mr. Stanley C. Erck
President and Chief Executive Officer
Procept, Inc.
840 Memorial Drive
Cambridge, MA 02139

Dear Sirs:

                  Reference is made to our recent discussions  relating to (i) a
proposed  investment  (the "Series A  Transaction")  by the Aries Domestic Fund,
L.P. (the "Partnership") and The Aries Trust (the "Trust") in Procept, Inc. (the
"Company") and (ii) a proposed  offering (the "Offering") of units (the "Units")
of Series B Preferred  Stock and Warrants (the "Series B Offering") to be issued
by Procept,  Inc.  (the  "Company")  as  hereinafter  described.  Based upon our
discussions,   financial   materials   which  you  have   submitted  to  us  and
representations  which  you  have  made to us  describing  the  Company  and its
principals,  the present and proposed business activities of the Company and the
Company's operations and financial condition, we hereby confirm in principle our
interest in (i) the Series A Transaction and (ii) Paramount Capital, Inc. acting
as placement agent (the "Placement  Agent"),  on a "best efforts" basis, for the
Series B Offering, upon the following basic terms and conditions:

                  1.  (a) The  Company  shall  sell to the  Partnership  and the
Trust,  $3,000,000 of Units (the "Series A Units"), the Series A Unit consisting
in the aggregate of (a) 30,061 shares of Series A Preferred Stock,  stated value
$100.00  per share,  of the  Company  (also  referred to herein as the "Series A
Preferred  Stock")  and (b) in the  aggregate  2,742,696  Class A warrants  (the
"Class A  Warrants")  at an  exercise  price of $.01 and (c)  7,602,132  Class B
warrants  (the "Class B  Warrants")  at an  exercise  price equal to $.5859 (the
Class A Warrants and the Class B Warrants being collectively  referred to as the
"Initial Warrants").  The rights and preferences of the Series A Preferred Stock
are  substantially as set forth in Exhibit A hereto.  The Initial Warrants shall
include the terms described in paragraph 1(e) below.

                  (b)  The Series A Transaction shall be subject to the 
completion of necessary corporate and legal due diligence and the execution of 
definitive



                                        1

<PAGE>



documentation  satisfactory to the Aries Domestic Fund, L.P. (the "Partnership")
and The Aries Trust (the "Trust"), in their sole discretion.

                  (c) The date of the  closing of the  purchase  of the Series A
Preferred Stock (the "Series A Closing Date") shall occur no later than June 30,
1997.

                  (d) The Company (i) shall  amend its current  proxy  statement
(the  "Proxy  Statement")  by no later  than  July 3,  1997,  and (ii)  with the
assistance of a proxy  solicitor  acceptable  to the Trust and the  Partnership,
shall use best  efforts  to obtain  approval  of the  inclusion  of blank  check
Preferred  Stock in its Certificate of  Incorporation  by no later than July 15,
1997.  In the  event  that  the  Company  fails  to  obtain  approval  from  its
stockholders of the inclusion in the Company's  Charter of blank check Preferred
Stock in  connection  with the Proxy  Statement,  the Company  shall obtain such
approval as set forth in paragraph 1(e) below.

                  (e) In addition to the obligations set forth in paragraph 1(d)
above,  as soon as possible and, in any event, no later than September 30, 1997,
the  Company  shall hold a  shareholders  meeting  to obtain  (i) any  requisite
shareholder  approvals  (the  "Required  Shareholder  Approvals")  necessary  to
consummate the Series A Transaction and related  transactions as contemplated by
this Letter of Intent and (ii) approval of the Series A Preferred  Stock, to the
extent not  previously  approved in  connection  with the Proxy  Statement.  The
Company  shall,  as  promptly  as  possible,   engage  a  nationally  recognized
independent  investment  banking  firm  to  render  a  fairness  opinion  on the
transactions contemplated herein and in the Purchase Agreement and such fairness
opinion  shall be included in the proxy  statement  circulated by the Company to
its   shareholders  in  connection  with  obtaining  the  Required   Shareholder
Approvals.  "Required  Shareholder  Approvals"  shall  include,  at least to the
extent  required  by law or the Nasdaq  National  or  SmallCap  Market,  (x) any
approval required to the extent a change of control of the Company may be deemed
to occur,  (y) any  approval  that may be deemed to be  required in light of the
number, the voting rights, the price and any other terms of the securities being
issued by the Company, and (z) any approval that may be deemed to be required in
order to authorize any securities being issued by the Company.  Upon the receipt
of  the  Required  Shareholder  Approvals  or in the  event  that  the  Required
Shareholder  Approvals  are not  obtained by September  30,  1997,  each Initial
Warrant shall be converted  into a New Warrant (as  hereinafter  defined).  "New
Warrants"  shall mean a new class of warrants  entitling the holders  thereof to
purchase,  at any time over a five year  period one share of Common  Stock at an
exercise price equal to the lesser of (x) $.29 or (y) 50% of the average closing
bid price of the Common  Stock for either (i) the five (5)  consecutive  trading
days immediately  succeeding the date of the shareholder approval (the "Approval
Date") or September 30, 1997, or (ii) the thirty (30)  consecutive  trading days
immediately  preceding the Approval Date or September 30, 1997 or (iii) the five
(5)  consecutive  trading  days  immediately  preceding  the  Approval  Date  or
September 30, 1997,  whichever is lowest. In addition,  to the extent that there
are no shareholder  approvals required,  the Initial Warrants shall convert into
New  Warrants and the  exercise  price of the New Warrants  shall be adjusted to
equal the lesser of (x) $.29, (y) the Series



                                        2

<PAGE>



A Preferred  Conversion Price (as defined in Exhibit A hereto) or (z) 50% of the
average  closing  bid  price of the  Common  Stock for  either  (i) the five (5)
consecutive trading days immediately  succeeding September 30, 1997, or (ii) the
thirty (30) consecutive  trading days preceding  September 30, 1997 or (iii) the
five (5)  consecutive  trading days  immediately  preceding  September 30, 1997,
whichever is lowest.  Notwithstanding  the foregoing,  the exercise price of the
New Warrants is subject to an additional  one time reset  adjustment at the time
of the Series B Final  Closing  Date (as defined in  paragraph 3 below),  if the
exercise price of the Class C Warrants (as defined in paragraph 3 below) is less
than  twice  the  exercise  price of the New  Warrants.  In such  event  the New
Warrants  exercise price shall be reduced to equal a 50% discount to the Class C
Warrants exercise price.

                  (f) In  addition  to the  foregoing,  in the  event  that  the
Company fails to obtain  approval from its  stockholders of the inclusion in the
Company's  Charter of blank check  Preferred  Stock in connection with the Proxy
Statement  prior to June 30, 1997, the Series A Preferred  Stock included in the
Units shall be replaced by $200,000  principal  amount of 12% Convertible  Notes
and shares of the Company's  Common Stock (the "Alternate  Offering") (the terms
of the Initial and New Warrants  included in the Units shall remain as set forth
herein),  such Alternate  Offering to occur as set forth in accordance  with the
terms and  conditions  of, and such Notes and  shares of the  Company's  Company
stock to have the terms set forth in, the form of Securities  Purchase Agreement
attached as Exhibit B hereto  (including  any changes  that are  included in any
final execution copy of the Purchase Agreement) (the "Purchase Agreement").  The
holders of the Common  Stock  shall  have a put right  (the "Call  Right")  with
respect to the Series A Preferred Stock upon approval of the stockholders of the
Company  of the  inclusion  of blank  check or Series A  Preferred  Stock in the
Company's Certificate of Incorporation.

                  2. At any time  after  October  1, 1997,  in  addition  to the
Series A Transaction, subject to the completion of necessary corporate and legal
due  diligence (as to which the  Placement  Agent shall be the sole judge),  the
Placement Agent, at the Company's request,  shall serve as placement agent, on a
"best  efforts"  basis,  of a private  placement to  "accredited  investors"  as
defined in Regulation D promulgated under the Securities Act of 1933, as amended
(the  "Act") for the  purchase  of Units (the  "Series B Units") and the Company
will  sell  directly  to such  purchasers  a minimum  of 25 Series B Units  (the
"Minimum  Offering")  and  a  maximum  of  100  Series  B  Units  (the  "Maximum
Offering"),  with an  option in favor of the  Placement  Agent to offer up to an
additional 50 Series B Units to cover over-allotments. Each Unit will consist of
(a) 1,000 shares of Series B Preferred Stock, stated value $100.00 per share, of
the Company (also referred to herein as the "Series B Preferred  Stock") and (b)
333,333 Class C Warrants (the "Class C Warrants"). The rights and preferences of
the  Series  B  Preferred  Stock  are  substantially  the  same as the  Series A
Preferred Stock except that the initial  conversion  price of the Series B shall
be equal to the lesser of (a) the closing  bid price of the Common  Stock at the
time the Series B Offering is commenced  and (b) 75% of the average  closing bid
price of the Common  Stock for either (i) the thirty  (30)  consecutive  trading
days immediately preceding any



                                        3

<PAGE>



Series B closing date, or (ii) the five (5) consecutive trading days immediately
preceding  any  Series B closing  date,  whichever  is the  lowest.  Subject  to
restrictions on transferability under applicable securities laws, the components
of the Units will be immediately separable.

                  3. Subject to market and other  conditions  at the time of the
Series B  Offering  contemplated  herein,  the Series B Units will be offered at
$100,000 per Unit.

                  4. An escrow agent reasonably  acceptable to the Company shall
be designated by the Placement  Agent to hold  subscriptions  for the benefit of
customers  pending the closing of the Series B Offering.  The final closing date
of the Series B Offering will occur no later than sixty (60) days  following the
date of the offering  memorandum (the  "Memorandum")  for the Series B Offering,
subject to  extension  at the option of the  Placement  Agent for an  additional
sixty  (60)  days  (the  "Final  Closing   Date").   In  the  event  that  valid
subscriptions  for at least 25 Units are not received by the Final Closing Date,
subscriptions  will be released  from escrow and  returned  to  customers,  with
interest.  Upon receipt of the Minimum Offering amount,  the Placement Agent may
hold a closing (the "Initial  Closing") and may hold  subsequent  closings on an
interim basis until the Maximum  Offering amount  (including any  over-allotment
amount) has been reached or until the Series B Final Closing Date,  whichever is
earlier.

                  5. Pending completion or termination (pursuant to paragraph 10
below) of the  Offerings,  the  Company  agrees  that it will not,  directly  or
indirectly,  through  any  officer,  director,  agent  or  otherwise,  initiate,
solicit, encourage,  negotiate or discuss with any third party (including by way
of furnishing non-public  information  concerning the Company or its businesses,
assets or properties), or take any other action to facilitate any inquiries with
respect to the making of, any proposal  that  constitutes  or may  reasonably be
expected  to lead  to,  a  Competing  Transaction  provided,  however,  that the
foregoing  prohibitions  shall terminate either (x) on the date that is 210 days
after the Series A Closing  Date if the Company does not proceed with the Series
B  Offering  or (y) upon the Series B Final  Closing  Date if the  Company  does
proceed  with the Series B Offering.  For  purposes  hereof the term  "Competing
Transaction"  shall mean any proposal  with respect to (a) a possible  public or
private offering or placement of its securities, (b) a recapitalization,  merger
or other business  combination  involving the Company or any of its subsidiaries
or (c) the  acquisition  of a substantial  portion of the assets of the Company.
Notwithstanding the foregoing,  nothing shall prohibit the Board of Directors of
the Company from (i) furnishing  information to, or entering into discussions or
negotiations with, any person or entity that makes an unsolicited  proposal with
respect to a Competing  Transaction,  if, and only to the extent  that,  (A) the
Board of the Directors of the Company,  after  consultation  with and based upon
the written advice of independent  legal counsel,  determines in good faith that
such action is  necessary  for the Board of  Directors  of the Company to comply
with its fiduciary  duties to  stockholders  under  applicable  law, but only in
response  to  a  written,  bona  fide  proposal  with  respect  to  a  Competing
Transaction that the Board of Directors of the Company,  after consultation with
its



                                        4

<PAGE>



financial advisors,  determines is superior (including  financially superior) to
the  Company,  than the Series A  Transaction  and Series B Offering and related
transactions  (considered  together  as a  complete  transaction),  taking  into
account the ability of the party making such  proposal to finance such  proposal
and such  party's  ability to obtain any  required  regulatory  and third  party
approvals for such  Competing  Transaction  (a "Superior  Proposal") and (B) the
Company,  prior to furnishing such  information to, or entering into discussions
or  negotiations  with,  such  person  or  entity  (x)  provides  notice  to the
Partnership  and the  Trust  or the  Placement  Agent to the  effect  that it is
furnishing  information to, or entering into  discussions or negotiations  with,
such  person or entity and (y)  receives  from such person or entity an executed
confidentiality  agreement in reasonably  customary form; or (ii) complying with
its  obligations,  if any,  under  applicable  law to disclose the existence and
terms  of  any  proposal  for a  Competing  Transaction.  In  addition,  pending
completion  or  termination  (pursuant  to  paragraph  10 below) of the Series B
Offering,  the  Company  agrees  that it will not  dispose  of any assets of the
Company  (including,  without  limitation,   creating,  suffering  to  exist  or
permitting the imposition of any liens).

                  6. The Company  will,  as soon as  practicable,  but not later
than the  earlier  of (a) 30 days  after the  Series B Final  Closing  Date or a
Qualified  Offering  (as  defined  below)  and (b) 210 days  after the  Series A
Closing  Date  (each of (a) and/or (b)  referred  to herein as a "Filing  Target
Date"),  (i)  file a  shelf  registration  statement  (the  "Shelf  Registration
Statement")  with  respect  to (x) the  resale of the  shares  of  Common  Stock
issuable upon conversion of the Series A and Series B Preferred  Stock,  (y) the
Class C Warrants and (z) the shares of Common Stock  issuable  upon  exercise of
the Class A,  Class B and  Class C  Warrants  (including  the New  Warrants  (as
defined  in  paragraph  1(d)  hereof),  as  the  case  may  be)  (together,  the
"Registrable  Capital Stock") with the SEC and use its best efforts to have such
Shelf  Registration  Statement  declared  effective by the SEC prior to the date
which is 75 days  after  the  Series B Final  Closing  Date or other  applicable
Filing Target Date (subject to penalties for failure to effect such registration
in the time frames required) and (b) cause such Shelf Registration  Statement to
remain effective until such date as the holders of the securities have completed
the distribution  described in the Shelf Registration  Statement or at such time
that such shares are no longer,  by reason of Rule 144(k)  under the  Securities
Act,  required  to be  registered  for the  sale  thereof  by such  holders.  If
requested by the Trust,  the  Partnership  and/or the  Placement  Agent,  and in
accordance with applicable  securities  laws, the Shelf  Registration  Statement
shall cover the direct sale of such Registrable  Capital Stock to the holders of
such securities.  The Registrable  Capital Stock issued in any Series B Offering
(excluding any Registrable Capital Stock purchased by the Trust, the Partnership
or the  Placement  Agent in the  Series A  Transaction  and any other  shares of
capital  stock owned at any time by any of the  foregoing)  will be subject to a
staggered "lock-up" (the "Lock-Up") PURSUANT TO WHICH: (I) SEVENTY-FIVE  PERCENT
(75%) OF EACH HOLDER'S REGISTRABLE  SECURITIES SHALL BE SUBJECT TO A LOCK-UP FOR
THE FIRST THREE MONTHS  FOLLOWING THE EFFECTIVE DATE (THE  "EFFECTIVE  DATE") OF
THE SHELF  REGISTRATION  STATEMENT;  (II) FIFTY PERCENT (50%) OF SUCH SECURITIES
WILL BE SUBJECT TO SUCH A LOCK-UP UNTIL SIX MONTHS FOLLOWING THE EFFECTIVE DATE;
AND (III) THE REMAINING TWENTY-FIVE PERCENT (25%) OF SUCH



                                        5

<PAGE>



SECURITIES  WILL BE LOCKED-UP  UNTIL NINE MONTHS  FOLLOWING THE EFFECTIVE  DATE.
TWENTY- FIVE PERCENT (25%) OF THE REGISTRABLE  SECURITIES WILL NOT BE SUBJECT TO
ANY  LOCK-UP.  THE LOCK-UP MAY BE  MODIFIED  AS MAY BE DEEMED  ADVISABLE  BY THE
PLACEMENT  AGENT. A "QUALIFIED  OFFERING"  SHALL MEAN AN EQUITY  OFFERING (OTHER
THAN THE SERIES A TRANSACTION) OR SERIES OF EQUITY OFFERINGS WITH GROSS PROCEEDS
IN EXCESS OF $2,000,000 (A "QUALIFIED OFFERING").

                  7. The Placement Agent will receive cash commissions  equal to
9% of the  price of the  Units  issued  in the  Series  B  Offering  (the  "Cash
Commissions").  The  Placement  Agent  may,  in  its  discretion,  retain  other
placement  agents,  who  shall  be  members  in good  standing  of the  National
Association of Securities Dealers,  Inc. ("NASD"), to act as selected dealers in
placing  the Units.  Such other  placement  agents  will be  compensated  by the
Placement Agent out of its  commissions.  The Company has advised the Trust, the
Partnership  and the  Placement  Agent that no person is  entitled,  directly or
indirectly,  to  compensation or success fees from the Company for services as a
finder,  placement agent,  investment banker or otherwise in connection with the
proposed Offering or any other transaction contemplated by this Letter of Intent
except for  pre-existing  agreements  provided to the Trust and the  Partnership
prior to the date hereof.

                  8.  Each  Class C  Warrant  entitles  the  holder  thereof  to
purchase,  at any time over a five year  period one share of Common  Stock at an
exercise  price  equal to the  lesser  of (a) the  market  price at the time the
Series B Offering is commenced  and (b) 75% of the average  closing bid price of
the Common Stock for either (i) the thirty consecutive  trading days immediately
preceding  any  Series B  Offering  closing  date or (ii)  the five  consecutive
trading days immediately preceding any Series B Offering closing date, whichever
is the lowest. The Class C Warrant exercise price is subject to adjustment under
certain  customary  circumstances,   including,  without  limitation,  upon  the
occurrence of a merger, reorganization,  consolidation,  reclassification, stock
dividend  or stock  split  which will  result in an  increase or decrease in the
number of shares  of Common  Stock  outstanding  and upon  below  market  and/or
exercise price issuances.  The Class C Warrants are subject to redemption by the
Company  at $.01 per share for each share  subject  to each  Warrant on 60 days'
prior  written  notice,  provided  that the closing bid quotation for the Common
Stock as reported on the NASDAQ,  or on such  exchange on which the Common Stock
is then traded or listed,  exceeds 250% of the  exercise  price per share for 20
consecutive  trading  days ending  three days prior to the date of the notice of
redemption.  The Class C Warrants  are not  redeemable  on or prior to the first
anniversary  of their  issuance.  The  Company  will pay the  Placement  Agent a
commission  of 5% upon the  exercise  of any of the Class A,  Class B or Class C
Warrants.  The Placement Agent may allow a portion of this commission to members
in good  standing  of the NASD.  Any costs  incurred by the  Placement  Agent in
connection  with the  solicitation  of Warrant  exercises or the  redemption  of
Warrants shall be borne by the Company.

                  9.       Pending completion of each the Series A Transaction 
and Series



                                        6

<PAGE>



B Offering and for a 30 day period thereafter,  the Company will not issue press
releases or other  communication,  hold any press  conference or engage in other
publicity without obtaining the prior written consent of the Partnership and the
Trust or the Placement  Agent, as the case may be, except to the extent required
by law, the rules of the Nasdaq National or SmallCap  Markets or as necessary to
obtain the Required Shareholder Approvals.  The Company shall make a Rule 135(c)
(under  the  Securities  Act of  1933,  as  amended)  announcement  prior to the
commencement  of the  Series B  Offering.  During  the 36 months  following  the
closing of the Series A  Transaction,  the Company shall not,  without the prior
written  consent of the Partnership and the Trust or, to the extent such consent
right is not exercised by the  Partnership  or the Trust,  the Placement  Agent,
offer  or  sell  any  of its  securities  in  reliance  on  Regulation  S of the
Securities  Act of 1933,  as amended.  During the 24 month period  following the
earlier of (x) October 1, 1997 and (y) the closing of the Series B Offering, the
Placement  Agent shall have the right of first refusal to act as placement agent
for the private  offering of any  securities of the Company (such right of first
refusal shall have a standard twenty day notice  requirement,  pursuant to which
the Placement Agent shall have twenty days to determine whether or not it wishes
to exercise such right,  which notice  requirement will only be triggered in the
event that the  Company  has  received a bona fide offer from any third party to
serve as  placement  agent which it is willing to  accept).  During the 36 month
period  following  the  closing  of the  Series A  Transaction  (as  defined  in
paragraph 14 below),  the Company will not extend the  expiration  date or lower
the exercise or the  conversion  price of any options,  warrants or  convertible
securities,  without the prior written  consent of the Partnership and the Trust
or, to the extent such consent right is not exercised by the  Partnership or the
Trust,  the Placement  Agent.  During the 5 year period following the closing of
the Series A Transaction,  the Partnership and the Trust, or, to the extent such
right is not exercised by the  Partnership  or the Trust,  the Placement  Agent,
shall be entitled to designate  (the "Board  Right") a majority of the Directors
or observers to the Board of Directors of the Company provided, however, that to
the extent such right would  cause the  Company to violate  Rule  4460(i) of the
National Association  Securities  Dealers's  Marketplace Rules, the Partnership,
the Trust,  or the  Placement  Agent,  as the case may be,  shall not elect such
number of directors as would violate such rule until the earlier of (x) the date
of  approval  by the  holders of the  Company of the  transactions  contemplated
herein  and in the Letter of  Intent,  (y) the date that Rule  4460(i) no longer
applies to such  transactions  and (z) September 30, 1997.  Notwithstanding  the
foregoing,  the  Partnership  and the Trust or, to the extent  such right is not
exercised  by  the  Partnership  or  the  Trust,  the  Placement  Agent,   shall
immediately  and during the  entirety  of such 5 year  period  have the right to
appoint at least 3 designees to the Board of  Directors.  The Company  agrees to
nominate the Trust's,  the  Partnership's  and/or the Placement's  Agent's Board
designees  for  election to the Board of  Directors  and to use best  efforts to
ensure that such  nominees are elected to the Board.  The Company shall take all
action  necessary to limit the size of the Board of Directors to no greater than
7 members  or such  lesser or greater  amount as  designated  by the Trust,  the
Partnership  and/or the Placement  Agent.  The Company shall not use the name of
the  Placement  Agent,  the Trust,  the  Partnership  or any officer,  director,
employee or shareholder of the foregoing without the express



                                        7

<PAGE>



written consent of the Placement  Agent, the Trust, the Partnership and any such
person except to the extent  required by law as a result of  consummation of the
transactions  specifically  described herein, in which case any disclosure shall
still require prior written consent of each of the named persons however consent
to such use shall not be unreasonably withheld.

                  10. The Company  shall be  responsible  for and shall bear all
expenses  directly  and  necessarily  incurred in  connection  with the proposed
Series A  Transaction  and Series B Offering,  including  but not limited to the
costs of  preparing  and  printing  the  Memorandum  and all  exhibits  thereto;
preparing,   printing  and  delivering   exhibits  thereto  and  copies  of  the
preliminary, final and supplemental prospectus; the costs of preparing, printing
and filing with the  Securities  and Exchange  Commission  (the "SEC") the Shelf
Registration Statement and amendments, post-effective amendments and supplements
thereto;  preparing,  printing and delivering exhibits thereto and copies of the
preliminary,   final  and  supplemental  prospectus;   preparing,  printing  and
delivering  all selling  documents,  including  but not limited to the Placement
Agency  Agreement,   subscription  agreements,   warrant  agreements,  blue  sky
memorandum and stock and warrant  certificates;  blue sky fees,  filing fees and
legal fees and  disbursements  of blue sky counsel for the  offerings;  fees and
disbursements of the transfer and warrant agent; the cost of a total of two sets
of bound closing volumes for the Placement  Agent and its counsel;  and the cost
of three tombstone advertisements,  at least one of which shall be in a national
business  newspaper and one of which shall be in a major New York  newspaper (OR
AT THE PLACEMENT  AGENT'S  OPTION,  40 LUCITE DEAL  MEMENTOS)(COLLECTIVELY,  THE
"COMPANY   EXPENSES").   THE  COMPANY  SHALL  PAY  TO  THE  PLACEMENT   AGENT  A
NON-ACCOUNTABLE  EXPENSE  ALLOWANCE  EQUAL TO 4% OF THE  TOTAL  PROCEEDS  OF THE
SERIES B OFFERING  (THE "EXPENSE  ALLOWANCE")  TO COVER THE COST OF OUR MAILING,
TELEPHONE,  TELEGRAPH, TRAVEL, DUE DILIGENCE MEETINGS AND OTHER SIMILAR EXPENSES
INCLUDING  LEGAL FEES AND COSTS OF THE  PLACEMENT  AGENT'S  COUNSEL  (OTHER THAN
LEGAL FEES AND COSTS  INCURRED IN  CONNECTION  WITH BLUE SKY MATTERS AS TO WHICH
FEES,  AS SET FORTH ABOVE,  THE COMPANY SHALL BE  RESPONSIBLE)  OF WHICH $20,000
SHALL BE DUE AND PAYABLE UPON THE DATE THAT THE  MEMORANDUM IS COMPLETED  (WHICH
$20,000  PAYMENT  SHALL BE CREDITED TO THE COMPANY AND OFFSET  AGAINST THE TOTAL
EXPENSE  ALLOWANCE  DUE THE  PLACEMENT  AGENT IN  CONNECTION  WITH THE  SERIES B
OFFERING).  SUCH  PREPAID  EXPENSE  ALLOWANCE  SHALL BE  NON-REFUNDABLE.  IF THE
PROPOSED SERIES A TRANSACTION OR SERIES B OFFERING IS NOT COMPLETED  BECAUSE THE
COMPANY  PREVENTS  IT OR  BECAUSE OF A BREACH BY THE  COMPANY OF ANY  COVENANTS,
REPRESENTATIONS  OR WARRANTIES  CONTAINED  HEREIN,  THE COMPANY SHALL PAY TO THE
TRUST, THE PARTNERSHIP  AND/OR THE PLACEMENT AGENT, AS THE CASE MAY BE, A FEE OF
$100,000 (IN ADDITION TO THE COMPANY EXPENSES FOR WHICH THE COMPANY SHALL IN ALL
EVENTS  REMAIN  LIABLE).  IF,  AFTER THE  SERIES A CLOSING  DATE,  THE  REQUIRED
SHAREHOLDER  APPROVALS  ARE NOT OBTAINED BY SEPTEMBER  30, 1997 ON THE TERMS AND
CONDITIONS  CONTEMPLATED  HEREIN AND IN THE LETTER OF INTENT, OR IF THE REQUIRED
ADJUSTMENTS  TO THE SERIES A CONVERSION  PRICE OR THE  CONVERSION OF THE CLASS A
AND CLASS B WARRANTS INTO NEW WARRANTS HAS NOT BEEN APPROVED OR HAS NOT OCCURRED
OR, IN THE CASE OF THE ALTERNATE OFFERING,  THE APPROVAL ISSUANCE (AS DEFINED IN
THE PURCHASE  AGREEMENT)  HAS NOT BEEN APPROVED OR HAS NOT  OCCURRED,  OR IF THE
PARTNERSHIP, THE TRUST AND/OR THE PLACEMENT AGENT HAVE NOT



                                        8

<PAGE>



APPOINTED A MAJORITY OF THE COMPANY'S BOARD OF DIRECTORS, OR PURCHASERS HAVE NOT
ACQUIRED CAPITAL STOCK OF THE COMPANY REPRESENTING IN EXCESS IN THE AGGREGATE OF
51% OF THE TOTAL VOTING SHARES (AS DEFINED IN PARAGRAPH 14 HEREOF),  AS A RESULT
OF THE FAILURE OF THE COMPANY TO OBTAIN THE REQUIRED SHAREHOLDER APPROVAL OR FOR
ANY OTHER REASON, THEN, IN ADDITION TO ANY OTHER RIGHTS OF THE PARTNERSHIP,  THE
TRUST AND THE  PLACEMENT  AGENT OR  OBLIGATIONS  OF THE COMPANY  HEREUNDER,  THE
COMPANY  SHALL  PAY TO THE  PARTNERSHIP  AND  THE  TRUST A FEE OF  $500,000.  IN
ADDITION  TO AND  NOTWITHSTANDING  THE  FOREGOING,  WHETHER OR NOT THE  PROPOSED
FINANCINGS  ARE  COMPLETED  AND  IRRESPECTIVE  OF THE REASON  THAT THE  PROPOSED
FINANCINGS ARE NOT COMPLETED  (INCLUDING A DETERMINATION BY THE PLACEMENT AGENT,
THE TRUST AND/OR THE  PARTNERSHIP  NOT TO PROCEED WITH THE  TRANSACTION  FOR ANY
REASON) THE COMPANY SHALL BE RESPONSIBLE  FOR AND SHALL  REIMBURSE THE TRUST AND
THE  PARTNERSHIP  FOR ALL  COSTS  INCURRED  IN  CONNECTION  WITH  THE  SERIES  A
TRANSACTION AND THE  TRANSACTIONS  CONTEMPLATED  HEREWITH  (INCLUDING,  WITHOUT,
LIMITATION, ATTORNEY'S FEES, EXPENSES AND DISBURSEMENTS).

                  11.  UPON THE FINAL  CLOSING OF THE SALE OF THE SERIES B UNITS
BEING  OFFERED,  THE  COMPANY  WILL  GRANT TO THE  PLACEMENT  AGENT  AND/OR  ITS
DESIGNEES WARRANTS (THE "PLACEMENT WARRANTS") TO PURCHASE ADDITIONAL UNITS EQUAL
TO 10% OF THE UNITS SOLD IN EACH SUCH OFFERING  EXERCISABLE FOR A PERIOD OF FIVE
YEARS  COMMENCING  SIX MONTHS AFTER THE FINAL CLOSING DATE AT AN EXERCISE  PRICE
EQUAL  TO 110% OF THE  INITIAL  OFFERING  PRICE OF THE  UNITS  OR THE  QUALIFIED
OFFERING  PRICE,  AS THE CASE MAY BE. THE  SECURITIES  UNDERLYING  THE PLACEMENT
WARRANTS  WILL NOT BE SUBJECT  TO  MANDATORY  CONVERSION  OR  REDEMPTION  BY THE
COMPANY NOR WILL THEY BE CALLABLE BY THE COMPANY.  THE PLACEMENT WARRANTS CANNOT
BE TRANSFERRED,  SOLD,  ASSIGNED OR HYPOTHECATED FOR SIX MONTHS EXCEPT THAT THEY
MAY BE  ASSIGNED  IN WHOLE OR IN PART  DURING  SUCH  PERIOD  TO ANY NASD  MEMBER
PARTICIPATING  IN THE OFFERING OR ANY OFFICER OR EMPLOYEE OF THE PLACEMENT AGENT
OR ANY SUCH NASD MEMBER. THE PLACEMENT WARRANTS WILL CONTAIN A CASHLESS EXERCISE
FEATURE,  ANTIDILUTION  PROVISIONS  AND THE  RIGHT  TO HAVE  THE  RESALE  OF THE
SECURITIES  UNDERLYING THE PLACEMENT WARRANTS INCLUDED ON THE SHELF REGISTRATION
STATEMENT.

                  12. IF  REQUESTED  BY THE TRUST,  THE  PARTNERSHIP  AND/OR THE
PLACEMENT  AGENT, AS THE CASE MAY BE, THE COMPANY WILL OBTAIN FROM THE EXECUTIVE
OFFICERS, DIRECTORS AND 5% STOCKHOLDERS OF THE COMPANY, AN AGREEMENT THAT, FOR A
PERIOD OF UP TO TWENTY-FOUR  MONTHS FROM THE CLOSING OF THE SERIES A TRANSACTION
AND/OR  SERIES B OFFERING,  THEY WILL NOT SELL,  ASSIGN OR TRANSFER ANY OF THEIR
SHARES OF THE COMPANY'S  SECURITIES  WITHOUT THE PLACEMENT AGENT'S PRIOR WRITTEN
CONSENT.

                  13. THE CASH COMMISSIONS, EXPENSES ALLOWANCE AND PLACEMENT AND
ADVISORY  WARRANTS (AS DEFINED BELOW) AS SET FORTH IN THIS LETTER OF INTENT WILL
APPLY TO INVESTORS  INTRODUCED TO THE COMPANY BY THE PLACEMENT  AGENT WHO INVEST
IN THE COMPANY DURING THE TWELVE MONTHS  FOLLOWING THE FINAL CLOSING DATE OF THE
SERIES A TRANSACTION AND SERIES B OFFERING. IN ADDITION, UPON THE CLOSING OF THE
SERIES A  TRANSACTION,  THE COMPANY AND THE  PLACEMENT  AGENT WILL ENTER INTO AN
ENGAGEMENT  AGREEMENT WHEREBY PARAMOUNT WILL ACT AS THE COMPANY'S  NON-EXCLUSIVE
FINANCIAL  ADVISOR.  SUCH  ENGAGEMENT  AGREEMENT WILL PROVIDE THAT THE PLACEMENT
AGENT RECEIVE



                                        9

<PAGE>



A MONTHLY RETAINER OF $4,000 (MINIMUM ENGAGEMENT OF TWENTY-FOUR MONTHS), OUT-OF-
POCKET  EXPENSES AND CUSTOMARY CASH AND EQUITY  SUCCESS FEES. IN ADDITION,  UPON
COMPLETION  OF THE SERIES B OFFERING OR THE CLOSING OF A QUALIFIED  OFFERING AND
PURSUANT TO THE TERMS OF SUCH ENGAGEMENT AGREEMENT, THE COMPANY WILL SELL TO THE
PLACEMENT AGENT AND/OR ITS DESIGNEES, FOR $.001 PER WARRANT SHARE, WARRANTS (THE
"ADVISORY WARRANTS") TO PURCHASE ADDITIONAL UNITS EQUAL TO 15% OF THE UNITS SOLD
IN THE SERIES B OFFERING OR THE QUALIFIED  OFFERING  EXERCISABLE FOR A PERIOD OF
FIVE YEARS  COMMENCING  SIX MONTHS AFTER THE SERIES B FINAL  CLOSING DATE OR THE
QUALIFIED  OFFERING,  AT AN EXERCISE PRICE EQUAL TO 110% OF THE INITIAL OFFERING
PRICE OF THE SERIES B UNITS.  THE SECURITIES  UNDERLYING  THE ADVISORY  WARRANTS
WILL NOT BE SUBJECT TO MANDATORY  CONVERSION  OR  REDEMPTION  BY THE COMPANY NOR
WILL THEY BE CALLABLE BY THE  COMPANY.  THE  ADVISORY  WARRANTS  WILL  CONTAIN A
CASHLESS  EXERCISE  FEATURE,  ANTIDILUTION  PROVISIONS AND THE RIGHT TO HAVE THE
SECURITIES  UNDERLYING THE ADVISORY WARRANTS INCLUDED ON THE SHELF  REGISTRATION
STATEMENT.

                  14. THE COMPANY  SHALL NOT USE ANY PROCEEDS  FROM THE SERIES A
TRANSACTION OR SERIES B OFFERING TO REPURCHASE,  REDEEM OR OTHERWISE ACQUIRE ANY
SHARES OF  CAPITAL  STOCK OF THE  COMPANY  OR TO REPAY ANY  INDEBTEDNESS  OF THE
COMPANY,  INCLUDING  BUT NOT LIMITED TO ANY  INDEBTEDNESS  TO CURRENT  EXECUTIVE
OFFICERS,  EMPLOYEES,  DIRECTORS OR PRINCIPAL  STOCKHOLDERS OF THE COMPANY,  BUT
EXCLUDING  ACCOUNTS  PAYABLE  INCURRED  IN  THE  ORDINARY  COURSE  AND  PAID  IN
ACCORDANCE  WITH ROMAN NUMERAL (IV) BELOW,  WITHOUT THE PRIOR WRITTEN CONSENT OF
THE TRUST,  THE PARTNERSHIP  AND/OR  PLACEMENT  AGENT, AS THE CASE MAY BE. UNTIL
SUCH  TIME  AS THE  PLACEMENT  AGENT,  THE  PARTNERSHIP,  THE  TRUST  AND  THEIR
AFFILIATES,  IN THE  AGGREGATE,  OWN LESS  THAN FIVE  PERCENT  (5%) OF THE TOTAL
VOTING  SHARES OF THE  COMPANY'S  CAPITAL  STOCK  (TAKING  INTO  ACCOUNT  SHARES
ISSUABLE UPON CONVERSION OR EXERCISE OF SHARES HELD BY THEM),  THE PRIOR WRITTEN
CONSENT OF THE TRUST,  THE PARTNERSHIP  AND, TO THE EXTENT SUCH CONSENT RIGHT IS
NOT EXERCISED BY THE  PARTNERSHIP  OR THE TRUST,  THE PLACEMENT  AGENT,  WILL BE
REQUIRED  TO  APPROVE  (I)  THE  INCORPORATION  OF  ANY  SUBSIDIARY,   (II)  ANY
TRANSACTION BETWEEN THE COMPANY AND ITS AFFILIATES,  (III) THE INCURRENCE OF ANY
INDEBTEDNESS  BY THE COMPANY  (INCLUDING BUT NOT LIMITED TO ANY  INDEBTEDNESS TO
CURRENT EXECUTIVE OFFICERS,  EMPLOYEES,  DIRECTORS OR PRINCIPAL  STOCKHOLDERS OF
THE COMPANY,  BUT EXCLUDING ACCOUNTS PAYABLE INCURRED IN THE ORDINARY COURSE AND
PAID IN ACCORDANCE WITH ROMAN NUMERAL (IV) AS FOLLOWS IMMEDIATELY HEREAFTER) AND
(IV) PRIOR TO AUGUST 15, 1997,  ANY PAYMENTS BY THE COMPANY IN EXCESS OF $25,000
AND  THEREAFTER,  ANY  PAYMENTS BY THE COMPANY IN EXCESS OF $50,000.  THE "TOTAL
VOTING  SHARES"  SHALL  MEAN ALL  OUTSTANDING  SHARES  OF ANY  CLASS OR  CLASSES
(HOWEVER DESIGNATED) OF CAPITAL STOCK ENTITLED TO VOTE GENERALLY IN THE ELECTION
OF MEMBERS OF THE BOARD OF DIRECTORS.

                  15. (A) THE COMPANY  AGREES TO INDEMNIFY AND HOLD HARMLESS THE
PLACEMENT  AGENT AND EACH SELECTED  DEALER  SELECTED BY THE PLACEMENT  AGENT, IF
ANY, THE PARTNERSHIP AND THE TRUST AND THEIR  RESPECTIVE  PARTNERS,  AFFILIATES,
SHAREHOLDERS, DIRECTORS, OFFICERS, AGENTS, ADVISORS, REPRESENTATIVES, EMPLOYEES,
COUNSEL AND  CONTROLLING  PERSONS  WITHIN THE  MEANING OF THE ACT (A  "PARAMOUNT
INDEMNIFIED PARTY") AGAINST ANY AND ALL LOSSES, LIABILITIES, CLAIMS, DAMAGES AND
EXPENSES  WHATSOEVER  (AND ALL  ACTIONS IN  RESPECT  THEREOF),  AND TO  PROMPTLY
REIMBURSE ANY SUCH PARAMOUNT



                                       10

<PAGE>



INDEMNIFIED  PARTY FOR LEGAL FEES AND RELATED  EXPENSES AS INCURRED  (INCLUDING,
BUT NOT LIMITED TO THE COSTS OF GIVING  TESTIMONY  OR  FURNISHING  DOCUMENTS  IN
RESPONSE  TO A SUBPOENA OR  OTHERWISE,  THE COSTS OF  INVESTIGATING,  PREPARING,
PURSUING  OR  DEFENDING  ANY SUCH  ACTION OR CLAIM  WHETHER  OR NOT  PENDING  OR
THREATENED AND WHETHER OR NOT THE PLACEMENT  AGENT OR ANY PARAMOUNT  INDEMNIFIED
PARTY IS A PARTY THERETO), INSOFAR AS SUCH LOSSES, LIABILITIES,  CLAIMS, DAMAGES
OR EXPENSES  ARISE OUT OF, RELATE TO, ARE IN INCURRED IN CONNECTION  WITH OR ARE
IN ANY WAY A RESULT OF (I) THE  ENGAGEMENT  OF THE PLACEMENT  AGENT  PURSUANT TO
THIS LETTER OF INTENT, THE PLACEMENT AGENCY AGREEMENT,  ADVISORY  AGREEMENT,  OR
OTHER  OFFERING  DOCUMENTS  OR ANY  OF THE  TRANSACTIONS  CONTEMPLATED  BY  THIS
AGREEMENT AND THE OTHER  OFFERING  DOCUMENTS (THE  "ENGAGEMENT"),  INCLUDING ANY
MODIFICATIONS  OR FUTURE  ADDITIONS TO SUCH  ENGAGEMENT  AND RELATED  ACTIVITIES
PRIOR TO THE DATE HEREOF,  (II) ANY ACT BY THE PLACEMENT AGENT, THE PARTNERSHIP,
THE TRUST OR ANY OTHER PARAMOUNT  INDEMNIFIED PARTY TAKEN IN CONNECTION WITH THE
ENGAGEMENT  OR  THE  TRANSACTIONS   CONTEMPLATED   HEREIN  (INCLUDING,   WITHOUT
LIMITATION,  THE  PURCHASE  OF SERIES A UNITS,  THE  SHARES OF COMMON  STOCK AND
WARRANTS IN THE ALTERNATE  OFFERING OR THE EXERCISE OF BOARD RIGHTS AS CONTAINED
IN  PARAGRAPH  9  HEREIN),  (III)  A  BREACH  OF ANY  REPRESENTATION,  WARRANTY,
COVENANT,  OR AGREEMENT OF THE COMPANY  CONTAINED IN THIS LETTER OF INTENT,  THE
PLACEMENT AGENCY AGREEMENT,  THE PURCHASE  AGREEMENTS  BETWEEN THE COMPANY,  THE
PARTNERSHIP  AND THE  TRUST OR ANY OF THE  OTHER  OFFERING  DOCUMENTS,  (IV) THE
EMPLOYMENT BY THE COMPANY OF ANY DEVICE,  SCHEME OR ARTIFICE TO DEFRAUD,  OR THE
ENGAGING  BY THE  COMPANY  IN ANY ACT,  PRACTICE  OR  COURSE OF  BUSINESS  WHICH
OPERATES OR WOULD OPERATE AS A FRAUD OR DECEIT,  OR ANY CONSPIRACY  WITH RESPECT
THERETO,  IN CONNECTION WITH THE SALE OF THE UNITS, OR (V) ANY UNTRUE  STATEMENT
OR ALLEGED UNTRUE  STATEMENT OF A MATERIAL FACT CONTAINED IN ANY OF THE SERIES A
OR SERIES B OFFERING  DOCUMENTS OR THE OMISSION OR ALLEGED OMISSION THEREFROM OF
A MATERIAL FACT NECESSARY IN ORDER TO MAKE THE STATEMENTS  THEREIN,  IN LIGHT OF
THE CIRCUMSTANCES UNDER WHICH THEY WERE MADE, NOT MISLEADING;

                      (B) THE COMPANY AGREES TO INDEMNIFY AND HOLD HARMLESS A
PARAMOUNT  INDEMNIFIED PARTY TO THE SAME EXTENT AS THE FOREGOING INDEMNITY,  AND
SUBJECT  TO THE  LIMITATIONS  SET  FORTH  THEREIN,  AGAINST  ANY AND  ALL  LOSS,
LIABILITY,  CLAIM,  DAMAGE AND EXPENSE  WHATSOEVER  DIRECTLY  ARISING OUT OF THE
EXERCISE BY ANY PERSON OF ANY RIGHT UNDER THE SECURITIES ACT OR THE EXCHANGE ACT
OR THE  SECURITIES OR BLUE SKY LAWS OF ANY STATE ON ACCOUNT OF VIOLATIONS OF THE
REPRESENTATIONS,  WARRANTIES OR AGREEMENTS  SET FORTH HEREIN AND IN THE SERIES A
AND/OR SERIES B OFFERING DOCUMENTS.

                  16. IT IS CURRENTLY  INTENDED  THAT THE GENERAL TERMS OF A SIX
MONTH OPERATING PLAN ("OPERATING  PLAN") OF THE COMPANY SHALL BE AS SET FORTH IN
EXHIBIT C ATTACHED  HERETO.  THE  PARTIES  AGREE THAT THE  OPERATING  PLAN SHALL
REMAIN AT ALL TIMES  SUBJECT TO THE APPROVAL OF THE  PARTNERSHIP,  THE TRUST AND
THE PLACEMENT  AGENT,  AND THE DISCRETION AND BUSINESS  JUDGMENT OF THE BOARD OF
DIRECTORS AND, THAT THE PARTNERSHIP'S,  THE TRUST'S AND THE PLACEMENT'S  AGENT'S
INTENTION   REGARDING   SUCH  PLAN  MAY  CHANGE  FROM  TIME  TO  TIME  BASED  ON
CONSIDERATIONS RELATED TO AND AFFECTING THE COMPANY'S BUSINESS.

                  THE FOREGOING IS ONLY A BRIEF OUTLINE OF THE PROPOSED SERIES A
TRANSACTION



                                       11

<PAGE>



AND SERIES B OFFERING AND EACH OF THE FOREGOING TERMS MUST BE INTERPRETED IN THE
FORM  IN  WHICH  IT  FINALLY  APPEARS  IN THE  PROPOSED  DEFINITIVE  TRANSACTION
DOCUMENTS AND PLACEMENT AGENCY AGREEMENT AND RELATED DOCUMENTS RESPECTIVELY.  WE
WILL,  OF COURSE,  CONTINUE TO CONDUCT OUR DUE  DILIGENCE  INVESTIGATION  OF THE
COMPANY UNTIL THE SERIES A TRANSACTION  AND THE SERIES B OFFERING ARE COMPLETED,
AND SUCH DUE DILIGENCE  INVESTIGATION  SHALL,  IN ALL EVENTS,  BE SUBJECT TO OUR
SATISFACTION  AS TO WHICH WE SHALL BE THE SOLE JUDGE.  WHILE IT IS THE INTENTION
OF THE PARTIES HERETO THAT THE SERIES A TRANSACTION AND THE SERIES B OFFERING OF
THE  COMPANY'S  UNITS BE MADE,  THIS LETTER  CANNOT IN ANY WAY BE CONSTRUED AS A
COMMITMENT BY US TO COMPLETE THE SERIES A  TRANSACTION  OR SERIES B PLACEMENT OF
THE UNITS AND WE MAY, IN OUR SOLE  JUDGEMENT  AND  DISCRETION,  DETERMINE AT ANY
TIME NOT TO PROCEED WITH THE  TRANSACTIONS.  THIS LETTER SHALL BE CONDITIONED IN
ITS ENTIRETY  UPON THE EXECUTION  AND DELIVERY OF A  SATISFACTORY  (I) PLACEMENT
AGENCY  AGREEMENT  BETWEEN THE COMPANY AND THE PLACEMENT AGENT AND (II) PURCHASE
AGREEMENTS  BETWEEN THE COMPANY,  THE PARTNERSHIP AND THE TRUST (AND THIS LETTER
IS NOT TO BE CONSTRUED AS SUCH  CONTRACTS NOR AS AN AGREEMENT TO ENTER INTO SUCH
CONTRACTS)  TO BE  ENTERED  INTO  IMMEDIATELY  PRIOR TO THE TIME OF THE SERIES A
TRANSACTION  AND/OR  SERIES B OFFERING  AND SHALL BE  CONDITIONED  FURTHER  UPON
COMPLIANCE  BY THE COMPANY  WITH THE TERMS  CONTAINED IN THIS LETTER AND IN SUCH
PLACEMENT AGENCY AGREEMENT AND OTHER AGREEMENTS.  NOTWITHSTANDING THE FOREGOING,
THE  PROVISIONS  OF  PARAGRAPHS  5, 9,  10,  AND 15  HEREOF,  HOWEVER,  SHALL BE
EFFECTIVE AND BINDING UPON THE COMPANY UPON THE EXECUTION HEREOF.





                                       12

<PAGE>



                  IF THE FOREGOING CONFORMS TO YOUR UNDERSTANDING,  PLEASE SIGN,
DATE AND RETURN TO US THE ENCLOSED COPY OF THIS LETTER.

                                     VERY TRULY YOURS,

                                     PARAMOUNT CAPITAL, INC.


                                BY:   /s/ Lindsay A. Rosenwald, M.D.
                                    ------------------------------------
                                        LINDSAY A. ROSENWALD, M.D.
                                        CHAIRMAN

THE FOREGOING IS IN CONFORMITY
WITH OUR UNDERSTANDING:

PROCEPT, INC.


BY:   /s/ Stanley C. Erck
      ----------------------------------------------------
         STANLEY C. ERCK
         PRESIDENT AND CHIEF EXECUTIVE OFFICER


FOR PURPOSES OF PARAGRAPHS 1, 10, 14 AND 15 ONLY:

ARIES DOMESTIC FUND, L.P.


BY:   /s/ Lindsay A. Rosenwald, M.D.
      ----------------------------------------------------
         LINDSAY A. ROSENWALD, M.D.
         PRESIDENT, PARAMOUNT CAPITAL ASSET MANAGEMENT, INC.
         GENERAL PARTNER OF ARIES DOMESTIC FUND, L.P.


FOR PURPOSES OF PARAGRAPHS 1, 10, 14 AND 15 ONLY:

THE ARIES TRUST

BY:   /s/ Lindsay A. Rosenwald, M.D.
      ----------------------------------------------------
         LINDSAY A. ROSENWALD, M.D.
         PRESIDENT, PARAMOUNT CAPITAL ASSET MANAGEMENT, INC
         INVESTMENT ADVISER TO THE ARIES TRUST



                                       13

<PAGE>



                                                                       EXHIBIT A


              RIGHTS AND PREFERENCES OF SERIES A PREFERRED STOCK(TM)


SERIES A PREFERRED STOCK

The Company will file a Certificate of Designation  designating 30,000 shares of
Preferred  Stock as Series A Preferred  Stock (the "Series A Preferred  Stock").
Giving effect to completion of the Series A Transaction, 30,000 shares of Series
A Preferred  Stock will be fully paid,  validly issued and  non-assessable.  The
stated value per share of Series A Preferred Stock shall be $100.00.

                  VOTING

The holders of the Series A Preferred  Stock will have the right at all meetings
of the  stockholders  to that  number of votes  equal to the number of shares of
Common Stock issuable upon  conversion of such shares at the record date for the
determination  of the  stockholders  entitled to vote on such  matters or, if no
such record date is  established,  at the date such vote is taken.  As long as a
majority  of the shares of Series A  Preferred  Stock  remain  outstanding,  the
holders of 50% of the outstanding shares of the Series A Preferred Stock will be
entitled to (i) approve any securities issued by the Company which are senior to
or on parity with the Series A Preferred  Stock with respect to  liquidation  or
dividends  (other than the Series B  Preferred  Stock which shall be on parity),
(ii)  approve any  securities  issued by the  Company  which are senior to or on
parity with the Series A Preferred  Stock with respect to voting (except for (x)
class  voting  rights  required by law,  (y)  issuances  of Common Stock and (z)
issuances  of the Series B Preferred  Stock  which  shall be on  parity),  (iii)
approve any alteration or change to the rights, preferences or privileges of the
Series A Preferred Stock, or (iv) approve any  liquidation,  dissolution or sale
of all or substantially all of the assets of the Company.

                  DIVIDENDS

The  holders  of the  Series A  Preferred  Stock  shall be  entitled  to receive
dividends  as,  when and if  declared  by the  Board of  Directors  out of funds
legally  available  therefor.  No dividend or distribution,  as the case may be,
shall be  declared  or paid on any junior  stock  unless the same is paid to the
Series A  Preferred  Stock.  In  addition,  following  the Reset Date as defined
below,  the  Preferred  Stock  will  be  entitled  to a  cumulative,  compounded
payment-in-kind dividend of 10% per annum, which shall accrue on a monthly basis
and be payable annually or at such time that the Preferred Stock is converted by
any holder.

                  LIQUIDATION

Upon (i) a  liquidation,  dissolution,  or  winding up of the  Company,  whether
voluntary  or  involuntary  or  (ii)  a  sale  or  other  disposition  of all or
substantially all of the assets


<PAGE>


                                                                              ii

of the Company (a "Liquidation  Event"),  after payment or provision for payment
of the debts and other  liabilities of the Company,  the holders of the Series A
Preferred Stock then outstanding will first be entitled to receive, pro rata (on
the  basis of the  number  of  shares  of the  Series  A  Preferred  Stock  then
outstanding),  on a pari passu basis with the shares of Series B Preferred Stock
and in  preference  to the holders of the Common  Stock and any series of junior
preferred  stock,  an amount  per share  equal to $14 plus  accrued  but  unpaid
dividends,  if any. Mergers and similar events in which a majority of the voting
control of the Company's  capital stock is transferred will be treated similarly
with respect to the merger consideration.

                  CONVERSION

The Series A Preferred  Stock will be converted  into Common Stock at an initial
conversion  price,  subject to adjustment  as set forth below,  equal to $.46875
(the "Series A Preferred Conversion Price"),  representing an initial conversion
rate of 213.333333 per share. Upon the earlier of the Approval Date or September
30, 1997,  the Series A Preferred  Conversion  Price shall be reset to equal the
lesser of (i) $.29 and (ii) 50% of the  average  closing bid price of the Common
Stock  for  either  (i)  the  five  (5)  consecutive  trading  days  immediately
succeeding the date of shareholder  approval (the "Approval  Date") or September
30,  1997,  or (ii) the thirty  (30)  consecutive  trading  days  preceding  the
Approval  Date or September 30, 1997 or (iii) the five (5)  consecutive  trading
days immediately preceding the Approval Date or September 30, 1997, whichever is
lowest.  In  addition,  to the extent  that there are no  shareholder  approvals
required,  the Series A Preferred  Conversion  Price shall be reset to equal the
lesser of (x) $.29 or (y) 50% of the  average  closing  bid price of the  Common
Stock  for  either  (i) the  thirty  (30)  consecutive  trading  days  preceding
September  30, 1997,  or (ii) the five (5)  consecutive  trading days  preceding
September 30, 1997 or (iii) the five (5)  consecutive  trading days  immediately
succeeding September 30, 1997, whichever is lowest.

If,  upon any of the  closings of the Series B Offering  or the  Company's  next
Qualified  Offering,  the  resulting  Series  B  Preferred  Conversion  Price or
effective price per share of Common Stock  ("Qualified  Offering  Price") of the
Company in such  Qualified  Offering  is less then twice the Series A  Preferred
Conversion Price at such time, the Series A Preferred  Conversion Price shall be
reset at such time to equal  fifty  (50%) of such  resulting  Series B Preferred
Conversion Price or Qualified Offering Price.

The Series A Preferred Stock may be converted at the option of the holder at any
time after the initial  issuance date of the Series A Preferred  Stock for fully
paid  nonassessable  shares of Common Stock.  The Series A Preferred  Conversion
Price is subject to adjustment upon the occurrence of a merger,  reorganization,
consolidation, reclassification, stock dividend or stock split which will result
in an increase or decrease in the number of shares of Common  Stock  outstanding
and upon below market and/or exercise price issuances.




<PAGE>


                                                                             iii


In addition,  the conversion price in effect  immediately prior to the date that
is 12 months  after the Series A Final  Closing Date (the "Series A Reset Date")
will be  adjusted  and  reset  effective  as of the  Series A Reset  Date if the
average closing price for the 20 consecutive trading days immediately  preceding
the Series A Reset Date (the "12-Month  Trading Price") is less than 140% of the
then applicable Series A Preferred  Conversion Price (a "Series A Reset Event").
Upon the  occurrence  of a Series A Reset Event,  the then  applicable  Series A
Preferred Conversion Price will be reduced to be equal to the greater of (i) the
12-Month Trading Price divided by 1.4 and (ii) 25% of the then applicable Series
A Preferred Conversion Price.

The Series A Preferred  Conversion  Price will  similarly be reset in connection
with any  Series B Reset  Event in  accordance  with the  terms of the  Series B
Preferred Stock.

                  MANDATORY CONVERSION

Unless converted earlier, the Company has the right at any time after the Series
A Reset Date to cause the Series A Preferred Stock to be converted,  in whole or
in part,  on a pro rata  basis,  into  shares of Common  Stock on 60 days' prior
written notice,  provided that the closing bid quotation for the Common Stock as
reported on the NASDAQ,  or on such  exchange on which the Common  Stock is then
traded or listed, exceeds 300% of the Series A Preferred Conversion Price for 20
consecutive  trading  days ending  three days prior to the date of the notice of
mandatory conversion.

                  SERIES A PREFERRED STOCK REPURCHASE

In the event that the Required  Shareholder Approval (as defined in Section 1 of
the Letter of Intent) is not  obtained  by  September  30,  1997 (the  "Required
Approval Date") of the Series A Final Closing Date, the holders of a majority of
the  outstanding  shares  of  Series  A  Preferred  Stock  may,  by vote of such
majority,  immediately  elect to require the Company to repurchase  the Series A
Preferred Stock at $14 per share (the "Repurchase Election").  In the event that
the Company  fails to  repurchase  such shares within three days of a Repurchase
Election,  the Series A Preferred Stock shall, at the option of the holders of a
majority of the  outstanding  shares of Series A Preferred  Stock,  be converted
into a senior  secured  convertible  note in amount  equal to the  extent of the
repurchase  obligation,  with the Series A Preferred  Stock holders  obtaining a
first priority  perfected security interest for such amount in all of the assets
of the Company. Notwithstanding the previous sentence, at any time after receipt
by the  Company of a  Repurchase  Election,  the  Company  shall at all times be
obligated to repurchase,  on a pro rata basis,  the shares of Series A Preferred
Stock required to be  repurchased,  to the extent that it has available funds to
do so.


<PAGE>
                                   EXHIBIT M

                           CERTIFICATE OF DESIGNATION

                                       for

                      SERIES A CONVERTIBLE PREFERRED STOCK

                                       of

                                  PROCEPT, INC.

                         Pursuant to Section 151 of the
                General Corporation Law of the State of Delaware


                  PROCEPT,  INC., a corporation organized and existing under the
laws of the State of Delaware  (the  "Corporation"),  does hereby  certify that,
pursuant to the authority conferred on the board of directors of the Corporation
(the "Board of Directors")  by the Restated  Certificate  of  Incorporation,  as
amended to date (the "Certificate of Incorporation"),  of the Corporation and in
accordance  with  Section  151 of the  General  Corporation  Law of the State of
Delaware, the Board of Directors adopted the following resolution establishing a
series of 30,061  shares of Preferred  Stock of the  Corporation  designated  as
"Series A Convertible Preferred Stock":

                  RESOLVED,  that  pursuant to the  authority  conferred  on the
         Board of Directors by the  Certificate  of  Incorporation,  a series of
         Preferred Stock, par value $.01 per share, of the Corporation is hereby
         established and created,  and that the designation and number of shares
         thereof  and the  voting and other  powers,  preferences  and  relative
         participating,  optional or other special rights of, the shares of such
         series and the qualifications, limitations and restrictions thereof are
         as follows:

                      Series A Convertible Preferred Stock

         I.       Designation and Amount and Definitions.

                  A. There shall be a series of Preferred  Stock  designated  as
"Series A  Convertible  Preferred  Stock" and the number of shares  constituting
such series shall be 30,061.  Such series is referred to herein as the "Series A
Preferred  Stock."  Such  number of shares  may be  increased  or  decreased  by
resolution of the Board of Directors;  provided, however, that no decrease shall
reduce the number of shares of Series A Preferred Stock to fewer than the number
of shares then issued and outstanding.


<PAGE>


                  B. As used in this  Certificate of Designation,  the following
terms shall have the following meanings:

                        1. The  "Closing  Bid Price" for any  security  for each
                  trading day shall be the reported per share  closing bid price
                  of such  security  regular  way on the  Stock  Market  on such
                  trading day, or, if there were no transactions on such trading
                  day, the average of the reported closing bid and asked prices,
                  regular way, of such security on the relevant  Stock Market on
                  such trading day.

                        2.  "Fair  Market  Value"  of any asset  (including  any
                  security)  means the fair  market  value  thereof as  mutually
                  determined by the Corporation and the holders of a majority of
                  the  Series  A  Preferred  Stock  then  outstanding.   If  the
                  Corporation  and the  holders  of a  majority  of the Series A
                  Preferred Stock then outstanding are unable to reach agreement
                  on any valuation matter,  such valuation shall be submitted to
                  and   determined  by  a  nationally   recognized   independent
                  investment  bank  selected by the Board of  Directors  and the
                  holders of a majority  of the  Series A  Preferred  Stock then
                  outstanding  (or,  if such  selection  cannot be  agreed  upon
                  promptly, or in any event within ten days, then such valuation
                  shall  be  made  by  a   nationally   recognized   independent
                  investment  banking firm selected by the American  Arbitration
                  Association  in New York City in  accordance  with its rules),
                  the  costs  of  which  valuation  shall  be  paid  for  by the
                  Corporation.

                        3.  "Market  Price"  shall mean the average  Closing Bid
                  Price for twenty (20)  consecutive  trading days,  ending with
                  the trading day prior to the date as of which the Market Price
                  is  being   determined  (with   appropriate   adjustments  for
                  subdivisions  or  combinations  of shares effected during such
                  period),  provided  that  if  the  prices  referred  to in the
                  definition of Closing Bid Price cannot be determined  for such
                  period, "Market Price" shall mean Fair Market Value.

                        4.  "Registered  Holders"  shall mean, at any time,  the
                  holders of record of the Series A Preferred Stock.

                        5. The "Stock  Market"  shall mean,  with respect to any
                  security,  the principal national securities exchange on which
                  such  security  is listed or  admitted  to trading or, if such
                  security is not listed or admitted to trading on any  national
                  securities  exchange,  shall mean The Nasdaq  National  Market
                  System  ("NNM")  or The Nasdaq  SmallCap  Market  ("SCM"  and,
                  together  with  NNM,  "Nasdaq")  or, if such  security  is not
                  quoted on  Nasdaq,  shall mean the OTC  Bulletin  Board or, if
                  such security is not quoted on the OTC Bulletin  Board,  shall
                  mean the  over-the-counter  market  as  furnished  by any NASD
                  member firm selected from time to time by the  Corporation for
                  that purpose.


                                       -2-


<PAGE>

                        6.  A  "trading  day"  shall  mean a day  on  which  the
                  relevant Stock Market is open for the transaction of business.

                        7.  "Trading  Price"  shall  mean  the  lower of (i) the
                  average   Closing   Bid  Price  of  the  Common   Stock  (with
                  appropriate  adjustments  for  subdivisions or combinations of
                  shares  effected  during  such  period)  for the  thirty  (30)
                  consecutive trading days immediately  preceding the date as of
                  which the Trading Price is being determined,  (ii) the average
                  Closing  Bid  Price  of the  Common  Stock  (with  appropriate
                  adjustments   for   subdivisions  or  combinations  of  shares
                  effected during such period) for five (5) consecutive  trading
                  days,  immediately  preceding the date as of which the Trading
                  Price is being  determined,  and (iii) the average Closing Bid
                  Price of the Common Stock (with  appropriate  adjustments  for
                  subdivisions  or  combinations  of shares effected during such
                  period) for five (5)  consecutive  trading  days,  immediately
                  succeeding  the date as of which  the  Trading  Price is being
                  determined,  provided  that if the prices  referred  to in the
                  definition of Closing Bid Price cannot be  determined  for any
                  of such periods, "Trading Price" shall mean Fair Market Value.

         II.      Dividends and Distributions.

                  A.  Commencing  on the Reset Date (as  defined  in  Subsection
4(a)),  the holders of the Series A Preferred Stock shall be entitled to receive
cumulative  dividends on each share of Series A Preferred  Stock, at the rate of
10% per annum  (computed on the basis of a 360-day year of twelve 30 day months)
of the Dividend Base Amount (as defined below),  payable  annually in arrears or
at such time as the  conversion  of, and with respect to, any shares of Series A
Preferred Stock that are converted.  Such dividends shall be paid in cash, or at
the option of the Company,  in kind,  with duly  authorized,  fully paid and non
assessable  shares of Series A Preferred  Stock.  Such  dividends  shall  accrue
monthly and accumulate whether or not they have been declared and whether or not
there are profits,  surplus or other funds of the Corporation  legally available
for the payment of dividends.  The "Dividend  Base Amount" shall be $140.00 plus
all accrued but unpaid dividends  (subject to appropriate  adjustment to reflect
any stock split, combination, reclassification or reorganization of the Series A
Preferred Stock).

                  B. In addition to the foregoing,  subject to the rights of the
holders of any shares of any series or class of capital stock ranking prior, and
superior  to, or pari passu with,  the shares of Series A  Preferred  Stock with
respect to dividends, the holders of shares of Series A Preferred Stock shall be
entitled to receive, as, when and if declared by the Board of Directors,  out of
assets legally  available for that purpose,  dividends or distributions in cash,
stock or otherwise.

                  C.  The   Corporation   shall  not  declare  any  dividend  or
distribution  on any Junior Stock (as defined below) of the  Corporation  unless
and until a special  dividend or  distribution  of $140.00 per share (subject to
appropriate adjustment to reflect any stock split,


                                       -3-


<PAGE>

combination, reclassification or reorganization of the Series A Preferred Stock)
has been  declared and paid on the Series A Preferred  Stock.  In the event that
such  special  dividend or  distribution  is  declared  and paid on the Series A
Preferred  Stock, an aggregate per share dividend or  distribution  equal to (i)
$140.00 divided by (ii) the effective  Conversion Rate (as defined below) at the
time of such special  dividend or  distribution  on the Series A Preferred Stock
may be  declared  and  paid  on the  Common  Stock.  Except  as  aforesaid,  the
Corporation  shall not declare any dividend or  distribution on any Junior Stock
or stock on a parity with the Series A Preferred  Stock,  unless the Corporation
shall, concurrently with the declaration of such dividend or distribution on the
Junior Stock or stock on a parity with the Series A Preferred  Stock,  declare a
like  dividend  or  distribution,  as the case may be, on the Series A Preferred
Stock.

                  D. Any dividend or distribution (other than that referenced in
the first  sentence of Subsection  II.C.  payable to the holders of the Series A
Preferred Stock pursuant to this Section II shall be paid to such holders at the
same time as the  dividend  or  distribution  on the  Junior  Stock or any other
capital stock of the Corporation by which it is measured is paid.

                  E. All dividends or  distributions  declared upon the Series A
Preferred Stock shall be declared pro rata per share.

                  F. Any reference to  "distribution"  contained in this Section
II shall not be deemed to include any distribution made in connection with or in
lieu of any Liquidation Event (as defined below).

                  G. No interest, or sum of money in lieu of interest,  shall be
payable in respect of any dividend payment or payments on the Series A Preferred
Stock which may be in arrears.

                  H. So long as any shares of the Series A  Preferred  Stock are
outstanding,  no dividends, except as described in the next succeeding sentence,
shall be  declared  or paid or set apart for  payment  on any class or series of
stock of the Corporation ranking, as to dividends, on a parity with the Series A
Preferred   Stock,   for  any  period   unless  all   dividends   have  been  or
contemporaneously  are declared and paid, or declared and a sum  sufficient  for
the payment thereof set apart for such payment, on the Series A Preferred Stock.
When  dividends are not paid in full or a sum sufficient for such payment is not
set apart, as aforesaid, upon the shares of the Series A Preferred Stock and any
other  class or series of stock  ranking  on a parity as to  dividends  with the
Series A Preferred Stock, all dividends  declared upon such other stock shall be
declared  pro rata so that the amounts of  dividends  per share  declared on the
Series A  Preferred  Stock and such other  stock shall in all cases bear to each
other the same  ratio  that  accrued  dividends  per share on the  shares of the
Series A Preferred Stock and on such other stock bear to each other.

                  I. So long as any shares of the Series A  Preferred  Stock are
outstanding,  no other  stock of the  Corporation  ranking on a parity  with the
Series A Preferred Stock as to


                                       -4-


<PAGE>

dividends  or upon  liquidation,  dissolution  or winding up shall be  redeemed,
purchased or otherwise  acquired for any consideration (or any moneys be paid to
or made available for a sinking fund or otherwise for the purchase or redemption
of any shares of any such stock) by the  Corporation  unless the  dividends,  if
any,  accrued on all  outstanding  shares of the Series A Preferred  Stock shall
have been paid or set apart for payment.

                  J.  "Junior  Stock" shall mean the Common Stock and any shares
of preferred stock of any series or class of the Corporation,  whether presently
outstanding  or  hereafter  issued,  which are  junior to the shares of Series A
Preferred Stock with respect to (i) the  distribution of assets on any voluntary
or involuntary liquidation,  dissolution or winding up of the Corporation,  (ii)
dividends or (iii) voting.

         III.     Liquidation Preference.

                  A. In the event of a (i)  liquidation,  dissolution or winding
up of the Corporation,  whether  voluntary or involuntary,  (ii) a sale or other
disposition  of all or  substantially  all of the assets of the  Corporation  or
(iii)  any   consolidation,   merger,   combination,   reorganization  or  other
transaction in which the  Corporation  is not the surviving  entity or shares of
Common  Stock  constituting  in  excess  of  50%  of  the  voting  power  of the
Corporation  are  exchanged  for or changed into stock or  securities of another
entity, cash and/or any other property (a "Merger Transaction") (items (i), (ii)
and (iii) of this  sentence  being  collectively  referred to as a  "Liquidation
Event"),  after payment or provision for payment of debts and other  liabilities
of the Corporation the holders of the Series A Preferred Stock then  outstanding
shall be entitled to be paid out of the assets of the Corporation  available for
distribution to its stockholders,  whether such assets are capital,  surplus, or
earnings, before any payment or declaration and setting apart for payment of any
amount  shall be made in  respect  of any Junior  Stock of the  Corporation,  an
amount equal to $140.00 per share plus an amount  equal to all  declared  and/or
accrued unpaid dividends  thereon;  provided,  however,  in the case of a Merger
Transaction,  such  $140.00 per share may be paid in cash,  property  (valued as
provided  in  Subsection  III.B.)  and/or  securities  (valued  as  provided  in
Subsection III.B.) of the entity surviving such Merger Transaction.  In the case
of  property  or in the  event  that  any  such  securities  are  subject  to an
investment letter or other similar restriction on transferability,  the value of
such  property  or  securities  shall be  determined  by  agreement  between the
Corporation  and the holders of a majority of the Series A Preferred  Stock then
outstanding.  If upon any Liquidation  Event,  whether voluntary or involuntary,
the assets to be  distributed  to the  holders of the Series A  Preferred  Stock
shall be  insufficient  to permit the payment to such  shareholders  of the full
preferential amounts aforesaid,  then all of the assets of the Corporation to be
distributed  shall be so  distributed  ratably  to the  holders  of the Series A
Preferred Stock on the basis of the number of shares of Series A Preferred Stock
held.  Notwithstanding  item  (iii) of the  first  sentence  of this  Subsection
III.A.,  any  consolidation,   merger,  combination,   reorganization  or  other
transaction  in  which  the  Corporation  is not the  surviving  entity  but the
stockholders of the  Corporation  immediately  prior to such  transaction own in
excess of 50% of the voting power of the corporation  surviving such transaction
and own such interest in substantially the same


                                       -5-


<PAGE>

proportions as prior to such transaction,  shall not be considered a Liquidation
Event provided that the surviving corporation shall make appropriate  provisions
to ensure that the terms of this  Certificate  of  Designation  survive any such
transaction as provided in Subsection  IV.C.2.  All shares of Series A Preferred
Stock shall rank as to payment  upon the  occurrence  of any  Liquidation  Event
senior to the Common  Stock as  provided  herein  and,  unless the terms of such
series shall provide otherwise,  senior to all other series of the Corporation's
preferred stock.

                  B. Any  securities  or other  property to be  delivered to the
holders of the Series A Preferred  Stock  pursuant to Subsection  III.A.  hereof
shall be valued as follows:

                        1.  Securities  not subject to an  investment  letter or
                  other similar restriction on free marketability:

                              (a) If  actively  traded  on a Stock  Market,  the
                        value  shall be deemed to be the Market  Price as of the
                        third day prior to the date of valuation.

                              (b) If not actively traded on a Stock Market,  the
                        value shall be the Fair Market Value.

                        2. For  securities  for which there is an active  public
                  market but which are subject to an investment  letter or other
                  restrictions  on free  marketability,  the value  shall be the
                  Fair  Market  Value   thereof,   determined   by   discounting
                  appropriately the Market Price thereof.

                        3. For all other securities, the value shall be the Fair
                  Market Value thereof.

         IV.      Conversion.

                  A. Right of Conversion. The shares of Series A Preferred Stock
shall be  convertible,  in whole or in part, at the option of the holder thereof
and upon notice to the Corporation as set forth in Subsection  IV.B., into fully
paid and  nonassessable  shares of Common  Stock and such other  securities  and
property as  hereinafter  provided.  The initial  conversion  price per share of
Common Stock shall be equal to $0.48675  (the  "Conversion  Price") and shall be
subject to adjustment as provided herein.  The rate at which each share Series A
Preferred  Stock is convertible  at any time into Common Stock (the  "Conversion
Rate") shall be determined by dividing the then existing  Conversion  Price into
$100.00.

                  The Conversion Price is subject to adjustment immediately upon
the  earliest  of (i)  the  approval  by the  holders  of  Common  Stock  of the
Corporation  of the  transactions  contemplated  by the Purchase  Agreement  (as
defined  below) and the Letter of Intent between the  Corporation  and Paramount
Capital, Inc., dated June 29, 1997 (the "Letter of Intent"), to


                                       -6-

<PAGE>

the extent such  approval is necessary  pursuant to Rule 4460(i) of the National
Association  of  Securities  Dealers'  Marketplace  Rules,  (ii) any event which
renders  such  stockholder  approval  unnecessary  or which  renders  such  rule
inapplicable  and (iii)  September 30, 1997 (such  earliest  date, the "Approval
Date"). In such event, the Conversion Price shall be reduced to equal the lesser
of (x)  $0.29  and (y) 50% of the  Trading  Price  at such  Approval  Date.  The
Conversion  Price is  further  subject  to  adjustment,  upon the Series B Final
Closing Date (as defined in the Letter of Intent),  if the  conversion  price of
the  preferred  stock  (the  "Series B  Preferred  Stock")  sold in the Series B
Offering  (as  defined  in the  Letter  of  Intent)  is less  than two times the
Conversion  Price. In such event, the Conversion Price shall be reduced to equal
50% of the conversion price of such Series B Preferred Stock as in effect on any
of the  respective  closing  dates in the Series B  Offering.  In the event that
there is no  Series B Final  Closing  Date,  or the  above  referenced  Series B
Offering is not  commenced  or otherwise  terminated,  if the price per share of
Common Stock (or the effective  price,  conversion  price or exercise  price per
share of Common  Stock,  as the case may be, of a security  convertible  into or
exchangeable  for Common  Stock)  offered to investors  in the next  offering or
series of related  offerings of equity  securities  of the  Corporation  (or any
securities convertible into or exercisable for equity securities),  whether in a
public offering or a private placement, following the offering of Series A Units
which yields gross  proceeds to the  Corporation  in excess of $2,000,000 in the
aggregate (a "Qualified  Offering")  shall be less than two times the Conversion
Price then in effect,  the Conversion Price shall be reduced to equal 50% of the
lowest of any such  offering  price (or  effective  price,  conversion  price or
exercise  price,  as the case may be) per share of Common  Stock to investors in
such Qualified Offering.

                  The Board of  Directors,  or a committee  designated by it for
such purpose,  may specify an initial  conversion price applicable to the shares
of  Series A  Preferred  Stock  issued at any  closing  lower  than the  initial
conversion   price  that  would  otherwise  obtain  pursuant  to  the  preceding
paragraphs  of this  Subsection  IV.A.  and, in the event an initial  conversion
price is so  specified,  it shall be  applicable  to all  shares of the Series A
Preferred Stock.

                  The  Corporation  shall  prepare a  certificate  signed by the
Chairman or  President,  and by the  Treasurer or an Assistant  Treasurer or the
Secretary  or an  Assistant  Secretary,  of the  Corporation  setting  forth the
Conversion Rate as of the Final Closing Date,  showing in reasonable  detail the
facts upon which such adjusted  Conversion Rate is based,  and such  certificate
shall  forthwith  be filed with the  transfer  agent of the  Series A  Preferred
Stock. A notice stating that the Conversion  Rate has been adjusted  pursuant to
the second preceding  paragraph of this Subsection  IV.A., or that no adjustment
is necessary, and setting forth the Conversion Rate in effect as of the Series B
Final Closing Date (as defined in the Letter of Intent),  the final closing date
of any  Qualified  Offering or the Approval  Date shall be mailed as promptly as
practicable after the Series B Final Closing Date, the final closing date of any
Qualified Offering or the Approval Date by the Corporation to all record holders
of the Series A Preferred  Stock at their last addresses as they shall appear in
the stock transfer books of the Corporation.


                                       -7-


<PAGE>

                  The Conversion  Price  (subject to adjustment  pursuant to the
provisions of  Subsection  IV.C.) in effect  immediately  prior to June 30, 1998
(the "Reset Date") shall be adjusted and reset effective as of the Reset Date if
the Market  Price as of the Reset Date (the  "12-Month  Trading  Price") is less
than 140% of the then applicable  Conversion  Price (a "Reset Event").  Upon the
occurrence of a Reset Event,  the Conversion  Price shall be reduced to be equal
to the greater of (A) the 12-Month Trading Price divided by 1.40, and (B) 25% of
the then applicable  Conversion  Price. If there is any change in the Conversion
Price as a result of the preceding  sentence,  then the Conversion Rate shall be
changed  accordingly  as set  forth  above.  The  Corporation  shall  prepare  a
certificate signed by the principal financial officer of the Corporation setting
forth the Conversion Rate as of the Reset Date, showing in reasonable detail the
facts upon which  such  Conversion  Rate is based,  and such  certificate  shall
forthwith be filed with the transfer  agent of the Series A Preferred  Stock.  A
notice  stating  that the  Conversion  Rate has been  adjusted  pursuant to this
paragraph, or that no adjustment is necessary,  and setting forth the Conversion
Rate in effect as of the Reset Date shall be mailed as promptly  as  practicable
after the Reset Date by the  Corporation  to all record  holders of the Series A
Preferred  Stock at their  last  addresses  as they  shall  appear  in the stock
transfer books of the Corporation.

                  Furthermore,  in the  event  that the  terms  of the  Series B
Preferred  Stock  or of any  Qualified  Offering  Security  requires  that  such
security's  conversion  price,  exercise  price or  effective  price  (the "B or
Qualified Share Price") be reduced in a manner  analogous to the above described
reset (a "B or Qualified  Reset"),  the Conversion Price then in effect shall be
adjusted on the date of such B or Qualified  Reset (the "Second  Reset Date") to
be the  lesser  of (a) the  product  of (i) the  Conversion  Price at such  time
multiplied  by  (ii) a  fraction,  the  numerator  of  which  shall  be the B or
Qualified Share Price  immediately  succeeding such B or Qualified Reset and the
denominator  of  which  shall  be the B or  Qualified  Share  Price  immediately
preceding  such B or  Qualified  Reset and (b) the B or  Qualified  Share  Price
immediately  following such B or Qualified Reset. In addition,  if there is no B
or  Qualified  Reset  by June 30,  1999,  then the  Conversion  Price in  effect
immediately prior to June 30, 1999 (the  "Alternative  Second Reset Date") shall
be adjusted and reset effective as of the  Alternative  Second Reset Date if the
Market Price as of the Second Reset Date (the "24-Month  Trading Price") is less
than 200% of the applicable  Conversion Price (a "Second Reset Event") provided,
however,  that there shall be no reset of the Conversion  Price pursuant to this
paragraph  if (i) the  Company  conducts  a B or  Qualified  Offering;  (ii) the
securities issued by the Company in such B or Qualified Offering contain a reset
provision  analogous to the one described in the previous paragraph and (iii) no
B or  Qualified  Reset is required  pursuant to the terms of such B or Qualified
securities  because the Market Price is in excess of the applicable target price
as of the date  prescribed  for such  reset  pursuant  to the  terms of the B or
Qualified  securities.  Upon  the  occurrence  of  a  Second  Reset  Event,  the
Conversion  Price  shall be  reduced  to be equal to the  greater of (A) the 24-
Month  Trading  Price  divided  by  2.00,  and  (B) 25% of the  then  applicable
Conversion  Price. If there is any change in the Conversion Price as a result of
the preceding sentence, then the Conversion Rate shall be changed accordingly as
set forth above.  The  Corporation  shall  prepare a  certificate  signed by the
principal financial officer of the Corporation setting forth the


                                       -8-


<PAGE>

Conversion  Rate as of the Second  Reset Date or the  Alternative  Second  Reset
Date, as the case may be, showing in reasonable detail the facts upon which such
Conversion Rate is based, and such certificate shall forthwith be filed with the
transfer  agent of the  Series A  Preferred  Stock.  A notice  stating  that the
Conversion  Rate  has  been  adjusted  pursuant  to this  paragraph,  or that no
adjustment is necessary,  and setting forth the Conversion  Rate in effect as of
the Second Reset Date or the Alternative  Second Reset Date, as the case may be,
shall be mailed as promptly as  practicable  after the Second  Reset Date or the
Alternative  Second Reset Date,  as the case may be, by the  Corporation  to all
record  holders of the Series A Preferred  Stock at their last addresses as they
shall appear in the stock transfer books of the Corporation.

                  B.  Conversion  Procedures.  Any  holder of shares of Series A
Preferred  Stock  desiring  to convert  such  shares  into  Common  Stock  shall
surrender the  certificate or  certificates  evidencing  such shares of Series A
Preferred  Stock at the office of the transfer  agent for the Series A Preferred
Stock,  which certificate or certificates,  if the Corporation shall so require,
shall be duly endorsed to the  Corporation or in blank, or accompanied by proper
instruments  of  transfer  to  the  Corporation  or  in  blank,  accompanied  by
irrevocable  written  notice to the  Corporation  that the  holder  elects so to
convert such shares of Series A Preferred Stock and specifying the name or names
(with  address) in which a  certificate  or  certificates  evidencing  shares of
Common  Stock  are to be  issued.  The  Corporation  need not  deem a notice  of
conversion to be received  unless the holder  complies  with all the  provisions
hereof.  The  Corporation  will  instruct the  transfer  agent (which may be the
Corporation)  to make a  notation  of the date  that a notice of  conversion  is
received,  which  date shall be deemed to be the date of  receipt  for  purposes
hereof.

                  The  Corporation  shall,  as soon as  practicable  after  such
deposit  of  certificates   evidencing   shares  of  Series  A  Preferred  Stock
accompanied  by the  written  notice and  compliance  with any other  conditions
herein  contained,  deliver at such office of such transfer  agent to the person
for whose account such shares of Series A Preferred  Stock were so  surrendered,
or to the nominee or nominees of such person, certificates evidencing the number
of full  shares  of Common  Stock to which  such  person  shall be  entitled  as
aforesaid,  together  with a cash  adjustment  of any  fraction  of a  share  as
hereinafter  provided.  Subject to the following  provisions of this  paragraph,
such  conversion  shall  be  deemed  to have  been  made as of the  date of such
surrender  of the shares of Series A Preferred  Stock to be  converted,  and the
person or  persons  entitled  to  receive  the  Common  Stock  deliverable  upon
conversion of such Series A Preferred Stock shall be treated for all purposes as
the  record  holder or  holders of such  Common  Stock on such  date;  provided,
however,  that the  Corporation  shall not be  required to convert any shares of
Series A Preferred  Stock while the stock transfer books of the  Corporation are
closed  for any  purpose,  but the  surrender  of Series A  Preferred  Stock for
conversion  during  any  period  while  such  books are so closed  shall  become
effective for conversion  immediately upon the reopening of such books as if the
surrender had been made on the date of such reopening,  and the conversion shall
be at the  conversion  rate in effect on such date. No adjustments in respect of
any dividends on shares surrendered for conversion or any dividend on the Common
Stock


                                       -9-


<PAGE>

issued upon conversion shall be made upon the conversion of any shares of Series
A Preferred Stock.

                  All  notices of  conversion  shall be  irrevocable;  provided,
however,  that if the  Corporation  has  sent  notice  of an event  pursuant  to
Subsection  4(g)  hereof,  a holder  of Series A  Preferred  Stock  may,  at its
election,  provide in its notice of conversion that the conversion of its shares
of Series A  Preferred  Stock shall be  contingent  upon the  occurrence  of the
record  date or  effectiveness  of such  event (as  specified  by such  holder),
provided that such notice of conversion is received by the Corporation  prior to
such record date or effective date, as the case may be.

                  C.       Adjustment of Conversion Rate and Conversion Price.

                         1. Except as otherwise  provided  herein,  in the event
the  Corporation  shall, at any time or from time to time after the date hereof,
(1) sell or issue any shares of Common Stock for a consideration  per share less
than  either  (i) the  Conversion  Price in  effect  on the date of such sale or
issuance or (ii) the Market Price of the Common Stock as of the date of the sale
or  issuance,  (2) issue any shares of Common  Stock as a stock  dividend to the
holders of Common Stock, or (3) subdivide or combine the  outstanding  shares of
Common Stock into a greater or lesser number of shares (any such sale, issuance,
subdivision or combination being herein called a "Change of Shares"),  then, and
thereafter  upon each further Change of Shares,  the Conversion  Price in effect
immediately  prior to such Change of Shares shall be changed to a price (rounded
to the nearest cent)  determined by multiplying  the Conversion  Price in effect
immediately prior thereto by a fraction, the numerator of which shall be the sum
of the number of shares of Common  Stock  outstanding  immediately  prior to the
sale or issuance of such  additional  shares or such  subdivision or combination
and the  number  of shares of Common  Stock  which the  aggregate  consideration
received (determined as provided in Subparagraph IV.C.4.(e)) for the issuance of
such additional shares would purchase at the greater of (i) the Conversion Price
in effect on the date of such  issuance  or (ii) the Market  Price of the Common
Stock as of such  date,  and the  denominator  of which  shall be the  number of
shares of Common  Stock  outstanding  immediately  after the sale or issuance of
such additional shares or such subdivision or combination. Such adjustment shall
be made successively whenever such an issuance is made.

                         2.   In   case   of   any   reclassification,   capital
reorganization or other change of outstanding shares of Common Stock, or in case
of any  consolidation  or merger of the Corporation  with or into another entity
(other than a consolidation or merger in which the Corporation is the continuing
entity and which does not result in any reclassification, capital reorganization
or other  change of  outstanding  shares of Common  Stock  other than the number
thereof), or in case of any sale or conveyance to another entity of the property
of  the  Corporation  as,  or  substantially  as,  an  entirety  (other  than  a
sale/leaseback,  mortgage or other financing transaction), the Corporation shall
cause effective  provision to be made so that each holder of a share of Series A
Preferred Stock shall be entitled to receive, upon conversion of


                                      -10-


<PAGE>

such share of Series A Preferred  Stock,  the kind and number of shares of stock
or  other   securities  or  property   (including  cash)  receivable  upon  such
reclassification, capital reorganization or other change, consolidation, merger,
sale or  conveyance  by a holder of the  number of shares of Common  Stock  into
which such share of Series A Preferred Stock was convertible  immediately  prior
to such reclassification, capital reorganization or other change, consolidation,
merger,  sale or  conveyance.  Any such  provision  shall include  provision for
adjustments  that shall be as nearly  equivalent  as may be  practicable  to the
adjustments  provided for in this  Subsection  IV.C. The  Corporation  shall not
effect any such consolidation,  merger or sale unless prior to or simultaneously
with the  consummation  thereof the  successor  (if other than the  Corporation)
resulting from such  consolidation or merger or the entity  purchasing assets or
other  appropriate  entity  shall  assume,  by written  instrument  executed and
delivered to the transfer agent for the Series A Preferred  Stock (the "Transfer
Agent"),  the  obligation  to  deliver  to the  holder of each share of Series A
Preferred  Stock such shares of stock,  securities  or assets as, in  accordance
with the foregoing  provisions,  such holders may be entitled to receive and the
other obligations under this Agreement. The foregoing provisions shall similarly
apply to successive reclassifications, capital reorganizations and other changes
of outstanding shares of Common Stock and to successive consolidations, mergers,
sales or conveyances.

                         3.  After  each  adjustment  of  the  Conversion  Price
pursuant to this  Subsection  IV.C.,  the  Corporation  will promptly  prepare a
certificate  signed by the  Chairman or  President,  and by the  Treasurer or an
Assistant  Treasurer  or  the  Secretary  or  an  Assistant  Secretary,  of  the
Corporation  setting forth:  (i) the Conversion  Price as so adjusted,  (ii) the
Conversion  Rate  corresponding  to  such  Conversion  Price  and  (iii) a brief
statement of the facts  accounting for such  adjustment.  The  Corporation  will
promptly file such certificate with the Transfer Agent and cause a brief summary
thereof to be sent by  ordinary  first class mail to each  registered  holder of
Series A Preferred  Stock at his or her last  address as it shall  appear on the
registry  books of the  Transfer  Agent.  No failure to mail such notice nor any
defect  therein or in the  mailing  thereof  shall  affect the  validity of such
adjustment.  The affidavit of an officer of the Transfer  Agent or the Secretary
or an Assistant  Secretary of the  Corporation  that such notice has been mailed
shall,  in the  absence of fraud,  be prima facie  evidence of the facts  stated
therein.  The Transfer Agent may rely on the  information in the  certificate as
true and  correct  and has no duty or  obligation  to  independently  verify the
amounts or calculations set forth therein.

                  4. For purposes of  Subsection  IV.C.1  hereof,  the following
provisions (a) to (e) shall also be applicable:

                                        (a)  No  adjustment  of  the  Conversion
                              Price shall be made unless such  adjustment  would
                              require an  increase  or decrease of at least $.01
                              in such price; provided that any adjustments which
                              by  reason  of  this   Subparagraph  (a)  are  not
                              required  to be made shall be carried  forward and
                              shall be made at the time of and together with the
                              next subsequent  adjustment  which,  together with
                              adjustments so carried forward, shall


                                      -11-


<PAGE>

                              require an  increase  or decrease of at least $.01
                              in the Conversion Price then in effect hereunder.

                                        (b) In  case of (i)  the  sale or  other
                              issuance  by  the  Corporation   (including  as  a
                              component  of a unit) of any rights or warrants to
                              subscribe for or purchase,  or any options for the
                              purchase  of,  Common  Stock  or  any   securities
                              convertible  into or exchangeable for Common Stock
                              (such  securities   convertible,   exercisable  or
                              exchangeable into Common Stock being herein called
                              "Convertible Securities"), or (ii) the issuance by
                              the  Corporation,   without  the  receipt  by  the
                              Corporation of any consideration  therefor, of any
                              rights or warrants to  subscribe  for or purchase,
                              or any options for the purchase  of,  Common Stock
                              or  Convertible  Securities,  whether  or not such
                              rights,  warrants  or  options,  or the  right  to
                              convert or exchange such  Convertible  Securities,
                              are immediately exercisable, and the consideration
                              per share for which Common Stock is issuable  upon
                              the exercise of such  rights,  warrants or options
                              or  upon  the   conversion  or  exchange  of  such
                              Convertible Securities (determined by dividing (x)
                              the minimum aggregate consideration,  as set forth
                              in the instrument  relating thereto without regard
                              to  any   antidilution   or   similar   provisions
                              contained  therein for a subsequent  adjustment of
                              such amount,  payable to the Corporation  upon the
                              exercise of such rights, warrants or options, plus
                              the consideration  received by the Corporation for
                              the issuance or sale of such  rights,  warrants or
                              options,  plus,  in the  case of such  Convertible
                              Securities,  the minimum  aggregate amount, as set
                              forth in the instrument  relating  thereto without
                              regard to any  antidilution or similar  provisions
                              contained  therein for a subsequent  adjustment of
                              such amount, of additional consideration,  if any,
                              other than such  Convertible  Securities,  payable
                              upon the  conversion or exchange  thereof,  by (y)
                              the  total  maximum  number,  as set  forth in the
                              instrument  relating thereto without regard to any
                              antidilution  or  similar   provisions   contained
                              therein  for  a  subsequent   adjustment  of  such
                              amount,  of shares of Common Stock  issuable  upon
                              the exercise of such  rights,  warrants or options
                              or  upon  the   conversion  or  exchange  of  such
                              Convertible  Securities issuable upon the exercise
                              of such rights,  warrants or options) is less than
                              either the Conversion Price or the Market Price of
                              the Common Stock as of the date of the issuance or
                              sale of such  rights,  warrants or  options,  then
                              such  total  maximum  number  of  shares of Common
                              Stock  issuable  upon the exercise of such rights,
                              warrants  or  options  or upon the  conversion  or
                              exchange of such Convertible Securities (as of the
                              date of the  issuance  or  sale  of  such  rights,
                              warrants or options) shall be deemed to be "Common
                              Stock" for purposes of Subsection IV.C.1 and shall
                              be deemed to have been sold for an amount equal to
                              such  consideration  per share and shall  cause an
                              adjustment   to  be   made  in   accordance   with
                              Subsection IV.C.1.


                                      -12-


<PAGE>

                                        (c)  In   case   of  the   sale  by  the
                              Corporation of any Convertible Securities, whether
                              or  not  the  right  of   conversion  or  exchange
                              thereunder  is  immediately  exercisable,  and the
                              price per share for which Common Stock is issuable
                              upon   the   conversion   or   exchange   of  such
                              Convertible Securities (determined by dividing (x)
                              the total amount of consideration  received by the
                              Corporation  for  the  sale  of  such  Convertible
                              Securities,  plus the minimum aggregate amount, as
                              set  forth  in  the  instrument  relating  thereto
                              without  regard  to any  antidilution  or  similar
                              provisions  contained  therein  for  a  subsequent
                              adjustment   of   such   amount,   of   additional
                              consideration, if any, other than such Convertible
                              Securities,   payable  upon  the   conversion   or
                              exchange thereof, by (y) the total maximum number,
                              as set forth in the  instrument  relating  thereto
                              without  regard  to any  antidilution  or  similar
                              provisions  contained  therein  for  a  subsequent
                              adjustment  of such  amount,  of  shares of Common
                              Stock  issuable upon the conversion or exchange of
                              such  Convertible  Securities) is less than either
                              the  Conversion  Price or the Market  Price of the
                              Common  Stock  as of the  date of the sale of such
                              Convertible  Securities,  then such total  maximum
                              number of shares of Common Stock issuable upon the
                              conversion   or  exchange   of  such   Convertible
                              Securities  (as of the  date  of the  sale of such
                              Convertible  Securities)  shall  be  deemed  to be
                              "Common  Stock" for purposes of Subsection  IV.C.1
                              and  shall  be  deemed  to have  been  sold for an
                              amount equal to such  consideration  per share and
                              shall cause an adjustment to be made in accordance
                              with Subsection IV.C.1.

                                        (d) In case the Corporation shall modify
                              the rights of conversion,  exchange or exercise of
                              any of the  securities  referred to in (b) and (c)
                              above or any other  securities of the  Corporation
                              convertible,   exchangeable   or  exercisable  for
                              shares of Common Stock,  for any reason other than
                              an event that would require  adjustment to prevent
                              dilution   pursuant  to  the  terms  of  any  such
                              convertible,     exchangeable    or    exercisable
                              instrument,  so that the  consideration  per share
                              received   by   the    Corporation    after   such
                              modification  is less than  either the  Conversion
                              Price or the Market  Price as of the date prior to
                              such  modification,  then such securities,  to the
                              extent not  theretofore  exercised,  converted  or
                              exchanged,  shall be  deemed  to have  expired  or
                              terminated  immediately  prior to the date of such
                              modification  and the Corporation  shall be deemed
                              for  purposes  of  calculating   any   adjustments
                              pursuant to this  Subsection  IV.C. to have issued
                              such new  securities  upon  such new  terms on the
                              date of modification. Such adjustment shall become
                              effective   as  of  the  date  upon   which   such
                              modification  shall take effect. On the expiration
                              or  cancellation  of any such  right,  warrant  or
                              option or the  termination or  cancellation of any
                              such  right  to  convert  or  exchange   any  such
                              Convertible Securities,  the Conversion Price then
                              in effect hereunder shall forthwith


                                      -13-


<PAGE>

                              be  readjusted to such  Conversion  Price as would
                              have  obtained (i) had the  adjustments  made upon
                              the  issuance  or sale of such  rights,  warrants,
                              options or Convertible  Securities  been made upon
                              the basis of the  issuance  of only the  number of
                              shares  of  Common  Stock   theretofore   actually
                              delivered  (and the total  consideration  received
                              therefor)   upon  the  exercise  of  such  rights,
                              warrants  or  options  or upon the  conversion  or
                              exchange of such  Convertible  Securities and (ii)
                              had  adjustments  been  made on the  basis  of the
                              Conversion  Price as adjusted  under clause (i) of
                              this  sentence for all  transactions  (which would
                              have affected such adjusted Conversion Price) made
                              after  the   issuance  or  sale  of  such  rights,
                              warrants, options or Convertible Securities.

                                        (e) In case of the sale of any shares of
                              Common  Stock,  any  Convertible  Securities,  any
                              rights or warrants to  subscribe  for or purchase,
                              or any options for the purchase  of,  Common Stock
                              or  Convertible   Securities,   the  consideration
                              received  by the  Corporation  therefor  shall  be
                              deemed  to  be  the  gross  sales  price  therefor
                              without  deducting  therefrom  any expense paid or
                              incurred by the  Corporation  or any  underwriting
                              discounts or commissions  or  concessions  paid or
                              allowed   by   the   Corporation   in   connection
                              therewith.  In the event that any securities shall
                              be issued in connection with any other  securities
                              of  the  Corporation,   together   comprising  one
                              integral   transaction   in  which   no   specific
                              consideration  is allocated  among the securities,
                              then  each of such  securities  shall be deemed to
                              have been  issued  for such  consideration  as the
                              Board of Directors of the  Corporation  determines
                              in  good  faith;  provided,  however  that  if the
                              Registered Holders of in excess of 10% of the then
                              outstanding Series A Preferred Stock disagree with
                              such determination,  the Corporation shall retain,
                              at its  own  expense,  an  independent  investment
                              banking  firm  for the  purpose  of  obtaining  an
                              appraisal.

                  5.  Notwithstanding  any other provision hereof, no adjustment
to the Conversion Price will be made:

                                        (a)  upon  the  exercise  of  any of the
                              options or warrants outstanding on the date hereof
                              under  the  Corporation's  existing  stock  option
                              plans; or

                                        (b) upon the  issuance  or  exercise  of
                              options  which may  hereafter  be granted with the
                              approval of the Board of Directors,  or exercised,
                              under any employee benefit plan of the Corporation
                              to officers, directors,  consultants or employees,
                              but  only  with  respect  to such  options  as are
                              exercisable  at prices no lower  than the  Closing
                              Bid Price (or, if the


                                      -14-


<PAGE>

                              price  referenced in the definition of Closing Bid
                              Price cannot be determined, the Fair Market Value)
                              of the  Common  Stock  as of  the  date  of  grant
                              thereof; or

                                        (c) upon the issuance of stock which may
                              hereafter  be  purchased or sold with the approval
                              of the Board of Directors, under the 1993 Employee
                              Stock   Purchase  Plan  of  the   Corporation   to
                              officers, directors, consultants or employees, but
                              only with respect to such shares as are  purchased
                              and/or sold in  accordance  with the current  plan
                              and at prices no lower than 85% of the Closing Bid
                              Price  (or,  if  the  prices   referenced  in  the
                              definition   of  Closing   Bid  Price   cannot  be
                              determined,  85% of the Fair Market  Value) of the
                              Common  Stock  as of the date of  purchase  and/or
                              sale thereof; or

                                        (d) upon  issuance  or  exercise  of the
                              Placement Warrants, or the Advisory Warrants,  (as
                              defined  in  the  Letter  of  Intent  between  the
                              Corporation,    Paramount   Capital,   Inc.   (the
                              "Placement Agent"),  the Aries Domestic Fund, L.P.
                              and The  Aries  Trust,  dated as of June 29,  1997
                              (the  "Letter  of  Intent"))  (collectively,   the
                              "Paramount   Warrants"),   upon  the  exercise  or
                              conversion of the Class A and Class B Warrants (as
                              defined in the Securities Purchase Agreement dated
                              as of June 30, 1997 (the "Purchase Agreement")) or
                              any A Notes (as defined in the Purchase Agreement)
                              or upon the  issuance,  conversion  or exercise of
                              the  Series  B  Preferred  Stock  or the  Class  C
                              Warrants  to be  issued  (i)  on or  prior  to the
                              Series B Final  Closing  Date or (ii)  pursuant to
                              the exercise of the  Paramount  Warrants,  or upon
                              the issuance, conversion or exercise of any Series
                              A or Series B Preferred  Stock or Class A, Class B
                              or Class C  Warrants  approved  in  writing by the
                              Placement Agent, or upon the issuance of any other
                              equity securities of the Corporation to the extent
                              that such  issuance  causes an  adjustment  to the
                              Conversion  Price pursuant to the second paragraph
                              of Subsection IV.A.; or

                                        (e) upon the  issuance or sale of Common
                              Stock or  Convertible  Securities  pursuant to the
                              exercise  of any  rights,  options or  warrants to
                              receive, subscribe for or purchase, or any options
                              for the purchase of,  Common Stock or  Convertible
                              Securities,  whether or not such rights,  warrants
                              or  options  were  outstanding  on the date of the
                              original  issuance of the Series A Preferred Stock
                              or were thereafter  issued or sold,  provided that
                              an  adjustment  was either made or not required to
                              be made in accordance  with  Subsection  IV.C.1 in
                              connection  with  the  issuance  or  sale  of such
                              securities  or  any   modification  of  the  terms
                              thereof; or


                                      -15-


<PAGE>

                                        (f) upon the  issuance or sale of Common
                              Stock  upon   conversion   or   exchange   of  any
                              Convertible   Securities,    provided   that   any
                              adjustments  required to be made upon the issuance
                              or  sale  of such  Convertible  Securities  or any
                              modification  of the terms  thereof  were so made,
                              and  whether  or not such  Convertible  Securities
                              were  outstanding on the date of the original sale
                              of the Series A Preferred Stock or were thereafter
                              issued or sold.

Subparagraph  IV.C.4.(d)  shall  nevertheless  apply to any  modification of the
rights of conversion,  exchange or exercise of any of the securities referred to
in  Subparagraphs  (a),  (b),  (c),  (e), (f) and, to the extent  effected  with
respect to fewer than all of such securities, Subparagraph (c) of this Paragraph
IV.C.5.  Notwithstanding  the  foregoing,  IV.C.4.(d)  shall  not  apply  to any
modification  of the  exercise  price of,  or  number of shares of Common  Stock
subject  to, the Class A, Class B or Class C Warrants  that are  required by the
terms of those respective instruments.

                  6. As used in this Subsection  IV.C.,  the term "Common Stock"
shall mean and include the Corporation's  Common Stock authorized on the date of
the  original  issue of the Series A Preferred  Stock and shall also include any
capital stock of any class of the Corporation  thereafter authorized which shall
not be  limited  to a fixed sum or  percentage  in  respect of the rights of the
holders  thereof to participate in dividends and in the  distribution  of assets
upon the voluntary  liquidation,  dissolution or winding up of the  Corporation;
provided,  however,  that the shares  issuable  upon  conversion of the Series A
Preferred  Stock  shall  include  only  shares of such class  designated  in the
Certificate of  Incorporation  as Common Stock on the date of the original issue
of the Series A  Preferred  Stock or (i),  in the case of any  reclassification,
change,  consolidation,  merger, sale or conveyance of the character referred to
in Subsection IV.C.2 hereof,  the stock,  securities or property provided for in
such  section  or (ii),  in the case of any  reclassification  or  change in the
outstanding  shares of Common Stock  issuable  upon  conversion  of the Series A
Preferred  Stock as a result of a subdivision  or combination or consisting of a
change in par value,  or from par value to no par value, or from no par value to
par value, such shares of Common Stock as so reclassified or changed.

                  7.  Any  determination  as to  whether  an  adjustment  in the
Conversion Price in effect hereunder is required pursuant to Subsection IV.A. or
IV.C, or as to the amount of any such adjustment,  if required, shall be binding
upon the holders of the Series A Preferred  Stock and the Corporation if made in
good faith by the Board of Directors of the Corporation.

                  D.  No  Fractional  Shares.  No  fractional  shares  or  scrip
representing  fractional  shares of Common Stock shall be issued upon conversion
of Series A Preferred Stock. If more than one certificate  evidencing  shares of
Series A Preferred  Stock shall be surrendered for conversion at one time by the
same holder, the number of full shares issuable upon conversion thereof shall be
computed  on the basis of the  aggregate  number of shares of Series A Preferred
Stock so  surrendered.  Instead of any  fractional  share of Common  Stock which
would otherwise


                                      -16-


<PAGE>

be  issuable  upon  conversion  of any shares of Series A Preferred  Stock,  the
Corporation  shall pay a cash adjustment in respect of such fractional  interest
in an amount  equal to the same  fraction of the Market Price as of the close of
business on the day of conversion.

                  E. Concurrent Grant. If, at any time or from time to time, the
Corporation  shall issue or  distribute to the holders of shares of Common Stock
evidence of its  indebtedness,  any other  securities of the  Corporation or any
cash,  property or other assets (excluding an issuance or distribution  governed
by Subsection IV.C. and also excluding cash dividends or cash distributions paid
out of net profits  legally  available  therefor in the full amount thereof (any
such non-excluded event being herein called a "Special Dividend")), then in each
case the  holders  of the  Series A  Preferred  Stock  shall  be  entitled  to a
proportionate share of any such Special Dividend as though they were the holders
of the number of shares of Common  Stock of the  Corporation  into  which  their
shares of Series A Preferred  Stock are  convertible as of the record date fixed
for the determination of the holders of Common Stock of the Corporation entitled
to receive such Special Dividend.

                  F. Reservation of Shares; Transfer Taxes, Etc. The Corporation
shall  at all  times  reserve  and keep  available,  out of its  authorized  and
unissued  shares of Common  Stock,  solely  for the  purpose  of  effecting  the
conversion of the Series A Preferred Stock,  such number of shares of its Common
Stock free of preemptive  rights as shall be sufficient to effect the conversion
of all  shares  of  Series  A  Preferred  Stock  from  time to time  outstanding
(including,  without limitation, shares of Common Stock issuable upon conversion
of the Series A Preferred  Stock in the case of a Reset Event).  The Corporation
shall use its best efforts from time to time, in accordance with the laws of the
State of Delaware to increase the authorized number of shares of Common Stock if
at any time the number of shares of authorized,  unissued and unreserved  Common
Stock  shall  not  be   sufficient   to  permit  the   conversion   of  all  the
then-outstanding shares of Series A Preferred Stock.

                  The  Corporation  shall pay any and all  issue or other  taxes
that may be  payable in  respect  of any issue or  delivery  of shares of Common
Stock on conversion of the Series A Preferred Stock. The Corporation  shall not,
however,  be  required  to pay any tax which may be  payable  in  respect of any
transfer  involved in the issue or delivery of Common Stock (or other securities
or assets)  in a name other than that in which the shares of Series A  Preferred
Stock so converted were registered.  and no such issue or delivery shall be made
unless and until the person  requesting  such issue has paid to the  Corporation
the  amount  of  such  tax  or  has  established,  to  the  satisfaction  of the
Corporation, that such tax has been paid.

                  G.       Prior Notice of Certain Events.  In case:

                              1. the Corporation  shall declare any dividend (or
                    any other distribution); or


                                                      -17-


<PAGE>

                              2. the Corporation shall authorize the granting to
                    the  holders  of  Common  Stock of  rights  or  warrants  to
                    subscribe  for or purchase  any shares of stock of any class
                    or of any other rights or warrants; or

                              3. of any  reclassification of Common Stock (other
                    than a subdivision or combination of the outstanding  Common
                    Stock, or a change in par value, or from par value to no par
                    value, or from no par value to par value); or

                              4.  of any  consolidation  or  merger  (including,
                    without  limitation,  a Merger  Transaction)  to  which  the
                    Corporation  is a  party  and  for  which  approval  of  any
                    stockholders of the Corporation shall be required, or of the
                    sale or transfer of all or  substantially  all of the assets
                    of the  Corporation  or of  any  compulsory  share  exchange
                    whereby the Common Stock is converted into other securities,
                    cash or other property; or

                              5. of the  voluntary or  involuntary  dissolution,
                    liquidation  or  winding up of the  Corporation  (including,
                    without limitation, a Liquidation Event);

then the  Corporation  shall cause to be filed with the  transfer  agent for the
Series A  Preferred  Stock,  and  shall  cause to be  mailed  to the  Registered
Holders,  at their last  addresses as they shall appear upon the stock  transfer
books of the Corporation,  at least 20 days prior to the applicable  record date
hereinafter  specified, a notice stating (x) the date on which a record (if any)
is to be taken for the  purpose of such  dividend,  distribution  or granting of
rights or warrants or, if a record is not to be taken,  the date as of which the
holders of Common Stock of record to be entitled to such dividend, distribution,
rights  or  warrants  are  to be  determined  and a  description  of  the  cash,
securities or other  property to be received by such holders upon such dividend,
distribution  or  granting  of rights or  warrants or (y) the date on which such
reclassification,   consolidation,   merger,  sale,  transfer,  share  exchange,
dissolution, liquidation or winding up or other Liquidation Event is expected to
become  effective,  the date as of which it is expected  that  holders of Common
Stock of record  shall be entitled to exchange  their shares of Common Stock for
securities  or other  property  deliverable  upon  such  exchange,  dissolution,
liquidation  or winding  up or other  Liquidation  Event and the  consideration,
including securities or other property, to be received by such holders upon such
exchange;  provided,  however, that no failure to mail such notice or any defect
therein or in the mailing  thereof  shall affect the  validity of the  corporate
action required to be specified in such notice.

                  H. Other Changes in Conversion Rate. The Corporation from time
to time may increase the Conversion Rate by any amount for any period of time if
the period is at least 20 days and if the  increase  is  irrevocable  during the
period. Whenever the Conversion Rate is so increased, the Corporation shall mail
to the  Registered  Holders a notice of the increase at least 15 days before the
date the increased Conversion Rate takes effect, and such notice shall state the
increased Conversion Rate and the period it will be in effect.


                                      -18-


<PAGE>

                  The  Corporation  may make such  increases  in the  Conversion
Rate,  in addition to those  required or allowed by this Section IV, as shall be
determined by it, as evidenced by a resolution of the Board of Directors,  to be
advisable  in order to avoid or  diminish  any  income  tax to holders of Common
Stock resulting from any dividend or distribution of stock or issuance of rights
or warrants to purchase or subscribe for stock or from any event treated as such
for income tax purposes.

                  Notwithstanding  anything to the contrary  herein,  in no case
shall the  Conversion  Price be  adjusted to an amount less than $.01 per share,
the  current  par value of the Common  Stock  into which the Series A  Preferred
Stock is convertible.

                  I.   Ambiguities/Errors.   The  Board  of   Directors  of  the
Corporation  shall have the  power,  subject to the  approval  of the  Placement
Agent, to resolve any ambiguity or correct any error in the provisions  relating
to the convertibility of the Series A Preferred Stock.

         V.  Mandatory  Conversion.  At any time on or after the Reset Date, the
Corporation  at its  option,  may  cause  the  Series  A  Preferred  Stock to be
converted  in  whole  or in  part,  on a pro rata  basis,  into  fully  paid and
nonassessable  shares of Common Stock at the then effective  Conversion  Rate if
the Closing Bid Price (or, if the price  referenced in the definition of Closing
Bid Price cannot be determined, the Fair Market Value) of the Common Stock shall
have  exceeded  300%  of  the  then  applicable  Conversion  Price  for  the  20
consecutive  trading  days  ending  three  days  prior to the date of  notice of
conversion. Any shares of Series A Preferred Stock so converted shall be treated
as having been  surrendered  by the holder  thereof for  conversion  pursuant to
Section IV on the date of such mandatory conversion (unless previously converted
at the option of the holder).

                  No greater than 60 nor fewer than 20 days prior to the date of
any such  mandatory  conversion,  notice by first class mail,  postage  prepaid,
shall be given to the  holders of record of the Series A  Preferred  Stock to be
converted,  addressed  to such  holders at their last  addresses as shown on the
stock transfer books of the Corporation. Each such notice shall specify the date
fixed for  conversion,  the place or places for  surrender of shares of Series A
Preferred Stock, and the then effective Conversion Rate pursuant to Section IV.

                  Any  notice  which  is  mailed  as  herein  provided  shall be
conclusively  presumed  to have been duly given by the  Corporation  on the date
deposited in the mail, whether or not the holder of the Series A Preferred Stock
receives such notice;  and failure  properly to give such notice by mail, or any
defect in such notice,  to the holders of the shares to be  converted  shall not
affect the validity of the proceedings for the conversion of any other shares of
Series A Preferred Stock. On or after the date fixed for conversion as stated in
such notice,  each holder of shares called to be converted  shall  surrender the
certificate evidencing such shares to the Corporation at the place designated in
such notice for conversion. Notwithstanding that the certificates evidencing any
shares  properly  called for  conversion  shall not have been  surrendered,  the
shares  shall no longer be deemed  outstanding  and all rights  whatsoever  with
respect to the


                                      -19-


<PAGE>

shares so called for conversion (except the right of the holders to convert such
shares upon surrender of their certificates therefor) shall terminate.

         VI.      [Reserved]

         VII.     Voting Rights.

                  A.  General.  Except  as  otherwise  provided  herein,  in the
Certificate of Incorporation or the By-laws of the Corporation or as required by
applicable law, the holders of shares of Series A Preferred  Stock,  the holders
of shares of Common Stock and the holders of any other class or series of shares
entitled to vote with the Common  Stock shall vote  together as one class on all
matters  submitted to a vote of  stockholders  of the  Corporation.  In any such
vote, each share of Series A Preferred Stock shall entitle the holder thereof to
cast the  number of votes  equal to the number of votes  which  could be cast in
such vote by a holder of the  Common  Stock  into  which  such share of Series A
Preferred Stock is convertible on the record date for such vote, or if no record
date has been established,  on the date such vote is taken. Any shares of Series
A  Preferred  Stock  held by the  Corporation  or any entity  controlled  by the
Corporation  shall not have voting rights  hereunder and shall not be counted in
determining  the  presence  of a quorum.  Notwithstanding  the above,  until the
Approval Date, the holders of Series A Preferred  Stock shall not be entitled to
vote in any election of directors of the Corporation,  except to the extent that
exercise of such voting  rights  would not cause a violation  of Rule 4460(i) of
the National Association of Securities Dealers Market Place Rules.

                  B. Class Voting  Rights.  In addition to any vote specified in
Section VII.A., so long as at least 5% of the shares of Series A Preferred Stock
shall be outstanding, the Corporation shall not, without the affirmative vote or
consent of the  holders of at least 50% of all  outstanding  Series A  Preferred
Stock, voting separately as a class, (i) amend, alter or repeal any provision of
the  Certificate  of  Incorporation  or  the  Bylaws  of the  Corporation  so as
adversely  to  affect  the   relative   rights,   preferences,   qualifications,
limitations or  restrictions of the Series A Preferred  Stock,  (ii) approve the
alteration  or change to the rights,  preferences  or privileges of the Series A
Preferred Stock,  (iii) incur or voluntarily repay prior to the maturity thereof
any  indebtedness  in excess of $100,000 or (iv) authorize or issue, or increase
the authorized  amount of, any equity security  ranking prior to, or on a parity
with,  the Series A Preferred  Stock (other than  additional  Series A Preferred
Stock approved in writing by the holders of greater than 50% of the  outstanding
shares of Series A  Preferred  Stock)  (A) upon a  Liquidation  Event,  (B) with
respect to the payment of any dividends or  distributions or (C) with respect to
voting rights (except for class voting rights required by law).

         VIII.   Outstanding   Shares.  For  purposes  of  this  Certificate  of
Designation,  a share of Series A Preferred Stock, when issued,  shall be deemed
outstanding  except  (i) from the date,  or the deemed  date,  of  surrender  of
certificates evidencing shares of Series A Preferred Stock, all shares of Series
A Preferred Stock converted into Common Stock and (ii) from the date of


                                      -20-


<PAGE>

registration of transfer,  all shares of Series A Preferred Stock held of record
by the Corporation or any subsidiary of the Corporation.

         IX.  Status of  Acquired  Shares.  Shares of Series A  Preferred  Stock
received  upon  conversion  pursuant  to Section  IV or  Section V or  otherwise
acquired by the  Corporation  will be restored to the status of  authorized  but
unissued shares of Preferred  Stock,  without  designation as to class,  and may
thereafter be issued, but not as shares of Series A Preferred Stock.

         X. Preemptive  Rights.  The Series A Preferred Stock is not entitled to
any  preemptive  or  subscription  rights in  respect of any  securities  of the
Corporation.

         XI.  Severability  of  Provisions.  Whenever  possible,  each provision
hereof  shall be  interpreted  in a manner as to be  effective  and valid  under
applicable  law,  but if any  provision  hereof is held to be  prohibited  by or
invalid under  applicable law, such provision  shall be ineffective  only to the
extent of such  prohibition or  invalidity,  without  invalidating  or otherwise
adversely  affecting the remaining  provisions  hereof.  If a court of competent
jurisdiction  should  determine  that a  provision  hereof  would  be  valid  or
enforceable  if a period of time were  extended  or  shortened  or a  particular
percentage were increased or decreased, then such court may make such changes as
shall be necessary to render the provision in question effective and valid under
applicable law.

         XII. No Amendment nor Impairment.  The Corporation  shall not amend its
Certificate of Incorporation nor participate in any reorganization,  transfer of
assets, consolidation,  merger, dissolution,  issue or sale of securities or any
other  voluntary  action,  for the  purpose of  avoiding or seeking to avoid the
observance  or  performance  of any of the  terms to be  observed  or  performed
hereunder  by the  Corporation,  but will at all times in good  faith  assist in
carrying out all such action as may be reasonably  necessary or  appropriate  in
order to protect  the rights of the  holders  of the  Series A  Preferred  Stock
against impairment.

         XIII. Repurchase  Requirement.  The holders of Series A Preferred Stock
may,  pursuant to the Non-Approval Put (as defined and contained in the Purchase
Agreement),  elect to require the  Corporation to repurchase any or all of their
respective  shares of the Series A Preferred Stock under the  circumstances  set
forth in Section 7.27 of the Purchase Agreement.


                                      -21-


<PAGE>


                  IN  WITNESS  WHEREOF,   Stanley  C.  Erck,  President  of  the
Corporation,  acting  for  and  on  behalf  of  the  Corporation,  has  hereunto
subscribed his name on August 1, 1997.




                                      By: /s/ Stanley C. Erck
                                         -------------------------
                                             Name:  Stanley C. Erck
                                             Title: President




                                      -22-



© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission