<PAGE>
EXHIBIT 1
JOINT FILING AGREEMENT
Pursuant to and in accordance with Rule 13d-1(k)(1) under the
Securities Exchange Act of 1934, the undersigned hereby agree to jointly file
the Schedule 13D dated October 23, 2000 and any amendments thereto with respect
to the beneficial ownership by each of the undersigned of shares of common stock
of Impax Laboratories, Inc. Such joint filings may be executed by one or more of
us on behalf of each of the undersigned.
This Agreement may be executed in any number of counterparts, each of
which shall be deemed an original.
Executed this 23rd day of October, 2000.
CHEMICAL COMPANY OF MALAYSIA BERHAD
/s/ Oh Kim Sun, Group Executive Director
----------------------------------------
Oh Kim Sun, Group Executive Director
/s/ Oh Kim Sun
----------------------------------------
Oh Kim Sun
12
<PAGE>
APPENDIX 1
ADDRESS, ORGANIZATION AND PRINCIPAL BUSINESS OF EACH REPORTING PERSON REQUIRED
BY ITEM 2 AND OTHER PERSONS REQUIRED BY ITEM 5
<TABLE>
<CAPTION>
REPORTING PERSON PRINCIPAL BUSINESS AND OFFICE PLACE OF ORGANIZATION PRINCIPAL OCCUPATION
-------------------------------- ----------------------------- ----------------------- ----------------------
<S> <C> <C> <C>
Chemical Company of Malaysia Wisma Sime Darby Malaysia
Berhad 14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Oh Kim Sun Wisma Sime Darby Malaysia Chief Executive
14 Jalan Raja Laut Officer, CCM
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
</TABLE>
13
<PAGE>
APPENDIX 2
INFORMATION ABOUT REPORTING PERSONS REQUIRED BY ITEM 2
EXECUTIVE OFFICERS AND DIRECTORS OF
CHEMICAL COMPANY OF MALAYSIA BERHAD.
Name: Tan Sri Dato' Mohd Sheriff B Mohd Kassim
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Chairman
Name: Dato' Lim Say Chong
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Group Managing Director
Name: Oh Kim Sun
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Group Executive Director
Name: Tan Sri Dato' Thong Yaw Hong
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Director
14
<PAGE>
Name: Tan Sri Dato' Dr. Khoo Kay Peng
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Director
Name: Dato' N Sadasivan
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Director
Name: Tuan Haji Hassan Jaafar
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Director
Name: En Paisol bin Ahmad
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Director
Name: Hiu Woong Choong
Citizenship: Malaysia
Business Address: Wisma Sime Darby
14 Jalan Raja Laut
P.O. Box 10284
50708 Kuala Lumpur
Malaysia
Title: Director
15