<PAGE>
P R O X Y
Algos Pharmaceutical Corporation
1333 Campus Parkway
Neptune, NJ 07753-6815
This proxy is solicited on behalf of the Board of Directors for the Special
Meeting on , 2000.
The undersigned hereby appoints and as proxies with the
powers the undersigned would possess if personally present, and with full power
of substitution, to vote all common shares of the undersigned in Algos at the
special meeting of stockholders to be held at on , 2000 at
(local time), and at any adjournment of this special meeting, upon all subjects
that may properly come before the meeting, including the matters described in
the proxy statement/prospectus furnished with this proxy card, subject to any
directions indicated on the other side of the proxy card. If no directions are
given, the proxies will vote in accord with the Directors' recommendations on
the subjects listed on the other side of the proxy card. Please sign on the
other side and return promptly to . If you do not sign and return a
proxy card, vote by telephone or Internet, or attend the meeting and vote by
ballot, your shares will not be voted.
Form of Proxy Card-1
<PAGE>
[X] Please mark votes as in this example.
Your Board of Directors recommends a vote "FOR" item 1:
<TABLE>
<CAPTION>
FOR AGAINST ABSTAIN
----- ------- -------
<C> <S> <C> <C> <C>
1. To approve and adopt the merger agreement in [_] [_] [_]
connection with the merger of Algos
Pharmaceutical Corporation with and into
Endo Inc., a newly formed, wholly owned
subsidiary of Endo Pharmaceuticals Holdings Inc.
</TABLE>
MARK HERE [_] IF YOU PLAN TO ATTEND THE SPECIAL MEETING.
MARK HERE [_] IF YOU ELECT TO RECEIVE NON-TRANSFERABLE WARRANTS IN THE MERGER.
Signature(s): Date:
Please sign this proxy as name(s) appears above and return it promptly
whether or not you plan to attend the meeting. If signing for a corporation or
partnership or as agent, attorney or fiduciary, indicate the capacity in which
you are signing. If you do attend the meeting and decide to vote by ballot,
that vote will supersede this proxy.
Form of Proxy Card-2
