Exhibit 3.3


                            CERTIFICATE OF AMENDMENT
                                       OF
                          CERTIFICATE OF INCORPORATION



CHEMEX PHARMACEUTICALS, INC., a corporation organized and existing under and by
virtue of the General Corporation Law of the State of Delaware,

DOES HEREBY CERTIFY:

FIRST: That at a meeting of the Board of Directors of Chemex Pharmaceuticals,
Inc., resolutions were duly adopted setting forth a proposed amendment of the
Certificate of Incorporation of said corporation, declaring said amendment to be
advisable and calling a meeting of the stockholders of said corporation for
consideration thereof. The resolution setting forth the proposed amendment is as
follows:

         "RESOLVED, that Article V, Section A of the Certificate of
         Incorporation of this corporation be amended by deleting said Article
         V, Section A in its entirety and substituting the following therefor:

                  'A.  The  aggregate number of shares of common stock which the
                   Corporation shall have authority to issue is twenty-two
                   million (22,000,000) shares with a par value of four cents
                   ($0.04) per share.'"

SECOND: That thereafter, pursuant to the resolution of its Board of Directors, a
meeting of the stockholders of said corporation was duly called and held, upon
notice in accordance with Section 222 of the General Corporation Law of the
State of Delaware at which meeting the necessary number of shares as required by
statute were voted in favor of the amendment.

THIRD:  That said amendment was duly adopted in accordance  with the provisions
of Section 242 of the General  Corporation Law of the State of Delaware.

                                      -2-




FOURTH:  That the capital of said corporation shall not be reduced under or by 
reason of said amendment.

IN WITNESS WHEREOF, said Chemex Pharmaceuticals, Inc. has caused this
certificate to be signed by Herbert H. McDade, Jr., its President, and Ralph L.
Poucher, its Secretary, this 13th day of August, 1992.


                                                BY:  /s/ Herbert H. McDade, Jr.
                                                   -----------------------------
                                                     Herbert H. McDade, Jr.


                                            ATTEST:  /s/ Ralph L. Poucher
                                                   -----------------------------
                                                     Ralph L. Poucher