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                                 EXHIBIT 10.3(c)

                          THIRD AMENDMENT TO AGREEMENT

         This Third Amendment to Agreement ("Third Amendment"), is made by and
between Atrix Laboratories, Inc., a Delaware corporation ("Atrix") with its
principal place of business at 2579 Midpoint Drive, Fort Collins, Colorado
80525-4417, and Block Drug Corporation, a New Jersey corporation ("Block") with
its principal place of business at 105 Academy Street, Jersey City, New Jersey
07302-9988, as of this 4th day of February, 1998, with respect to that certain
Agreement dated as of December 16, 1996 (the "Agreement") between Atrix and
Block, as amended by that certain First Amendment to Agreement dated as of June
10, 1997, and as further amended by that certain Second Amendment to Agreement
dated as of July 31, 1997.

         WHEREAS, the parties desire to further amend the Agreement on the terms
and conditions set forth herein.

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby amend
the Agreement as follows:

         1.       Section 3.02(a)(i) is amended to read as follows:

                  (i)      following receipt by Block of Notice from Atrix that
                           the FDA has issued an Approvable Letter for the NDA
                           for Atridox(TM) with the following indication:
                           "Atridox(TM) is indicated for gain in clinical
                           attachment and reduction in probing depth in patients
                           with chronic adult periodontitis" (the "Atridox(TM)
                           NDA"), the sum of [**] if said Approvable Letter is
                           issued on or before June 30, 1998, or [**] if said
                           Approvable Letter is issued after June 30, 1998.

         2. Section 8.04(a) of the Agreement is amended to read as follows:

                  (a)      Subject to the provisions of the following sections
                           8.04(a)(i) and 8.04(a)(ii), each party shall pay
                           fifty percent (50%) of the cost of all Developments
                           approved by Block (the "Development Expenses").

                           (i)      Notwithstanding the provisions of section
                                    8.04(a), Atrix shall be solely responsible
                                    for payment of the first [**] of Development
                                    Expenses incurred in connection with
                                    Developments covered by the Agreement,
                                    thereafter; Block shall be responsible for
                                    payment of fifty percent (50%) of
                                    Development Expenses for such Developments.

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**       Confidential Treatment Requested by Atrix on March 23, 1999



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                           (ii)     The Steering Committee shall solicit bids
                                    from Atrix and from third parties and
                                    determine which is the most appropriate and
                                    award the contract for the Development to
                                    the successful bidder.

         3.       In the event that the Approvable Letter for the Atridox(TM)
                  NDA is not issued by the FDA on or before June 30, 1998, then
                  the terms and conditions of Paragraphs 1 and 2 of this Third
                  Amendment shall be null and void and the original terms and
                  conditions of Sections 3.02(a)(i) and 8.04 of the Agreement
                  shall be reinstated, effective as of the date of this Third
                  Amendment.

         4.       All capitalized terms used and not otherwise defined herein
                  shall have the same meanings as set forth in the Agreement.

         5.       Except as expressly modified by the terms hereof, the terms
                  and provisions of the Agreement shall remain in full force and
                  effect as originally written.

         6.       Signatures on this Third Amendment may be communicated by
                  facsimile transmission and shall be binding upon the parties
                  transmitting the same by facsimile transmission. Counterparts
                  with original signatures shall be provided to the other party
                  within five (5) days of the applicable facsimile transmission;
                  provided, however, that failure to provide the original
                  counterpart shall have no affect on the validity or binding
                  nature of this Third Amendment. If executed in counterparts,
                  this Third Amendment will be as effective as if simultaneously
                  executed.

         IN WITNESS WHEREOF, the parties hereto have executed this Third
Amendment as of the date first written above.



ATRIX LABORATORIES, INC.                     BLOCK DRUG CORPORATION


By /s/ John E. Urheim                      By /s/ Michael C. Alfano         
  -------------------------------            ----------------------------------
   John E. Urheim, Vice Chairman              Michael C. Alfano, Senior Vice
   and Chief Executive Officer                President Research and Technology