Magistrate Recommends Denial of CollaGenex Pharmaceuticals Motion for Preliminary Injunction to Prevent Launch of Generic Forms of Periostat by IVAX and CorePharma.

NEWTOWN, Pa. -- CollaGenex Pharmaceuticals, Inc. (Nasdaq:CGPI) today announced that Magistrate Judge Pohorelsky of the United States District Court for the Eastern District of New York had issued a report late in the day on March 16, 2005, recommending denial of its motion seeking to prevent the launch of generic forms of Periostat(R) by IVAX Pharmaceuticals Inc. and CorePharma, LLC (the "Defendants"). CollaGenex has ten days within which to file objections to the report. In the event the District Court issues an order consistent with the recommendation of the Magistrate Judge, the Defendants will be able to market and sell generic equivalents of Periostat as soon as they are approved by the FDA. Neither IVAX nor CorePharma has yet indicated that it has received FDA approval.

Periostat is the registered trademark of CollaGenex's proprietary 20 mg tablets of doxycycline hyclate approved by the FDA as the only systemic adjunct to scaling and root planing for the treatment of adult periodontitis. In lawsuits filed in October 2004, CollaGenex alleges that the Defendants' submissions of Abbreviated New Drug Applications covering their 20 mg tablets of doxycycline hyclate infringe United States Patent RE 34,656, of which CollaGenex is the exclusive licensee. This litigation is ongoing.

Colin Stewart, president and chief executive officer of CollaGenex, said "The recommendation is obviously a disappointment to us. We are studying the recommendation and considering all of our options, including filing objections. However, if we are unsuccessful and one or more generic forms of Periostat are launched, we expect our sales of Periostat, including Mutual's branded version of Periostat, to decline significantly. We will execute contingency plans to respond to events as they occur. Meanwhile, we have made significant progress in our Oracea(TM) Phase III clinical trials in rosacea patients and, regardless of the outcome of the current litigation, we will continue to execute our long term strategy. We believe our IMPACs(TM) and Restoraderm(R) technologies form the basis for an exciting platform on which we intend to build the future of CollaGenex and continue to bring new medical therapies to our patients."

CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company focused on providing innovative medical therapies to the dental and dermatology markets. Currently, the Company's professional dental pharmaceutical sales force markets Periostat, which is indicated as an adjunct to scaling and root planing for the treatment of adult periodontitis. Periostat is the first and only pharmaceutical to treat periodontal disease by inhibiting the enzymes that destroy periodontal support tissues and by enhancing bone protein synthesis. The dental sales force also promotes Atridox(R), Atrisorb FreeFlow(R) and Atrisorb-D FreeFlow(R), which are products of QTL, Inc., the successor to Atrix Laboratories, Inc., for the treatment of adult periodontitis. The Company's professional dermatology sales force markets Pandel(R), a prescription topical corticosteroid licensed from Altana, Inc.

Research has shown that certain unique properties of the tetracyclines discovered during the development of Periostat may be applicable to other diseases involving inflammation and/or destruction of the body's connective tissues. CollaGenex is further evaluating Periostat and other IMPACS compounds, including Oracea, to assess whether they are safe and effective in these other applications. Oracea is currently in Phase III clinical trials to evaluate its effectiveness in treating rosacea, a dermatological condition. In addition, CollaGenex has acquired the Restoraderm(R) technology, a unique, proprietary dermal drug delivery system, and plans to develop a range of topical dermatological products with enhanced pharmacologic and cosmetic properties.

To receive additional information on the Company, please visit our Web site at www.collagenex.com, which does not form part of this press release.

Forward-Looking Statements

Statements in this press release regarding management's future expectations, beliefs, goals, plans or prospects, including statements relating to the Company's intellectual property rights, its ongoing litigation with IVAX and CorePharma, contingency plans and its future development efforts, may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. CollaGenex' actual results could differ materially from those stated or implied in forward-looking statements due to a number of factors, including those factors contained in CollaGenex' most recent Annual Report on Form 10-K for the year ended December 31, 2004 under the section "Additional Factors That May Affect Future Results" as well as other documents that may be filed by CollaGenex from time to time with the Securities and Exchange Commission. Forward-looking statements include statements regarding CollaGenex' expectations, beliefs, intentions or strategies regarding the future and can be identified by forward-looking words such as "anticipate", "believe", "could", "estimate", "expect", "intend", "may", "should", "will", and "would" or similar words. CollaGenex assumes no obligations to update the information included in this press release.

Periostat(R) is a registered trademark and Periostat-MR(TM), Restoraderm(TM), IMPACS(TM) and Oracea(TM) are trademarks of CollaGenex Pharmaceuticals, Inc.

All other trade names, trademarks or service marks are the property of their respective owners and are not the property of CollaGenex Pharmaceuticals, Inc. or any of our subsidiaries.

Pandel(R) is a trademark of Taisho Pharmaceuticals.

Atridox(R), Atrisorb(R) and Atrisorb-D(R) are registered trademarks of QLT USA, Inc.