CollaGenex Pharmaceuticals Announces USPTO Allowance of Oracea Patent.

NEWTOWN, Pa. -- CollaGenex Pharmaceuticals, Inc. (NASDAQ:CGPI) today announced that the U.S. Patent and Trademark Office (USPTO) has listed the status of its patent application No. 10/117,709, covering Oracea(TM) (the '709 Patent Application), as "allowed." This patent covers the use of sub-antimicrobial tetracyclines for the treatment of acne and acne rosacea, including Oracea. CollaGenex received FDA approval for Oracea on May 26, 2006 and is currently marketing Oracea to the U.S. dermatology community.

In August 2005, the USPTO issued a notice of allowance of the '709 Patent Application. However, prior to its scheduled issuance in May 2006, CollaGenex requested that the USPTO continue its examination of the '709 Patent Application in light of new references identified by CollaGenex that could be considered relevant.

None of the references submitted by CollaGenex in its request for a continued examination relate to the use of non-antimicrobial tetracyclines for the treatment of acne and acne rosacea. Consequently, the Company agreed with the USPTO to expedite the process by focusing continuing examination on the use of sub-antimicrobial tetracyclines for the treatment of acne and acne rosacea. CollaGenex will prosecute claims relating to the use of non-antimicrobial tetracyclines to treat acne and acne rosacea, including incyclinide, in a separate divisional patent application, which was filed in 2004 and remains pending.

Colin W. Stewart, president and chief executive officer of CollaGenex, stated, "Clearly we are very pleased with this outcome and believe that it considerably strengthens our patent estate. We will prosecute the incyclinide divisional patent application in the coming months and we expect that, after examination by the USPTO, claims covering incyclinide will also issue."

CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company currently focused on developing and marketing proprietary, innovative medical therapies to the dermatology market. CollaGenex recently launched Oracea, the first FDA-approved systemic product for the treatment of rosacea. CollaGenex's professional dermatology sales force also markets Pandel(R), a prescription topical corticosteroid licensed from Altana, Inc., Alcortin(TM) (1% iodoquinol and 2% hydrocortisone), a prescription topical antifungal steroid combination, and Novacort(TM) (2% hydrocortisone acetate and 1% pramoxine HCl), a prescription topical steroid and anesthetic. Alcortin and Novacort are marketed by the Company under a Promotion and Cooperation agreement with Primus Pharmaceuticals, Inc. CollaGenex is conducting a 300-patient, Phase II dose-finding study to evaluate its second dermatology candidate, incyclinide, for the treatment of acne. CollaGenex is also conducting Phase I clinical trials to evaluate COL-118, a topical compound based on the SansRosa technology, for the treatment of redness associated with rosacea and other skin disorders.

CollaGenex additionally currently sells Periostat(R), which the Company developed as the first pharmaceutical to treat periodontal disease by inhibiting the enzymes that destroy periodontal support tissues and by enhancing bone protein synthesis, and Atridox(R), Atrisorb FreeFlow(R) and Atrisorb-D FreeFlow(R), which are products of QLT Inc., the successor to Atrix Laboratories, Inc., for the treatment of adult periodontitis.

Research has shown that certain tetracyclines can be chemically modified to remove their antibiotic effects while retaining the properties that may make them effective in treating diseases involving inflammation and/or destruction of the body's connective tissues. CollaGenex is evaluating various chemically modified tetracyclines (so called "IMPACS" compounds because they are Inhibitors of Multiple Proteases And CytokineS") to assess whether they are safe and effective in these applications. The Company has a pipeline of innovative product candidates with possible applications in dermatology and other disease states. 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.

Statements in this press release regarding management's future expectations, beliefs, intentions, goals, strategies, plans or prospects, including statements relating to the Company's plans, timing and success related to its patent applications and the launch of Oracea for the treatment of inflammatory lesions of rosacea, 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 the most recent Form 10-Q for the quarter ended June 30, 2006 under the section "Risk Factors" 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 or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Periostat(R) and Restoraderm(R) are registered trademarks and 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.

Novacort(TM) and Alcortin(TM) are trademarks of Primus Pharmaceuticals, Inc.

Pandel(R) is a trademark of Taisho Pharmaceuticals.

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