CollaGenex Pharmaceuticals Provides Update on Oracea Patent.

NEWTOWN, Pa. -- CollaGenex Pharmaceuticals, Inc. (NASDAQ:CGPI) today announced that the U.S. Patent and Trademark Office (USPTO) has posted on its Website a nonfinal rejection of CGPI's patent application for Oracea.

On May 17, 2006, the Company announced that it had submitted additional information to the USPTO that may be relevant to the examination of U.S. Patent Application, Serial No. 10/117,709. This application relates to the use of sub-antimicrobial and non-antimicrobial tetracyclines for the treatment of acne and acne rosacea, including Oracea(TM) and incyclinide. The USPTO had previously issued a Notice of Allowance of this patent application in August 2005, and a patent was scheduled to issue on May 23, 2006. The examination to review this additional information is ongoing. In addition to this patent, there are four additional patents issued or pending covering Oracea.

Colin W. Stewart, president and chief executive officer of CollaGenex, stated, "This nonfinal rejection by the patent office is an expected and routine part of the patent review process. Indeed, we received a similar rejection of the same patent application several months prior to receiving the original notice of allowance from the USPTO in August 2005. We continue to expect that valid patent claims will issue covering Oracea and incyclinide. Moreover, we do not expect that this nonfinal rejection will affect our anticipated timing and outcome of the review process."

Mr. Stewart concluded, "Today, we concluded a very successful launch meeting for Oracea and we are excited that our sales force will begin detailing the product tomorrow. Based on the feedback we have received from the dermatology community, we expect an enthusiastic reception for Oracea."

CollaGenex Pharmaceuticals, Inc. is a specialty pharmaceutical company currently focused on developing and marketing proprietary, innovative medical therapies to the dermatology market. CollaGenex's professional dermatology sales force 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 recently launched Oracea, the first FDA-approved systemic product for the treatment of rosacea, and 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 developing COL-118, utilizing the technology acquired in the SansRosa acquisition, as a preclinical topical compound for the treatment of redness associated with rosacea and other skin disorders.

CollaGenex also 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 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 March 31, 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.