Stiefel Laboratories Will Enter Into Private Equity Minority Investment Agreement with The Blackstone Group

Partnering with The Blackstone Group provides robust platform for continued growth

CORAL GABLES, Fla. – AUGUST 9, 2007 – Stiefel Laboratories, Inc. announced today that private equity funds of The Blackstone Group have agreed to make a $500 million minority investment in Stiefel Laboratories.

“This is a carefully considered strategy,” company President and CEO Charles W. Stiefel said. “Stiefel Laboratories is on a strong upward trajectory that is sustained by our product development, licensing, and acquisition activities. Taking on a private equity partner increases our ability to accelerate that upward trend.”

The company considered a number of private equity firms and selected Blackstone through an evaluative process that examined a number of factors, including the compatibility of the two companies.

Charles Stiefel emphasized the opportunities the deal brings to Stiefel Laboratories. “Following this investment, we will be in an even better position to make additional investments in products, technologies and companies,” he said.

The private equity funds of Blackstone will make a minority investment in Stiefel Laboratories. In connection therewith, Blackstone will have the right to designate for election one member of the company’s board of directors. The investment will be accomplished pursuant to the issuance by Stiefel Laboratories of a new class of preferred stock to the private equity funds of Blackstone. No current shareholders will sell any shares as part of the transaction.

The closing of the transaction is subject to customary closing conditions. The closing is expected to occur in the next couple of days.

Stiefel Laboratories, the world’s largest independent pharmaceutical company specializing in dermatology, will continue to be privately held, and the Stiefel family will retain control and continue to hold a majority-share ownership of the company.

Chinh Chu, Senior Managing Director of Blackstone, commented, “We are excited to invest alongside the Stiefel family. Stiefel Laboratories has a robust and diversified product portfolio across the entire field of dermatology, with numerous pipeline products and international expansion opportunities. We are very impressed with Stiefel’s world-class management team, and we look forward to working with the team to continue the company’s strong growth trajectory.”

By many indicators, 2007 will be a banner year for Stiefel Laboratories. In addition to commemorating its 160th anniversary, the company celebrated the grand opening of its new research and development facility in Research Triangle Park, N.C., will launch two innovative prescription products using the VersaFoam® technology it acquired through the December 2006 acquisition of Connetics Corporation, and will enter the aesthetic dermatology market with its novel REVALÉSKIN™ skin care products.

Deutsche Bank Securities Inc. acted as exclusive financial advisor and Willkie Farr & Gallagher LLP acted as legal counsel to Stiefel Laboratories on this transaction. Merrill Lynch & Co. and Simpson Thacher & Bartlett LLP acted as advisors to Blackstone.

About Stiefel Laboratories, Inc.

Founded in 1847, Stiefel Laboratories (a privately held company) is the world’s largest independent pharmaceutical company specializing in dermatology. The company manufactures and markets a variety of prescription and non-prescription dermatological products. Some of the newest and bestknown brands include Duac® Topical Gel (clindamycin, 1% – benzoyl peroxide, 5%); Evoclin® (clindamycin phosphate) Foam, 1%; Luxiq® (betamethasone valerate) Foam, 0.12%; MimyX®; Olux™ (clobetasol propionate) Foam, 0.05%; Olux-E™ (clobetasol propionate) Foam, 0.05%; Soriatane® (acitretin) capsules; Verdeso™ (desonide) Foam, 0.05%; Brevoxyl® Creamy Wash (benzoyl peroxide, 4% or 8%) packaged in the convenient new Brevoxyl Acne Wash Kit; Oilatum®; Physiogel®; Stieprox® (ciclopirox olamine); and Sarna®. Its wholly-owned global network is comprised of more than 30 subsidiaries, manufacturing plants in six countries, research and development facilities on four continents, and products marketed in more than 100 countries around the world.

Stiefel Laboratories supplements its R&D efforts by seeking strategic partnerships and acquisitions around the world. To learn more about Stiefel Laboratories, Inc. visit www.stiefel.com.

About The Blackstone Group

The Blackstone Group (NYSE: BX) is a leading global alternative asset manager and provider of financial advisory services. Its alternative asset management businesses include the management of corporate private equity funds, real estate opportunity funds, funds of hedge funds, mezzanine funds, senior debt funds, proprietary hedge funds and closed-end mutual funds. The Blackstone Group also provides various financial advisory services, including mergers and acquisitions advisory, restructuring and reorganization advisory and fund placement services. For more information, visit www.blackstone.com.