IMPAX Announces Favorable Decision in Claritin Patent Appeal

August 4, 2003

HAYWARD, Calif.--(BUSINESS WIRE)--Aug. 4, 2003--IMPAX Laboratories, Inc. (Nasdaq:IPXL - News) announced today that the Court of Appeals for the Federal Circuit in Washington, D.C. upheld a lower court decision that ruled against certain claims by Schering-Plough Corporation (NYSE:SGP - News) of U.S. Patent No. 4,569,716 (the '716 patent) in litigation relating to the antihistamine product Claritin® (loratadine).

"This ruling adds to our recent successes in the courtroom and our efforts to bring more affordable pharmaceuticals to consumers," said Barry R. Edwards, Co-Chief Executive Officer of IMPAX. "This ruling should close the book on Schering's efforts to block the introduction of our generic versions of Claritin-D 12-hour and Claritin Reditabs," he added. "Additional litigation on a formulation patent on our generic version of Claritin-D 24-hour is, however, still pending in the courts."

The Company continues to ship Loratadine and Pseudoephedrine Sulfate (5mg/120mg) 12-hour Extended Release Tablets to Schering-Plough and Wyeth under previously announced agreements for the over-the-counter market.

IMPAX has 20 applications pending at the FDA, including three tentatively approved that address approximately $6.2 billion in U.S. branded product sales for the twelve months ended May 31, 2003. Fifteen of these filings were made under Paragraph IV of the Hatch-Waxman Amendments.

IMPAX Laboratories, Inc. is a technology based specialty pharmaceutical company applying its formulation expertise and drug delivery technology to the development of controlled-release and specialty generics in addition to the development of branded products. IMPAX markets its generic products through its Global Pharmaceuticals division and intends to market its branded products through the IMPAX Pharmaceuticals division. Additionally, where strategically appropriate, IMPAX has developed marketing partnerships to fully leverage its technology platform. IMPAX Laboratories is headquartered in Hayward, California, and has a full range of capabilities in its Hayward and Philadelphia facilities. For more information, please visit the Company's Web site at: