IMPAX Comments on Shire's Lawsuit Related to Generic Version of Adderall XR

December 30, 2003

HAYWARD, Calif., Dec 30, 2003 (BUSINESS WIRE) -- IMPAX Laboratories, Inc. (Nasdaq:IPXL) today announced that Shire Laboratories Inc., a subsidiary of Shire Pharmaceuticals Group plc (Nasdaq:SHPGY; TSX:SHQ; LSE:SHP), has filed a lawsuit against the Company in the United States District Court for the district of Delaware alleging patent infringement related to IMPAX's filing of an Abbreviated New Drug Application (ANDA) for a generic version of Adderall XR(R) 30mg Capsules.

Adderall XR is a once daily, extended-release, mixed salts of a single-entity amphetamine product used for the treatment of Attention Deficit and Hyperactivity Disorder (ADHD). According to NDCHealth, U.S. sales of Adderall XR Capsules were approximately $550 million in the twelve months ended October 31, 2003.

The U.S. Food and Drug Administration (FDA) accepted for review IMPAX's application to market a generic version of Shire's Adderall XR 30 mg capsules in September 2003. IMPAX's submission included a Paragraph IV certification stating the Company believes its product does not infringe upon Shire's listed patents.

Barry R. Edwards, Co-Chief Executive Officer of IMPAX Laboratories, commented, "This type of lawsuit has become standard practice in the industry and we are not surprised that Shire filed this action. It is a routine part of the process we need to go through in getting these complex generic products to market. We believe our product as formulated does not infringe upon Shire's patents and will provide a safe, effective and affordable alternative in the marketplace. We will proceed accordingly to defend our application."

IMPAX currently has 20 applications pending at the FDA, including four tentatively approved, which address approximately $7.1 billion in U.S. branded product sales for the 12 months ended October 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: www.impaxlabs.com.

"Safe Harbor" statement under the Private Securities Litigation Reform Act of 1995:

To the extent any statements made in this news release contain information that is not historical; these statements are forward-looking in nature and express the beliefs and expectations of management. Such statements are based on current expectations and involve a number of known and unknown risks and uncertainties that could cause Impax's future results, performance or achievements to differ significantly from the results, performance or achievements expressed or implied by such forward-looking statements. Such risks and uncertainties include, but are not limited to, Impax's ability to obtain sufficient capital to fund its operations, the difficulty of predicting FDA filings and approvals, consumer acceptance and demand for new pharmaceutical products, the impact of competitive products and pricing, Impax's ability to successfully develop and commercialize pharmaceutical products, Impax's reliance on key strategic alliances, the uncertainty of patent litigation, the availability of raw materials, the regulatory environment, dependence on patent and other protection for innovative products, exposure to product liability claims, fluctuations in operating results and other risks detailed from time to time in Impax's filings with the Securities and Exchange Commission. Forward-looking statements speak only as to the date on which they are made, and Impax undertakes no obligation to update publicly or revise any forward-looking statement, regardless of whether new information becomes available, future developments occur or otherwise.

SOURCE: IMPAX Laboratories, Inc.

IMPAX Laboratories, Inc.
Barry R. Edwards, 215-289-2220, ext. 1771
Larry Hsu, Ph.D., 510-476-2000, ext. 1111
Cornel C. Spiegler, 215-289-2220, ext. 1706
www.impaxlabs.com
or
Investor Relations Contacts:
Lippert/Heilshorn & Associates, Inc.
Kim Sutton Golodetz (kgolodetz@lhai.com)
212-838-3777
or
Bruce Voss (bvoss@lhai.com)
310-691-7100
www.lhai.com
Customize your Business Wire news & multimedia to match your needs.
Get breaking news from companies and organizations worldwide.
Logon for FREE today at www.BusinessWire.com.