IMPAX Announces Ruling Related to Generic Rilutek(R)

July 27, 2007
HAYWARD, Calif., Jul 27, 2007 (BUSINESS WIRE) -- IMPAX Laboratories, Inc. (OTC:IPXL) today announced that the U.S. District Court for the District of Delaware has ruled that Aventis Pharmaceutical's patent 5,527,814 related to the use of Rilutek(R) for the treatment of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is not invalid on the grounds of anticipation. This decision comes following a remand from the Court of Appeals for the Federal Circuit in November, 2006, in which the Court of Appeals had vacated an earlier decision of patent validity and remanded for further findings relating to a specific validity issue of anticipation by a prior art patent. IMPAX's ANDA for its generic version of Rilutek (riluzole) 50mg tablets was approved on January 29, 2003 by the U.S. Food and Drug Administration, but the product has never been sold due to an injunction entered in this patent litigation and therefore the ultimate outcome of this litigation is not expected to have a material impact on the Company's financial results.

According to Wolters Kluwer Health, U.S. sales of Rilutek were $39 million in the 12 months ended May 31, 2007.

About IMPAX Laboratories, Inc.

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 markets 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, possible adverse effects resulting from the delisting of and suspension of trading in IMPAX's stock, the SEC proceeding to determine whether to suspend or revoke the registration of IMPAX's securities under section 12 of the Securities Exchange Act, IMPAX's delay in filing its 2004 Form 10-K, its Form 10-Q for each of the first three quarters of 2005 and 2006, its Form 10-K for 2005 and 2006, and its Form 10-Q for the first quarter of 2007, the actual time that will be required to complete the filing of IMPAX's delinquent periodic reports, 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.

Company Contacts:
IMPAX Laboratories, Inc.
Larry Hsu, Ph.D. President & CEO, 510-476-2000, Ext. 1111
or
Arthur Koch, CFO, 215-933-0351
www.impaxlabs.com
or
Investor Relations Contacts:
Lippert/Heilshorn & Associates, Inc.
Kim Sutton Golodetz, 212-838-3777
kgolodetz@lhai.com
or
Bruce Voss, 310-691-7100
bvoss@lhai.com
www.lhai.com