Impax Laboratories Confirms Patent Challenge Relating to OXYCONTIN® 10, 15, 20, 30, 40, 60, and 80 mg

HAYWARD, Calif.--(BUSINESS WIRE)--Impax Laboratories, Inc. (NASDAQ: IPXL) today confirms that it has initiated a challenge of the patents listed by Purdue Pharma L.P. in connection with Oxycontin® (Oxycodone hydrochloride) 10, 15, 20, 30, 40, 60, and 80 mg controlled-release tablets.

Impax filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic version of Oxycontin® with the U.S. Food & Drug Administration (FDA). Following receipt of the notice from FDA that Impax’s ANDA had been accepted for filing, Impax notified the New Drug Application holder and patent owners of its paragraph IV certification.

On April 8, 2011, Purdue Pharma L.P., The P.F. Laboratories, Inc., Purdue Pharmaceuticals L.P., Rhodes Technologies, Board of Regents of the University of Texas System, and Grunenthal GBMH filed suit for patent infringement against Impax Laboratories, Inc. in the United States District Court for the Southern District of New York. This action formally initiates the patent challenge process under the Hatch-Waxman Act.

Once the ANDA is approved by FDA, Global Pharmaceuticals, Impax’s generic division, will commercialize the products.

Oxycontin® is indicated for the management of moderate to severe pain when a continuous, around-the-clock opioid analgesic is needed for an extended period of time. According to Wolters Kluwer Health, aggregate U.S. sales of Oxycontin® since launch were approximately $2.8 billion for the twelve months ending January, 2011.

About Impax Laboratories, Inc.

Impax Laboratories, Inc. (“Impax”) 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, Philadelphia and Taiwan 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 the Company’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, the effect of current economic conditions on the Company’s industry, business, financial position and results of operations, the ability to maintain an effective system of internal control over financial reporting, fluctuations in revenues and operating income, the ability to successfully develop and commercialize pharmaceutical products, reductions or loss of business with any significant customer, the impact of competition, the ability to sustain profitability and positive cash flows, any delays or unanticipated expenses in connection with the operation of the Taiwan facility, the effect of foreign economic, political, legal and other risks on operations abroad, the uncertainty of patent litigation, consumer acceptance and demand for new pharmaceutical products, the difficulty of predicting Food and Drug Administration filings and approvals, the inexperience of the Company in conducting clinical trials and submitting new drug applications, the ability to successfully conduct clinical trials, reliance on alliance and collaboration agreements, the availability of raw materials, the ability to comply with legal and regulatory requirements governing the healthcare industry, the regulatory environment, the ability to protect the Company’s intellectual property, exposure to product liability claims and other risks described in the Company’s periodic reports filed 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.