HAYWARD, Calif.--(BUSINESS WIRE)--IMPAX Laboratories, Inc. (OTC:IPXL) today confirmed reports that it has provided notice to Endo Pharmaceuticals Holdings Inc. and Penwest Pharmaceuticals Co. that it has submitted an Abbreviated New Drug Application (ANDA) for oxymorphone hydrochloride extended-release tablets CII, generic of Opana® ER, to the U.S. Food and Drug Administration (FDA). IMPAX’s ANDA, as amended, contains a Paragraph IV certification stating that the Company believes its product does not infringe US Patent No. 7,276,250, or that the patent is invalid or unenforceable. Following an acceptance for filing by the FDA the Company was informed by the agency that it has rescinded its initial acceptance. IMPAX believes that the rescission is inappropriate and is working with the FDA to correct any deficiencies of the ANDA.
