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.
