Impax hit with lawsuit regarding Ultram patent

HAYWARD, Calif. Impax Laboratories faces a patent infringement suit in the United States District Court for the District of Delaware over its application to the Food and Drug Administration for the approval of a generic version of Ultram extended-release tablets, Impax announced Tuesday.

The plaintiffs in the suit are Purdue Pharma Products, Napp Pharmaceutical Group, Biovail Laboratories International and Ortho-McNeil. They allege that Impax’s application violates U.S. Patent No. 6,254,887.

The drug, in 100 mg tablets, is known generically as tramadol hydrochloride and is approved for the treatment of moderate to moderately severe chronic pain. The brand version had U.S. sales of $62 million between June 2007 and June of this year, according to Wolters Kluwer Health.