The following patents are listed in Orange Book for Tramadol hydrochloride 100 mg, 200 mg and 300 mg ER tablets (Ultram ER):
US6254887 (Assignee: Euro-Celtique S.A ; Expiry: May 10, 2014): The patent covers A controlled release oral pharmaceutical preparation suitable for dosing every 24 hours comprising a substrate comprising a pharmaceutically effective amount of tramadol or a salt thereof; said substrate coated with a controlled release coating; said preparation having a dissolution rate in vitro when measured using the Ph. Eur. Paddle Method at 100 rpm in 900 ml 0,1 N hydrochloric acid at 37.degree. C. and using UV detection at 270 nm, between 0 and 50% tramadol released after 1 hour; between 0 and 75% tramadol released after 2 hours; between 3 and 95% tramadol released after 4 hours; between 10 and 100% tramadol released after 8 hours; between 20 and 100% tramadol released after 12 hours; between 30 and 100% tramadol released after 16 hours; between 50 and 100% tramadol released after 24 hours; and greater than 80% tramadol released after 36 hours, by weight, said preparation providing a therapeutic effect for about 24 hours after oral administration.
US7074430 (Assignee: Euro-Celtique S.A ; Expiry: May 10, 2014): The patent covers a solid controlled release oral dosage form, comprising, a therapeutically effective amount of tramadol or a pharmaceutically acceptable salt thereof incorporated into a normal release matrix, said matrix overcoated with a controlled release coating comprising a polymethacrylate or a water insoluble cellulose, said dosage form providing a therapeutic effect for at least about 24 hours.
The holder of the patent Purdue Pharma (and partners like Biovail, Napp and ORTHO-McNEIL) were in litigation with generic player Par for this product in United States District Court for the District of Delaware since 2007.
Further, Judge rejected Par’s inequitable conduct charges (during prosecution of disputed patents with USPTO) against innovator Purdue and opined that patents is not invalid due to inequitable conduct.
Labopharm comments on judgment in Purdue patent litigation
This judgment could permit Par to market its generic formulation of Ultram ER in the U.S., should it receive final regulatory approval from the U.S. Food and Drug Administration. Although Labopharm is not a party to this action, if Par was to launch its generic formulation of Ultram ER, it could impact U.S. sales of Labopharm's own once-daily tramadol product, Ryzolt(TM), which is marketed in the U.S. by Purdue. Ultram ER, and therefore any generic version of it, is not A/B rated to Ryzolt, meaning it cannot be substituted for Ryzolt at the pharmacy. Labopharm is currently in discussions with Purdue to evaluate next steps in this matter, including a potential appeal of the decision.
