Pfizer sues Impax over Detrol patent

HAYWARD, Calif. Impax Laboratories is being sued for patent infringement by Pfizer, according to pulished reports.

Pfizer is suing because Impax filed an application with the Food and Drug Administration to release a generic version of Pfizer’s overactive bladder drug Detrol LA (tolterodine tartrate) in 2 mg and 4 mg.

“This suit is just a delaying tactic to prevent patients from accessing generic drugs sooner,” Impax chief executive officer Larry Hsu said in a statement.

According to Wolters Kluwer Health, U.S. sales of Detrol LA capsules were approximately $857 million in the 12 months ended Jan. 31, 2008.