Global speciality group Shire Pharmaceuticals is taking Watson Pharmaceuticals to court claiming that the US group has infringed on patents for its attention-deficit hyperactivity disorder drug Adderall XR.

The group said its subsidiary Shire LLC has filed a lawsuit in the US District Court for the Southern District of New York against Watson and its subsidiaries for infringement of Shire’s US patents and also for breach of contract.

The move was spurred by an Abbreviated New Drug Application (ANDA) recently filed by Watson seeking to market generic versions of 5mg, 10mg, 15mg, 20mg, 25mg and 30mg of Adderall XR (mixed amphetamine salts) before Shire's intellectual protection for its drug expired.

According to Shire, all of the generic strengths infringe the patents-in-suit, and its lawsuit also claims that Watson has violated existing settlement and license agreements between the companies dating back to November 2007, following an ANDA filed by the latter in 2006 also looking for clearance to sell copycat versions of Adderall XR.