Shire Pharmaceuticals says it has filed a legal action against US drugs firm Impax Laboratories for an alleged patent infringement.
Shire, Britain's third-largest drugmaker, said today the legal dispute concerned a move by Impax to produce a generic version of Adderall XR, which treats people who suffer from attention deficit and hyperactivity disorder and is one of Shire's key products.
Impax officials could not be immediately reached for comment.
