Shire Pharmaceuticals Group announced that its subsidiary Shire Laboratories Inc. has filed a lawsuit in the US District Court of Delaware against Impax Laboratories, Inc. for infringement of Shire Laboratories' US patent Nos. 6,322,819 ('819 Patent) and 6,605,300 ('300 Patent).

The lawsuit results from an ANDA (Abbreviated New Drug Application) filed by Impax for a generic version of 30 mg Adderall XR, pursuant to which Impax provided notice that it would seek to market its generic product before the expiration of the '819 and '300 Patents in 2018.

Adderall XR is Shire's leading extended release Attention Deficit Hyperactivity Disorder (ADHD) medicine.

Shire Pharmaceuticals Group plc is a global specialty pharmaceutical company with a strategic focus on meeting the needs of the specialist physician and currently focuses on developing projects and marketing products in the areas of central nervous system (CNS), gastrointestinal (GI) and renal diseases. Shire has operations in the world's key pharmaceutical markets (US, Canada, UK, France, Italy, Spain and Germany) as well as a specialist drug delivery unit in the US.