Barr Pharmaceuticals, Inc. confirmed that its subsidiary, Barr Laboratories, Inc., has initiated a challenge of the patents listed by Novartis Pharmaceuticals Corporation in connection with its Ritalin LA (methylphenidate hydrochloride) extended-release capsules, 10 mg, 20 mg, 30 mg and 40 mg.

Barr filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic Ritalin LA product with the US Food & Drug Administration (FDA) in May 2007, and received notification of the application's acceptance for filing in September 2007. Following receipt of the notice from the FDA that Barr's ANDA had been accepted for filing, Barr notified the New Drug Application (NDA) and patent holders.

On November 2, 2007, Celgene Corporation, Novartis Pharmaceuticals Corporation and Novartis Pharma AG filed suit in the US district court of New Jersey (Newark) to prevent Barr from proceeding with the commercialization of its product. This action formally initiates the patent challenge process under the Hatch-Waxman Act.

Ritalin LA (methylphenidate hydrochloride) extended-release capsules are indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). The product had sales of approximately $109 million in the US, based on IMS sales data ending August 2007.