Alcon Laboratories has filed a patent infringement lawsuit in the U.S. District Court Southern District of Indiana (Indianapolis Division) against the generic manufacture Apotex alleging infringement of the U.S. Patent No. 5,641,805 (the ‘805 patent). The lawsuit is in response to Apotex’s notification to Alcon dated October 02, 2006 regarding Para IV certification for Patanol ophthalmic solution. Earlier Apotex filed abbreviated new drug application (ANDA) No. 78-350 with the US FDA, seeking marketing approval for generic Patanol ophthalmic solution against its prior to the expiration of Orange Book listed ‘805 patent. Generically known as olopatadine hydrochloride, Patanol is approved for the treatment of the signs and symptoms of allergic conjunctivitis.