Barr challenges Alcon patents on eye drug

Oct 25 (Reuters) - Barr Pharmaceuticals Inc BRL.N said it filed a patent challenge of Alcon Inc's (ACL.N) conjunctivitis drug, Patanol, following an Alcon suit that sought to prevent Barr from commercializing a generic version of the product.

Barr had in September received a U.S. regulatory nod for filing a generic version of the drug containing a paragraph IV certification and had in turn notified the patent holder of this, it said in a statement.

A paragraph IV certification is submitted by a generic drug applicant stating that the listed patent is either invalid or will not be infringed by the generic product. (Reporting by Swagata Gupta in Bangalore)