The Food and Drug Administration approved Bausch & Lomb's ( BOL) abbreviated new drug application for a generic form of Alphagan, an eye drop designed to lower intraocular pressure in people with open-angle glaucoma or ocular hypertension.

The company said the FDA granted marketing exclusivity for the generic medication until Sept. 20.

Brimonidine tartrate ophthalmic solution, 0.2%, is sold under the brand name Alphagan and is manufactured by Allergan ( AGN), which had tried to block the generic formulation by filing two patent-infringement lawsuits.

Bausch & Lomb's generic version of the prescription eye drop is available immediately. The company makes the product at its pharmaceuticals facility in Tampa.

Shares of Bausch & Lomb closed New York Stock Exchange trading Wednesday at $37.20. Allergan ended at $73.12.