Protocol for evaluation of topical ophthalmic drug products in different compartments of fresh eye tissues in a rabbit model.

Topical ophthalmic drugs are the most commonly used dosage form to treat diseases of the anterior segment of the eye. Although this dosage form has the advantages of ease of application, small volume dose, and rapid action and is largely devoid of systemic adverse effects, the bioavailability is low due to pre-corneal anatomical barriers and the nature of the drug formulation itself. Some complex generic formulations (suspensions, ointments, gels) for topical ophthalmic products face impediments to rapid regulatory approval because of the complex nature of the formulations and difficulties in determining bioequivalence with the innovator product.