Corneal Penetration into Rabbit Aqueous Humor Is Comparable between Preserved and Preservative-Free Tafluprost

Abstract

Background: Some studies have shown that benzalkonium chloride (BAK), a preservative used in antiglaucoma medications, can increase corneal permeability by acting as a penetration enhancer. Tafluprost is a new prostaglandin F₂_α analog in clinical use for the treatment of ocular hypertension and glaucoma. Methods: This study evaluated the corneal penetration of preservative-free tafluprost 0.0015% eye drops and tafluprost 0.0015% eye drops preserved with 0.01% BAK into the aqueous humor of rabbits. Results: After the administration of a single topical dose (30 μl), the maximum concentrations at 45 min of tafluprost acid in aqueous humor were 4.50 ng/ml for preservative-free tafluprost and 3.99 ng/ml for preserved tafluprost. The area under the concentration-time curves from 45 min to 3 h was 5.14 ng h/ml for the preservative-free formulation and 4.54 ng h/ml for the preserved formulation. Conclusions: These data indicate that BAK does not affect the corneal penetration of tafluprost into the rabbit aqueous humor.