Aqueous Penetration of Gatifloxacin and Levofloxacin into the Rabbit Aqueous Humor Following Topical Dosing

Abstract

The aqueous penetration of the commercial preparations of the fluoroquinolone antibiotics ofloxacin, ciprofloxacin, levofloxacin, and gatifloxacin were compared following topical dosing in a rabbit model. Levofloxacin achieved the highest aqueous concentrations, with a mean aqueous level of 4.8014 μcg/mL (p = 0.002, p = 0.00002, p = 0.015.) Ofloxacin (2.5136 μcg/mL) and gatifloxacin (2.4817 μcg/mL) achieved statistically equal aqueous concentrations (p = 0.479). Ciprofloxacin reached the lowest levels in the aqueous humor (0.9616 μcg/mL, p = 0.00002, 0.00004, 0.008). Gatifloxacin alone achieved concentrations in excess of the MIC₉₀s of gram-positive pathogens of concern.