Aqueous penetration of gatifloxacin and levofloxacin into the rabbit aqueous humor following topical dosing

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 mucg/mL (p = 0.002, p = 0.00002, p = 0.015.) Ofloxacin (2.5136 mucg/mL) and gatifloxacin (2.4817 mucg/mL) achieved statistically equal aqueous concentrations (p = 0.479). Ciprofloxacin reached the lowest levels in the aqueous humor (0.9616 mucg/mL, p = 0.00002, 0.00004, 0.008). Gatifloxacin alone achieved concentrations in excess of the MIC(90)s of gram-positive pathogens of concern.