The kinetics of anterior chamber ofloxacin penetration

Thirty-five patients received topical ofloxacin 0.3% before routine cataract surgery. Ofloxacin was administered one drop every 2 h for five doses 1 day before surgery and one drop every 5 min for five doses immediately before surgery. Aqueous sampling was performed at variable periods 30-150 min after the last topical dose. The mean aqueous ofloxacin concentration was 793 ± 516 ng/ml (range, 143-2,400 ng/ml. A significant correlation between time from last dose and aqueous humor concentration was found (r = 0.39, p = 0.025). The mean ofloxacin concentration was greater in those patients who received their last dose >1 h before aqueous aspiration (957 ± 559 ng/ml versus 554 ± 338 ng/ml, p = 0.02). From a best-fit scatter plot of concentration versus time, the maximal aqueous concentration of 1.000 ng/ml occurs at ~2 h after topical administration.