Ocular penetration and pharmacokinetics of topical gatifloxacin 0.3% and moxifloxacin 0.5% ophthalmic solutions after keratoplasty

Purpose: To compare the corneal and aqueous penetration and pharmacokinetics of gatifloxacin 0.3% and moxifloxacin 0.5% ophthalmic solutions and their effect on corneal reepithelialization after penetrating keratoplasty. Methods: In this randomized, open-label, parallel-controlled study, corneal and aqueous penetration and the pharmacokinetic parameters of topically applied gatifloxacin 0.3% and moxifloxacin 0.5% (2 preoperative doses of I drop given 5 minutes apart) were estimated by using a sparse sampling method. Corneal and aqueous samples were collected 0.25, 0.5. 1, or 2 hours after the final dose. The concentration was determined by a high-performance liquid chromatography method. Stromal C-max:MBC50 (maximum drug concentration in serum to 50% minimum bactericidal concentration) ratios for selected ocular pathogens were also assessed. Postoperative corneal reepithelialization at days 1, 3, and 7 was evaluated and compared between groups. Results: The calculated pharmacokinetic parameters were higher with moxifloxacin 0.5% than with gatifloxacin 0.3%. The stromal C-max was 48.5 versus 15.7 mu g/g (P = 0.04), and the stromal AUC(0-2) (area under the concentration-time curve from 0 to 2 hours) was 30.9 versus 13.6 mu g center dot h/g (P < 0.05). The endothelial C-max was 76.1 versus 7.3 mu g/g (P > 0.05), and the endothelial AUC(0-2) was 43.9 versus 9.8 mu g-h/g (P < 0.05). The aqueous C-max was 0.9 versus 0.3 mu g/mL (P > 0.05), and the aqueous AUC(0-2) was 1.2 versus 0.4 mu g center dot h/mL (P < 0.05). Stromal C-max:MBC50 ratios were higher in the moxifloxacin 0.5% group for each pathogen tested. The corneal reepithelialization rates were comparable between groups. Conclusions: Topical preoperative moxifloxacin 0.5% achieved greater corneal and aqueous penetration than did gatifloxacin 0.3%. The clinical significance of this difference is not known. Postoperative use of these agents had similar effects on corneal reepithelialization.