Single and Multidose Ocular Kinetics and Stability Analysis of Extemporaneous Formulation of Topical Voriconazole in Humans

Purpose: The purpose of the present study was to evaluate the kinetics of single and multiple doses of topical, non-preserved voriconazole (VZ) in human eyes. Methods: For single dose kinetics, 119 patients undergoing cataract surgery were divided into group I and group II and each group received a single drop (30 mu l) of either 1% or 0.1% VZ formulation. Aqueous humor was collected at designated time intervals. For multidose kinetics, a single drop of 1% VZ was instilled 5 times either hourly or every 2 hr. The aqueous humor was tested for VZ at the 5th hr and 9th hr, respectively, after initial instillation. The stability and efficacy of the reconstituted VZ formulations were also evaluated after 30 days. Results: Single dose ocular kinetics of 1% VZ resulted in a maximum mean aqueous concentration of 3.333 +/- 1.61 mu g/ml in 30 min whereas 0.1% showed a maximum mean aqueous concentration of 0.817 +/-.36 mu g/ml. In the multidose kinetic study, hourly and bi-hourly dosing resulted in mean aqueous concentrations of 7.47 +/- 2.14 mu g/ml and 4.69 +/- 2.7 mu g/ml, respectively. The reconstituted VZ formulations were stable at all studied temperatures, and their efficacy was maintained throughout the study period. Conclusion: The present study showed that the achieved mean concentration of VZ in both single dose and multi dose kinetic studies satisfactorily met the MIC90 for almost all causative fungal organisms. The frequency of instillation may be designed for an "every 2 hr regimen" to maintain a therapeutic concentration for successful therapy.