Stability of extemporaneously prepared voriconazole ophthalmic solution

Abstract

The stability of extemporaneously prepared voriconazole ophthalmic solution was studied. Voriconazole solutions (2% and 1%) were reconstituted from the i.v. formulation. After thorough mixing, 3-mL samples of each of the resulting 2% and 1% solutions were filtered into eyedroppers. Three samples for both solutions were analyzed in triplicate at each time point. The 2% voriconazole ophthalmic solutions were stored at 2-8 degrees C, 25 degrees C, and 40 degrees C. The 1% voriconazole eye drops were stored at 2-8 degrees C. The 2% voriconazole solution samples were analyzed at time 0 and at weeks 1, 2, 4, 8, 16, and 32. The 1% solution samples were analyzed at time 0 and at weeks 6 and 14. Stability was measured using high-performance liquid chromatographic analysis. The 2% voriconazole ophthalmic solution demonstrated excellent stability at 2-8 degrees C and 25 degrees C for up to 16 weeks. The voriconazole solution displayed no significant change in pH at all time intervals. No change in visual appearance or clarity was observed in the 2% voriconazole eye drops at any point of the study for all study temperatures. Voriconazole 1% solution was stable at 2-8 degrees C for up to 14 weeks. Voriconazole 2% (20 mg/mL) solution preserved with 0.01% benzalkonium chloride prepared as alternative antifungal eye drops was stable for 16 weeks when stored at 2-8 degrees C and 25 degrees C and for 8 weeks when stored at 40 degrees C, while voriconazole 1% solution was stable at 2-8 degrees C for up to 14 weeks.