A microemulsion-based hydrogel formulation containing voriconazole for topical skin delivery

Abstract

Microemulsion-based hydrogels (MBHs) containing voriconazole were prepared as a possible topical delivery system for enhancing drug absorption at the site of action, as well as reducing the frequency of systemic side effects. Microemulsions were prepared with N-methyl-2-pyrrolidone as a surfactant, benzyl alcohol as an oil, and an ethanol/phosphatidylcholine mixture (3:2, w/w) as a cosurfactant. MBHs were prepared by adding carbopol 940 or xanthan gum as a gelling agent. In vitro skin permeation and deposition studies were performed using static vertical diffusion Franz cells and hairless mouse skin. The in vitro permeation data showed that the optimized microemulsion formulations consisting of voriconazole (1 %, w/w) and benzyl alcohol (10 %, w/w) showed significantly higher drug permeation rates and skin deposition compared to propylene glycol (control). However, the addition of a gelling agent did not significantly change the permeation profiles compared to the microemulsions. In vivo skin deposition studies conducted on hairless mice with MBHs also confirmed the superiority of MBHs compared to the control. These results suggested the MBH system to be a promising vehicle for topical delivery of voriconazole.