Microemulsion based vaginal gel of antifungal drug: design, development and evaluation

The purpose of the present study was to develop and evaluate microemulsion based gel for the delivery of fluconazole (FLZ). The solubility of FLZ in oils and surfactants was evaluated to identify the components of the microemulsion. Microemulsion base was prepared by using iso propyl myristate as oil phase, tween 80 as surfactant and propylene glycol as co-surfactant. Microemulsion existence region was determined by using the pseudo-ternary phase diagrams for different formulations.

Microemulsion formulations were evaluated for pH, viscosity, conductivity and dilutability. Globule size of drug loaded microemulsions was ranges from 29.4 nm to 21.4 nm. Polydispersity index of microemulsion was ranges from 0.555 to 0.135. Zeta potential of selected batches was found to be zero which show neutral charge as the microemulsion formulations consisted of nonionic surfactant.

Various gelling agents were evaluated for their potential to gel the FLZ microemulsion without affecting its structure. FLZ microemulsion based gel (MBG-FLZ) was characterized for viscosity, transmission electron microscopy and spreadability. In-vitro permeation of FLZ from the gel was evaluated using Franz diffusion cells mounted with rat skin. The results indicated that the MBG-FLZ would be a promising tool for enhancing the percutaneous delivery of fluconazole.