PREPARATION, OPTIMIZATION AND IN VITRO MICROBIOLOGICAL EFFICACY OF ANTIFUNGAL MICROEMULSION

Recently much attention has been paid to the application of microemulsion as drug delivery system. Part of this interest appears as a consequence of their transparency, ease of preparation and long-term stability. These properties as well as their ability for incorporating drugs of different lipophilicity are some of the reasons why microemulsions have been thoroughly considered for pharmaceutical purpose. The aim of the present study is to improve the solubility of Terbinafine Hydrochloride, a slightly water-soluble antifungal drug by formulating a microemulsion made up of oil, surfactant and solubilizing agent/cosolvent. Tween 80, ajowan oil and peppermint oil were selected for preparing a microemulsion. Propylene glycol (PG) was used as a solubilizing agent. The effect of formulation variables on droplet size distribution was investigated. Droplet size was measured with Malvern Zetasizer instrument based on Photon Correlation Spectroscopy principle. The mean droplet diameter of microemulsions containing 1% w/w of terbinafine hydrochloride was below 100 nm and for the optimized formulation it was 8.1 nm. The optimized microemulsion was found to be stable and showed no physical changes when exposed to freeze-thaw cycles for 72 hours. Also it showed promising results in terms of achieving in vitro drug concentration above the MIC