Design and Evaluation of Microemulsion Based Drug Delivery System

Abstract

The present study was conducted to investigate the microemulsion based topical drug delivery system of antifungal drug Fluconazole (FLZ) in order to bypass its gastrointestinal adverse effects and to improve patient compliance. The pseudo ternary phase diagrams were developed for combinations of Isopropyl Palmitate (IPP) or Light Liquid Paraffin (LLP) as the oil phase, Aerosol OT as surfactant and Sorbitan Monooleate as cosurfactant using water titration method. Microemulsions obtained were analyzed for transdermal permeability of fluconazole using Keshary-Chien diffusion cell through an excised rat skin. Higher invitro permeation was observed from IPP based microemulsion. Thus it was selected for further formulation studies. The developed microemulsion was characterized for optical birefringence, globule size and polydispersibility index. The average globule size of the microemulsion was found be less than 100µm. Centrifugation studies were carried out to confirm the stability of the developed formulation. The formulation was thickened with a gelling agent carbopol 940, to yield a gel with desirable properties facilitating the topical application. The developed microemulsion based gel was characterized for pH, spreadability, refractive index and viscosity. Optimized formulation was then subjected to invitro antifungal screening in comparison to currently available marketed gel formulation of fluconazole (Flucos gel). Optimized microemulsion based gel formulation was found to exhibit significant antifungal activity as compared to marketed formulation. The safety of gel formulation for topical use was evaluated using skin irritation test. Thus the present study indicates that microemulsion can be a promising vehicle for the topical delivery of fluconazole.