Miconazole Nitrate Microemulsion: Preparation, Characterization and Evaluation for Enhancement of Antifungal Activity

The aim of this study was to prepare a miconazole nitrate microemulsion (ME) and to evaluate its antifungal activity. The solubility of miconazole nitrate was determined in oils, surfactants and cosurfactants. The pseudo-ternary phase diagram was constructed using the water titration method. ME formulations selected from the pseudo ternary phase diagram were characterized for pH, conductivity, viscosity, particle size, zeta potential and in vitro permeation studies. Agar well diffusion method was used for antifungal studies against Candida albicans and compared with 1 and 2% commercial available miconazole nitrate formulation. Eucalyptus oil as oil, tween 80 as surfactant and propylene glycol (PG) as cosurfactant, were selected for phase diagram on the basis of high solubility. Five ME formulations were selected and successfully prepared with acceptable topical limits. The final selected ME formulation showed enhanced antifungal activity than the commercially available formulation and concluded that ME is a promising carrier system for topical delivery of miconazole nitrate.