Characterization and Antifungal Activity Evaluation of Clove Oil-Based Microemulsions Containing Fluconazole

Abstract

Topical drug delivery represents an effective approach for the management of cutaneous fungal infections, as it minimizes the risk of systemic adverse effects. Nevertheless, successful formulation design requires adequate enhancement of drug permeation through the skin barrier. The present study aimed to develop clove oil-based microemulsions incorporating 2% w/w fluconazole. Four formulations were selected from the microemulsion region identified through the construction of a pseudoternary phase diagram comprising clove oil, 1:1 mixture of water and propylene glycol, and Tween 80. The properties of the formulations, along with their antifungal activity against four Candida species including C. albicans, C. krusei, C. lusitaniae and C. tropicalis were evaluated. The experimental results indicated that all prepared formulations were oil-in-water microemulsions. They appeared as clear yellow liquids. Their pH and viscosity values were within an acceptable range for topical application. All clove oil-based microemulsions demonstrated antifungal activity against the tested strains, which can be attributed to eugenol, the principal constituent of clove oil. The inhibition zone diameter ranged from 23.0-30.3 millimeters for fluconazole-loaded microemulsions, which was significantly greater than that of the corresponding blank formulations. This research revealed that the developed clove oil-based microemulsions containing fluconazole show promise as topical antifungal formulations and warrant further investigation. The most interesting formulation for further study was FLZ-ME-1 which was composed of fluconazole, clove oil, 1:1 mixture of water and propylene glycol, and Tween 80 at 2.0%, 9.8%, 49% and 39.2% w/w, respectively.