Microemulsion as a Potential Transdermal Carrier for Poorly Water Soluble Antifungal Drug Itraconazole

Abstract

The objective of our study was to design a novel microemulsion system of broad spectrum antifungal agent Itraconazole for its sustained and prolong action without using an additional permeation enhancer. Pseudoternary phase diagrams were constructed, and various microemulsion formulations were prepared using combination of isopropyl myristate (IPM) and oleic acid (1:1) as oil, Tween-80 as a surfactant and Transcutol P as a cosurfactant. Developed formulations were subjected to thermodynamic stability test. All the microemulsion formulations had small droplet size (<80 nm), uniform size distribution (PI, <0.202), and low viscosity (<125 mP). The results showed that the droplet size and viscosity of microemulsion decreases with the decrease in the concentration of surfactant, whereas transdermal flux was increased. The optimized formulation, which contained oleic acid + IPM (1:1) (8% w/w), 15% w/w Smix (Tween-80 + Transcutol P) and water (77% w/w) showed significant increase (P < 0.01) in the transdermal flux (0.2235 ± 0.090 mg h−1 cm−2). Furthermore, for the optimized formulation antifungal activity study was conducted. The result showed that prepared formulation exhibited better antimicrobial activity. Results obtained indicates that the developed microemulsion systems can be a promising carrier for the transdermal delivery of Itraconazole for prolonged period along with reduced side effects, and offers a novel means for the treatment of fungal infections like blastomycosis, histoplasmosis, onychomycosis, etc.