Ebselen nanoemulgel for the treatment of topical fungal infection.

Superficial mycoses are the fungal infections of skin, hair and nail which affect thousands of people worldwide. Emerging resistance to azole antifungals is a common problem in the treatment of superficial or systemic fungal infection. Ebselen (EB), an organoselenium compound, has demonstrated promising activity against pathogenic yeasts. EB showed negligible dynamic and kinetic solubility in water (~ 4.2 µg/mL) which severely limits the scope of conventional formulations. The objective of present study was to develop and characterize a novel topical nanoemulgel of EB for enhancing solubility and permeability. Based on saturation solubility study, EB loaded self-nanoemulsifying preconcentrate (EB-P) was prepared using Dimethylacetamide, Kolliphor® ELP and Medium chain triglyceride which spontaneously formed 54.82 ± 1.26 nm size nanoglobules with zeta potential of -1.69 mV. Nanoemulgel was prepared by homogenous dispersion of EB-P in various gel/ointment bases. Scanning electron microscopy images showed significant drug precipitation in nanoemulgels prepared without Soluplus®. Rheological study confirmed shear thinning behavior of Soluplus® based HPMC K4M (SBH) gel. EB-P loaded SBH showed 2.3 and 5-fold higher Strat-M® deposition of EB compared to HPMC gel and Aquaphor®, respectively. EB-P showed marked anti-fungal activity at 20 µM against Candida albicans and Candida tropicalis while terbinafine was ineffective even at 100 µM concentration. Thus, topical nanoemulgel of EB could be a promising alternative to existing therapy for treatment of candidiasis.