Tolnaftate-Loaded Ethosomal Gel for Topical Delivery: Formulation and In Vitro Evaluation

Abstract

Objectives Tolnaftate (TOL) is used as a topical antifungal agent but has poor skin penetration. Therefore, the present study is designed to formulate an ethosomal gel of TOL to enhance drug penetration through the skin. Methods Using the cold method ethosomal formulations with different concentrations of ethanol and soy phosphatidylcholine (SPC) were formulated. The formulation of ethosomes was characterized by vesicle size, polydispersity index and zeta potential, % drug entrapment efficiency (EE), and scanning electron microscopy (SEM). The optimized ethosomal formula was incorporated in a 1% Carbopol hydrogel dosage. Evaluation of in vitro penetration of prepared gel was performed on goat skin using Franz diffusion cells and compared with conventional gel. Result The ethosomal formulation EF5 showed the highest % EE (76.82%) with a small vesicle size of 210.1 nm and was selected as the optimized formulation. The SEM result shows that the vesicles were spherical, smooth, and in the 200-nm range. In vitro, permeability study shows that steady-state flux of TOL from ethosomal and conventional gels were 6.667 and 3.685 µg/cm/h, respectively (p < 0.001). It indicated that the flux of Ethosomal hydrogel (EHG) is 2.0-fold higher than conventional hydrogel (CHG); this may be due to the flexible nature of ethosomes and ethosomal core containing ethanol, which dissolves the lipid bilayer of skin and overcomes the barrier. In vitro, an antifungal study shows that the incorporation of TOL in ethosomal hydrogel retains their activity. Conclusion From the results, it was concluded that TOL topical ethosomal gel for antifungal activity will possibly be a good choice.