Formulation and Assessment of Tolnaftate Microsponges for Topical Medication Deliverance

Objective: This study aimed to develop and evaluate the sustained delivery of Tolnaftate using topical polymeric microsponges. Materials and Methods: Tolnaftate-loaded microsponges made of ethyl cellulose were prepared via quasi-emulsion solvent diffusion. The effects of the drug-to-polymer ratio on active drug content, particle size, and entrapment efficiency were examined. The optimized formulation was incorporated into a Carbopol gel and evaluated for drug content, pH, viscosity, and in vitro drug release. The study considered internal phase volume, stirring rate, and emulsifier concentration as variables and analyzed their impact on entrapment efficiency and particle size. Results: Increasing stirring speed reduced particle size and improved entrapment efficiency, while a higher volume of dichloromethane decreased particle size. Scanning electron microscopy revealed porous and spherical microsponges. The 1.5:1 drug-to-polymer ratio yielded the highest active drug content, optimal entrapment efficiency, and smallest particle size, making it the preferred ratio for further studies. Conclusions: The drug release from the microsponge gel was more sustained compared to both the marketed product and pure drug gel. An ex vivo drug deposition study using rat abdominal skin showed satisfactory drug deposition. These polymeric microsponges show potential as a topical drug delivery system for antifungal therapy.