Efinaconazole nail lacquer for the transungual drug delivery: Formulation, optimization, characterization and in vitro evaluation

Aim: The objective of the present study was to develop a nail lacquer of Efinaconazole for the onychomycosis treatment. Materials and methods: Hydration enhancement study was carried out for initial screening of penetration enhancers and enhancers with highest hydration enhancement factor value was further evaluated to select the enhancer to be incorporated in the Nail lacquer formulation. 32 full factorial design with different solvent and polymer ratio was employed to optimize the nail lacquer formulation. Optimized formulation was selected on the basis of drying time, flux and viscosity which was further evaluated for non-volatile content, water resistance, film adhesion, blush test, scanning electron microscopy analysis and Fourier transform infrared spectroscopy. Results: 2-mercaptoethanol, N-acetyl-L-cysteine and thioglycolic acid showed highest hydration enhancement factor value and 2-mercaptoethanol was selected for incorporation in nail lacquer formulation as it showed better penetration in comparison to other enhancers. Optimized formulation comprised of 70:30 solvent ratio and 50:50 polymer ratio. The formulation was able to achieve flux of 181.98 +/- 3.19 mu g/cm(2)/h in comparison to 52.88 +/- 3.11 mu g/cm(2)/h of the marketed preparation. The promising potential of the nail lacquer was proven by scanning electron microscopy analysis. Conclusion: For the efficient transungual delivery of Efinaconazole, promising and durable nail lacquer was formulated which ensured drug is delivered to the nail bed and effective onychomycosis treatment is achieved.