Development of ethosomal vesicular carrier for topical application of griseofulvin: effect of ethanol concentration

Vesicular carriers (VCs) offer enhanced and sustained delivery of drugs. The aim of this study was to explore the effects of ethanol concentration in VCs on topical delivery of a poorly water-soluble drug, using griseofulvin as prototype. VCs containing varying quantities of ethanol were prepared by solvent evaporation using Phospholipon ® 90H (P90H) and characterized for entrapment efficiency (EE), morphology, size and size distribution, stability, viscosity and skin retention. Permeation profiles were assessed using rat skin and Franz diffusion cell and withdrawn samples analyzed spectrophotometrically. Spherical vesicles of average size of 137.70 ± 51.62 nm and polydipersity index of 0.555 were produced. Vesicle sizes decreased with increase in ethanol concentration. EE of 68.0 ± 5.6% was obtained for the optimized formulation. Differential scanning calorimetry indicated reversible perturbation of the skin layers as the mechanism of permeation. Permeation generally increased with increase in ethanol concentration. Ethosomal nanovesicular carriers encapsulating griseofulvin were formulated, which showed potentials for sustained and enhanced delivery through rat skin in direct proportion with ethanol concentration.