Enhanced Skin Permeation of Hydrocortisone Using Nanoemulsion as Potential Vehicle

The current work was performed to estimate the solubility and Hansen solubility parameters of a poorly soluble corticosteroid hydrocortisone (HCN) in various components of nanoemulsion and to enhance the skin permeation rate of HCN using nanoemulsions as potential vehicles. Screening studies suggested the use of Capryol-90 (oil), Triton-X100 (surfactant) and Transcutol-HP (cosurfactant) in the preparation of HCN nanoemulsions. HCN nanoemulsions were developed using low energy emulsification technique and characterized for droplet size, plolydispersity index (PDI), zeta potential (ZP), refractive index (RI), percent of transmittance (% T) and transmission electron microscopy (TEM) and evaluated for drug release behavior. Selected nanoemulsions and control (HCN suspension) were subjected to in vitro skin permeation studies. Optimized formula HSN8 showed droplet size of 52.6 nm, PDI of 0.109, ZP of -33.72 mV, RI of 1.337 and % T of 97.68%. TEM confirmed spherical-shaped droplets in nanometer range. In vitro drug release evaluation suggested significant release of HCN from optimized nanoemulsion (98.52%) compared with control (35.85%). Skin permeation profile of HCN from optimized nanoemulsion was also significant compared with control. These results suggested the potential of nanoemulsion in enhancing the transdermal delivery of HCN via rat skin.