Effect of combination of hydrophilic and lipophilic permeation enhancers on the skin permeation of kahalalide F

Objectives The purpose of this study was to investigate the influence of combination of various lipophilic and hydrophilic chemical enhancers on skin delivery of kahalalide F (KF). Methods KF formulations comprising a combination of lipophilic and hydrophilic chemical enhancers with varied per cent were prepared and evaluated for skin permeation studies. In vitro skin permeation of KF formulations was performed using Franz diffusion cell. Stability studies of KF formulations were performed according to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use guideline, and the therapeutic efficacy of KF formulation was evaluated using allergic contact dermatitis animal model. Key findings The efficacy of KF formulations to improve skin delivery of KF was sequenced in the order of: formulation #4 > formulation #2 > formulation #1 > formulation #3, where formulation #4 contains labrasol (40% w/v), ethyl oleate (5% w/v) and span 80 (5% w/v) along with transcutol (40% w/v) and ethanol (10% w/v). Further, all the formulations were stable for 1 month when stored at 30°C/65% relative humidity. Conclusions The results of present study suggest that therapeutically effective concentrations of KF can be delivered in the skin using combination of lipophilic and hydrophilic chemical enhancers.