Clobetasol-loaded nanostructured lipid carriers for epidermal targeting

Objectives The aim of this study was to investigate in vitro the epidermal targeting potential of clobetasol propionate-loaded nanostructured lipid carriers (CP-NLC) when compared to that of chitosan-coated (CP-NLC-C). Methods CP-NLC were prepared by microemulsion method and characterized by dynamic light scattering, transmission electron microscopy, in vitro release and permeation studies. To verify epidermal targeting, permeation studies were performed in two sets of experiments. For the first set, the skin was removed from the diffusion cell and stratum corneum (SC) was separated from the remaining skin (RS). For the second set, the whole epidermis (EP) was separated from the dermis (DER). CP quantification was performed in each skin layer. Key findings A novel clobetasol propionate-loaded NLC was produced with 1/5th of the drug dose used in commercial formulations and, even so, presented greater skin permeation. Both chitosan-coated and uncoated NLC enhanced the amount of CP in the epidermis more than 80-fold when compared to the commercial formulation (20.26 +/- 2.77; 17.85 +/- 0.49 and 0.22 +/- 0.02 mu g/cm(2), respectively). Differently from chitosan-coated NLC, the uncoated NLC did not show dermal retention. Conclusions NLC proved to be a system with potential for targeting drug delivery to the epidermal layer.