Stability, Release Property and Skin Penetration of Stearic Acid Nanoparticles

Abstract

Stearic acid nanoparticles were prepared by a melt-emulsification method. The nanoparticles were stable in terms of the size and the appearance when the concentrations of sodium lauryl sulfate in the suspensions were less than 1.443%. And, they were stable in the aspect of their integrity when the concentrations of ethanol in the suspensions were less than 20%. For the release and the skin permeation experiment, hinokitiol (HKL) was used as a model drug and it was encapsulated in the nanoparticles. The % release of HKL was observed in distilled water and alcoholic solutions of 5% and 10%. The release increased up to 45%–55% for the first 8 h and thereafter no significant release was observed. According to the results of a confocal laser scanning microscopy, the nanoparticles were found to be in the dermis of a hairless mouse skin. The nanoparticles present in the dermis would act as depots for the dermal delivery of HKL.