Preparation and In Vitro Skin Permeation of Cubosomes Containing Hinokitiol

Submicron monoolein (MO) cubosomes containing hinokitiol (HKL) were prepared by hydrating dry MO/HKL film, and then homogenizing the suspension in a bath-type sonicator. The ratios of MO/HKL in the dry film were 0:100, 0.16:99.84, 0.88:99.12, 1.8:98.2, 5.3:94.7, 9.9:90.1, and 24.9:75.1, and Pluronic F127 was used as a dispersant. The mean size of the cubosomes were not varied significantly even at the ethanol concentration of 16%. On the contrary, a marked reduction in the size was observed at sodium lauryl sulfate (SLS) concentration of 0.04%, and the cubosomes were completely solubilized at the concentration of 0.32%. In vitro skin permeation experiments revealed that the flux of HKL loaded in cubosome was much higher than in case of HKL dissolved in water, even though the concentration of HKL in cubosome suspension was lower than the concentration in the aqueous solution.