SUPPRESSED PERMEATION OF LINOLEIC ACID IN A LIPOSOMAL FORMULATION THROUGH RECONSTRUCTED SKIN TISSUE.

This study by researchers at Okayama University Graduate School of Natural Science and Technology, SUNSTAR, Inc., and the University of Shizuoka School of Pharmaceutical Sciences demonstrated that MatTek’s MelanoDerm in vitro human skin tissue equivalent is an excellent in vitro model for testing the effectiveness of novel skin whitening agents in both damaged and undamaged (by UVB irradiation) skin. Since the liposomal formulation of linoleic acid (LA) exhibited an enhanced skin whitening effect, the influence of liposomalization on the cutaneous absorption of LA was examined by scientists at the Okayama University Graduate School of Natural Science and Technology, SUNSTAR, Inc., and the Dept. of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences using a three-dimensional (3D) reconstructed skin model (MelanoDerm, MatTek Corp.). Liposome entrapped [14C]-LA was applied on the MelanoDerm skin model, and the permeation of LA through the skin was monitored. The permeation rate of LA in the liposomal formulation was found to be lower than that in the conventional formulation without liposomes, suggesting the increased retention of time of LA in the skin by liposomal formulation. Next, to investigate the dependence of the LA permeation on melanocyte conditions and intactness of the reconstructed skin model, the effect of UV irradiation on LA permeation was examined. Low-dose UVB irradiation (0.03 J/cm^2 for 3 times), which activated melanocytes in the skin, did not influence the extent of the LA permeation, while high-dose irradiation (0.30 J/cm^2 for 3 times) enhanced the permeation of LA in both the conventional and liposomal formulation. The present results suggest the importance of skin intactness for LA permeation and that the MelanoDerm 3D reconstructed skin model would be useful for evaluating the characteristics of skin-oriented cosmetics and drugs.

Cutaneous absorption, Hyperpigmentary, Linoleic acid, Liposomal formulation, MEL-300-A, MelanoDerm, Permeation, Reconstructed skin tissue, Transdermal permeation, UV irradiation, UVB irradiation

Linoleic acid, Liposomes