title: Suppressed permeation of linoleic acid in a liposomal formulation through reconstructed skin tissue.
abstract: 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 using a three-dimensional (3D) reconstructed skin model. Liposome entrapped [(14)C]-LA was applied on the 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 time of LA in the skin by the 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 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 3D reconstructed skin model would be useful for evaluating the characteristics of skin-oriented cosmetics and drugs.
authors.affiliation: Okayama University Graduate School of Natural Science and Technology, Japan. yasutami.shigeta@sunstar.con
authors.forename: Yasutami
authors.initials: Y
authors.lastname: Shigeta
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Imanaka
authors.forename: Sei
authors.initials: S
authors.lastname: Yonezawa
authors.forename: Naoto
authors.initials: N
authors.lastname: Oku
authors.forename: Naomichi
authors.initials: N
authors.lastname: Baba
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Makino
mesh_terms: D002626:Chemistry, Pharmaceutical; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D019787:Linoleic Acid / Q000737:chemistry / Q000493:pharmacokinetics*; D008081:Liposomes; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D010539:Permeability / Q000187:drug effects; D012869:Skin Absorption / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D008081:Liposomes; D019787:Linoleic Acid