Penetration studies of vitamin E acetate applied from cosmetic formulations to the stratum corneum of an in vitro model using quantification by tape stripping, UV spectroscopy, and HPLC.
The skin activation and penetration capability of vitamin E acetate as an ingredient in a basic o/w cream (lamellar type), in liposomes (Rovisome) and microparticles (Roviparts), was investigated under in vitro conditions (BUS model) by the adhesive stripping method. The aim of the study was to compare the analytical results obtained by UV spectroscopy (transmission) and the conventional HPLC method. For the quantitative spectrometric assay, a classical least-squares evaluation of the spectra between 265 and 350 nm, based on the constituent spectra, was used. UV spectroscopy is an economic analytical method for evaluating a large population of samples of the horny layer taken by the adhesive tape stripping method, which is an established tool for depth profiling of substances within the stratum corneum. With regard to the irritation test, no cytotoxicity was recorded for all formulations tested. However, the Roviparts and Rovisome cream formulations induced a considerable activation of the epidermal cells that may contribute to the penetration efficiency of Rovisome-formulated vitamin E acetate. The Rovisome-formulated cream delivered a maximum amount of vitamin E acetate into the horny layer compared to the other formulations tested. The difference can be explained by an alteration of the plasticity of the horny layer inducing a strong reservoir capacity and an activation of upper epidermal cells. Moreover, the opening of the potential pathway for a follicular penetration may be part of the increased reservoir capacity.
Lampen
P
P
Institute of Spectrochemistry and Applied Spectroscopy, D-44013 Dortmund, Germany.
Pittermann
W
W
Heise
H M
HM
Schmitt
M
M
Jungmann
H
H
Kietzmann
M
M
D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D066298:In Vitro Techniques; D008956:Models, Chemical; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D024505:Tocopherols; D024502:alpha-Tocopherol / Q000031:analogs & derivatives* / Q000032:analysis / Q000493:pharmacokinetics*
D024502:alpha-Tocopherol; D024505:Tocopherols