In vivo confocal Raman spectroscopy study of the vitamin A derivative perfusion through human skin

In vivo confocal Raman spectroscopy is a powerful non-invasive technique able to analyse the skin constituents. This technique was applied to transdermal perfusion studies of the vitamin A derivative in human skin. The composition of the stratum corneum (lipid bilayer) is decisive for the affinity and transport of the vitamin through skin. The vitamin A is significantly absorbed by human skin when applied with water in oil emulsion or hydro-alcoholic gel. The purpose of this study is to elucidate the behaviour of vitamin A derivative into human skin without the presence of enhancers. The results showed that the intensity band of the derivative (around 1600 cm(-1)), which represents the -C=O vibrational mode, was detected in different stratum corneum depths (up to 20 mu m). This Raman peak of vitamin A derivative has non-coincident band with the Raman spectra of the skin epidermis, demonstrating that compound penetrated in forearm skin.