A modification for the calculation of water depth profiles in oil-treated skin by in vivo confocal Raman microscopy

In this study, an extended calculation method for the determination of the water profiles in oil-treated skin is proposed, which is based on the calculation of the ratio between the Raman band intensities of water (3350-3550 cm(-1)) and keratin Amide I at 1650 cm(-1). The proposed method is compared with the conventional method based on the ratio of the Raman band intensities of water (3350-3550 cm(-1)) and keratin at 2930 cm(-1). The conventional method creates artifacts in the depth profiles of the water concentration in oil-treated skin, showing a lower amount of water in the upper and intermediate layers of the stratum corneum, which is due to the superposition of oil- and keratin-related Raman bands at 2930 cm(-1). The proposed extended method shows no artifacts and has the potential to determine the water depth profiles after topical application of formulations on the skin.