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.
