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. 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 extended method shows no artifacts and has the potential to determine the water depth profiles after topical application of formulations on the skin.