In vivo evaluation of two forms of urea in the skin by Raman spectroscopy after application of urea-containing cream

摘要

Background/purposeAs urea is one of the natural moisturizing factor (NMF) components in the stratum corneum, it has been used in topical products to improve skin conditions. However, the penetration behavior of urea in the skin after application of urea-containing cream has not been determined as there has been no technique with which to measure the urea content in the skin in vivo non-invasively. We therefore applied Raman spectroscopy to evaluate the depth profile of urea content in the skin. We investigated changes in depth profiles of two forms of urea to evaluate the penetration behavior of urea after application of urea-containing cream.