Abstract
The key technology for hair-treatment products and hair-coloring products controls the permeability of product components into human hair to express their function effectively. It is necessary to obtain inside information about targeted human hair accurately for efficient pharmaceutical development, and to establish measurement methods for analyzing the permeability of product components into human hair directly and simply. We have evaluated the distribution of chemical composition (amide chemical-bond and CH chemical-bond) of the human hair cross section using infrared microspectroscopy and reported that the localization of product components was confirmed. In this study, we were able to obtain more detailed composition data on the human hair cross section than in previous reports as a result of changes in the optical system of SPring-8 BL43IR. Consequently, image mapping of amide chemical-bond provides a clearer outline of human hair than ever before, showing composition changes to protein inside the hair due to chemical damage. We aim to utilize this method more universally by further confirming the range of the targeted human hair for which this analytical method is applicable and by attempting to reduce measurement time.
