Quantitative molecular absorption of cosmetic active molecules in human skin using coherent Raman imaging (CARS and SRS)
Résumé
We introduce and validate a framework for imaging and quantifying active molecule penetration into human skin ex vivo and in vivo. Our approach combines nonlinear imaging microscopy modalities, such as two-photon excited auto-fluorescence (TPEF) and coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS). The imaging framework is exemplified first on topically applied glycerol diluted in various vehicles such as water and xanthan gel and second, on retinol applied on ex vivo excised human skin. The proposed framework allows for the 3D percutaneous monitoring of active cosmetic molecules and their formulation across human skin. We demonstrate the reservoir property of topically applied xanthan gel vehicle that releases glycerol continuously over time together with the hydrophobic penetration of retinol between corneocyte.