Abstract:

Analyzing and detecting the penetration depth and content of niacinamide in SC （stratum corneum） by skin Raman spectroscopy before and after using products which contained niacinamide was performed to evaluate the penetration ability of niacinamide and validation the feasibility of confocal Raman spectroscopy in transdermal absorption research. The results show that the characteristic peaks in Raman spectrum of niacinamide are stable in different substrates. After the cream containing 3% niacinamide is applied to the skin, the penetration content of niacinamide in SC increases with time and the content （AUC） of niacinamide in SC after 2 h is about 55 520.06. From the qualitative and quantitative perspectives of changes in Raman spectrum and penetration content, it shows that after applying cream with 3% nicotinamide to the skin for 2 h, the penetration depth of nicotinamide is about 16 μm. Confocal Raman spectroscopy is effectively applied in the penetration ability study of niacinamide in SC, and the research method can be a reference for the penetration of cosmetics, pharmaceuticals and other ingredients.

Key words: niacinamide, confocal Raman spectroscopy, penetration, spectrum analysis, in vivo test