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Methodology for Evaluation of Skin Transparency and the Efficacy of an Essence That Can Improve Skin Transparency
Author(s) -
Masuda Y.,
Kunizawa N.,
Takahashi M.
Publication year - 2006
Publication title -
international journal of cosmetic science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 62
eISSN - 1468-2494
pISSN - 0142-5463
DOI - 10.1111/j.1467-2494.2006.00301_4.x
Subject(s) - transparency (behavior) , stratum corneum , specular reflection , specular highlight , cosmetics , melanin , materials science , diffuse reflection , dermatology , optics , computer science , biomedical engineering , chemistry , medicine , physics , pathology , biochemistry , computer security
Transparency of the skin is an important factor for realizing beautiful skin, but there is only a visual sensory evaluation method by a beauty specialist. It is unclear how skin physiological characteristics can give transparency. Our purpose is to establish an objective method for evaluating the transparency of the skin and to develop a special cosmetics product which can enhance skin transparency, after investigating the mechanism of the skin characteristics which yield transparency. We developed an optical instrument that could independently measure a diffuse reflection as well as a specular reflection by assembling a polarizing filter in a gonio‐spectrum photometer. We analyzed the relationship among skin transparency, specular reflection light and diffuse reflection light. It was shown that there was a strong positive correlation between the skin transparency and the intensity of the diffuse reflection light ( r = 0.699) and no correlation between the skin transparency and the intensity of the specular reflection light ( r = 0.190). The results of partial least squares (PLS) analysis of the skin transparency and the skin physiological characteristics showed that a highly transparent skin has a fine skin surface texture with a high hydration of stratum corneum, a low melanin content and a low hemoglobin content. On the basis of these results, we developed an essence that can improve skin texture and blood flow, reduce melanin content, and increase the moisture in the stratum corneum. After eight weeks’ usage of this product by consumer panels ( n = 30), it was confirmed that the skin transparency was improved by the increase of the intensity of the diffuse reflection light by gonio‐spectrum photometer measurement and by consumers’ self‐assessment.