Purpose: The aim of this study was to develop a new technique enabling visual evaluation in vivo of 'complexion radiance' based on sensory analysis, and to apply this methodology to a practical case.
Methods: This evaluation, conducted by trained assessors, was based on a visual analysis in vivo of the following seven descriptors, clearly defined by consensus: a red-pink, olive, beige, and light-pink skin coloring (C), as well as the luminosity (L), brightness (B), and transparency (T) of each subject's facial skin. The scoring of perceived skin descriptor intensity was made possible with the help of structured and analogical scales. Once the assessors were considered to be accurate and repeatable, a method was designed to evaluate a cosmetic product's effect on complexion radiance. The study was conducted on 20 healthy female subjects, between 20 and 35 years of age, who met the 'dull complexion' criteria. Product 'A' (Oligo 25, Laboratoires Vichy, Asnieres, France), formulated to improve 'complexion radiance,' was applied by each subject for 28 days, once a day in the morning, in a homogeneous fashion over the entire face, using a standard quantity and a specific way of massaging the product in. The clinical parameters were evaluated at T0, T+1 h, and at T+28 days. This test was a non-comparative open study and each subject served as her own reference.
Results: One hour after its application, product A produced an immediate significant effect by decreasing the complexion's 'olive' skin cast and improving its 'light-pink' coloring, its 'luminosity,' and 'brightness.' The data concerning the long-term effect of product A following 28 days of application showed that there was significant improvement in these first four descriptors, while the 'beige' skin coloring was ultimately diminished in addition.
Conclusion: This in vivo C.L.B.T. trade mark sensory methodology is a technique enabling the visual evaluation of a product's multi-factorial claim that it improves 'the complexion's radiance.' It made it possible to show, in a reliable and repeatable fashion, the efficacy of a cosmetic product in improving the 'radiance of the complexion' of members of a test panel. This methodology also substantiated the immediate and long-term effects produced by product A, which made the skin pinker and less sallow, more luminous, more uniform (skin coloring), more regular (skin texture), and then lighter. To conclude, five descriptors out of the seven determining complexion radiance were improved.