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The immunosuppressive properties of Benzophenone-4, an UV-filter and three ingredients, Allantoin, Bisabolol and Enoxolon used in sunscreen formulation, previously characterized as anti-inflammatory compounds, are studied. The results of this study demonstrate that four tested molecules have effects on DCs and T cells which are the most important cells of the immune system. The impact is also visible on keratinocyte cells which are in the direct contact with skin sunscreens. Each ingredient should be used with caution at reduced doses or even removed from some cosmetic preparations, such as sunscreens.

When determined in vitro, the SPF of certain commercial sunscreen products can be lower than the SPF indicated on the label. The study of the composition of this type of product enabled us to note that the majority contained substances reputed to have anti-inflammatory properties. This effect is shown by inhibiting the erythema, without protecting the skin, which constitutes a serious public health problem. The anti-inflammatory effects of αbisabolol-, allantoin- and 18-β-glycyrrhetinic acid-based emulsions, as well as commercial sun products containing any one of these molecules, have been tested with phorbol myristate acetate on mice. The effectiveness of these sunscreens products is quantified using two indicators: SPF (sun protection factor) and PF-UVA (protection factor-UVA) by in vitro method. We were thus able to show that certain sun products have an anti-inflammatory effect, which in turn causes the SPF value shown on the product to be overestimated, indeed sometimes by considerably large margins.

The objective of this research was to study the effect of pH on the photodegradation of aqueous solutions of 5×10–5 M acesulfame-K (λmax, 226 nm;e, 11 400 mol–1 L cm–1). Photodegradation followed first-order kinetics and was found to be pH-dependent. The degradation rate constant was calculated to be 6.7×10–2 min–1, 4.5×10–2 min–1, 3.4×10–2 min–1 and 17.4×10–2 min–1, respectively, at pH 3, pH 9 and pH 12.

The HPLC separation of fluorescent o-phtaldialdehyde (OPA) derivatives has been applied to the assay of free amino acids from five microalgae commonly used in aquaculture: Tetraselmis suecica, Skeletonema costatum, Chaetoceros calcitrans, Thalassiosira sp. and Isochrysis galbana, as part an assessment of their potential use in cosmetic products. Thirteen free amino acids were analyzed using High Performance Liquid Chromatography. There were considerable differences between species. However, four amino acids were responsible for more than 60% total concentration in all species: ASP, GLU, ARG and TYR; the next most important (accounting for less than 30%) were: ALA, VAL, PHE and LYS.