Modern cosmetics with efficacy claims like “Anti-Ageing” or “Oxidative Protection” are among others complex mixtures of UV filters and antioxidants. Proof of efficacy must be obtained with sound scientific methods for such claims. Sunlight (UV radiation) is the main cause of premature skin aging (photo-ageing), primarily due to generation of free radicals and the oxidative stress associated with them. The biggest challenge in claim support is non-invasive yet sensitive measurement of oxidative stress on subjects.
This is the only in vivo approach that takes into account all physiological processes in living skin and provides efficacy data with the greatest possible relevance for the in-use situation. UV filters reduce radical formation and antioxidants produce a faster and/or more effective radical neutralization and detoxification.
By measuring the chemiluminescence (ultraweak photon emission) as the by-product of radical reactions in biological tissue like skin, the ICL-S method (Induced Chemiluminescence of Human Skin) allows measurement of oxidative stress in real time. Proof of efficacy of antioxidants and UV filters can therefore be provided for raw materials during product development and for finished products after topical application (In-Use Situation).

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