Sunscreen Cosmetics Research Articles

Skin tanning and light protection-theory, agents and analytic aspects. 1. Skin tanning and skin tanning agents

The different approaches to achieving skin tanning with emphasis on natural tanning, due to UV radiation of the sun or solaria, and artificial tanning through tannings agents are described. In contrast to the artificial tan the natural tan is a protection against UV radiation and is caused by pigmentation (melanin formation). The artificial tanning is based on a chemical reaction usually by means of dihydroxy acetone (melanoidin formation). Reaction mechanisms by both agents are reported. The determination of dihydroxy acetone in cosmetic tanning preparations by TLC, GC, HPLC, enzymatic tests and by a new method for capillary GC including sample preparation is described. When exceeding the natural protection mechanisms the skin should be protected by physico-chemical measures. The active principles in sunscreens are the UV filtering substances. UV filters permitted in the EG are listed. 2-Hydroxy benzophenone is used as an example to explain the mechanism of UV filtering substances. Analysis of UV filtering substances in cosmetic sunscreens by TLC, GC, HPLC is described as well as a fast and simple method for separation of lipophilic UV filters followed by capillary GC determination.