In vivo evaluation of radical scavenger compounds in cosmetic formulations by means of skin reflectance spectrophotometry

The protective effect of tocopherol (I) and some of its esters with different lipophilicity tocopheryl acetate (II) tocopheryl nicotinate (III) and tocopheryl succinate (IV) against UVB-induced skin erythema in human volunteers was assessed monitoring the extent of erythema by reflectance spectrophotometry. Two different formulations(gel and O/W emulsion) of each active compd. tested were topically applied after skin exposure to UVB radiation. All compds. tested significantly decreased UVB-induced skin erythema compared to control(formulations without active compds.) both from gel and O/W emulsions. No significant difference was obsd. from gel and O/W emulsions. I and II showed comparative activity but they were less active than III and IV.