Determination of UVA protection factors by means of immediate pigment darkening in normal skin.
A method is described for screening potentially useful photoprotective agents against UVA radiation by the use of immediate pigment darkening as an end point. Threshold doses of immediate pigment darkening showed a log normal distribution and the response was found to obey dose-reciprocity at irradiance levels below 50 mW/cm2. With this procedure, several marketed sunscreens containing benzophenone-3 as the only UVA absorber were found to have poor UVA protection factors, whereas those containing combinations of benzophenone-3 and butyl methoxydibenzoyl methane or melanin were more effective. There was no correlation between the sun protection factor cited on the label and the calculated immediate pigment darkening-protection factor.
Department of Dermatology, Hospital of the University of Pennsylvania, 19104-4283.
K H
KH
Kaidbey
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A
Barnes
D000293:Adolescent; D000328:Adult; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012880:Skin Pigmentation / Q000187:drug effects / Q000528:radiation effects*; D013473:Sunscreening Agents / Q000494:pharmacology*; D014466:Ultraviolet Rays
D013473:Sunscreening Agents