Multicenter evaluation of sunscreen UVA protectiveness with the protection factor test method.
BACKGROUND
Currently there is no consensus on a test method to determine the protectiveness of sunscreens in the UVA region alone.


OBJECTIVE
The protection factor in UVA (PFA) test method was evaluated to determine its ability to detect dose-response, specificity for UVA protection only, and repeatability between laboratories, and to detect whether the protection factors depended on the skin response observed (erythema or tanning).


METHODS
Sunscreens containing 0%, 2%, or 5% oxybenzone, or 7% octyl dimethyl para-aminobenzoic acid were tested by the PFA protocol in five laboratories.


RESULTS
The test method demonstrated ability to distinguish differences between the protection in the oxybenzone formulations but not between the placebo (0%) and the 7% octyl dimethyl para-aminobenzoic acid formula. The protection factors were independent of the type of skin response.


CONCLUSIONS
These data support the utility and validity of the PFA method for determining the UVA protection provided by sunscreen products.
Cole
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Johnson & Johnson Consumer Products, Inc., Skillman, NJ 08558.
D010129:4-Aminobenzoic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D000368:Aged; D001577:Benzophenones / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004890:Erythema / Q000209:etiology; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000528:radiation effects*; D012869:Skin Absorption; D012880:Skin Pigmentation / Q000528:radiation effects; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D014466:Ultraviolet Rays; D062366:para-Aminobenzoates
D001577:Benzophenones; D010919:Placebos; D013473:Sunscreening Agents; D062366:para-Aminobenzoates; C015402:octyl dimethyl 4-aminobenzoic acid; C005290:oxybenzone; D010129:4-Aminobenzoic Acid