UVA protection efficacy of sunscreens can be determined by the persistent pigment darkening (PPD) method. (Part 2).
BACKGROUND
The UVA-induced Persistent Pigment Darkening (PPD) in vivo has been proposed as an end point for the evaluation of UVA protection.


OBJECTIVE
This study was designed to determine whether PPD can be used to correctly evaluate the in vivo effectiveness of UVA filters such as oxybenzone, avobenzone, ecamsule and zinc oxide concentrated and together with UVB filters.


METHODS
The UVA protection effectiveness of a number of commercial sunscreen products with either SPF 15 or SPF 30 was determined.


RESULTS
The UVA protection increased closely with the concentration of the UVA filters and was independent of UVB filters. The PPD method proved sensitive to all UVA filters irrespective of their range of absorbance within the UVA range.


CONCLUSIONS
The results show PPD to be a stable end point inducible by all the UVA wavelengths, not affected by fluence rate, i.e. a reliable endogenous UVA dosimeter in the skin.
Moyal
D
D
L'Oréal Research, Clichy, France.
Chardon
A
A
Kollias
N
N
D004341:Drug Evaluation; D005260:Female; D006801:Humans; D008297:Male; D011837:Radiation-Protective Agents; D012880:Skin Pigmentation / Q000528:radiation effects*; D013473:Sunscreening Agents; D014466:Ultraviolet Rays / Q000009:adverse effects
D011837:Radiation-Protective Agents; D013473:Sunscreening Agents