Ex-vivo spectroscopic quantification of sunscreen efficacy: proposal of a universal sun protection factor.
The sun protection factor (SPF) describes the protective behavior of sunscreens insufficiently, because this factor takes into account only the UVB spectral range, and strains the volunteers during its determination by invasively invoking an erythema. A new noninvasive method is proposed that is based on the UV spectroscopic measurement of tape strips taken from a sunscreen-treated skin area. The resulting sum transmission spectra of the tape strips reflect the in-vivo distribution of the absorber on the skin and quantify the protective efficacy of the applied sunscreens over the complete UV spectral range. The spectroscopic data provide a basis for the calculation of a universal sun protection factor (USPF). The comparison of the concrete values of USPF and SPF results in the following statements. 1. An unique functional correlation is not to be expected because a different UVB / UVA dependence exists. 2. The size of the differences between both values is influenced clearly by the intensity relation of the average sum transmission in the UVB in comparison to the UVA range. 3. The USPF values objectively assess the efficacy of sunscreens considering a protection against all irradiation injuries.
Weigmann
Hans-Juergen
HJ
Charité-Universitätsmedizin Berlin, Department of Dermatology and Allergy, Center of Experimental and Applied Cutaneous Physiology (CCP), 10098 Berlin, Germany.
Schanzer
Sabine
S
Teichmann
Alexa
A
Durat
Fabienne
F
Antoniou
Christina
C
Schaefer
Hans
H
Sterry
Wolfram
W
Lademann
Juergen
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012879:Skin Physiological Phenomena / Q000528:radiation effects*; D012882:Skin Tests / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013473:Sunscreening Agents / Q000008:administration & dosage*; D016896:Treatment Outcome
D013473:Sunscreening Agents