title: Prediction of sun protection factors and UVA parameters of sunscreens by using a calibrated step film model.
abstract: At the stage of screening of new sun protection formulations, quick and inexpensive methods for estimation of the ultraviolet (UV) screening performance are highly desirable. It has been shown recently that apart from measurements of sun protection factors in vitro, calculations using a calibrated step film model are also a possibility. In the present investigation, further evidence for the usefulness of the step film model in terms of prediction of the sun protection factor is shown. In addition, it is demonstrated that parameters, which characterize the protection in the UVA range such as the UVA/UVB ratio and the critical wavelength can be calculated in good accordance with experimental data. Although with less accuracy, the estimation of UVA protection factors is also possible, if the photodegradation some filters undergo upon irradiation is taken into consideration.
authors.affiliation: Ciba Specialty Chemicals Inc., G-9001.228, P.O. Box 1266, 79630 Grenzach-Wyhlen, Germany. bernd.herzog@cibasc.com
authors.forename: Bernd
authors.initials: B
authors.lastname: Herzog
authors.forename: Sébastien
authors.initials: S
authors.lastname: Mongiat
authors.forename: Katja
authors.initials: K
authors.lastname: Quass
authors.forename: Cyrille
authors.initials: C
authors.lastname: Deshayes
mesh_terms: D002138:Calibration / Q000592:standards; D008954:Models, Biological; D011237:Predictive Value of Tests; D013473:Sunscreening Agents / Q000737:chemistry / Q000528:radiation effects* / Q000592:standards; D014466:Ultraviolet Rays
chemical_list: D013473:Sunscreening Agents