Kockott, D.*, Tronnier,
H.', Hölzner, B.**, Heinrich, U.**
Automatic in Vitro
Evaluation of Suncare Products
UV Technik, 63456 Hanau, Germany
** Institute for Experimental Dermatology,
University Witten/Herdecke, 58455 Witten, Germany
With all in vitro methods used at present, the spectral transmittance
of suncare products is measured in a spectral photometer. From the spectral transmittance,
characteristic values for the protective effect in UV13 and UVA are derived. The
protective effect of a sun care product regarding the erythema is described by
the SPF (Sun Protection Factor).
Measuring method and device:
The sample is irradiated by simulated solar radiation. The radiation source is
a Xe lamp, whose radiaions is filtered by two selectively reflecting mirrors and
different filters such that the spectral distribution in the wavelength range
290 nm < X:5 400 nm corresponds to the norm sun of COLIPA and DIN 67501.
Behind the sample there are two radiation receivers which are used alternatively
for UVA and UVB and are automatically driven into the path of the rays.
Objective of a new method and device:
The new device (Sunscreen Tester)
used for measuring the protective effect of suncare products realizes the irradiation
conditions analogous to a normal in vivo measurement. During the irradiation process
it continuously measures both the SPF and the spectral transmittance behind the
sample. From the latter, further protection parameters are calculated. Information
about the stability of a suncare product is automatically obtainable.
Results and conclusions:
The presented in vitro method and the accompanying
device Sunscreen Tester allow a fast and automatic determination of all factors
characterizing the protective effect of suncare products during irradiation.
a number of commercial suncare products with sun protection factors between 4
and 30, the SPF was determined by both the in vivo method and the new in vitro
method presented. Both SPFs correspond to each other within an error range of
It is also possible to calculate other characteristic values,
such as the critical wavelength k, according to Diffey and the ratio of protective
effect UVA/UVB from the spectral absorptance.
Tronnier, D. Kockott, B. Meick, N. Hani, U. Heinrich: Zur in vitro Bestimmung
des SPF; Parfümerie und Kosmetik, 77.326 329 (1996)
2. H. Tronnier, B.
Hölzner, U. Heinrich, D. Kockott, B. Reubke Gothe: Zur Praxis der in vitro
Bewertung von Sonnenschutzmitteln; Kosmetische Medizin 18.344 350 (1998)
D. Kockott: In vitro Bewertungen von Sonnenschutzmitteln; Kosmetische Medizin
19.290 293 (1998)
4. U. Heinrich, H. Tronnier Ein neues in vitro Verfahren
zur Bestimmung des UVA Schutzes von Lichtschutzpräparaten; SÖFW Journal
12.40 41 (1999)