Method and apparatus for determining effectiveness of sunscreens and other skin preparations in shielding human skin from uva radiation
OwnerRachel Haywood, Peter Wardman +2inventors
InventorsRachel Haywood, Peter Wardman, Roy Sanders, Claire Linge
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Abstract
The present invention provides a method and apparatus for measuring the effectiveness of a sunscreen composition or other skin preparation in reducing the exposure of human skin to UVA radiation, wherein differential electron spin resonance spectroscopy is used to quantify the extent of UVA-induced ascorbate or other measurable radical production in the shielded skin, in comparison with reference, preferably unshielded, skin.
Claims17
A method for measuring the effectiveness of a sunscreen composition or other skin preparation in reducing the exposure of human skin to UVA radiation, the method comprising:
- irradiating a sample of human skin or of an effective substitute therefor (herein:
- “skin”), shielded with the sunscreen composition or other skin preparation to be tested, with UV radiation comprising UVA wavelengths, and determining by electron spin resonance (ESR) spectroscopy the level of induced production of ascorbate radical in the shielded skin;
- and
- determining a quantitative measure of the effectiveness of the sunscreen composition in reducing the exposure of human skin to UVA radiation by comparison of the said level of ascorbate radical production in the shielded skin with the level of ascorbate radical production induced in reference skin under substantially quantitatively comparable conditions.
Apparatus for testing the effectiveness of a sunscreen composition or other skin preparation in reducing the exposure of human skin to UVA radiation, the apparatus comprising:
- at least one sample of human skin or of an effective substitute therefor (herein:
- “skin”);
- a source of UV radiation comprising UVA wavelengths;
- means for determining by electron spin resonance (ESR) spectroscopy the level of induced production of ascorbate or other measureable radical in a skin sample on exposure of the skin to the UV radiation;
- means for shielding a skin sample with the sunscreen composition or other skin preparation to be tested;
- and
- means for determining a quantitative measure of the effectiveness of the sunscreen composition or other skin preparation in reducing the exposure of human skin to UVA radiation by comparison of the level of ascorbate or other measureable radical production in the shielded skin with the level of ascorbate or other measureable radical production induced in reference skin under substantially quantitatively comparable conditions.
A method for measuring the effectiveness of a sunscreen composition or other skin preparation in reducing the exposure of human skin to UVA radiation comprising the step of using differential ESR spectroscopy to determine an induced ascorbate radical production level.
Dependencies are inferred from the claim text.