Method for determining an integral sun protection factor encompassing UVA and UVB radiation
US7567080B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 14, 2005 |
| Grant date | Jul 28, 2009 |
| Priority date | — |
| Expiry date | Apr 14, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a method for determining an integral sun protection factor (∫ SPF or iSPF) which encompasses both UVA and UVB radiation and can be used for classifying cosmetic and dermatological sunscreens. The method comprises the steps of applying a defined amount of the sunscreen onto a defined area of a skin substrate impregnated with a spin trap, exposing the skin substrate to a defined amount of UVA- and UVB rays by a sun simulator, subjecting the skin substrate exposed to radiation to an electron spin resonance (ESR) measurement, recording the number of free radicals trapped as a real number×1012 free radicals/mg of skin sample, and determining the integral sun protection factor ∫ SPF according to the equations (1) and (2) and (8)
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.