Method for determining the efficacy of a composition on the skin of a person, in particular for determining the sunscreen factor of a sunscreen composition

摘要

Method and apparatus for determining the efficacy of a composition applied to the skin of a person, in particular for determining the sunscreen factor of a sunscreen composition in vivo, in which a fluorescent substance and the composition to be investigated are applied to an area of the skin, the relevant area is irradiated from a radiation source of known characteristics, and the resulting reaction radiation is collected and its intensity and wavelength are recorded so that the sunscreen factor can be calculated from the intensities as a function of, for example, the wavelength or the length of time a person stays in water.