Spectroscopic Evaluation of Sun Protection Factors of Sunscreen Preparations Using Dimethylsulfoxide As the Solvent

Abstract

The use of dimethylsulfoxide as a solvent for various sunscreen preparations allows for the direct photometric assay of the sun protection factor(SPF). Plots of the reciprocal of transmittance versus SPF have correlation coefficients that range from 0.831 to 0.979. Most of the error may be ascribed to the large standard deviation inherent in the determination and reporting of the SPF.