COLORIMETRIC METHOD FOR QUANTIFYING HUMAN STRATUM-CORNEUM REMOVED BY ADHESIVE-TAPE-STRIPPING

Tape-stripping of the skin is a useful method for removing the stratum corneum and obtaining more information about the function of this ski n layer as the main barrier for skin penetration. The amount of stratu m corneum removed is of relevance in establishing the concentration pr ofile of chemicals within the stratum corneum after topical applicatio n. Weighing is the preferred method for measuring the amount stripped, but because it is often subject to artifacts, alternative methods are sought. We present a simple, colorimetric method for determining the amount stratum cor neum removed by sequential adhesive-tape-stripping of human skin in vivo. The method is based on quantification of the so dium hydroxide soluble protein fraction using a commercially available protein assay similar to the Lowry assay. The method is shown to be a n accurate and reproducible alternative to weighing, also demonstratin g uniform removal of stratum corneum layers following the very initial strips.