ABSTRACT
The accurate determination of the mass of the horny layer removed by tape stripping is a decisive prerequisite for the application of this technique in penetration studies. A novel method using optical spectroscopy to determine the amount of stratum corneum (SC) is presented. We could show that the absorbance measured in the visible spectral range accurately reflects the mass of the SC fixed on individual tapes. Furthermore, absorbance measurement allows determination of the absolute mass of corneocyte aggregates on the removed tape strips. Topically applied substances do not disturb the spectroscopic measurements in contrast to the conventionally employed weight determination. Identical results were obtained when performing spectroscopic horny layer quantification independently in two separate institutions. Taken together, this new method is rapid, sensitive, reproducible, and accurate. We anticipate a wide application in penetration studies as well as in dermatopharmacokinetics.