Comparison of gravimetric and spectroscopic approaches to quantify stratum corneum removed by tape-stripping.

Skin surface tape-stripping is an extensively used technique to examine the distribution profile, penetration and safety of various active compounds. It is also a widely accepted method to probe skin barrier properties and more specifically, those of the stratum corneum (SC). The amount of SC removed by tape-stripping is generally determined either gravimetrically or by extraction and measurement of SC proteins. A novel infra-red densitometry (IRD) technique has recently been introduced to measure SC protein content. In the present study, IRD was investigated as an alternative method to measure the mass of SC removed by tape-stripping. Tape-stripping experiments were conducted on human volunteers. The weight of the stratum corneum removed was assessed by the gravimetric approach and by IRD. Transepidermal water loss (TEWL) was also measured before and after each tape-strip. A linear correlation coefficient was obtained for the data from the gravimetric and IRD measurements (r(2)=0.65; n=240). IRD is therefore proposed as a rapid, non-destructive alternative to the gravimetric approach to estimate the amount of SC removed by tape-stripping in vivo.