Chemical enhancers abating the barrier function of the stratum corneum act
in a number of ways. Their relative effects in mixtures are notoriously dif
ficult to determine. Corneoxenometry is a bioassay where xenobiotic interac
tions with corneocytes are assessed using reflectance colorimetry, It was u
sed to evaluate comparatively the effects of ethanol and laurocapram at var
ious dilutions. In addition, a 10% propylene-glycol-based gel supplemented
with N-acetyl-L-cysteine, urea and salicylic acid in various concentrations
was tested, The relative index or irritancy (RII) was calculated for each
formulation. RII is a surrogate marker of lipid removal and disorganization
, and of protein denaturation in the stratum corneum, It is likely a good p
redictor for barrier function alterations and represents a cheap and rapid
alternative to animal testing. Copyright (C) 2000 S. Karger AG, Basel.