In vivo Evaluation of the Stratum corneum Barrier Function in Blacks, Caucasians and Asians with Two Noninvasive Methods

Abstract

This study compared in man the in vivo barrier function of stratum corneum in three racial groups: black, Caucasian and Asian, by two noninvasive technics. They were transepidermal water loss (TEWL) determination measured with an evaporimeter and laser Doppler velocimetry (LDV) to measure the lag time before the vasodilatation induced by application of methyl nicotinate (10 μl of 0.5% solution in ethanol/propylene glycol 95/5 v/v). Both methods were performed simultaneously on each forearm of 7 black, 8 Caucasian and 6 Asian subjects before and after removal of the stratum corneum by stripping. TEWL measurements were higher (p < 0.01) in Asians and Blacks compared to Caucasians. Stripping (8 or 12 strips) increased TEWL in all groups; TEWL increase percentage was higher (p < 0.05) in Asians compared to Caucasians. Vasodilatation lag times assessed by LDV showed that skin permeability was more important in Asians (p < 0.01) and in Caucasians (p < 0.05) than in blacks. Lag times decreased with stripping. After 8 or 12 strips, the order of sensitivity was: Asian > Caucasian > black. Our study showed that, with both noninvasive methods, removal of the stratum corneum increased permeability, with racial differences.

Ethnic and Atopic Dermatitis: What Have We Learned in Asian Population?

“…In particular, after stripping Asians showed the highest TEWL (Asians 1.7 times greater than Caucasians). 9,10 They concluded a resemblance with previous studies, 11,12 which concluded that skin permeability measured by TEWL, was higher in blacks than in Caucasians. They also concluded that Asian skin had the highest permeability among the study groups.…”

Treatment of Seborrhoeic Dermatitis in Asia: A Consensus Guide

“…Studies generally indicate that Asians have higher stratum corneum water content [25] and higher stratum corneum lipid levels than other races [20,26,27] . Investigations involving the removal of the stratum corneum by tape stripping indicated that Asian skin may have a poor barrier function [28][29][30] . Asians compared with non-Asians have a heightened dermatological response to irritants commonly found in topical, over-the-counter, or cosmetic preparations [23,[31][32][33][34][35] .…”

Interaction of a partially fluorinated long-chain nicotinate with dipalmitoylphosphatidylcholine

“…1 . The starting material for its synthesis, 11,11,12,12,13,13,14,14,15,15,16,16,16-tridecafluorohexadecan-1-ol, was synthesized using the methodology described previously (23). F-NA18 and its hydrocarbon analog, NA18, were synthesized from nicotinic acid and the corresponding alcohol according to literature procedures (8,16,24).…”

“…Because of the protective effect against lung injury mediated by reactive oxygen species, there is growing interest in the pulmonary administration of nicotinates, especially partially fluorinated nicotinates, using a perfluorocarbon vehicle (7,8). In addition to their biological effects, nicotinates have been widely used as models to study drug uptake in vitro (9)(10)(11)(12) and in vivo (9,(13)(14)(15). Because of their potential applications, the physicochemical characteristics, such as octanol-water partition coefficients and stability toward chemical and enzymatic degradation, have been well studied (8).…”