Evaluation of anionic surfactants effects on the skin barrier function based on skin permeability

Abstract

Anionic surfactants are often used for cleaning and pharmaceutical purposes because of their strong surfactancy and foaming property. However, they are rarely ingested orally, the skin is a part of the human body most affected by surfactants. Barrier function of the skin is very strong, but the anionic surfactants can cause serious damages to it. Recently, amino acid-based surfactants have attracted attention as a safer option owing to their biocompatibility. Cytotoxicity examinations revealed that the amino acid-based surfactants are superior to sulfate-based surfactants. However, a systematical and comprehensive study related to the effect of these surfactants on skin barrier function has not yet been reported. In this work, skin permeation test using the skin of hairless mice and HPLC method is carried out. The material transmission speed through skin in a steady state was different between each surfactant treatment. We performed a comprehensive analysis of the effect of surfactants on skin barrier function and defined Transmission Index as an index for the degree of effect of surfactants. Glutamate series amino acid-based surfactant were effective to Transmission Index and we guessed the cause was due to adsorption. Based on the finding this study, we suggest using adsorptive property as a measure to the effect on the skin barrier function.

The involvement of protein denaturing activity in the effect of surfactants on skin barrier function

“…The effect on skin barrier function was evaluated by the TI method. The previously reported TI values of the 12 kinds of anionic surfactants 20 and four kinds of quaternary ammonium salt type surfactants 22 are shown in Figure 1, alongside the TI values of the other surfactants measured in this study. The initial 12 surfactants were arranged on the basis of the alkyl structure: (1) sodium laurate, (2) sodium lauryl sulfate, (3) sodium polyoxyethylene laurylether sulfate, (4) sodium lauroyl glutamate, (5) sodium lauroyl methyl taurate, (6) sodium cocoyl alaninate, (7) sodium cocoyl sarcosinate, (8) sodium cocoyl glutamate, (9) potassium cocoyl glutamate, (9) potassium cocoyl glutamate, (10) triethanolamine cocoyl glutamate, (11) sodium cocoyl methyltaurate, and (12) sodium taurine cocoyl methyltaurate.…”

“…The TI method, which we reported previously, 20 was used to evaluate the effect of two cationic surfactants, three amphoteric surfactants, and two nonionic surfactants on the skin barrier function. Dimethyldistearylammonium chloride (Sanyo Chemical Industries, Ltd.) and trimethylstearylammonium chloride (Toho Chemical Industry Co., Ltd.) were prepared as cationic surfactants.…”

“…Previously, we developed the Transmission Index (TI) method, which evaluates changes in the skin penetration rate of drugs as a comprehensive measure of the effects of surfactants on the skin 20 . The TI value, which comprehensively represents the degree to which the surfactant effects skin barrier function, is high for surfactants that are considered to result in "strong skin irritation."…”

“…Interestingly, while amino acid surfactants are considered to have low cytotoxicity and low irritation, we previously reported that the TI value of the glutamate surfactant was relatively high. We have presumed that the glutamate surfactants have a strong affinity with the stratum corneum of the skin surface to reduce the skin barrier function by adsorbing to the skin 20 . In addition, Japan Ministry of Economy, Trade and Industry mentioned the anti‐virus activity of quaternary ammonium salt type surfactant at April 2020 21 ; however, the effect on the skin barrier function of them was not considered.…”

Sulfate-based lipids: Analysis of healthy human fluids and cell extracts

“…administration of synthetic N-acyl taurines (NATs) accelerated wound closure in mice and stimulated repair-associated responses in primary cultures of human keratinocytes and fibroblasts (Sasso et al, 2016) and to actively regulate differentiation of fibroblasts and mitogenesis in human keratinocytes (Sasso et al, 2016). In another study, several amino acid-based surfactants were evaluated to their in vitro skin permeation (Okasaka et al, 2018) where taurine-based surfactants exhibited an intermediate behaviour and a more biocompatible option to sulfate-based surfactants (i.e. SDS).…”