Tupker R A, Vermeulen K, Fidler V, Coenraads P J
1Department of Dermatology, University Hospital, Groningen and2Department of Medical Statistics, University of Groningen, The Netherlands.
Skin Res Technol. 1997 May;3(2):133-6. doi: 10.1111/j.1600-0846.1997.tb00175.x.
BACKGROUND/AIMS: The irritant potency of soap (sodium laurate, LAU) as opposed to other anionic detergents is not uniformly agreed upon. The aim of the study was to compare the irritancy of sodium laurate with that of sodium laurylsulphate (SLS), sodium cocoyl isethionate and disodium lauryl 3-ethoxysulphosuc-cinate by means of a 4-day repeated open exposure model in order to achieve a more realistic mimicry of daily practice.
The effects of the exposures were evaluated by: a) number of fulfilled exposures, b) visual score after exposures, and c) transepidermal water loss (TEWL) after exposures.
In the majority of subjects, exposure to LAU had to be stopped because of burning sensations, erythema and/or scaling. The number of fulfilled exposures to LAU was lower than that of SLS. The other agents were tolerated very well. These less irritative agents had much lower visual scores and TEWL values after the repeated exposures compared with LAU and SLS.
The explanation for the irritant nature of LAU in the present study might be the type of alkyl chain length distribution. Its 12-carbon chain content was ≤ 99%, and this agent can therefore be designated as pure sodium laurate. The same holds true for SLS. In daily practice, however, soap is a mixture of different - less irritant - chain lengths. Therefore, these findings cannot be extrapolated to commercially available soap bars.
背景/目的：与其他阴离子洗涤剂相比，肥皂（月桂酸钠，LAU）的刺激强度尚未得到一致认可。本研究的目的是通过4天重复开放暴露模型比较月桂酸钠与月桂醇硫酸酯钠（SLS）、椰油酰羟乙磺酸钠和月桂醇聚醚硫酸琥珀酸二钠的刺激性，以便更真实地模拟日常使用情况。
通过以下方式评估暴露的影响：a）完成暴露的次数，b）暴露后的视觉评分，以及c）暴露后的经表皮水分流失（TEWL）。
在大多数受试者中，由于烧灼感、红斑和/或脱屑，不得不停止LAU暴露。LAU的完成暴露次数低于SLS。其他制剂耐受性良好。与LAU和SLS相比，这些刺激性较小的制剂在重复暴露后的视觉评分和TEWL值要低得多。
本研究中LAU具有刺激性的原因可能是烷基链长度分布类型。其12碳链含量≤99%，因此该制剂可称为纯月桂酸钠。SLS也是如此。然而，在日常使用中，肥皂是不同链长（刺激性较小）的混合物。因此，这些发现不能外推到市售肥皂块。
