Antoine J L, Contreras J L, Van Neste D J
Unit of Occupational and Environmental Dermatology, Catholic University of Louvain, Brussels, Belgium.
Derm Beruf Umwelt. 1989 May-Jun;37(3):96-100.
Even though various experimental methods have been proposed for in vitro testing of detergents such as LSL (sodium laurylsulfate) no absolutely relevant clinical information can be inferred from them as to the irritancy of a given compound. In particular the relative importance of pH needs further assessment. This study reports on in vivo evaluation of skin function changes under given experimental conditions with SLS applied at 3 different pH values. There is a dramatic increase of transepidermal water loss (TEWL), i.e. a substantial reduction in the barrier function of the skin, when SLS is applied under occlusion for 48 H. The alkaline control solution (NaOH pH 9) induced low-grade, but significant TEWL increases, as compared to the other controls (distilled water pH 7; HCl pH 5), which had no influence on TEWL. The changes obtained with the controls were much lower than those observed with SLS. The barrier-function changes induced by the surfactant SLS could, however, promote transepidermal passage of acid and/or alkaline molecules, hence increasing toxic damage of the skin; yet no such effects could be observed, indicating that the main effects are due to detergency. Assessment of cutaneous blood flow values (CBFV) by laser Doppler velocimetry showed increased values after SLS. When pH-adjusted SLS solutions were compared, there was neither a difference in relation to pH nor did the control solutions induce any significant CBFV change. This study reveals that TEWL and CBFV are probably the most reliable methods to investigate acute irritancy by SLS. Accordingly, pH cannot be considered as a major contributive factor of irritancy when SLS solutions are applied under occlusion (48 h).(ABSTRACT TRUNCATED AT 250 WORDS)
尽管已经提出了各种用于洗涤剂（如十二烷基硫酸钠，LSL）体外测试的实验方法，但关于给定化合物的刺激性，无法从这些方法中推断出绝对相关的临床信息。特别是pH的相对重要性需要进一步评估。本研究报告了在给定实验条件下，用3种不同pH值的十二烷基硫酸钠（SLS）进行体内皮肤功能变化评估的情况。当在封闭条件下应用SLS 48小时时，经表皮水分流失（TEWL）显著增加，即皮肤屏障功能大幅降低。与其他对照（蒸馏水pH 7；盐酸pH 5，对TEWL无影响）相比，碱性对照溶液（氢氧化钠pH 9）引起了轻度但显著的TEWL增加。对照所产生的变化远低于SLS所观察到的变化。然而，表面活性剂SLS引起的屏障功能变化可能会促进酸和/或碱性分子的经表皮通透，从而增加皮肤的毒性损伤；但未观察到此类影响，表明主要影响是由于去污力。通过激光多普勒测速法评估皮肤血流值（CBFV）显示，应用SLS后该值增加。当比较pH调节后的SLS溶液时，与pH无关，对照溶液也未引起任何显著的CBFV变化。本研究表明，TEWL和CBFV可能是研究SLS急性刺激性最可靠的方法。因此，当在封闭条件下（48小时）应用SLS溶液时，pH不能被视为刺激性的主要促成因素。（摘要截短于250字）
