Brunton Elizabeth R, Whelan Ian P, French Rebecca, Burgess Mark N, Burgess Ian F
Insect Research & Development Limited, Cambridge, Cambridgeshire, United Kingdom.
EctoMedica Limited, Cambridge, Cambridgeshire, United Kingdom.
PeerJ. 2019 Apr 15;7:e6759. doi: 10.7717/peerj.6759. eCollection 2019.
The eggs of head lice are fixed to the hair of their hosts by means of a persistent glue-like fixative that is not chemically bound to the substrate. Eggshells stuck to hairs after successfully treating the infestation are a cosmetic issue and a source of misunderstanding about whether the infestation is eliminated. Hitherto, no effective treatment to loosen louse eggs and nits has been found.
An extensive screening of surface active compounds, oils, esters, and other cosmetic lubricants used a slip-peel device to measure the forces required to release the grip of the fixative. Promisingly effective compounds were formulated into suitable carriers for further testing. The most effective combination formulation was tested, as a commercial product (Hedrin Stubborn Egg Loosening Lotion), in a usage study of 15 children with nits, in which one half of the head was combed only on damp hair and the other half combed after a 10 min treatment using the product.
Laboratory tests of the forces required to remove nits found that pelagonic acid derivatives, particularly isononyl isononanoate, in the presence of a polymeric gelling agent and water, were most effective to reduce the initial grip of the fixative as well as reducing friction as the eggshell is drawn along the hair shaft and that the final product was significantly ( < 0.05) more effective than several other marketed materials. In the usage study significantly ( = 0.01046) more louse eggs and nits were removed after treatment with the gel.
The product developed through this study is the first with a demonstrable efficacy for loosening the grip of the louse egg fixative from hair. Consequently, until now, and despite the availability of effective pediculicidal treatments, dealing with the eggshells persisting after an infestation has been an onerous task for most households. This type of product can enable families to deal more easily with persistent eggshells and improve self-esteem in affected children.
头虱卵通过一种持久的类似胶水的固定剂固定在宿主头发上，这种固定剂与底物没有化学结合。成功治疗头虱感染后粘在头发上的蛋壳是一个美容问题，也是关于感染是否已消除的误解来源。迄今为止，尚未找到有效松开虱卵和虮子的治疗方法。
对表面活性化合物、油类、酯类及其他化妆品润滑剂进行广泛筛选，使用滑动剥离装置测量松开固定剂所需的力。将有前景的有效化合物配制成合适的载体进行进一步测试。在一项针对15名有虮子儿童的使用研究中，对最有效的组合配方作为商业产品（Hedrin顽固卵松动洗剂）进行测试，其中一半头部仅在湿发时梳理，另一半在使用该产品处理10分钟后梳理。
去除虮子所需力的实验室测试发现，在聚合胶凝剂和水存在的情况下，壬酸衍生物，特别是异壬酸异壬酯，在减少固定剂的初始附着力以及当蛋壳沿着毛干拉动时减少摩擦方面最有效，并且最终产品比其他几种市售材料显著更有效（P<0.05）。在使用研究中，使用凝胶处理后显著（P = 0.01046）去除了更多的虱卵和虮子。
通过本研究开发的产品是首个对松开头发上虱卵固定剂的附着力具有可证明疗效的产品。因此，直到现在，尽管有有效的灭虱治疗方法，但对于大多数家庭来说，处理感染后残留的蛋壳一直是一项艰巨的任务。这种类型的产品可以使家庭更容易处理残留的蛋壳，并提高受影响儿童的自尊心。
