High efficacy of a dimeticone-based pediculicide following a brief application: in vitro assays and randomized controlled investigator-blinded clinical trial

Abstract

BackgroundIncreasing resistance of head lice against neurotoxic agents and safety concerns have led to the search for treatment alternatives. Dimeticones with a physical mode of action are safe, and bear a reduced risk for the development of resistance.MethodsWe performed in vitro bioassays to assess pediculicidal and ovicidal activities of a new dimeticone-based product, and a randomized controlled clinical trial to assess efficacy, following 10 min application. Of 153 individuals screened, 100 participants with active head louse infestations were randomly assigned to treatment with either a dimeticone-based test product, or a 0.5% permethrin-based reference product (50 participants per group). Participants received two topical applications of either the test (10 min) or reference products (45 min) at days 0 and 7 or 8. Outcome measures included the efficacies of treatment and their safety, as well as global and local tolerability at baseline, and days 1, 7, and 10.ResultsAfter 10 min exposure, all lice treated with the dimeticone test product were classified as non-viable in the in vitro assay. Ovicidal activity after treatment of eggs with the dimeticone test product was 96.8%. In the clinical trial, 96 patients completed all study visits. In the full analysis set (FAS) population, on day 1 after one application, 98% of patients were cured in the test group, as compared to 84% cured in the reference group. All participants in both groups were free of head lice on day 10, following two applications (100% cure rate). In total, 42 adverse events (AEs) in 23 patients of both treatment groups were recorded, with the majority of AEs classified as mild.ConclusionsWe have shown a high level of pediculicidal and ovicidal activity, and clinical efficacy and safety, of a brief application of a new dimeticone-based product. The short application time and reduced risk for the development of resistance are key drivers for improved patients’ compliance.Trial registrationEU Clinical Trials Register EudraCT 2016–004635-20. Registered 14 November 2016.

Effectiveness and tolerability of a squalane and dimethicone-based treatment for head lice

“…This carefully designed combination of dimethicones of different molecular weights together with high concentration of squalane and a small amount of lauryl alcohol improves its mortality potency and confers good cosmeticity. Its good efficacy is similar to the data reported in other studies of different silicone-based commercial pediculicides (Gallardo et al 2012 ; Heukelbach et al 2019 ). Furthermore, the formulation shows full efficacy in only 2 min, following the global tendency to reduce the application time in order to increase treatment compliance.…”

“…Furthermore, the formulation shows full efficacy in only 2 min, following the global tendency to reduce the application time in order to increase treatment compliance. Other in vitro studies of physical acting agents confirm that motile head lice and eggs can be killed within a few minutes, although not all formulations achieve 100% ovicidal activity (Abdel-Ghaffar et al 2012 ; Abdel-Ghaffar et al 2010 ; Gallardo et al 2012 ; Heukelbach et al 2019 ; Mehlhorn et al 2011 ; Oliveira et al 2007 ; Strycharz et al 2012 ).…”

The effect of educational intervention on efficacy of 1% permethrin shampoo and 4% dimeticone lotion to treat head lice infestation using propensity score matching (PSM)

“…In other words, teaching the way of using pediculicides properly and health tips were effective in treating and reducing recurrence. Several studies have been conducted in the treatment of head lice infestation [ 18 – 19 ]. Most studies have compared different treatments [ 19 – 21 ], and several studies have been conducted on the effectiveness of training programs on preventing pediculosis capitis [ 22 – 23 ].…”

In vitro experiments of Pediculus humanus capitis (Phthiraptera: Pediculidae) resistance to permethrin and 6-paradol in East Jakarta: Detoxification enzyme activity and electron microscopic changes in lice

“…Heukelbach et al . [ 42 ] indicated that the efficacy of dimethicone for treating lice was 98%. kdr -type gene mutations cause the poor efficacy of permethrin.…”