Efficacy of soap and water based skin decontamination using in vivo animal models: a systematic review.

Water-only or soap and water solutions are considered a gold standard for skin decontamination. However, there is lack of conclusive data regarding their efficacy. The aim of this study was to summarize in vivo animal model data on skin decontamination using water-only, and/or soap and water. Covidence, Embase, MEDLINE, PubMed, Web of Science, and Google Scholar were searched to identify relevant articles using water-only or soap and water decontamination methods in in vivo animals. Data extraction was completed from studies, representing three animal models, and 11 contaminants. Results demonstrated water-only decontamination solutions led to complete decontamination in 3.1% (n = 16/524) protocols, incomplete decontamination in 90.6% (n = 475/524) of protocols, and mortality in 6.3% (n = 33/524) of protocols. Soap and water decontamination solutions resulted in complete decontamination in 6.9% (n = 8/116) protocols, incomplete decontamination in 92.2% (n = 107/116) of protocols, and mortality in 6.9% (n = 8/116) of protocols. Although water only, or soap and water is considered a gold standard for skin decontamination, most papers investigated found that water only, and soap and water provided incomplete decontamination. Due to the insufficient data, and limitations that hinder the applicability of available data, evidence indicates that more contemporary studies investigating skin decontamination are needed, and compared to other model species, including humans, when practical.

Systemic absorption of benzalkonium chloride after maximal use of a consumer antiseptic wash product.

An in vivo pharmacokinetic study was conducted using consumer antiseptic wash containing 0.13% benzalkonium chloride (BAC) to assess the effect of dermal absorption on long-term systemic exposure to BAC. The objective of the study was to determine blood levels of BAC under maximal use conditions. Subjects were enlisted to wash their hands 60 s with soap containing 0.13% BAC 30 times per day over an 8-9 h time period for 5 consecutive days. The test product with the highest absorption potential was selected based on market share and results from in vitro permeation testing. Blood plasma was collected from subjects on 32 occasions over the 6-day study period. Plasma samples were analyzed for the C12 and C14 homologs of BAC using LC-MS/MS with a lower limit of quantitation (LLOQ) of 106.9 and 32.6 ng/L, respectively. For the 32 subjects, C12 homolog was detected above the LLOQ in only four of 1,024 plasma samples at 117.8-191.7 ng/L, and C14 homolog was detected in only one sample at 59.5 ng/L. Consequently, systemic exposure to BAC in antimicrobial soap is very low and below the level of concern identified by the U.S. Food and Drug Administration (500 ng/L) even under maximal use conditions.

Soap and syndets: differences and analogies, sources of great confusion.

OBJECTIVE: Soap has been used by humankind since ancient times and was probably already known to the Sumerians. It is a fatty acid salt obtained from the reaction of a strong base with a fatty substance of animal (tallow) or plant origin (oil). This reaction is called saponification. Syndets, on the other hand, are much more recent and have been in use for about a century. In the case of liquid syndets, they are mainly alkyl sulphates and their derivatives alkyl ether sulphates while isethionates and sarcosinates are more commonly found in solid syndets. Synthetic soaps and detergents are surfactants and, as such, they have detergent properties. The way soap works accounts for its antimicrobial properties. Thanks to its amphiphilic structure, it is able to interact with the lipid membranes of microorganisms (viruses, bacteria, etc.) and inactivate them. In this coronavirus pandemic period, health authorities worldwide recommend hand washing with soap and water. We therefore wanted to provide a summary of the chemical characteristics and applications of soaps, on the one hand, and synthetic detergents, on the other. Soap is not the only product used for hand hygiene and, given the current situation, alternatives are complex and varied.