The preparation and antibacterial activities of anionic surfactant based liquid hand soaps

Soap is the essential cleansing material which is necessary for prohibiting diseases and the propagation of harmful microorganisms. For 30 years, the usage of antibacterial soaps has increased as these products are claimed to be highly effective against bacteria and inhibit their reproduction. Several synthetic chemicals such as triclosan (TCS) and triclocarban (TCC) have been introduced within formulation of these antibacterial soaps as an antibacterial and antifungal agent. However, FDA banned several chemicals including TCS and TCC in 2016 due to lack of sufficient data on their safety and effectiveness. Additionally, it is well known that antibacterial liquid hand soaps have relatively lower foaming performances due to the presence of cationic surfactants. The purpose of this study is to produce an anionic liquid hand soap which bears adequate antibacterial activity and contend with commercial alternatives along with sufficient cleansing and foaming performances in the absence of banned antibacterial agents. For this purpose, synthetic surfactant (LS), fatty acids (FAS) and coconut oil (NLS) based liquid hand soaps were prepared in the presence and absence of essential oils (lavender and cinnamon) which have previously shown to exhibit antibacterial activities. The viscosity measurements indicated that LS in the presence and absence of cinnamon and lavender oil showed convenient thickness as the amounts of salt and thickener optimized while these samples offer high foaming performances. Moreover, the addition of lavender and cinnamon oils enhanced the antibacterial activity of LS on Escherichia Coli and Staphylococcus Aureus where even plain LS presented inhibition effect comparable to the commercial market product. Finally, the panel test revealed that the synthetic anionic surfactant based soaps prepared in the presence of natural and biocompatible essential oils exhibit almost identical consumer satisfaction as compared to commercial alternatives. All these performed analysis and tests pointed out the possibility of producing a competent natural antibacterial liquid hand soap in the absence of detrimental and banned antibacterial agents simply by using natural alternatives.