Antimicrobial Assessment of Hand Sanitizers Formulated from Neem Leaf Extract (Azadirachta indica) and Coconut Shell Liquid Smoke

Abstract

Abstract The widespread use of alcohol/ethanol-based hand sanitizers has raised concerns due to the concurrent issues of skin irritation, allergies, childhood poisoning risks, and the potential for bacterial resistance to antibiotics, which may disrupt the human digestive system. This study explores the potential of Neem leaves (Azadirachta indica) and liquid smoke as natural alternatives to alcohol-based antiseptics. The objective is to assess the antimicrobial efficacy of hand sanitizers containing Neem leaf extract and coconut shell liquid smoke against Escherichia coli and Salmonella typhimurium. Hand sanitizers were prepared by mixing 4g of Neem leaf extract with varying quantities of coconut shell liquid smoke (labeled as A1, A2, A3, A4, and A5, corresponding to 0g, 1g, 3g, 5g, and 7g, respectively). distilled water was then added until the total volume reached 100 ml. The solution was then stabilized with 0.5g of Carboxyl Methyl Cellulose (CMC) and 10g of glycerin. Results indicate that formulations A1, A2, A3, and A5 exhibit moderate inhibitory activity against Escherichia coli, with inhibition zone diameters of 6.02 mm, 8.17 mm, 9.67 mm, and 9.11 mm, respectively. Notably, formulation A4 displays strong inhibitory activity (11.15 mm). For Salmonella typhimurium, formulations A4 and A5 demonstrate very strong antimicrobial properties with inhibition zones measuring 11.68 mm and 12.59 mm, respectively. These findings suggest that hand sanitizers comprising Neem leaf extract and liquid smoke possess the potential as environmentally friendly, natural antiseptics.