Evaluation of the Antibacterial Activity of Pepper Leaf Ethanol Extract in Hand Sanitizer Spray Against Escherichia coli

Abstract

Pepper plants are commonly used as alternative treatments for digestive tract infections, including diarrhoea caused by Escherichia coli. To help reduce bacterial resistance, natural ingredients such as pepper leaves are considered promising due to their active compounds—tannins, phenols, and alkaloids—which exhibit antimicrobial properties. This study aimed to evaluate the antibacterial activity of ethanol extract of pepper leaves formulated into hand sanitizer sprays against E. coli, by measuring the diameter of inhibition zones. A true experimental design with repeated measures was employed, involving three hand sanitizer formulations: Formula 1 (20% extract), Formula 2 (30%), and Formula 3 (40%). Each formulation was tested in nine replications (n = 9). The extract was prepared through ethanol maceration and formulated with glycerin, methyl paraben, and distilled water. Laboratory testing using the well diffusion method revealed the following average inhibition zone diameters: 23.8 mm (Formula 1), 26.8 mm (Formula 2), and 28.2 mm (Formula 3). Statistical analysis using Repeated Measures ANOVA showed a significant difference among the three formulations (p = 0.000, α < 0.05). In conclusion, all pepper leaf extract formulations demonstrated very strong antibacterial activity against E. coli, with the 40% concentration yielding the highest inhibition.