The Effect of Base Variations on the Physical Properties of Hand Sanitizer Gel Preparations Combining Ethanol Extracts of Basil Leaves and Kaffir Lime Peel

Abstract

Basil leaves (*Ocimum basilicum* L.) and kaffir lime peel (*Citrus hystrix* DC.) have the potential to be developed into hand antiseptics. Antiseptic gels are widely used for practical reasons when soap and water are unavailable, particularly in emergencies. These gels utilize natural ingredients considered safe for use that are capable of inhibiting microbial growth. Kaffir lime contains essential oils proven to inhibit the growth of and kill *Staphylococcus aureus* and *Escherichia coli*. This study aimed to determine the potential of a combination of basil leaf and kaffir lime peel ethanol extracts formulated into a hand sanitizer gel, as well as the influence of varying HPMC and glycerin concentrations on the product's physical properties. This was an experimental study employing a maceration isolation method with 70% ethanol solvent, chosen for its simplicity and ability to yield an optimal amount of extract. Basil leaf extract is known to inhibit bacterial and fungal growth and has applications regarding conditions such as bronchitis, asthma, malaria, diarrhea, and skin diseases. One-Way ANOVA results (p=0.008 < 0.05 and p=0.001 < 0.05) indicated that variations in HPMC and glycerin concentrations within the gel formula significantly affected spreadability and adhesiveness. The study results showed that while HPMC and glycerin variations influenced adhesiveness and spreadability, they did not affect organoleptic properties, pH, homogeneity, or protective capacity.