Comparison of Antibacterial Activity Against Staphylococcus aureus of Liquid Soap Formulations Made from Ethanol and Aquadest Extracts of Samanea saman Leaves

Natural antibacterial agents often exhibit relatively low inhibition zone values, which limits their practical effectiveness in hygiene applications. Samanea saman leaves extract demonstrated notable antibacterial activity, indicating its potential as natural antibacterial ingredient. Therefore, liquid soap formulation was selected to enable innovative formulation strategies that enhance antibacterial performance while maintaining the physicochemical stability of product. This study compares aquadest and ethanol as extraction solvents for Samanea saman leaves in developing renewable antibacterial agents in liquid soap. The study involved maceration of Samanea saman leaves using aquadest and ethanol, formulation of the extracts into liquid soap at concentrations of ۰, ۵, ۱۰, and ۱۵ mL for each solvent (one base without extract, three different concentrations for each of the two extracts, resulting seven formulas) via saponification, and evaluation of antibacterial activity against Staphylococcus aureus using the disc diffusion method. The soap formulation with ۱۵ mL of aquadest-based Samanea saman extract showed pH ۹, free alkali content ۰.۰۳۴%, density ۱.۰۷۰ g/mL, viscosity ۵۲۹.۱۸ cPs, foam stability ۹۴.۴۴%, and inhibition zone diameter ۱۹.۳ mm against Staphylococcus aureus. Meanwhile, the soap formulated with ۱۵ mL of ethanol-based extract presented pH ۸.۹, free alkali content ۰.۰۲۲%, density ۱.۰۷۱ g/mL, and viscosity ۵۰۷.۸۱ cPs. The antibacterial activity was higher, as indicated by a larger inhibition zone diameter ۲۱.۳ mm against Staphylococcus aureus. This study demonstrates that liquid soap enriched with Samanea saman leaf extract is a promising natural alternative to conventional antibacterial soaps, with the ethanol-based formulation exhibiting superior antibacterial activity compared to the aquadest-based formulation.

کلیدواژه ها:

antibacterial ، liquid soap ، Samanea saman Leaves ، Staphylococcus aureus