Development of a herbal soap using selected medicinal plants and evaluation of its antimicrobial activity

Abstract

Abstract: Soaps are used as a modality for topical application of medicinal plants used in the treatment of skin infections. In herbal soaps, natural bioactive constituents with a variety of therapeutic activities are incorporated into basic soap medium. Natural herbs are the main ingredients of herbal soap which are safer and beneficial than the commercial soaps. Antimicrobial activity of leaf extracts of Azadirachta indica, Cassia fistula and flower extract of Nelumbo nucifera has been evaluated individually and in combination by a previous study. This study aims to formulate a novel herbal soap using the above combined extract and to investigate its antimicrobial activity. Further, this study evaluates the physicochemical characteristics of the soap. The combined extract used in the formulation of soap was prepared by incorporating aqueous extracts of A. indica, N.nucifera and ethanol extract of C.fistula at a ratio of 4:1:1 according to the previous study. Soap was formulated by including the combined extract with other ingredients into the melted glycerin soap base. The antimicrobial activity of formulated soap was tested by agar well diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans and compared with standard drugs. Test was done in triplicate. Formulated soap exhibited antimicrobial activity against tested organisms with a highest activity against S aureus. Physiochemical parameters of soap were evaluated by determining the colour, pH, % free alkali and % of alcohol insoluble matter of the soap. pH at 28 ºC was 9.11 and % of alcohol insoluble matter was 24.6% which were within the accepted range. Further studies are pursued to evaluate the safety and efficacy of the formulated herbal soap.