Evaluation of the Antimicrobial Effectiveness of Topical Gels Containing Acalypha wilkesiana


Traditional medicines used in developing countries in the treatment and management of diseases are mostly used in their crude forms, consequently, users are exposed to unwanted toxic effects due to no dosing standards and/or poor packaging. This study aims to formulate Acalypha wilkesiana leaves known for its antimicrobial properties into an appropriate conventional topical gel and standardize the formulation for possible use in the treatment of superficial skin infections. The minimum inhibitory concentration and antimicrobial susceptibility tests of methanol extracts of the red and green variants of Acalypha wilkesiana leaves were determined against select bacteria and fungi. The physical and microscopic properties, stability and compatibility of the extracts in different topical gels such as hydrogels, bigels and organogels were investigated and the effective strength of the extract for incorporation into the appropriate gel form was determined using antimicrobial sensitivity studies. The organogel was the most appropriate gel form for incorporation of the methanolic extract of Acalypha wilkesiana. Both variants of Acalypha wilkesiana showed antibacterial activity against Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus albus and antifungal activity against Microsporum canis and Malassezia furfur. Both were inactive against Candida albicans and Trichophyton rubrum. The red Acalypha variant showed antibacterial activity against Klebsiella oxytoca at a concentration of 125 mg/mL in the organogel. A topical organogel compatible with the two variants of Acalypha wilkesiana was developed and the antimicrobial assay showed potential therapeutic efficacy in the treatment of microbial skin infections caused by common skin pathogens