Development of emulgel formulation from <i>Markhamia tomentosa</i> leaf extract: Characterization and <i>in vitro</i> antimicrobial activity against skin isolates

Abstract

Objectives: Skin infections are mild to severe infections often treated with antimicrobial agents. There is an increase in resistance to antimicrobial agents necessitating the search for new medicines. This study developed an emulgel formulation of Markhamia tomentosa leaf extract and evaluated its antimicrobial activity against skin isolates. Materials and Methods: A successive extraction of M. tomentosa leaves in five solvents – n-hexane, dichloromethane, ethyl acetate, ethanol, and distilled water was carried out. The activity of the extracts against skin isolates of Staphylococcus aureus, Staphylococcus epidermidis , and Bacillus subtilis was carried out. The distilled water extract was formulated into emulgel, characterized, and evaluated for antimicrobial activity. Results: The n-hexane and dichloromethane extracts of M. tomentosa were inactive against all organisms at concentrations used. The ethanol extract was active against S. aureus and S. epidermidis at 200 mg/mL. The ethyl acetate and distilled water extracts were active against S. epidermidis and B. subtilis at 100 and 50 mg/mL, respectively. All emulgel formulations of distilled water extract of M. tomentosa leaves were brown, smooth, and easy to spread on the skin and had a pH of 4.73–5.55. The formulation containing the distilled water extract was more viscous (7784cP) than the blank formulation (6328cP). The formulation was active against S. epidermidis . Conclusion: The distilled water extract of M. tomentosa leaves was the most active against S. epidermidis and B. subtilis . Its emulgel formulation had desirable physicochemical properties for application to the skin. Further studies can be carried out toward its development for the treatment of skin infection caused by organisms investigated.