Formulation and Antimicrobial Evaluation of a Niosomal Gel Incorporating Kigelia Africana Extract
Year: 2026
Type: article
Abstract: Topical delivery of herbal antimicrobials is often limited by poor stability and skin penetration of the free extract. This study aimed to develop and evaluate a niosomal gel loaded with the methanolic extract of Kigelia africana for topical antimicrobial application. Niosomes were prepared by the thin-film hydration (hand-shaking) technique using Span 60 and cholesterol in five surfactant-to-cholesterol ratios (F1–F5) and were characterized for particle size, polydispersity index (PDI), zeta potential, entrapment efficiency and surface morphology. The optimized niosomal dispersion was incorporated into a Carbopol 934 gel base and evaluated for appearance, pH, viscosity, spreadability, drug content, in-vitro drug release, and antimicrobial activity against Escherichia coli by the agar well diffusion method. Formulation F2 (Span 60: cholesterol, 150:100 mg) was identified as optimal, exhibiting the smallest particle size (128.42 nm), lowest PDI (0.241), highest negative zeta potential (−30.6 mV) and greatest entrapment efficiency (89.18 ± 0.51%) among the five formulations tested. Scanning electron microscopy confirmed spherical, smooth, uniformly distributed vesicles. The corresponding niosomal gel was brown, smooth and homogeneous, with a pH of 6.7 ± 0.03, viscosity of 5989 ± 0.54 cps, spreadability of 10.59 ± 0.12 g·cm/s and drug content of 97.82 ± 0.41%, and it exhibited sustained drug release reaching 92.7 ± 0.39% at 12 h. In the agar well diffusion assay, the niosomal gel produced a larger zone of inhibition against E. coli (13 ± 0.4 mm) than the pure extract (9.0 ± 0.3 mm), approaching the activity of standard ciprofloxacin (18 ± 0.2 mm, 10 μg/mL). These findings demonstrate that niosomal encapsulation markedly enhances the physicochemical performance and antimicrobial efficacy of Kigelia africana extract, supporting the developed gel as a promising, stable, natural alternative for the topical management of microbial skin infections.
Authors: Ajay Bisht, Reetika Rawat, Ramsha Aslam
Language: English
Subfield: Pharmaceutical Science
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W7204190197