Formulation, stability, antibacterial activity, and het-cam irritation testing of Clinacanthus nutans ethanol fraction emulgel

AbstractThis study examines the formulation, stability, antibacterial properties, and safety profile of the ethanol fraction emulgel derived from Clinacanthus nutans. The emulgel was developed utilising distinct concentrations of the C. nutans ethanol fraction (12.5% and 25%) and subjected to rigorous evaluation concerning its physicochemical characteristics, stability under freeze-thaw conditions, antibacterial efficacy, and potential for irritation, as assessed by the Hen’s Egg Test on Chorioallantoic Membrane (HET-CAM). The findings indicated that the emulgel formulations displayed homogeneity, characterised by a semisolid consistency and a slightly acidic pH, rendering them appropriate for dermal application. An inverse relationship was observed between viscosity and C. nutans concentration, with an accompanying enhancement in spreadability. Stability assessments confirmed the formulations’ robustness, with no evidence of phase separation detected. The antibacterial evaluations indicated that the 25% C. nutans emulgel presented considerable inhibitory effects on Staphylococcus aureus (13.94 mm), Proteus mirabilis (15.87 mm), and Pseudomonas aeruginosa (15.9 mm). Nonetheless, its comparative effectiveness was found to be lacking against standard antibiotics. The HET-CAM evaluation affirmed that all formulations were non-irritating. In summary, the C. nutans ethanol fraction emulgel emerges as a promising natural topical agent endowed with potential antibacterial activity, stability, and safety for cutaneous applications. It is advisable to pursue further optimisation and clinical trials to augment its efficacy and substantiate its therapeutic potential.