Rheological Characterization and In Vitro Antibacterial Dynamics of a Dual-Polymer Herbal Gel of Tridax Procumbens

Abstract

Tridax procumbens Linn. (Asteraceae), a traditionally used haemostatic and wound-healing herb, is rich in antimicrobial flavonoids, yet few studies have translated its extract into a stable, standardized topical hydrogel. This study aims to formulate and evaluate a Carbopol 940-HPMC based topical hydrogel incorporating the 90% ethanolic leaf extract of Tridax procumbens and assess its in vitro antimicrobial efficacy. Authenticated T. procumbens leaves were extracted using 90% ethanol, yielding 7.33% w/w of dried extract. The extract's flavonoid content was analytically confirmed via TLC (major Rf 0.577) and UV-visible spectrophotometry (λ max 253 nm, 383 nm) against a quercetin standard. A 1.0% w/w extract-loaded herba gel was formulated and exhibited ideal physicochemical properties, including a homogeneous green appearance, optimal pH (6.42), spread ability (21.72 g.cm/sec), and viscosity (4770-5340 cP). In vitro antibacterial screening via the agar well diffusion method revealed significant zones of inhibition against Staphylococcus aureus (15.00 ± 0.33 mm) and Escherichia coli (8.00 ± 0.33 mm). In conclusion, the developed Tridax Daisy Herba Gel is a physiochemically stable, skin-compatible formulation. It effectively retains broad-spectrum antimicrobial activity within the gel matrix, highlighting its potential as a standardized, plant-based therapeutic alternative for managing topical wound and skin infections.