Assessment of Herbal Hydrogels Derived From Cleome Viscosa L. and Boerhavia Diffusa L. Foliage Extracts: Phytochemical Analysis, Rheological Properties, and Antibacterial Efficacy

Abstract

Topical treatment of bacterial skin diseases increasingly relies on plant-derived bioactive compounds delivered via modern polymer systems. This research comparatively analyses the formulation, physical characteristics, and antibacterial effectiveness of topical hydrogels containing foliage extracts from Boerhavia diffusa L. (family Nyctaginaceae) and Cleome viscosa L. (family Cleomaceae). We shade-dried the collected viable plant foliage and extracted it by cold maceration using polar and non-polar solvents such as petroleum ether, acetone, and ethanol. Initial phytochemical analysis indicated that ethanolic extraction produced the most extensive range of bioactive secondary metabolites for both plant types. We developed two unique hydrogel compositions—Formulation-1 (F1, incorporating ethanolic foliage extract of C. viscosa) and Formulation-2 (F2, incorporating ethanolic foliage extract of B. diffusa)—using Hydroxypropyl Methylcellulose (HPMC K100M) and Carbopol 934 as the gelling polymers. In vitro agar well diffusion assays revealed that both unrefined ethanolic extracts and formulated hydrogels showed significant antibacterial efficacy against dermatological and systemic bacterial pathogens, including Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae. In comparison, Formulation-1 (C. viscosa) showed enhanced antibacterial efficacy, with larger zones of inhibition against the examined bacterial strains than Formulation-2 (B. diffusa). Physicochemical and rheological analyses showed that both formulations had stable, physiologically compatible pH levels (5.65 ± 0.020 to 5.72± 0.020), excellent spreadability, pseudoplastic (shear-thinning) flow, complete water solubility, and no skin irritation after 24 hours. In conclusion, Formulation-1 exhibited enhanced antibacterial efficacy and physical stability, confirming C. viscosa ethanolic foliage extract hydrogel as a promising, safe, and effective phytotherapeutic option for topical antibacterial use.