FORMULATION AND EVALUATION OF POLYHERBAL GEL FOR ANTIMICROBIAL ACTIVITY

The present study was designed to develop, optimise, and comprehensively evaluate a polyherbal antimicrobial gel made up from Azadirachta indica, Curcuma longa, Curcuma longa, Aloe vera, and Centella asiatica. Dry powder extracts were subjected to preliminary phytochemical screening, quantitative estimation of total phenolic content (TPC) and total flavonoid content (TFC), and validated HPTL.C In vitro antimicrobial activity of individual and combined extracts was evaluated by disc diffusion, broth microdilution minimum inhibitory concentration (MIC) determination, and checkerboard synergy assay (Fractional Inhibitory Concentration Index, FICI). Three polyherbal gel formulations (F1, F2, F3) were prepared using Carbopol 940 at 0.5%, 1.0%, and 1.5% w/w respectively. Physicochemical evaluation, in vitro antimicrobial activity by agar well diffusion, in vitro drug release, accelerated stability studies, and primary skin irritation by Draize patch test were performed. All five plant extracts demonstrated broad-spectrum antimicrobial activity. Formulation F2 (Carbopol 940, 1.0% w/w) was identified as optimal: pH 6.1 ± 0.1, viscosity 6,180 ± 204 cP, spreadability 8.2 ± 0.4 g.cm/s, and drug content within 95–105% for all markers. F2 produced a zone of inhibition of 20.4 ± 0.8 mm against clinical MRSA statistically superior to mupirocin 2% cream (16.8 ± 0.6 mm, p < 0.05). Drug release followed Korsmeyer-Peppas kinetics (R² = 0.9922, n = 0.482) with 78.4% cumulative release at 24 h. The Primary Irritation Index was 0.14 (non-irritant). The developed polyherbal gel is a stable, dermally safe, and pharmacologically potent topical formulation that demonstrated superior anti-MRSA activity compared to the established topical antibiotic mupirocin.