DEVELOPMENT, OPTIMIZATION, AND EVALUATION OF A POLYHERBAL TOPICAL CREAM FOR ANTIMICROBIAL AND ANTI-INFLAMMATORY APPLICATIONS

Microbial skin infections caused by bacterial and fungal pathogens remain a significant therapeutic challenge, highlighting the need for effective plant-based topical formulations. The present study aimed to develop and optimize an oil-in-water polyherbal cream containing extracts of Cassia fistula, Delonix regia, and Parkinsonia aculeata, and to evaluate its antimicrobial, anti-biofilm, and anti-inflammatory potential. Polyherbal cream formulations were prepared using an oil-in-water emulsification technique and optimized through a 3² factorial design by varying the oil phase and emulsifier concentrations. The optimized formulation (PHC-5) exhibited desirable physicochemical properties, including a mean globule size of 928.7±20.4 nm, polydispersity index 0.27±0.010, viscosity 6528.7±20.4 cps, and spreadability 41.54±2.95 g·cm/s, indicating suitable rheological behavior for topical application. Antimicrobial evaluation demonstrated that the optimized cream showed enhanced activity compared with the crude polyherbal extract. PHC-5 exhibited potent antifungal activity against Candida albicans with MIC 8.0±0.7 µg/mL and MBC 16.0±12.8 µg/mL, showing superior efficacy compared to activity against Escherichia coli. Additionally, the formulation significantly inhibited microbial adhesion and biofilm formation, while time-kill studies confirmed rapid and sustained microbial reduction. Overall, the optimized polyherbal cream demonstrated promising antimicrobial and anti-biofilm activity along with appropriate physicochemical characteristics, suggesting its potential as a natural topical alternative for the management of superficial microbial infections. Further in-vivo investigations are warranted to confirm its clinical applicability.