FORMULATION AND EVALUATION OF POLYHERBAL NANO-GEL FOR ENHANCED WOUND-HEALING ACTIVITY

Background: Chronic and infected wounds remain a major clinical burden, and conventional topical products often suffer from poor penetration, short residence time and limited antimicrobial activity. Curcumin-, asiaticoside- and acemannan-rich botanicals have long been used for wound care, but their poor aqueous solubility and instability restrict topical efficacy. Objective: To formulate a polyherbal nano-gel combining Curcuma longa rhizome extract, Centella asiatica herb extract and Aloe vera gel, and to evaluate its physicochemical properties, release behaviour, antimicrobial activity, stability and wound-healing efficacy. Methods: Herbal extracts were loaded into an oleic acid-based nanoemulsion prepared by high-shear homogenisation and probe sonication, and the optimised nanoemulsion (F3) was incorporated into a Carbopol 940 gel base. The nano-gel was characterised for particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, pH, viscosity, spreadability, in vitro release and stability. Antimicrobial activity was tested by agar well diffusion, and wound healing was assessed in an excision wound model in Wistar rats (n = 6 per group). Results: The optimised nano-gel had a mean droplet size of 168.4 nm, PDI of 0.214, zeta potential of −29.6 mV and curcumin entrapment efficiency of 89.4%. It showed sustained release (93.1% at 24 h; Korsmeyer–Peppas, n = 0.58), larger inhibition zones than the conventional gel, and remained stable for 90 days at 25 °C/60% RH. Treated animals achieved 97.8% wound contraction by day 16 and an epithelialisation period of 15.7 days, outperforming the conventional polyherbal gel and the povidone-iodine reference, with higher hydroxyproline content and organised collagen deposition on histology. Conclusion: Nano-structuring of a polyherbal combination improves delivery and wound-healing performance, supporting its further development as a topical wound-care product.