Nanostructured Benzoic Acid-Chitosan Nanogel Encapsulating a Synergistic Blend of Seven Essential Oils for Precision Pharmacological Delivery.

To develop and characterize a chemically modified chitosan-benzoic acid (CS-BA) nanogel for enhanced encapsulation, stability, and controlled release of essential oils with improved antimicrobial and antioxidant properties, the CS-BA nanogel was synthesized via carbodiimide-mediated coupling (EDC) of chitosan with benzoic acid. The nanogel was characterized using scanning electron microscopy (SEM) for morphology and Fourier transform infrared (FTIR) spectroscopy for chemical bonding analysis. The encapsulation efficiency of essential oils-Pinus roxburghii (PREO), Pinus wallichiana (PWEO), Cedrus deodara (CDEO), Thuja orientalis (TOEO), Cymbopogon citratus (CCEO), Cymbopogon khasianus (CKEO), and Mentha arvensis (MAEO) was evaluated, and in vitro release studies were conducted over 36 h. The CS-BA nanogel formed uniform spherical nanostructures (~ 1 µm diameter). FTIR confirmed successful covalent coupling via amide linkages. The encapsulation efficiency of the essential oils ranged from 79.70 ± 0.21% to 96.52 ± 0.14%. The nanogel provided sustained and controlled release of essential oils, reducing volatility and enhancing stability. The encapsulated oils exhibited significantly higher antimicrobial and antioxidant activities, maintaining prolonged functional efficacy at lower concentrations. The CS-BA nanogel serves as an efficient delivery system for essential oils, addressing stability and bioavailability challenges. This system holds promise for applications in food preservation, pharmaceuticals, and cosmeceuticals, providing a sustainable approach to enhance the functional properties of bioactive compounds.