Chitosan-Gum Arabic Coated Nanostructured Lipid Carriers for Enhanced Gastrointestinal Stability of Curcuminoids

Curcuminoids possess potent anti-inflammatory and antioxidant properties but suffer from poor aqueous solubility and rapid gastric degradation, limiting their therapeutic efficacy. This study developed turmeric curcuminoid-loaded nanostructured lipid carriers (TUR-NLCs) with chitosan-gum Arabic (CS-GA) polyelectrolyte complex coatings to enhance gastrointestinal stability and controlled oral delivery. TUR-NLCs were prepared via hot emulsification-microfluidization using optimized medium-chain triglyceride (MCT) and glycerol monostearate (GMS) ratios, followed by coating with a preformed CS-GA polyelectrolyte complex. The nanocarriers were comprehensively characterized for physicochemical properties, drug release kinetics, gastrointestinal stability, and biological activity. The optimized formulation (6MCT/3GMS) achieved a particle size of 53.20 ± 2.1 nm with 68.04 ± 0.98% encapsulation efficiency. Solid-state characterization indicated an amorphous or noncrystalline state of curcuminoids within the lipid matrix. The CS-GA coating significantly enhanced stability under simulated gastric conditions (pH 1.2), with controlled intestinal release following Fickian diffusion mechanisms (Korsmeyer-Peppas model, R ² > 0.94, n = 0.304-0.336). The nanocarriers demonstrated good in vitro safety in RAW 264.7 macrophages (IC₅₀ > 1000 μg/mL) while preserving anti-inflammatory activity (up to 25.91% NO inhibition at 100 μg/mL). This formulation development study demonstrates that CS-GA-coated NLCs provide enhanced gastrointestinal stability and controlled release characteristics, establishing proof of concept for the coating strategy. In vivo studies are warranted to validate therapeutic potential.