EXTRACTION, ISOLATION, CHARACTERIZATION AND NANOENCAPSULATION OF CURCUMIN FROM CURCUMA LONGA: DEVELOPMENT OF PLGA NANOPARTICLES FOR ENHANCED ORAL BIOAVAILABILITY

Background: Curcumin, the principal bioactive polyphenol of Curcuma longa, exhibits outstanding pharmacological properties including anti-inflammatory, antioxidant, anticancer, and neuroprotective activities. However, its clinical utility is fundamentally limited by extremely poor aqueous solubility (~11 ng/mL), low oral bioavailability (<1%), and rapid first-pass metabolism. Objectives: This study aimed to extract, isolate, and characterize curcumin from C. longa rhizomes, and develop PLGA-based polymeric nanoparticles to overcome its biopharmaceutical limitations. Methods: Curcumin was extracted using Soxhlet apparatus (95% ethanol, 60°C, 6 h) and isolated by recrystallization. Identity and purity were confirmed by UV-Vis spectrophotometry, TLC, and paper chromatography. Three nanoparticle formulations (F1–F3) were prepared by nanoprecipitation, varying curcumin:PLGA ratio (1:20, 1:10, 3:20) and PVA concentration (0.5%, 1.0%, 1.5%). Nanoparticles were evaluated for particle size, PDI, zeta potential, encapsulation efficiency (EE%), drug loading (DL%), and in vitro drug release kinetics. The optimized batch was filled into hard gelatin capsules and evaluated per Indian Pharmacopoeia specifications. Results: Soxhlet extraction yielded 5.86 ± 0.31% w/w crude curcuminoid extract. Recrystallization provided purified curcumin (melting point 182–183°C; λ-max 427 nm; R² = 0.9994; single-spot TLC). Optimized formulation F2 (curcumin:PLGA 1:10, PVA 1.0%) yielded nanoparticles of 218 ± 16 nm particle size, PDI 0.22, zeta potential −24.8 mV, EE% 78.6%, and DL% 7.4%. In vitro drug release followed Korsmeyer-Peppas kinetics (R² = 0.995, n = 0.68) with 83% sustained release over 72 h. Capsule evaluation confirmed compliance with all pharmacopoeial specifications. Conclusions: PLGA nanoparticle encapsulation of curcumin is a viable and effective strategy to achieve sustained oral drug delivery, with implications for anti-inflammatory, oncological, and neuroprotective therapeutic applications.