Sacha Inchi Oil-Based Nanostructured Lipid Carriers for Curcumin Delivery: Development and Physicochemical...

Curcumin exhibits potent antioxidant activity beneficial for the prevention of various degenerative diseases; however, its highly lipophilic nature and susceptibility to degradation limit its solubility and physicochemical stability. To address these limitations, curcumin was formulated into nanostructured lipid carriers (NLCs), a lipid-based colloidal delivery system composed of solid and liquid lipids stabilized by surfactants. In this study, sacha inchi oil, a natural oil rich in omega-3 and other unsaturated fatty acids, was investigated as a novel liquid lipid component to improve lipid matrix structure and drug accommodation.

Curcumin-loaded NLCs were prepared using the hot homogenization method followed by probe sonication. Curcumin served as the active compound, while solid lipids (oleum cacao, glyceryl behenate (Compritol^® 888 ATO), or glyceryl palmitostearate (Precirol^® ATO 5)), sacha inchi oil as the liquid lipid, and surfactants (Tween 80, Poloxamer, or a Tween 80-Span 80 combination) were used. The resulting NLCs were characterized in terms of particle size, polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE), physicochemical properties (FTIR, DSC, XRD), morphology, and in vitro release behavior.

Physicochemical analyses confirmed successful incorporation of curcumin into the lipid matrix without undesirable interactions. Among the tested formulations, CaTS2 (oleum cacao 4.5%, sacha inchi oil 1%, Tween 80 12.5%, Span 80 1%, and curcumin 0.1%) demonstrated the most favorable characteristics, with a particle size of 95.50 ± 0.87 nm, PDI of 0.119 ± 0.157, and ZP of -22.30 ± 0.98 mV. Entrapment efficiency reached 97.24% and morphological analysis showed predominantly spherical particles. In vitro release exhibited a biphasic pattern, consisting of an initial burst followed by sustained release up to 480 min. Kinetic modeling revealed that CaTS2 followed the Korsmeyer-Peppas model (R² = 0.793; n = 0.301), consistent with Fickian diffusion, whereas pure curcumin followed the Higuchi model (R² = 0.819). The similarity factor (f₂ = 29.04) indicated a distinctly different release profile between the two systems.

Sacha inchi oil-based nanostructured lipid carriers were successfully developed and demonstrated favorable physicochemical characteristics, supporting their potential as a stable delivery system for curcumin.