Influence of encapsulated functional lipids on crystal structure and chemical stability in solid lipid nanoparticles: Towards bioactive-based design of delivery systems

Abstract

We investigated the influence of physicochemical properties of encapsulated functional lipids--vitamin A, β-carotene and ω-3 fish oil--on the structural arrangement of solid lipid nanoparticles (SLN). The relationship between the crystal structure and chemical stability of the incorporated bioactive lipids was evaluated with different emulsifier compositions of a saponin-rich, food-grade Quillaja extract alone or combined with high-melting or low-melting lecithins. The major factors influencing the structural arrangement and chemical stability of functional lipids in solid lipid dispersions were their solubility in the aqueous phase and their crystallization temperature in relation to that of the carrier lipid. The results showed that the stabilization of the α-subcell crystals in the lattice of the carrier lipid is a key parameter for forming stable solid lipid dispersions. This study contributes to a better understanding of SLN as a function of the bioactive lipid.

Keywords: Crystallization; Docosahexaenoic acid (PubChem CID: 175542); Eicosapentaenoic acid (PubChem CID: 446284); Nanostructured lipid carriers; Oxidation; Phosphatidylcholine (PubChem CID: 10350317); Phosphatidylethanolamine (PubChem CID: 643792); Polymorphic transition; Quillaic acid (PubChem CID: 101810); Quillaja saponins; Solid lipid nanoparticles; Tristearin (PubChem CID: 11146); Vitamin A; Vitamin A acetate (PubChem CID: 638034); β-Carotene; β-Carotene (PubChem CID: 573); ω-3 fish oil.