Influences of trehalose‐modification of solid lipid nanoparticles on drug loading

The aim of the present work is to evaluate influences of doping trehalose into solid lipid nanoparticles (SLNs) on drug loading. SLNs were prepared by the emulsion-evaporation and low temperature-solidification method, using glyceryl monostearate as a lipid, phosphatidylcholine as a surfactant, trehalose as a modifier and resveratrol as a model drug. As the SLNs were doped by trehalose at a low amount [m(trehalose):m(lipids) = 1:5], entrapment efficiency and loading capacity were enhanced to (81.37 ± 1.50) and (8.71 ± 0.13)%, respectively. Based on morphology, phase transformation and crystalline structure of SLNs, trehalose was doped into lipid matrix in a non-crystalline state, disrupting the lipid crystallinity and inducing lattice defects.The lipid matrix was crystallized in polymorphic forms composed of α-form and β′-form and β-form, resulting in prevention of drug expulsion from the lipid matrix. The trehalose was interacted with the lipid, facilitating the formation of trehalose/lipid eutectic dopant. The dopant contained lattice defects, allowing for the incorporation of more resveratrol in a amorphous state, contributing to increase of entrapment efficiency and loading capacity. These results confirm stabilizing effects of doping trehalose on improvement of drug loading are attributed to the lipid crystal type and structure of lipid matrix containing lattice defects. Practical applications: Trehalose-doping is an innovative approach to the improvement of loading properties of SLNs. Compared with ordinary SLNs, SLNs doped with trehalose at low amounts exhibit higher drug loading, presenting the potential utility of these nanoparticles as a drug delivery system for hydrophobic drugs. Trehalose modification on improvement of drug loading of SLNs are attributed to the lipid crystal type and structure of lipid matrix containing lattice defects induced by doping trehalose.