Curcumin-loaded solid lipid nanoparticles have prolonged in vitro antitumour activity, cellular uptake and improved in vivo bioavailability

Purpose: The aim of the present study was to blend liquid lipids with solid lipids to encapsulate curcumin in solid lipid nanoparticles (SLNs), thereby improving the dispersibility and chemical stability of curcumin, prolonging its antitumour activity and cellular uptake and enhancing its bioavailability. Methods: Curcumin-loaded SLNs (C-SLNs) were prepared by high-pressure homogenisation with liquid lipid Sefsol-218 (R). The morphology, stability and release of curcumin in the optimised formulation were investigated. The anti-cancer activity of the formulation was evaluated in MCF-7 cells. Fluorescence spectrophotometry was used to quantify cellular uptake of the drug. The pharmacokinetic profiles of curcumin in SLNs after intravenous administration were studied in rats. Results: Blending Sefsol-218 (R) into a lipid matrix reduced the particle size without improving drug loading. An optimised formulation consisting of Dynasan 114 (R), Sefsol-218 (R), and Pluronic F68 (R) (630:70:300, w/w) loaded with 0.8% drug was prepared. This formulation could be dispersed in water with a mean particle size of 152.8 +/- 4.7 nm and a 90% entrapment efficiency. Curcumin displayed a two-phase sustained release profile from C-SLNs with improved chemical stability. Compared to the solubilised solution, C-SLNs exhibited prolonged inhibitory activity in cancer cells, as well as time-dependent increases in intracellular uptake. After intravenous administration to rats, the bioavailability of curcumin was increased by 1.25-fold. Conclusions: C-SLNs with improved dispersibility and chemical stability in an aqueous system have been successfully developed. C-SLNs may represent a potentially useful cancer therapeutic curcumin delivery system. (C) 2013 Elsevier B.V. All rights reserved.