Enhancing the oral bioavailability of curcumin using solid lipid nanoparticles.

To control the oral bioavailability of curcumin, we fabricated solid lipid nanoparticles (SLNs) using tristearin and polyethylene glycol (PEG)ylated emulsifiers. Lipolysis of prepared SLNs via simulated gastrointestinal digestion was modulated by altering the types and concentrations of emulsifiers. After digestion, the size/surface charge of micelles formed from SLN digesta were predictable and >91% of curcumin was bioaccessible in all of the SLNs. The curcumin permeation rate through mucus-covered gut epithelium in vitro was dependent on the size/surface charge of the micelles. Curcumin loaded in long-PEGylated SLNs rapidly permeated the epithelium due to the neutral surface charge of the micelles, resulting in a >12.0-fold increase in bioavailability compared to curcumin solution in a rat model. These results suggest that the bioavailability of curcumin can be controlled by modulating the interfacial properties of SLNs, which will facilitate the development of curcumin formulations for use in functional foods and pharmaceuticals.