ABSTRACT
Objective To prepare lutein ester (LE) nanoparticles (LE-NPs) by anti-solvent method using tetrahydrofuran as solvent, deionized water as antisolvent and Poloxamer 188 as surfactant, and to optimize the process of getting LE-NPs. Methods The concentration of LE, ratio of solvent to solvent, type and dosage of surfactant, precipitation time and stirring speed were investigated factors affecting the particle size of LE-NPs. The raw LE and LE-NPs were observed and analyzed by scanning electron microscopy, laser particle size analyzer, X-ray diffraction, and differential scanning calorimetry; Solvent residue was tested by GC method. What’s more, the solubility and dissolving capability of raw LE and LE-NPs also were detected in vitro in this study. Results The optimized preparation conditions of LE-NPs were as follows: 10 min of stirring time, 50 mg/mL of LE concentration, 1∶7 of the volume ratio of solvent to antisolvent, 0.5% at mass fraction of poloxamer 188, 950 r/min of stirring speed, 25 ℃ of precipitation temperature. The mean particle size of spherical LE-NPs was 164 nm. XRD and DSC results showed that LE-NPs had lower crystallinity compared to raw drug, and mainly in amorphous state. The solvent residue result showed that tetrahydrofuran residue content in LE-NPs was 344.3 μg/g. Furthermore, the solubility and dissolution rate of LE-NPs were about 2.91 times and 9.65 times of raw LE. Conclusion LE-NPs prepared by antisolvent method could become a new formulation, which has higher solubility and bioavailability than raw LE.