OBJECTIVETo prepare solid lipid nanoparticles (SLN) loaded tetrandrine (TET) extracted from traditional Chinese medicine with ultrasonication and high pressure homogenization, and to compare the physicochemical characteristics of the particles produced by the two methods.

METHODSTET was incorporated into SLN by ultrasonication and high pressure homogenization separately. Transmission electron microscopy was employed to study the shape. Particle characterization system and Zeta potential analyzer were used to study the diameter and Zeta potential of SLN in suspension. The entrapment efficiency was determined with the high-performance liquid chromatography. The stability of SLN was also studied.

RESULTSTET-SLNs prepared by these two methods were sheet-shaped and irregular, but the SLNs prepared by high pressure homogenization were smaller. The mean diameter of SLN prepared by ultrasonication was (92 +/- 6) nm with Zeta potential of (-21.11 +/- 2.12) mV in distilled water, and the mean entrapment efficiency was 95.27%. The mean diameter of TET-SLN prepared by high pressure homogenization was (47 +/- 3) nm with Zeta potential of (-32.99 +/- 2.54) mV, and up to 97.82% of TET was incorporated. The diameter of SLN prepared by high pressure homogenization and ultrasonication were (52 +/- 5) nm and (168 +/- 12) nm after 90 days of storage at room temperature.

CONCLUSIONCompared with ultrasonication, high pressure homogenization is a better method to prepare TET-SLN, which is smaller, steadier and highly incorporated.