The preparation technique of gypenoside pellets was investigated in this work. The optimum technical parameters for producing gypenoside pellet were obtained by single factor test. The extrusion frequency, spheronization frequency, and spheronization time were used as the influencing factors and the roundness of the pellets as the evaluationindex. The blank and gypenoside pellets were prepared by extrusion sphemnization and fluid-bed coating technology, respectively. Micromeritic properties and in vitro release of pellets were determined. The properties of gypenoside pellets were evaluated by infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed that the extrusion velocity, spheroization velocity and spheroization time were 30 Hz, 50 Hz, 4 min, respectively. The cumulative amount of gypenoside pellets was 95.98±8.92%, indicating the product complied with the requirements in pharmacopoeia. The friability, the roundness and the angle of repose of gypenoside pellets were 0.90%, 0.80±0.17, 38.70°. The pellets were uniform in diameter, round and smooth, and the fluidity was good. The results of electron microscopy, infrared and X-ray diffraction showed that the pellets were round and the distribution of gypenosides was uniform. It indicated that the process of preparation by extrusion-spheronization and fluid bed coating machines was simple and feasible. It can be applied industrially.
