Preparation and in vitro release evaluation of pH-dependent colon targetting pellets of Paridis Rhizoma saponin and Astragali Radix polysaccharide / 中草药

ABSTRACT

Objective: To prepare pH-dependent Paridis Rhizoma saponin (PRS) and Astragali Radix polysaccharide (ARP) colon targeting pellets for the treatment of colon cancer and finish its in vitro release performance evaluation. Methods: The colon targeted pellets were prepared with extrusion-spheronization and air-flow coating method and the the process parameters were optimized by orthogonal design. The coating fluid prescription was investigated by single factor test. In vitro release performance evaluation of the pellets was evaluated with polyphyllin I and II as the indexes. Results: The optimum technologic parameters of extrusion spheronization equipment were as follows the rate of extrusion was 60 r/min, the rate of spheronization was 1 200 r/min, and the time of spheronization was 5 min. The optimum coating liquid formulation of pH-dependent colon targetting pellets was 15% weight gains of Eudrugit S100, 1.5% anti-plastering aid amount of Glycerin monostearate, and 5% plasticizer amount of TEC. In vitro release test showed that cumulative release rate of berberine hydrochloride was close to 0% in artificial gastric juice after 2 h and less than 10% in artificial intestinal fluid after 4 h, but the cumulative release rate in artificial colon juice after 2 h was more than 90%. Conclusion: The preparation method can be applied to the preparation of colon targeted pellets and the pellets can achieve the targeted release in the colon.