Objective: To develop Jiedu Zhixie tablets into a new dosage form

which was stomach-colon two step and colon-targeted sustained release pellets.To investigate its preparation process and in vitro release. Method: Stomach-released and colon-targeted pellets were produced through roiling into ball method and pan coating technology

adjuvant materials and coating process were optimized by single factor tests.HPLC was adopted to determine the content of quercetin with mobile phase of methanol-0.4% phosphoric acid (53:47) and detection wavelength at 260 nm. Result: Mixed power of extract powder-carboxymethylcellulose sodium (8:1) was rolled into pellets with 95% alcohol as a wetting agent.Stomach-released pellets were prepared with increasing weight about 4% and 3% red iron as coating solution.Colon-targeted sustained release pellets were prepared with increasing weight about 6% and 6% combination solution of Eudragit L100-Eudragit S100 (1:2) as coating material.Stomach-released pellets released completely in artificial gastric fluid within 45 minutes.Colon-targeted sustained release pellets weren't released in artificial gastric fluid within 2 h

less than 20% were released in artificial intestinal fluid within 3 h

but pellets were slowly released in artificial colon fluid and released completely at 5 h. Conclusion: This preparation process is simple

reproducible and available for industrial production of Jiedu Zhixie pellets.