Résumé
OBJECTIVE: To study the preparation process of pH-dependent delayed colon targeting pellets of astragalus polysaccharide. METHODS: Colon targeting agents of APS pellets were produced by extrusion-spheronization and fluid bed coating method and the best preparation technology was chosen by response surface optimization method. RESULTS: The ratio of pill core: APS powder-avicel-tannic acid-carboxymethylcellulose sodium was 25:15:8:2, the wetting agent was water, the rate of extrusion was 60 r·min-1, the rate of spheronization was 1 400 r·min-1, and the time of spheronization was 4 min. The best fluid bed coating condition was as follows the fan frequency was 29.50 Hz, the pressure of spray gun was 0.70 kg·cm-2, the rate of coating flow was 3 mL·min-1, and the colon coating weight was 15%. The release degree of pill for simulated gastric fluid in 2 h was 0%, The release degree of pill for artificial intestinal fluid in 3 h was less than 5%. The release degree of pill for artificial colon fluid in 2 h was release completely. CONCLUSION: The preparation method can be qpplied to the preparation of APS pellets, it's simplicity of operator and had good reproducibility, it can be applied to the industrial production.