Preparation and in-vitro drug release of Baizhu Huanglian pellets containing colon-targeting capsules / 药学实践杂志

Objective Colon-targeting capsules based on gastric pellets and enteric pellets were prepared from Baizhu Huanglian prescription. The formulation composition and preparation process were optimized and the in-vitro release characteristics were investigated. Methods Optimum formulation composition and process parameters of Baizhu Huanglian pellets were screened out by single factor experiment and orthogonal design. The pellets core were prepared by extrusion-spheronization technique and coated in the fluid bed using bottom spray coating technique. To investigate the effect of coating level of the isolation layer, the proportion of polymer, the amount of plasticizer and weight gain of enteric coating on the release behavior of the enteric pellets. The pellets release behavior was fitted by model as well. Results The prescription of gastric pellets was drug loading 50%, PVPP 5%, MCC to lactose 1∶2 and wetting agent 40%. The process parameters were extrusion frequency 20 Hz, rounding speed 500 r/min and rounding time 5 min. The prescription of enteric pellets was drug loading 27%, PVPP 5%, MCC to lactose 5∶2, wetting agent 30% and adhesive 20%. The process parameters were extrusion frequency 20 Hz, rounding speed 700 r/min and rounding time 7 min. For enteric coating layer, the coating mixture of EUDRAGIT®L30D-55 to EUDRAGIT® FS30D was 1∶2. The amount of plasticizer was 10%. The increased weight of coating layer was 15%. The release time of enteric pellets in-vitro was up to 24 hours. The release behavior of the pellets conforms to the Higuchi model. Conclusion The colon targeting capsule of Baizhu Huanglian pellets were successfully prepared and showed the characteristics of sustained release and colon targeting.

Preparation of Nifedipine Sustained-Release Pellet Tablets and Study of Its Release Behavior in vitro / 医药导报

Objective To prepare nifedipine( NF)sustained-release pellet tablets,and study of its release behavior in vitro. Methods Soluplus was selected as a carrier to prepare solid dispersion of NF by hot melt extrusion technique( HME), and the ratio of the drug to carrier was 1:1. The samples were validated as the solid dispersion by differential scanning calorimetry(DSC). Extrusion-spheronization technique was introduced to prepare NF pellets and EudragitRS 30D was used as the coating material. The NF sustained-release tablets were prepared by direct compression of the coated pellets and suitable excipients. Results The release data in vitro proved that the drug release from the tablets was steady and complete over 24 hours. Conclusion The release of NF from sustained-release tablets is slow and steady. The method is easy to operate. The in vitro drug release pattern follows first-order kinetics.