Preparation and targeted release evaluation studies on micro-encapsulation of paclitaxel

The paper studies the technological conditions of the spray-drying method for the preparation of targeted delivery microcapsule with octenyl succinic anhydride modified ginkgo starch as wall material, paclitaxel as core, respectively. With microencapsulating efficiency as the main evaluating index, the processing technology for preparing paclitaxel micro-encapsulation by spray-drying was investigated and optimized by the orthogonal experiments as followed; the proportion of core material and wall material is 1: 8, the solid concentration of emulsion is 15.0%, the homogeneous pressure is 40.0 MPa, and the temperature of inlet wind for the spray-drying is 200 °C. Encapsulating rate of micro-encapsulation under the optimized technology is 96.82%, content of paclitaxel is 10.63% and its quality is good. The micro-encapsule was really stabe. The encapsulated paclitaxel released 4.27% after it was disposed in simulated gastric fluid and the accumulative drug-release percent in vitro at 240 min was 25.60% in simulated intestinal fluid; But in the simulated colonic fluid, the accumulated drug release percent reached 89.26% within 12.0 h, 95.34% at 24.0 h, nearly perfectly released. These results indicate that the paclitaxel of micro-encapsulation had the characteristics higher resistance to digestibility and as a colon-specific delivery system. The preparation process is simple and feasible, it would be a novel paclitaxel preparation in clinic for the treatment of tumor.