Résumé
OBJECTIVE: To prepare starch microspheres of diclofenac sodium by inverse crosslink emulsification method. METHODS: Mean particle size and encapsulation efficiency of starch microspheres were used as indicators, single factor and orthogonal design methods were performed for optimizing preparation process and formulations of starch microspheres. The appearance and structure of the microspheres were researched by optical microscope, transmission electron microscope, infrared spectroscopy and differential thermal analyzer. In vitro drug release behavior was investigated by dialysis method. RESULTS The preparation conditions optimized by orthogonal design; the concentration of starch 10%, crosslinking temperature 55℃, dosage of cross-linking agent 0.2 g, the volume ratio of oil phase and water 5:1, amount of emulsifier 5 mL, cross-linking time 60 min. Starch microsphere obtained by above condition has an average particle size of 9 μm, appearance is irregular spherical shape, and encapsulation efficiency was 67.52%. Results of IR spectra and DTA curves showed that starch cross-links have happened. CONCLUSION In vitro releasing curve showed that the diclofenac sodium starch microspheres have good sustain release effect, drug release complies with the Weibull equation.