Preparation of the Sustained-Release Microcapsules of Baicalin

[Objective] The aim was to prepare sustained-release microcapsules of baicalin,as well as to design and optimize the prescription,and to make initial quality standards for this preparation.[Method] Complex coacervation method was applied to prepare sustained-release microcapsules using gelatin and Arabic gum as capsule materials,baicalin capsule as core and Tween-80 as the wetting agent.Taking the entrapment efficiency as primary quality index,the preparation process of microcapsules was optimized by single factor experiment and orthogonal test.Morphology of microcapsule was observed using microscopy and electron microscopy;content of microcapsule was determined by ultraviolet spectrophotometry;the in vitro dissolution of this preparation was investigated using water as dissolution medium.[Result] The optimum prescription for baicalin microcapsules was:13.3 mg/ml gelatin and Arabic gum,50 ℃ reaction temperature,pH 3.90,and material-drug ratio 5:1.Microcapsule obtained by the optimum prescription had good dispersion,and significant loading rate.The morphology was round and smooth with approximately the same size.[Conclusion] Baicalin sustained-release microcapsules with high entrapment efficiency could be successfully prepared by complex coacervation method,and the product had good stability.This method was feasible,reproducible,and of some practical value.