pH依赖-时滞型核桃肽结肠定位微丸的制备

Preparation and in Vitro Release Evaluation of pH-based and Time-lag Type Pellets of Walnut Peptides for Colon-specific Delivery

采用挤出滚圆/流化床包衣技术制备p H依赖-时滞型核桃肽结肠定位微丸。通过单因素试验,以体外释放度为评价指标,对包衣处方进行优化,优化的包衣处方为:以小伦包衣材料为pH依赖材料,乙基纤维素为时滞层材料,小伦包衣材料/乙基纤维素比例4︰6,包衣增重15%。优化处方制备的核桃肽微丸在模拟胃液中2 h、模拟肠液中3 h核桃肽不释放,在模拟结肠液中4 h核桃肽释放完全,具有明显结肠定位性能。抗氧化活性试验结果表明微丸制备过程对核桃肽活性影响不大。

The pH-based and time-lag type pellets of walnut peptides(WPs) for colon-specific delivery were prepared by extrusion/spheronization and film coating. The preparation parameters of the film coating process were optimized by independent single factor experiments, and dissolution profile was selected as dependent variable. The results of optimum preparation parameters were as follows: Xiaolun chosen as pH-dependent material, ethyecellulose chosen as sustained-release material, the ratio of Xiaolun and ethylcellulose 4︰6 and the coating weight gain 15%. The results of in vitro release revealed that the optimum pellets showed no WP release in the simulated gastric fluid and intestinal fluid, while a complete WP released in the simulated colon fluid, which indicated the obvious features of colon-specific delivery. The results of antioxidant experiments showed that the formulation process held less influence on the bioactivity of walnut peptides.