Preparation, Characterization and in Vitro Release Performance Evaluation of Konjac Glucomannan Microparticles Loaded with Proanthocyanidins

In this study, konjac glucomannan was used as wall material and proanthocyanidins as core material. The micro-swelling properties of KGM in the ethanol system were used to prepare PC-loaded KGM microparticles, which provided a new technical idea for colon-targeted delivery of PC. KGM/PC microparticles were prepared by KGM adsorption of PC dissolved in ethanol aqueous solution. Single factor experiment and orthogonal experiment were used to optimize the preparation process of KGM/PC microparticles, and the properties of the microparticles were characterized by particle size analysis, scanning electron microscopy, infrared spectroscopy, etc. The release performance of the microparticles in vitro was investigated. The results showed that KGM could successfully encapsulate PC and the loading rate of PC was significantly affected by KGM and the amount of PC added. The optimum process conditions of encapsulating PC with KGM determined by orthogonal optimization, that is, when 16% (w:v) KGM (particle size 50~90 μm) and 11% (w:v) PC were added into 10% (v:v) ethanol solution, the loading rate of PC was (14.75%±0.27%). At the same time, after digestion in the stomach and small intestine for 4 h, 79.47% of PC in the KGM/PC microparticles was not released and reached the colon. To sum up, the encapsulated microparticles have great potential in colon-targeted delivery, which can provide a simple, effective, and safe encapsulation technology for industrial production.