Preparation of chitosan/ethylcellulose complex microcapsule and its application in controlled release of vitamin D2

A system which consists of chitosan (CS) microcores entrapped within enteric polymer is investigated. Vitamin D2 (VD2) used as a model drug, was efficiently entrapped in CS microcores using spray drying and was microencapsulated by coating of ethylcellulose. The morphology and release properties of microcapsules were tested. The factors which influenced the preparation, including molecular weight of CS, concentration of CS solution, concentration of acetic acid and loading of VD2, were discussed. The results of release in vitro showed that the microcapsules could realize sustained release in intestine juice.