pH依赖型植物基微胶囊的制备和体外释药研究

Study on the preparation and drug release of p H-dependent plant microcapsules in vitro

为研究新型肠溶植物基微胶囊,实现消化道定位给药,以植物多糖变性淀粉、果胶和卡拉胶为基质,制备了微胶囊并考察了其性质、体外释药行为和安全性。选用果胶、木薯醋酸酯淀粉与卡拉胶为材料,制备了p H依赖型微胶囊。考察了微胶囊的红外吸收特征、溶解性能、显微结构和细胞毒性,并进一步研究了微胶囊的释药行为。结果表明:当微胶囊中不含果胶时,其在不同p H条件下均不溶解且没有药物释放;当基质中果胶含量为1%,p H在中性偏酸性时微胶囊的释药量最大,随着果胶浓度的增大微胶囊的释药量降低,3%果胶含量微胶囊几乎没有释药。细胞毒性结果表明微胶囊是安全无毒的。果胶是p H依赖型微胶囊的关键成分,通过调节果胶含量可以实现微胶囊在p H中性环境下的有效释药,实现药物在肠道的定位释放,提高药物的生物利用度。

In order to study the new plant based enteric-coated microcapsules and realize the digestive tract drug delivery, the microcapsules were prepared by acetate starch, pectin and carrageenan and performed to investigate their characteristics and drug release process and safety. A kind of pH- dependent plant microcapsules was prepared by pectin, acetate starch and carrageenan.The microcapsules were characterized by Fourier transform infrared spectroscopy, dissolution property, scanning electron microscopy and cytotoxicity test, and the drug release behavior of microcapsules was further studied.The results showed that there was no dissolution or drug release in different pH conditions when the microcapsules contain no pectin. The microcapsulc containing one percent of pectin had the strongest release capacity under neutral partial acidity conditions. The drug release rate of microcapsules decreased with the increase of pectin concentration.There almost no drug release when the microcapsules contained three percent of pectin. The results of cytotoxicity showed that the microcapsules were safe and nontoxic.Pectin is a key component of pH- dependent microcapsules, which can be used for the effective release of microcapsules in pH neutral environment by regulating the pectin content, to achieve drug release in the intestinal tract and improve the bioavailability of drugs.