Department of Pharmacy, National University of Singapore, Singapore, Republic of Singapore.
J Microencapsul. 2011;28(4):268-79. doi: 10.3109/02652048.2011.559284. Epub 2011 Feb 24.
Calcium-pectinate (Ca-pectinate) beads have shown immense potential as colon-specific drug carrier. However, Ca-pectinate itself is unable to prevent its swelling/degradation in the upper gastro-intestinal (GI) conditions. Hence, polyethyleneimine (PEI) was added in the cross-linking solution to strengthen the Ca-pectinate network. Resveratrol was used as a model drug due to its promising therapeutic activity towards several colonic diseases. Beads were prepared by varying cross-linking solution pH and other formulation variables. The effects of these formulation variables were investigated on the bead's characteristics. Furthermore, surface morphology, drug-polymer interaction, stability, and in vivo pharmacokinetic study of the optimized formulation were performed. The optimized PEI-modified beads prevented drug release in the upper GI conditions, while released the drug in simulated colonic fluid. Furthermore, in vivo pharmacokinetics studies in rats demonstrated delayed appearance of drug in blood after oral administration. The optimized Ca-pectinate beads demonstrated both in vitro and in vivo colon-specific drug release.
钙-果胶酸盐（Ca-pectinate）珠粒作为结肠特异性药物载体具有巨大的潜力。然而，Ca-pectinate 本身无法防止其在上胃肠道（GI）条件下的膨胀/降解。因此，在交联溶液中添加聚乙烯亚胺（PEI）以增强 Ca-pectinate 网络。白藜芦醇被用作模型药物，因为它对几种结肠疾病具有有前途的治疗活性。通过改变交联溶液 pH 值和其他制剂变量来制备珠粒。研究了这些制剂变量对珠粒特性的影响。此外，对优化的制剂进行了表面形态、药物-聚合物相互作用、稳定性和体内药代动力学研究。优化的 PEI 修饰珠粒可防止药物在上胃肠道条件下释放，而在模拟结肠液中释放药物。此外，大鼠体内药代动力学研究表明，口服给药后药物在血液中的出现时间延迟。优化的 Ca-pectinate 珠粒在体外和体内均表现出结肠特异性药物释放。
