以多氨基酸共聚法 ,将L -天冬氨酸、L -谷氨酸、L -酪氨酸和L -苯丙氨酸合成低分子的聚合物。在酸性条件下将抗溃疡性结肠炎 (IBD)药物 5 -氨基水杨酸 ( 5 -ASA)同聚合物制成控释剂微球。控释剂药物的释放对溶液的 pH值有强烈的依赖性。紫外分光光度法测定 ,在酸性条件下 ,6h内 ,仅有不到 10 %的 5 -ASA被释放出来。当 pH 7 2时 ,在 3h内 ,约有 94 %的药物被释放出来。实验结果显示 ,控释剂微球对抗IBD具有良好的靶向作用 L - aspartic acid, L - glutamic acid, L - tyrosine and L - phenylalanine were synthesized by low molecular weight polyamino acid copolymerization. Under acidic conditions, 5 - aminosalicylic acid (5 - ASA), an antiulcerative colitis (IBD) drug, was co - polymerized into controlled - release microspheres. Controlled release drug release has a strong dependence on the pH of the solution. UV spectrophotometry, in acidic conditions, within 6h, less than 10% of 5-ASA is released. Approximately 94% of the drug was released within 3 h at pH 72. The experimental results show that the controlled release microspheres have a good targeting effect against IBD