pH敏感性P(AM-AA-co-C_8PhEO_(10)Ac)水凝胶溶胀动力学及其对茶碱的控释

Swelling Kinetics and Theophylline Controlled-Release Properties of pH-Sensitive P(AM-AA-co-C_8PhEO_(10)Ac) Hydrogel

以丙烯酰胺(AM)、丙烯酸(AA)和丙烯酸辛基酚聚氧乙烯醚酯(C8PhEO10Ac)为单体,采用自由基交联共聚法合成了具有pH敏感性的P(AM-AA-co-C8PhEO10Ac)水凝胶。研究了pH、单体配比对凝胶溶胀性能、溶胀动力学和退溶胀动力学的影响。初步探讨了模拟胃液(pH=1.4)、肠液(pH=7.4)中水凝胶对茶碱的控释情况。结果表明:凝胶具有高溶胀、退溶胀速率和良好的pH敏感性等特征;水凝胶的扩散行为在pH=7.4的缓冲溶液中为非Fickian扩散模式;载药凝胶在模拟肠液中对药物的累积释放率明显大于胃液中的累积释放率,其中n(C8PhEO10Ac)∶n(AM)∶n(AA)为1∶20∶30的载药水凝胶对茶碱的累积释放率最大。

A pH-sensitive P（AM-AA-co-C8PhEO10Ac） hydrogel was prepared using acrylamide（AM）, acrylic（AA） and octylphenyl polyoxyethylene acrylate（Ca PhEO10 Ac） as monomer by free radical crosslinking polymerization. Effect of pH and monomer ratio on swelling property, swelling and deswelling kinetics of the hydrogels were studied. Theophylline was chosen as a model drug and the controlled-release properties of hydrogels in stimulated gastric fluid （pH = 1. 4） and intestinal fluid （pH = 7. 4） were studied. Results showed that the hydrogel had the rapid swelling, deswelling rate and good pH sensitivity. The dynamic swelling behavior of P（AM-AA-co-C8PhEO10Ac） hydrogels belonged to non-Fickian mode in pH=7.4 buffer solutions. The cumulative release rates of drug-loaded hydrogels in stimulated intestinal fluid were higher than those in stimulated gastric fluid. The cumulative release rate of theophylline was the highest when n（CsPhEO10Ac） ： n（AM） ： n（AA） was 1 ： 20 ： 30.