Dashevsky A, Zessin G
Kiev Institute of Postgraduate Advance for Physicians, Ukraine.
J Microencapsul. 1997 May-Jun;14(3):273-80. doi: 10.3109/02652049709051132.
Microspheres of theophylline, with both ethylcellulose of high and low molecular weight and also their mixtures as a coating material, were prepared using the solvent evaporation technique. No permeability through intact isolated polymer films was found. Therefore, this study investigated the drug release dependence of structure and mechanical properties of the polymer matrix. In vitro dissolution studies exhibited the square-root of time (Higuchi model) release characteristics. The size distribution of microspheres was dependent on the ratio of ethylcellulose mixtures with high and low molecular weights.
采用溶剂蒸发技术制备了以高、低分子量乙基纤维素及其混合物为包衣材料的茶碱微球。未发现药物透过完整的分离聚合物膜。因此，本研究考察了聚合物基质的结构和力学性能对药物释放的依赖性。体外溶出研究显示出平方根时间（ Higuchi模型）释放特性。微球的粒径分布取决于高、低分子量乙基纤维素混合物的比例。
