【摘要】 低分子量的乙基纤维素 (EC)包覆氨苄青霉素钠 ,采用纳米沉淀法制备氨苄青霉素钠 -乙基纤维素纳米微球。乙基纤维素 (EC)被 34% (w/ w)硝酸降解可以得到低分子量的乙基纤维素 ;FTIR,1 3C- NMR,元素分析 ,X-射线衍射分析证实在硝酸降解过程中 ,除了聚合度和结晶度降低之外 ,乙基纤维素的基本特性和基本结构没有变化 ;EC分子量的大小影响纳米微球的粒径大小、粒径分布和对药物的包覆效率。体外试验表明 ,氨苄青霉素钠 -乙基纤维素纳米微球对氨苄青霉素钠的缓慢释放为 3～ 10 h更多还原

【Abstract】 Ampicillin sodium was embeded in ethylcellulose (EC) nanospheres made of low-molecular-weight EC. Low-molecular-weight EC was attained with ethylcellulose being degraded by 34%(w/w) nitric acid; Fourier transform infrared (FTIR) spectroscopy, 13C-NMR,element analysis confirmed that the basic structure and major properties of low-molecular-weight EC maintained agreement with those of undegraded EC except that the polymerization degree of EC decreased. Wide-angle X-ray diffraction demonstrated that the crystallinity of degraded EC decreased. Ampicillin sodium loaded EC nanospheres were characterized by transmission electron microscopy, FTIR and in vitro drug release. Molecular weight of EC would affect on the size of nanospheres,distribution and drug encapsulation efficiency. Drug loaded nanospheres resulted in the drug control release in 3～10 hours.更多还原