诺氟沙星插层镁铝水滑石新型药物-无机复合材料的超分子结构、热稳定性和缓释性能

Supramolecular Structure,Thermal Stability and Release Property of New Drug-inorganic Composites Norfloxacin-intercalated Mg-Al-layered Double Hydroxides

采用共沉淀和离子交换方法将抗生素类药物诺氟沙星(Nor)插入到Mg-Al-LDHs层间,制备了一种新型的药物-无机复合材料.借助XRD,FTIR,UV-Vis,TG-DTA和ICP等手段对样品进行了表征.结果表明,Nor-阴离子可取代层间的NO3-,组装得到晶体结构良好的Nor-LDHs.XRD表征得到Nor-LDHs的层间距为1·29～1·33nm,并与根据PM3半经验分子轨道法优化计算得到的Nor-三维尺寸进行比较,推测客体Nor-是沿短轴方向以单层垂直交替的方式排布于层间,与主体层板通过氢键与静电作用形成超分子结构;该超分子结构诺氟沙星-水滑石复合材料与诺氟沙星相比,其热稳定性、耐酸性及缓释性能均有大幅度提高,缓释实验数据符合Bhaskar方程和一级动力学方程模型.

A new drug-inorganic composite involving an antibiotic compound norfloxacin （Nor） intercalated Mg-Al layered double hydroxides（Nor-LDHs） was assembled with coprecipitation and ion-exchange methods. The samples thereby obtained were characterized via XRD, FTIR, UV-Vis, TG-DTA and ICP measurements. The results show that the original interlayer nitrate anions of the hydrotalcite can be replaced by norfloxacin anions, and norfloxacin intercalated Mg-Al layered double hydroxides were obtained with a good cry XRD analyses indicates that the interlayer spaces of as-synthesized Nor-LDHs were 1.29 nm to 1.33 compared with three-dimensional molecular size of Nor ion calculated from the PM3 semi-empirical orbital method. The norfloxacin guests were arranged alternately with monolayer vertical （along the stallinity nm, and molecular short axis orientation） between layers. It is found that the interaction of the host layers and the guests is through hydrogen bonding and electrostatic attraction, confirming that the intercalated hydrotalcite has a supramolecular structure. The thermal stability, acid resistance and sustained-release of norfloxacin anion-pillared hydrotalcite were enhanced to a considerable extent, comparing with that of norfloxacin. The release profiles were fitted by Bhaskar equation and the first-order equation, the fitting data primarily follow the experimental results.