微乳液成核-离子交联制备阿司匹林/壳聚糖纳米微球及其体外释放行为

以自制阿司匹林为药物模型,壳聚糖(CS)为载体源,采用微乳液成核-离子交联法制备了阿司匹林/壳聚糖纳米缓释微球.分别用傅里叶变换红外(FTIR)光谱、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、动态激光光散射(DLLS)、X射线粉末衍射(XRD)等表征了纳米微粒的化学组成、外观形貌、平均粒径和粒径分布、微球中壳聚糖的晶体结构以及阿司匹林的分布形态.结果表明,利用微乳液成核-离子交联法制备的阿司匹林/壳聚糖微球平均粒径约为88nm且粒径分布均匀,成核后壳聚糖结晶形态基本未变,阿司匹林以分子形态分布于微粒中,分子间未形成堆砌,为无定形态.采用UV-Vis分光光度计考察了微球的药物包封率、载药量,并对微球在生理盐水和葡萄糖溶液中的释药行为进行跟踪.结果表明,微球的载药量可达55%,药物包封率可达42%,实验条件下具有较好的药物缓释作用.

Preparation and Release Behavior in vitro of Aspirin/Chitosan Nanospheres by Nucleation and Ionic Crosslinking in Emulsion

Chitosan (CS) nanosphere loaded aspirin (aspirin/CS) was prepared by nucleation and ionic crosslinking in an emulsion used for medical and pharmaceutical applications. Chemical component, morphology, size distribution, and crystal structure of nanospheres were characterized by Fourier transforminfrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), dynamic laser light scattering (DLLS), and X-ray powder diffraction (XRD). Results showed that the diameter of a typical aspirin/CS nanosphere is about 88 nm and the distribution is uniform. The crystal structure of CS does not change during the nucleation process. The crystallinity of aspirin is dramatically reduced and aspirin is almost amorphous in the nanosphere. The drug content (mass fraction), the drug loading efficiency, and the in vitro release profiles under different conditions were investigated using UV-Vis spectrophotometry. Results showed that the drug content was about 55%, the drug loading efficiency reached 42%, and the chitosan nanosphere displayed an excellent drug-controlled release behavior under the experimental conditions.