海藻酸钠/壳聚糖层层裹覆凝胶微球的缓释性能

Sustained release property of hydrogel bead alternately wrapped by sodium alginate/chitosan multilayer

为了提高凝胶微球的缓释性能,以啶虫脒为模型药物,采用层层组装(LBL)方法,制得了海藻酸钠与壳聚糖交替裹覆的具有多层膜结构的凝胶微球。通过SEM、FT-IR、TG、溶胀实验和释药实验对微球的结构和性能进行了表征。结果表明裹覆后微球表面上海藻酸钠与壳聚糖通过静电作用形成了聚电解质复合物并且其断面出现了层层膜结构,微球热力学稳定性随膜层增加而降低以及溶胀过程中膜层脱落行为说明覆膜层数不宜过多。释药实验表明,0、1、3、5、7和9层膜微球在33h内的累计释药量分别为61.2、20.4、7.3、4.9、1.3和1.2mg,覆膜的方法能够有效的控制药物的释放,提高微球缓释性能。

To improve the sustained release performance, the hydrogel beads with multilayer structure alternately wrapped by sodium alginate and chitosan were prepared by the method of layer-by-layer assembly, using acetamiprid as a model drug. The structure and properties of beads were characterized by means of fourier transform infrared spectroscopy （FT-IR） ,scanning electron micrograph （SEM）, thermogravimetry （TG）, water-up tests and release study. The results showed that polyelectrolyte complexes of alginate and chitosan with the multilayer structure were formed on the surface of beads. The thermodynamic stability decreased with increasing membrane layer, and the membranes dropped off from the surface of beads during the swelling process. It indicated that the number of membranes coated on beads was not the more, the better. The cumulative release dosage were 61.2,20.4,7.3,4.9,1.3 and 1.2 mg respectively when the release time was 33 h, which indicated that the wrapping method of beads can effectively control the release of drugs and improved sustained- release performance.