Shu X Z, Zhu K J
Department of Polymer Science and Engineering, Zhejiang University, 310027, Hangzhou, People's Republic of China.
Int J Pharm. 2000 May 15;201(1):51-8. doi: 10.1016/s0378-5173(00)00403-8.
A novel approach was developed to improve the mechanical strength of tripolyphosphate (TPP)/chitosan beads prepared under coagulation condition at 4 degrees C in the presence of gelatin. Cross-sectional analysis indicated that the beads had a homogeneous crosslinked structure, as a result the beads were strengthened greatly (the mechanical strength increased more than ten times). Furthermore sodium alginate (a polyanion) can interact with cationic chitosan on the surface of these TPP/chitosan beads to form polyelectrolyte complex film for the improvement of the drug sustained release performances. The loading efficiency of model drugs (brilliant blue and FITC-dextran) in these beads was very high (more than 90%). Crosslinking time, TPP solution pH and other preparation factors had an effect on the drug release performance of beads. The release period of brilliant blue (a poor water soluble dye) was more than 2-months at a fairly constant rate in 0.9% NaCl, 10 mM PBS pH 7.4. However, for FITC-dextran (a water soluble polysaccharide) only 1-2 days in the same conditions. It seems that TPP/chitosan bead prepared by the novel method is a promising formulation for drug delivery.
开发了一种新方法来提高在4℃凝固条件下、明胶存在时制备的三聚磷酸钠（TPP）/壳聚糖珠的机械强度。横截面分析表明，这些珠子具有均匀的交联结构，结果珠子得到了极大的强化（机械强度提高了十多倍）。此外，海藻酸钠（一种聚阴离子）可以与这些TPP/壳聚糖珠表面的阳离子壳聚糖相互作用，形成聚电解质复合膜，以改善药物缓释性能。这些珠子中模型药物（亮蓝和异硫氰酸荧光素标记的葡聚糖）的负载效率非常高（超过90%）。交联时间、TPP溶液pH值和其他制备因素对珠子的药物释放性能有影响。在0.9%氯化钠、pH 7.4的10 mM PBS中，亮蓝（一种水溶性差的染料）的释放期超过2个月，且释放速率相当恒定。然而，对于异硫氰酸荧光素标记的葡聚糖（一种水溶性多糖），在相同条件下仅为1-2天。通过这种新方法制备的TPP/壳聚糖珠似乎是一种很有前景的药物递送制剂。
