Lin Wen-Ching, Yu Da-Guang, Yang Ming-Chien
Department of Polymer Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
Colloids Surf B Biointerfaces. 2005 Aug;44(2-3):143-51. doi: 10.1016/j.colsurfb.2005.06.010.
Porous chitosan (CS) polyelectrolyte complex (PEC) hydrogel microspheres were prepared via either wet phase-inversion or ionotropic crosslinking with sodium tripolyphosphate (Na+ - TPP) and dextran sulfate (DS). The resulting microspheres were characterized using scanning electron microscopy (SEM) and elemental analysis (EA). The controlled release behavior of ibuprofen (IBU) from these microspheres was investigated. The PEC microspheres were about 700-950 microm in diameter with large pores and open porous structure. The CS/TPP/DS microspheres resisted hydrolysis in strong acid and biodegradation in enzymatic surroundings. The swelling kinetics for CS microspheres was close to Fickian diffusion, whereas those for CS/TPP and CS/TPP/DS were non-Fickian. Furthermore, the equilibrium water content (EWC) and water diffusion coefficient (D) increased with the pH of the media. The release profiles of IBU from CS/TPP/DS microspheres were slow in simulated gastric fluid (SGF, pH 1.4) over 3 h, but nearly all of the initial drug content was released in simulated intestinal fluid (SIF, pH 6.8) within 6 h after changing media. Overall the results demonstrated that CS/TPP/DS microspheres could successfully deliver a hydrophobic drug to the intestine without losing the drug in the stomach, and hence could be potential candidates as an orally administered drug delivery system.
通过湿相转化法或与三聚磷酸钠(Na⁺ - TPP)和硫酸葡聚糖(DS)进行离子交联制备了多孔壳聚糖(CS)聚电解质复合物(PEC)水凝胶微球。使用扫描电子显微镜(SEM)和元素分析(EA)对所得微球进行了表征。研究了布洛芬(IBU)从这些微球中的控释行为。PEC微球直径约为700 - 950微米,具有大孔和开放的多孔结构。CS/TPP/DS微球在强酸中抗水解,在酶环境中抗生物降解。CS微球的溶胀动力学接近菲克扩散,而CS/TPP和CS/TPP/DS的溶胀动力学则为非菲克扩散。此外,平衡含水量(EWC)和水扩散系数(D)随介质pH值的升高而增加。在模拟胃液(SGF,pH 1.4)中,CS/TPP/DS微球中IBU的释放曲线在3小时内缓慢,但在更换介质后6小时内,几乎所有初始药物含量在模拟肠液(SIF,pH 6.8)中释放。总体而言,结果表明CS/TPP/DS微球可以成功地将疏水性药物输送到肠道,而不会在胃中损失药物,因此可能是口服给药系统的潜在候选者。