Kulkarni Raghavendra V, Sa Biswanath
Center for Advanced Research in Pharmaceutical Sciences, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700 032, India.
J Biomater Sci Polym Ed. 2009;20(2):235-51. doi: 10.1163/156856209X404514.
A pH-sensitive graft co-polymer of polyacrylamide (PAAm) and sodium alginate (SA) was synthesized by free radical polymerization under a nitrogen atmosphere followed by alkaline hydrolysis. The co-polymer was characterized by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis and thermogravimetric analysis (TGA). Ketoprofen-loaded graft co-polymer beads were prepared by ionotropic gelation/covalent cross-linking. The beads were characterized by swelling studies, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). A pulsatile swelling study indicated that the co-polymer exhibits considerable pH-sensitive behavior. Release of ketoprofen was significantly increased when the pH of the medium was changed from acidic to alkaline. Stomach histopathology of albino rats indicated that the beads were able to retard the release of the drug in the stomach, and gastric side-effects like ulceration, hemorrhage and erosion of gastric mucosa were diminished when the drug was entrapped into PAAm-g-SA-based pH-sensitive hydrogel beads.
在氮气氛围下通过自由基聚合然后进行碱水解合成了聚丙烯酰胺（PAAm）和海藻酸钠（SA）的pH敏感接枝共聚物。通过傅里叶变换红外（FT-IR）光谱、元素分析和热重分析（TGA）对该共聚物进行了表征。通过离子凝胶化/共价交联制备了载酮洛芬的接枝共聚物珠粒。通过溶胀研究、差示扫描量热法（DSC）和扫描电子显微镜（SEM）对珠粒进行了表征。脉动溶胀研究表明该共聚物表现出显著的pH敏感行为。当介质的pH从酸性变为碱性时，酮洛芬的释放显著增加。白化大鼠的胃组织病理学表明，珠粒能够延缓药物在胃中的释放，并且当药物被包封在基于PAAm-g-SA的pH敏感水凝胶珠粒中时，胃溃疡、出血和胃黏膜糜烂等胃部副作用会减少。
