Polymer Chemistry Laboratory, Department of Applied Chemistry, Indian School of Mines, Dhanbad 826004, India.
Colloids Surf B Biointerfaces. 2013 Oct 1;110:236-41. doi: 10.1016/j.colsurfb.2013.04.033. Epub 2013 Apr 30.
In the present study, hydroxypropyl methyl cellulose grafted with polyacrylamide (HPMC-g-PAM) hydrogel was evaluated in vitro as a potential carrier for controlled release of 5-amino salicylic acid (5-ASA). The graft copolymer was developed by grafting PAM chains onto HPMC backbone using potassium persulphate as initiator. The swelling behaviour of hydrogel based tablet was investigated as a function of pH and time in various buffer solutions similar to that of gastric and intestinal fluids. The % equilibrium swelling was found to be higher in case of simulated intestinal fluid (pH=7.4) and lower in simulated gastric fluid (pH=1.2), making an ideal matrix as required for colon specific drug delivery. The drug release study was performed at various pH values akin to the condition of GI tract. The release kinetics of 5-ASA showed non-Fickian diffusion behaviour. This indicates that the release is controlled by a combination of polymer relaxation or erosion of the matrix and diffusion of the drug from the swollen matrix.
在本研究中，评估了羟丙基甲基纤维素接枝聚丙烯酰胺（HPMC-g-PAM）水凝胶作为 5-氨基水杨酸（5-ASA）控制释放的潜在载体的体外性能。接枝共聚物是通过使用过硫酸钾作为引发剂将 PAM 链接枝到 HPMC 主链上而开发的。研究了水凝胶基片剂在不同缓冲溶液中的溶胀行为，这些缓冲溶液与胃和肠液相似。结果发现，在模拟肠液（pH=7.4）中的平衡溶胀率较高，在模拟胃液（pH=1.2）中的平衡溶胀率较低，这使其成为用于结肠特异性药物递送所需的理想基质。在类似于胃肠道条件的各种 pH 值下进行了药物释放研究。5-ASA 的释放动力学表现出非菲克扩散行为。这表明释放是由聚合物松弛或基质侵蚀以及药物从溶胀基质中的扩散的组合控制的。
