Patel V R, Amiji M M
Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts 02115, USA.
Pharm Res. 1996 Apr;13(4):588-93. doi: 10.1023/a:1016054306763.
The purpose of this study was to develop novel drug delivery systems with pH-sensitive swelling and drug release properties for localized antibiotic delivery in the stomach.
The drug delivery systems were synthesized by crosslinking chitosan and poly(ethylene oxide) (PEO) in a blend to form semi-interpenetrating polymer network (semi-IPN). Scanning electron microscopy was used to compare the surface and bulk morphology of the freeze-dried and air-dried chitosan-PEO semi-IPN. The hydrogels were allowed to swell and release the antibiotics--amoxicillin and metronidazole--in enzyme-free simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.2) at 37 degrees C.
Freeze-dried chitosan-PEO semi-IPN with a porous matrix had swollen extensively as compared to the air-dried hydrogel. The swelling ratio of freeze-dried and air-dried chitosan-PEO semi-IPN after 1 h in SGF was 16.1 and 2.30, respectively. More than 65% of the entrapped amoxicillin and 59% of metronidazole were released from the freeze-dried chitosan-PEO semi-IPN after 2 h in SGF.
The results of this study suggest that freeze-dried chitosan-PEO semi-IPN could be useful for localized delivery of antibiotics in the acidic environment of the gastric fluid.
本研究的目的是开发具有pH敏感溶胀和药物释放特性的新型药物递送系统，用于胃部局部抗生素递送。
通过将壳聚糖和聚环氧乙烷（PEO）在共混物中交联以形成半互穿聚合物网络（semi-IPN）来合成药物递送系统。使用扫描电子显微镜比较冻干和风干的壳聚糖-PEO半互穿聚合物网络的表面和整体形态。使水凝胶在37℃下于无酶模拟胃液（SGF，pH 1.2）和模拟肠液（SIF，pH 7.2）中溶胀并释放抗生素——阿莫西林和甲硝唑。
与风干水凝胶相比，具有多孔基质的冻干壳聚糖-PEO半互穿聚合物网络已大量溶胀。冻干和风干的壳聚糖-PEO半互穿聚合物网络在SGF中1小时后的溶胀率分别为16.1和2.30。在SGF中2小时后，超过65%的包封阿莫西林和59%的甲硝唑从冻干壳聚糖-PEO半互穿聚合物网络中释放。
本研究结果表明，冻干壳聚糖-PEO半互穿聚合物网络可用于在胃液的酸性环境中局部递送抗生素。
