Novel polymer network microformulations have been widely used for pharmaceutical applications. Especially challenging is to design and develop an ideal oral drug formulation due to many hostile factors in gastrointestinal (GI) tract microenvironment. Hydrogels attained striking attention for the use in controlled drug delivery systems, and for that purpose temperature- and pH-sensitive hydrogels have been extensively employed. This paper reports synthesis and characterization of innovative polymers-crosslinked hydrogel system consisted of N-isopropylacrylamide-graft-dextran (NiPAAm-g-Dex) and chitosan (Ch). Composition of the system was optimized to demonstrate distinguished encapsulation efficiency (EE) and release properties of diclofenac sodium (DS). The microspheres structure and morphology were confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR) and scanning electron microscopy (SEM), respectively. Prepared microparticles have successfully passed through the simulated gastric and small intestine and reached the intestine, where the release of DS was carried out. In vitro release studies showed smooth release profile in a controllable manner with up to 40% release of the model drug after 4 h at pH 7.20 ± 0.01. Based on the results, novel polymer microformulations show excellent potential as controlled release drug delivery system and represent a superb candidate for additional in vivo testing.

新型聚合物网络微制剂已广泛用于制药应用。由于胃肠道微环境中存在许多不利因素，设计和开发理想的口服药物制剂尤其具有挑战性。水凝胶在受控药物输送系统中的应用引起了人们的广泛关注，为此，温度和 pH 敏感的水凝胶已被广泛使用。本文报道了由N-异丙基丙烯酰胺-接枝葡聚糖 (NiPAAm-g-Dex) 和壳聚糖 (Ch) 组成的创新聚合物交联水凝胶系统的合成和表征。系统的组成经过优化，以展示双氯芬酸钠 (DS) 卓越的包封效率 (EE) 和释放特性。微球的结构和形态分别通过衰减全反射傅里叶变换红外光谱（ATR FT-IR）和扫描电子显微镜（SEM）得到证实。制备的微粒已成功通过模拟胃和小肠，到达肠道，并在肠道中进行DS的释放。体外释放研究显示，模型药物在 pH 7.20 ± 0.01 下 4 小时后释放率高达 40%，以可控方式实现平稳释放。根据结果​​，新型聚合物微制剂显示出作为控释药物递送系统的巨大潜力，并且是额外体内测试的绝佳候选者。