Iqbal Furqan Muhammad, Ahmad Mahmood, Tulain Ume Ruqia
Acta Pol Pharm. 2017 Mar;74(2):527-541.
A microwave induced irradiation synthesis, was proposed for the preparation of hydroxypropyl methylcellulose-graft-(polyvinylalcohal-co-acrylic acid) hydrogels. The hydrogels were separately synthesized by using microwave irradiation method and conventional water bath heating method. Moreover, the prepared hydrogels were loaded with an antihypertensive drug, captopril. Chemical groups, thermal stability and surface morphology of these hydrogels were characterized by FT-IR, DSC and SEM. Swelling ratios of the gels were measured gravimetrically at'pH 1.2 and 7.4. Results showed that micrographs obtained from scanning electron microscopy (SEM), revealed that gels synthesized using microwave irradiation had more uniformly porous network structures. The uniformity in porosity was due to rapid and instantaneous penetration of microwave energy throughout the surface and they had higher swelling ratios in comparison to hydrogels synthesized by water bath method. Thermal analysis (DCS and TGA) depicted that crosslinked polymers were more stable. FT-IR analysis had confirmed the formation of the new polymeric network. X-ray diffractogram revealed that crystallinity of HPMC was reduced in hydrogel prepared by microwave radiation. It had also been observed that high crosslinking density diminish swelling of hydrogel. A stable network of hydroxypropyl methylcellulose (HPMC), poly(vinylalcohal) (PVA) and acrylic acid was developed in shorter time period under influence of microwave radiations.
提出了一种微波诱导辐射合成法来制备羟丙基甲基纤维素接枝（聚乙烯醇 - 共丙烯酸）水凝胶。分别采用微波辐射法和传统水浴加热法合成水凝胶。此外，将抗高血压药物卡托普利负载到制备的水凝胶中。通过傅里叶变换红外光谱（FT - IR）、差示扫描量热法（DSC）和扫描电子显微镜（SEM）对这些水凝胶的化学基团、热稳定性和表面形态进行了表征。在pH 1.2和7.4条件下，采用重量法测量凝胶的溶胀率。结果表明，扫描电子显微镜（SEM）获得的显微照片显示，使用微波辐射合成的凝胶具有更均匀的多孔网络结构。孔隙率的均匀性归因于微波能量在整个表面的快速和瞬时渗透，并且与通过水浴法合成的水凝胶相比，它们具有更高的溶胀率。热分析（DCS和TGA）表明交联聚合物更稳定。FT - IR分析证实了新聚合物网络的形成。X射线衍射图显示，通过微波辐射制备的水凝胶中羟丙基甲基纤维素（HPMC）的结晶度降低。还观察到高交联密度会降低水凝胶的溶胀度。在微波辐射的影响下，较短时间内就形成了由羟丙基甲基纤维素（HPMC）、聚乙烯醇（PVA）和丙烯酸组成的稳定网络。
