Abstract: A composite material with improved sustained release properties, based on hybridization of sodium alginate (SA) and acidified-attapulgite (H⁺-ATP), was prepared by solution mixing and was developed for drug carrier. Diclofenac sodium (DS) was selected as the model drug to obtain release data from the composite-based matrix tablets in phosphate buffer solution (PBS) in vitro. The morphology and structure of the composite were characterized by FTIR, SEM and XRD. The effect of content of acid modifier, H⁺-ATP content and mixing time on the slow release properties of the composite were investigated to obtain optimum process condition. The composite with 60% H⁺-ATP treated by 12 mol·L^-1 HCl exhibited perfect release properties. Compared with pure alginate tablets, the burst release of 42.6 % in 2 h decreased to 23.7% for the prepared composite. The drug release process of the composite was better fitted by the Ritger-Peppas model and the rate of drug release was governed by both diffusion and swelling mode. The introduced H⁺-ATP improved the release properties of alginate significantly.

Key words: acidified-attapulgite, sodium alginate, composites, sustained release properties, mixing, carrier

摘要： 以海藻酸钠 (SA) 和酸化凹凸棒石 (H⁺-ATP) 为原料,运用溶液共混法制备了一种具有优良缓释性能的复合材料,并以其为基质材料制备了双氯芬酸钠 (DS) 缓释片.利用SEM、FTIR和XRD对复合材料形貌和结构进行了表征,考察了酸改性剂浓度、H⁺-ATP用量和复合时间对复合材料缓释性能的影响,以获得最佳复合工艺.结果表明,当用12 mol·L^-1盐酸酸化的ATP量占复合物总量60%时,复合缓释片在体外模拟肠液中缓释性能最佳.与单一海藻酸缓释片相比,复合缓释片2 h的累积释放率由42.6%下降到23.7%,有效改善了"突释"效应.释放动力学研究表明,复合缓释片的释药行为可以用Ritger-Peppas方程很好地拟合,释药速率受骨架溶蚀和药物扩散双重控制.H⁺-ATP的加入显著改善了海藻酸的缓释性能.

关键词: 酸化凹凸棒石, 海藻酸钠, 复合材料, 缓释性能, 共混, 载体