酸化凹凸棒石/海藻酸复合材料的制备及其缓释性能

Preparation and sustained release properties of acidified-attapulgite/ alginate composite material

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。

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.