Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China.
Drug Dev Ind Pharm. 2012 Jun;38(6):728-34. doi: 10.3109/03639045.2011.623702. Epub 2011 Oct 19.
The aim of this study was to prepare pH-sensitive sodium alginate/calcined hydrotalcite (SA/CHT) hybrid bead with improved the burst release effect of the drug. materials and methods: A series of pH-sensitive SA/CHT hybrid beads were prepared by using Ca²⁺ cross-linking in the presence of diclofenac sodium (DS) and SA. The structure and drug loading of the beads were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The swelling and the drug release of the fabricated beads were investigated by the pH of test medium and CHT content.
The formed positively charged hydrotalcite layers were adsorbed on the negatively charged SA polymer chains through electrostatic interaction and act as inorganic cross-linkers in the three-dimensional network. Compared to pure SA beads, the incorporation of CHT enhanced the drug encapsulation efficiency, improved the swelling behaviors and slowed the drug release from the hybrid beads.
The electrostatic interaction between hydrotalcite and SA has restricted the movability of the SA polymer chains, and then slowed down swelling and dissolution rates in aqueous solutions. The results provided a simple method to moderate drug release and matrix degradation of the SA beads.
本研究旨在制备 pH 敏感的海藻酸钠/水滑石（SA/CHT）杂化珠，以改善药物的突释效应。
采用钙离子交联法，在含有双氯芬酸钠（DS）和 SA 的条件下制备了一系列 pH 敏感的 SA/CHT 杂化珠。采用傅里叶变换红外光谱和 X 射线衍射对珠的结构和药物负载进行了表征。通过测试介质的 pH 值和 CHT 含量研究了所制备的珠的溶胀和药物释放。
形成的带正电荷的水滑石层通过静电相互作用被吸附在带负电荷的 SA 聚合物链上，并在三维网络中充当无机交联剂。与纯 SA 珠相比，CHT 的掺入提高了药物包封效率，改善了溶胀行为，并减缓了杂化珠中药物的释放。
水滑石和 SA 之间的静电相互作用限制了 SA 聚合物链的可动性，从而减缓了在水溶液中的溶胀和溶解速率。该结果提供了一种调节 SA 珠中药物释放和基质降解的简单方法。
