Department of Pharmaceutical Technology, School of Pharmacy, Université de Bourgogne, Dijon, France.
Acta Biomater. 2013 Apr;9(4):6218-25. doi: 10.1016/j.actbio.2012.11.031. Epub 2012 Dec 3.
The aim of this work is to develop novel organic-inorganic hybrid beads for colonic drug delivery. For this purpose, calcium pectinate beads with theophylline are prepared by a cross-linking reaction between amidated low-methoxyl pectin and calcium ions. The beads are then covered with silica, starting from tetraethyoxysilane (TEOS), by a sol-gel process. The influence of TEOS concentration (0.25, 0.50, 0.75 and 1.00 M) during the process is studied in order to modulate the thickness of the silica layer around the pectinate beads and thus to control the drug release. The interactions between the silica coating and the organic beads are weak according to the physicochemical characterizations. A good correlation between physicochemical and in-vitro dissolution tests is observed. At concentrations of TEOS beyond 0.25 M, the silica layer is thick enough to act as a barrier to water uptake and to reduce the swelling ratio of the beads. The drug release is also delayed. Silica-coated pectinate beads are promising candidates for sustained drug delivery systems.
本工作旨在开发用于结肠药物传递的新型有机-无机杂化珠。为此，通过酰胺化低甲氧基果胶和钙离子之间的交联反应制备含有茶碱的钙果胶珠。然后，通过溶胶-凝胶法从四乙氧基硅烷（TEOS）开始在珠上覆盖二氧化硅。研究了过程中 TEOS 浓度（0.25、0.50、0.75 和 1.00 M）的影响，以调节围绕果胶珠的二氧化硅层的厚度，从而控制药物释放。根据物理化学特性，二氧化硅涂层与有机珠之间的相互作用较弱。观察到物理化学和体外溶解测试之间的良好相关性。在 TEOS 浓度超过 0.25 M 的情况下，二氧化硅层足够厚，可以作为阻挡水吸收的屏障，并降低珠的溶胀比。药物释放也被延迟。二氧化硅涂层的果胶珠是用于持续药物传递系统的有前途的候选物。
