Alvarez-Manceñido Felipe, Braeckmans Kevin, De Smedt Stefaan C, Demeester Josepth, Landin Mariana, Martínez-Pacheco Ramón
Departamento Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
Int J Pharm. 2006 Jun 19;316(1-2):37-46. doi: 10.1016/j.ijpharm.2006.02.029. Epub 2006 Mar 6.
Konjac glucomannan (KGM) is a neutral polysaccharide with interesting properties as gelling agent and thickener. Its peculiar biodegradability, being not degradable in the small intestine but degradable by the anaerobic human intestinal bacteria, turn it into a promising candidate for colonic drug delivery systems. In this study aqueous systems (0.5%, w/v,) of KGM from three different origins and their mixtures with xanthan gum (XG) (1:1) were evaluated as regards their rheological properties and the diffusion coefficients and mobile fraction of macromolecules (dextrans of different molecular weight). Rheological data illustrate the synergism between KGM and XG at a stoichiometric relationship 1:1. Moreover, fluorescence recovery after photobleaching (FRAP) data indicate that diffusion of probes through the polysaccharide systems cannot be completely explained by the macroscopic properties of the medium but it is related to their molecular size and as a consequence to a sieving mechanism. The strong differences between KGM from different suppliers suggest the convenience of establishing specifications for this material in order to use it as pharmaceutical excipient.
魔芋葡甘聚糖（KGM）是一种中性多糖，具有作为胶凝剂和增稠剂的有趣特性。其独特的生物降解性，即在小肠中不可降解但可被人类肠道厌氧菌降解，使其成为结肠给药系统的一个有前景的候选物。在本研究中，对来自三种不同来源的KGM的水体系（0.5%，w/v）及其与黄原胶（XG）（1:1）的混合物的流变学性质、大分子（不同分子量的葡聚糖）的扩散系数和移动分数进行了评估。流变学数据说明了在化学计量比为1:1时KGM和XG之间的协同作用。此外，光漂白后荧光恢复（FRAP）数据表明，探针在多糖体系中的扩散不能完全由介质的宏观性质来解释，而是与其分子大小有关，因此与筛分机制有关。不同供应商的KGM之间存在很大差异，这表明为了将其用作药物赋形剂，有必要为这种材料制定规范。
