Dhawan Sanju, Singla Anil Kumar, Sinha Vivek Ranjan
University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India 160014.
AAPS PharmSciTech. 2004 Jul 26;5(4):e67. doi: 10.1208/pt050467.
The mucoadhesive properties of chitosan microspheres prepared by different methods were evaluated by studying the interaction between mucin and microspheres in aqueous solution. The interaction was determined by the measurement of mucin adsorbed on the microspheres. A strong interaction between chitosan microspheres and mucin was detected. The intensity of the interaction was dependent upon the method of preparation of chitosan microspheres and the amount of mucin added. The extent of mucus adsorption was proportional to the absolute values of the positive zeta potential of chitosan microspheres. The zeta potential in turn was found to be dependent upon the method of preparation of microspheres. The adsorption of type III mucin (1% sialic acid content) was interpreted using Freundlich or Langmuir adsorption isotherms. The values of r2 were greater for Langmuir isotherm as compared with Freundlich isotherm. The adsorption of a suspension of chitosan microspheres in the rat small intestine indicated that chitosan microspheres prepared by tripolyphosphate cross-linking and emulsification ionotropic gelation can be used as an excellent mucoadhesive delivery system. The microspheres prepared by glutaraldehyde and thermal cross-linking showed good stability in HCl as compared with microspheres prepared by tripolyphosphate and emulsification ionotropic gelation.
通过研究水溶液中粘蛋白与微球之间的相互作用,对不同方法制备的壳聚糖微球的粘膜粘附特性进行了评估。这种相互作用通过测量吸附在微球上的粘蛋白来确定。检测到壳聚糖微球与粘蛋白之间存在强烈的相互作用。相互作用的强度取决于壳聚糖微球的制备方法和添加的粘蛋白量。粘液吸附程度与壳聚糖微球正ζ电位的绝对值成正比。反过来,ζ电位又取决于微球的制备方法。使用弗伦德利希或朗缪尔吸附等温线来解释III型粘蛋白(唾液酸含量为1%)的吸附情况。与弗伦德利希等温线相比,朗缪尔等温线的r2值更大。壳聚糖微球在大鼠小肠中的吸附表明,通过三聚磷酸交联和乳化离子凝胶法制备的壳聚糖微球可作为一种优良的粘膜粘附给药系统。与通过三聚磷酸和乳化离子凝胶法制备的微球相比,通过戊二醛和热交联制备的微球在盐酸中显示出良好的稳定性。