Piyakulawat Pimwipha, Praphairaksit Nalena, Chantarasiri Nuanphun, Muangsin Nongnuj
Program of Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
AAPS PharmSciTech. 2007 Nov 16;8(4):E97. doi: 10.1208/pt0804097.
The polyelectrolyte complex (PEC) hydrogel beads based on chitosan (CS) and carrageenan (CR) have been studied as a controlled release device to deliver sodium diclofenac (DFNa) in the simulated gastrointestinal condition. Various factors potentially influencing the drug release (ie, CS/CR proportion, DFNa content, types and amount of cross-linking agents) were also investigated. The optimal formulation was obtained with CS/CR proportion of 2/1 and 5% (wt/vol) DFNa. The controlled release of the drug from this formulation was superior to other formulations and was able to maintain the release for approximately 8 hours. Upon cross-linking with glutaric acid and glutaraldehyde, the resulting beads were found to be more efficient for prolonged drug release than their non-cross-linking counterparts. The bead cross-linked with glutaraldehyde was able to control the release of the drug over 24 hours. The difference in the drug release behavior can be attributed to the differences in ionic interaction between the oppositely charged ions and to the concentrations of the drug within the beads, which depends on the compositions of the formulation and the pH of the dissolution medium. The release of drug was controlled by the mechanism of the dissolution of DFNa in the dissolution medium and the diffusion of DFNa through the hydrogel beads.
基于壳聚糖（CS）和角叉菜胶（CR）的聚电解质复合物（PEC）水凝胶珠已被研究作为一种控释装置，用于在模拟胃肠道条件下递送双氯芬酸钠（DFNa）。还研究了各种可能影响药物释放的因素（即CS/CR比例、DFNa含量、交联剂的类型和用量）。当CS/CR比例为2/1且DFNa含量为5%（wt/vol）时获得了最佳配方。该配方中药物的控释效果优于其他配方，并且能够维持约8小时的释放。与戊二酸和戊二醛交联后，发现所得珠子在延长药物释放方面比未交联的珠子更有效。与戊二醛交联的珠子能够在24小时内控制药物释放。药物释放行为的差异可归因于带相反电荷离子之间离子相互作用的差异以及珠子内药物的浓度，这取决于配方组成和溶解介质的pH值。药物的释放是由DFNa在溶解介质中的溶解机制以及DFNa通过水凝胶珠的扩散控制的。
