Department of Chemical and Material Engineering, National Yunlin University of Science and Technology, Dou-Liu, Yunlin, Taiwan.
Int J Pharm. 2009 Dec 1;382(1-2):39-44. doi: 10.1016/j.ijpharm.2009.07.035. Epub 2009 Aug 8.
This study investigates in vitro the drug delivery characteristics of new thermo-sensitive gels, P-CS/GA gels, in which a chitosan (CS) network is crosslinked with various concentrations of glutaraldehyde (GA) that interpenetrates Poloxamer (P) gels. The results indicate that the swelling ratios of all P-CS/GA gels are markedly superior to those of non-swelling P and P-CS gels. For example, P-CS/GA (0.1 wt.%) gels have swelling ratios of 13.2+/-1.0, which are maintained for approximately 18 h in water at 37 degrees C. In vitro releases of 5-FU from P-CS/GA (0.1 wt.%) gels had significantly lower initial burst release (P<0.01) and lasted much longer than those from gels without a CS network. For example, the duration of release of 5-FU was in a significantly sustained manner for up to 52 h, which was about 10 times or longer than the period of delivery using P or P-CS gels. The release of drugs from gels with an interpenetrating CS network could be modeled by Fickian diffusion; the characteristic constant 'k' of drug-gel systems decreased as increasing GA concentrations in the P-CS/GA gels, and increasing the viscosities of the P, P-CS and P-CS/GA solutions.
本研究考察了新的温敏凝胶 P-CS/GA 的体外药物传递特性，其中壳聚糖 (CS) 网络与不同浓度的戊二醛 (GA) 交联，GA 互穿聚氧乙烯 (P) 凝胶。结果表明，所有 P-CS/GA 凝胶的溶胀率明显优于非溶胀 P 和 P-CS 凝胶。例如，P-CS/GA（0.1wt%）凝胶的溶胀率为 13.2+/-1.0，在 37°C 水中约 18 小时保持不变。5-FU 从 P-CS/GA（0.1wt%）凝胶中的体外释放具有明显较低的初始突释（P<0.01），并且持续时间比没有 CS 网络的凝胶长得多。例如，5-FU 的释放持续时间显著延长至 52 小时，这大约是使用 P 或 P-CS 凝胶的递送时间的 10 倍或更长时间。具有互穿 CS 网络的凝胶中药物的释放可以通过菲克扩散模型来模拟；药物-凝胶系统的特征常数'k'随着 P-CS/GA 凝胶中 GA 浓度的增加而降低，并且随着 P、P-CS 和 P-CS/GA 溶液的粘度增加而降低。
