期刊
JOURNAL OF PHARMACEUTICAL SCIENCES
卷 92, 期 6, 页码 1234-1241出版社
JOHN WILEY & SONS INC
DOI: 10.1002/jps.10371
关键词
deacetylated gellan gum; in situ gelling; thiomers; crosslinking; rheology
The rheological properties of an in situ crosslinking thiolated deacetylated gellan gum were examined in vitro. Mediated by a carbodiimide, L-cysteine was covalently bound to deacetylated gellan gum (DGG). The deacetylated gellan gum-cysteine (DGG-Cys) conjugate displayed 216.53 +/- 59.54 mumol thiol groups per gram polymer (means +/- SD, n = 3). The thiolated polymer was capable of forming inter- and/or intramolecular disulfide bonds in aqueous solution (1.5%; m/m) at pH 7. After 6 h of incubation at room temperature, storage modulus, loss modulus, and complex viscosity increased 300-, 6.4-, and 26.6-fold, respectively, relative to the unthiolated polymer. Loss tangent of DGG-Cys was < 1, indicating a gel, whereas the corresponding unmodified polymer had a loss tangent of > 1, indicating a fluid. Frequency sweep measurements demonstrated an increase in crosslinking of the thiolated polymer as a function of time. DGG-Cys appeared to be superior to the unmodified polymer also in the presence of physiological cation concentrations found (e.g., in tear fluid and nasal secretion), which is referred to rheological properties. The polymer generated within this study represents a promising novel excipient for various drug delivery systems in which in situ gelling properties are favorable. (C) 2003 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据