Studies on absorption kinetics of scopoletin in rat stomachs and intestines
Xia, Y.-f.; Dai, Y.; Meng, Q.-y.; Wang, Q.; Qiu, L.-l.
Zhongguo Zhong Yao Za Zhi 33(15): 1890-1894
2008
ISSN/ISBN: 1001-5302 PMID: 19007024 Document Number: 619368
To study absorption kinetics of scopoletin in rat stomachs and intestines. Rats was cannulated for in situ recirculation. UV and HPLC methods were used to determine the concentrations of phenolsulfonphthalein and scopoletin, respectively. The absorption rates in rat stomachs at 2 h after administration was 76.31%; The absorption rates at colon, duodenum, ileum and jejunum were 46.25%, 40.54%, 38.21%, 32.77%, respectively. The absorption rate constant (Ka) at concentrations of 10.0144, 20.0288-40.0576 mg x L(-1) in intestine were 0.6434, 0.6137, 0.5970 h(-1), respectively. The Ka of scopoletin at pH of 6.0, 6.8 and 7.4 in intestine were 0.6217, 0.6033, 0.6137 h(-1), respectively. The concentrations and pH values of scopoletin solution had no distinctive effect on the absorption kinetics. The absorption of scopoletin was a first-order process with passive diffusion mechanism. Scopoletin was well absorbed at stomachs and intestines in rats. Colon was the best absorption site of scopoletin, which suggest that a sustained-release preparation should be suitable for this compound.