Uekama Kaneto

Improvement of oral and rectal bioavailabilities of carmofur by methylated β-cyclodextrin complexations

Abstract Inclusion complex formation of carmofur (1-hexylcarbamoyl-5-fluorouracil; HCFU) with β-CyD, heptakis(2,6-di-O-methyl)-β-cyclodextrin (DM-β-CyD) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CyD) were assessed by solubility method, thermal analysis and powder X-ray diffractometry. The hydrolysis of HCFU in aqueous solution was decelerated by three β-CyDs, depending on the magnitude of the stability constant of the inclusion complex (TM-β-CyD

Effect of bile on the intestinal absorption of α-cyclodextrin in rats

Abstract The effect of bile on the absorption of α-cyclodextrin from rat small intestine was examined using the in situ recirculating perfusion technique. Only very little intestinal absorption of α-cyclodextrin was observed when the bile duct was ligated, but some of it was absorbed from the intestine when bile was present; intact α-cyclodextrin then entered the systemic circulation. Sodium cholate and disodium ethylenediaminetetraacetate also promoted the absorption of α-cyclodextrin under the bile duct-ligated conditions and their promoting effects were completely inhibited by the addition of calcium choride. These results indicate that absorption of α-cyclodextrin from the intestine occurs through the paracellular pathway.