Previous Article | Next Article ![]()
Antimicrobial Agents and Chemotherapy, 02 1997, 445-448, Vol 41, No. 2
N Ruiz-Balaguer, A Nacher, VG Casabo and M Merino
Cefuroxime is commercially available for parenteral administration as a
sodium salt and for oral administration as cefuroxime axetil, the 1-
(acetoxy)ethyl ester of the drug. Cefuroxime axetil is a prodrug of
cefuroxime and has little, if any, antibacterial activity until hydrolyzed
in vivo to cefuroxime. In this study, the absorption of cefuroxime axetil
in the small intestines of anesthetized rats was investigated in situ, by
perfusion at four concentrations (11.8, 5, 118 and 200 microM). Oral
absorption of cefuroxime axetil can apparently be described as a
specialized transport mechanism which obeys Michaelis- Menten kinetics.
Parameters characterizing absorption of prodrug in free solution were
obtained: maximum rate of absorption (Vmax) = 289.08 +/- 46.26 microM h-1,
and Km = 162.77 +/- 31.17 microM. Cefuroxime axetil transport was
significantly reduced in the presence of the enzymatic inhibitor sodium
azide. On the other hand, the prodrug was metabolized in the gut wall
through contact with membrane-bound enzymes in the brush border membrane
before absorption occurred. This process reduces the prodrug fraction
directly available for absorption. From a bioavailability point of view,
therefore, the effects mentioned above can explain the variable and poor
bioavailability following oral administration of cefuroxime axetil. Thus,
future strategies in oral cefuroxime axetil absorption should focus on
increasing the stability of the prodrug in the intestine by modifying the
prodrug structure and/or targeting the compound to the absorption site.
Copyright © 1997 by the American Society for Microbiology. All rights reserved.
Nonlinear intestinal absorption kinetics of cefuroxime axetil in rats
Department of Pharmaceutics, Faculty of Pharmacy, University of Valencia, Burjassot, Spain.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»