Intestinal absorption of cefixime in rats.
OBJECTIVE
To study the intestinal absorption characters of cefixime (Cef) and the factors affecting Cef absorption.


METHODS
A rat intestine loop in situ technique was used to investigate the disappearance rate of Cef from the intestine. Cef concentration in the flux was measured by the reversed phase HPLC.


RESULTS
Cef was mainly absorbed from the upper part of the intestine. Its disappearance rate was apparently pH-dependent [(5.8 +/- 0.6) nmol.h-1/(g wet tissue) at pH 7.4, (8.9 +/- 1.4) nmol.h-1/(g wet tissue) at pH 5.0, P < 0.05)]. The uptake rate of Cef was curvilinear at 0.01-0.5 mmol.L-1. The values of apparent Kt, Jmax, and Kd were 0.114 mmol, 78.41 nmol.h-1/(g wet tissue), and 43.70 nmol.h-1.mmol-1/(g wet tissue), respectively. Sodium edetate markedly promoted the disappearance rate of Cef from the intestine.


CONCLUSIONS
Cef was transported partly via carrier-mediated transport system and partly via the paracellular transport system.
Hu
Y Q
YQ
Department of Biology, Nanjing University, China.
Qian
C Q
CQ
Zheng
L Y
LY
Yu
W H
WH
Tan
R X
RX
D000818:Animals; D020682:Cefixime / Q000493:pharmacokinetics*; D002511:Cephalosporins / Q000493:pharmacokinetics*; D004492:Edetic Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D051381:Rats
D002511:Cephalosporins; D020682:Cefixime; D004492:Edetic Acid