Intestinal absorption of cefixime in rats

AIM: To study the intestinal absorption characters of cefixime (Cef) and th e factors affecting Cef absorption. METHODS: A rat intestine loop in situ t echnique was used to investigate the disappearance rate of Cef from the int estine. Cef concentration in the nux was measured by the reversed phase HPL C. RESULTS: Cef was mainly absorbed from the upper part of the intestine. I ts 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 K-t, J(max), and K-d were 0.114 mmol, 78.41 nmol. h(-1)/(g wet tissue), and 43.70 nmol.h(-1).mmol(-1)/(g wet tissue), respect ively. Sodium edetate markedly promoted the disappearance rate of Cef from the intestine. CONCLUSION: Cef was transported partly via carrier-mediated transport system and partly via the paracellular transport system.