Pharmacokinetics, tissue distribution and excretion of vinflunine

The plasma pharmacokinetics, tissue distribution, excretion and binding to plasma proteins of vinflunine, were investigated after intravenous (iv) administration. We obtained plasma profiles after iv administration of vinflunine at the doses of 3.5, 7 and 14 mg/kg in rats. The t1/2 values for vinflunine were estimated to be 18.38+/-1.20, 17.05+/-0.77, 18.35+/-1.57 h, and the mean AUC0-t values were 3.48+/-0.38, 6.54+/-0.68, 12.79+/-2.93 microg x h/ml, respectively. Of the various tissues tested, vinflunine was widely distributed into tissues, with the highest concentrations of vinflunine being found in well perfused organs. Maximal concentration of vinflunine was reached at 0.5 h postdose in the majority of tissues. In tumor-bearing mice, the similar pattern of tissue distribution was observable, except that vinflunine can be distributed into tumor. The binding of vinflunine in human and rat plasma proteins were 39.6% and 58.4% respectively. Within 96 h after administration, 9.58%, 15.36% and 0.71% of the given dose was excreted in urine, feces and bile, respectively. In conclusion, Vinflunine had a longer terminal half-life, a wide tissue distribution and less than 25% of the given dose was excreted as unchanged drug, suggesting metabolism as a major style of elimination.