Serum concentrations of Erufosine after a single bolus injection (A+B) or repeated injections (C+D). A+B: NMRI nu/nu mice were treated with one intraperitoneal injection of 40 mg/kg body weight Erufosine and subdivided into three groups for blood collection at different time points: group 1, n = 6 (◇): 15 min, 30 min, 1, 2 hours; group 2, n = 5 (□): 30 min, 2, 4, 8 hours; group 3, n = 5 (black triangle): 1, 4, 12, 24 and 36 hours. Erufosine concentrations in serum were determined by LC-MS/MS analysis. Data represent means ± SD: A. Data show the initial serum concentrations of groups 1-3 separately. B. Data show mean Erufosine serum-concentrations for all animals from group 1-3 pooled (n = 16). Insert shows the pharmacokinetic parameters. C+D: NMRI nu/nu mice were treated with repeated intraperitoneal injections of Erufosine every 48 hours at the indicated concentrations. All values are means ± SD (n = 3-6). Erufosine concentrations in serum were determined by LC-MS/MS analysis. C. Concentration-dependent increase in the serum levels of Erufosine after a three weeks treatment with 5, 10, 20 and 40 mg/kg body weight Erufosine. D. Time course of the Erufosine serum concentrations after treatment with 20 and 40 mg/kg body weight Erufosine for one and three weeks.