Study On The Influence Of Ifosfamide's Metabolism In Rabbits With Administering Aidi Zhusheye Simultaneously

[Objective]: Study on the pharmacokinetics of ifosfamide in rabbit and identifying the influence of it's metabolism with administering traditional Chinese medicine aidi zhusheye simultaneously,to provide information for rational administration safely and efficiently in clinic.[Methods]: 1,Establishing the drug metabolism model of rabbit:Six rabbits were divided into two groups that were the control group and the test group. After three weeks of administration, two groups made a cross over. The control group was given ifosfamide and NS,and the test group was given ifosfamide and aidi zhusheye. The drug was given to the rabbits by intravenous injection whose dose was according to body weight, then took blood 1mL at 5,10,20,30,45min and 1,1.5,2,2.5,3,5,7h after administration . 2,Treatment of blood sample:The C18 solid phase extraction column was determined to handle the blood samples and the method included following steps. (1) Activation of column was to elute the column by 2mL acetonitrile and 2mL NS. (2) Adding sample was to add 0.5mL blood sample and 12.5uL internal standard to the column. (3) Washing was to get rid of impurity by 1mL NS and 1mL 5% acetonitrile after the blood sample outflowing completely. (4) Eluting was to wash out the subject drugs by 0.5mL 60% acetonitrile, then took 20uL elutant to determine drug concentrate. 3,The method of determining ifosfamide by HPLC:With cyclophosphamide as internal standard, the serum sample was determined on Zorbox -ODS C18 at room temperature.The mobile phase consisted of acetonitrile -water (25∶75) at a flow rate of 1 mL·min - 1 and a detection wave -length of 200nm.4,Analysis of experimental data:Dealed with the data of concentrations by 3p97 programme to select the best fit compartment model and obtain the pharmacokinetics parameters.Then handled the parameters by SPSS13.0. The measurement datas were expressed by mean and standard deviation to carry out two period crossover design ANOVA and test ; finally compared with the bioavailability of two groups.[Results]:1,The linear range(n=7) of ifosfamide was 2.5²00μg·mL^-1 (γ= 0.999),with the lowest detectable limite of at 0.5μg·mL^-1 (S/N=3).Both the intraday and interday RSD were less than 5%.The extraction recoveries of ifosfamide at high,middle,low concentrations were ranged between 89.3% and 93.6%. 2,The concentrations were handled by 3p97 programme and found that two compartments model was best fit for both of two groups, then obtained the pharmacokinetic parameters. The control group were : t_α/2 =0.44±0.12h ,t_β/2=5.32±3.09h,CL=1.66±0.81 L·h^-1,k₂₁=0.25±0.43h^-1,k₁₀=1.21±0.40h^-1,k₁₂=0.39±0.50h^-1 , V=1.44±0.25L , AUC_0-∞=140.53±39.26mg·L^-1·h ,AUC_0-t=128.37±34.26mg·L^-1·h ; the test group were : t_α/2 =0.35±0.21h ,t_β/2=3.15±0.53h,CL=1.96±0.56L·h^-1,k₂₁=2.55±2.88h^-1,k₁₀=1.44±0.34h^-1,k₁₂=2.0±2.52h^-1 , V=1.39±0.35L , AUC_0-∞=120.02±25.89mg·L^-1·h ,AUC_0-t=119.18±25.51mg·L ^-1·h. 3,Comparing the biology availability of two groups by SPSS13.0 found that the test group was significantly smaller than the control group.[Conclusion]:1,The method which uses the C18 solid phase extraction column is of high recovery,and the sample treatment by which is simple, convenience,accurate,and pollution-free; and the method of determining ifosfamide by HPLC was applicable for the monitoring of serum concentration and pharmacokinetic study of ifosfamide. 2,The two groups's pharmacokinetic parameters of ifosfamide are both according with two compartments model. 3,When ifosfamide and aidi are administered to the rabbits,the bioavailability of ifosfamide reduces significantly,that suggests the drug metabolism of ifosfamide was effected significantly. In addition, aidi zhusheye made the concentrations of IFO in rabbits lower significantly, so the effect of IFO was attenuated probably.