| Part one Determination of rivaroxaban plasma by LC-MS/MS and the effect of nateglinide on pharmacokinetics of rivaroxaban in ratObjectives: To establishment a method of LC-MS/MS to determination the concentration of rivaroxaban in rat plasma, which is sensitive and rapid. And to investigate the effect of nateglinide on pharmacokinetics of rivaroxaban in rats,which provides the theoretical foundation for the joint clinical application of the two drugs.Methods: The analytical column was Diamonsil C18(150 mm×4.6 mm,5 μm). Detection was carried out by electrospray positive ionization mass spectrometry in the multiple reaction monitoring(MRM) mode. The MRM transitions were m/z 436.2â†'145.2 and 370.1â†'278.0, which respectively were used to quantify rivaroxaban and imrecoxib. The mobile phase consisted of 10 mmol/L ammonium acetate(p H=3.14)- acetonitrile(50:50,V/V)at a flow rate of 0.8 ml/min;The temperature of column was set at 30℃. The injected volume was 20μl. Imrecoxib was selected as the internal stanstard. A total of 36 healthy male SD rats were randomly divided into experimental group and control group,18 rats in each group. The experimental group was gavaged nateglinide suspension(12 mg/kg) 3 times a day,and the control group every day was gavaged the same volume that of the suspension above,for 3 consecutive days. At the morning of the fourth day,the experimental group and the control group were randomly administrated nateglinide and suspension.After 30 minutes, each rat was given rivaroxaban suspension(2.6 mg/kg). And draw blood from inner canthus before(0h)and after 10,20,30,45 min,1,1.5,2,3,4,6,8,12,24 h gavaged rivaroxaban. The plasma concentration of rivaroxaban was determined byLC-MS/MS. The pharmacokinetic software of DAS2.1.1 was used to imitated the pharmacokinetic parameters, and the statistical software of SPSS 17.0 wasused to compared of the parameters of pharmacokinetics in the two groups.Results: The main pharmacokinetic parameters of test group and control group were obtained: AUC0-t was(2572.67±1017.607) μg·h/L and(1692.752±654.7170) μg·h/L,AUC0-∞ was(2713.29±1101.596) μg·h/L and(1760.246±649.113) mg·h/L,t1/2 was(3.998±1.48)h and(3.457±1.096)h,Tmax was(0.861±0.154)h and(0.694±0.202)h,CL(1.111±0.43)L/(h·kg)and(1.675±0.599)L/(h·kg),V was(5.795±1.63)L and(7.951±2.742)L,Cmax was(537.826±141.351)μg/L and(438.194±122.023)μg/L,Results showed that the experimental group of t1/2 has no significant difference compared with control group(P> 0.05). But there were significant difference on AUC0-t,AUC0-∞,Cmax,Tmax between test group and control group. They were increased obviously(P < 0.05).There were significant differences on CL and V. They were decrease obviously(P< 0.05).Conclusion: This experiment has established the LC- MS/MS method which was developed for the determination of the rivaroxaban in rat plasma concentration. This method is simple,high sensitivity,good reproducibility,which was applied to study the rivaroxaban in rat plasma concentration determination and pharmacokinetic. The nateglinide can significantly increase the absorption of rivaroxaban in rat and slow down the slimination of rivaroxaban when use together.Part two The effect of nateglinide on pharmacodynamicsof rivaroxaban in ratObjective: To observe the effect of nateglinide on Pharmacodynamics of Rivaroxaban in rat.Method:18 male SD rats were randomly divided into three groups: rivaroxaban group, nateglinide group, rivaroxaban + nateglinide group(combined group). Rivaroxaban group was given rivarxaban(2.6 mg/kg) once a day and the same volume that of nateglinide group for three times; Nateglinide group was given nateglinide(12mg/kg)3 times a day and the same volume that of rivarxoban group once a day and nateglinide(12mg/kg)3 times a day; The combined group was given rivarxoban(2.6 mg/kg) once a day and nateglinide(12mg/kg)3 times a day; rivaroxaban group, nateglinide group and the combination group for 5 consecutive days. Everyday after administration of 45 mins, inner canthus blood of rats were drawed to the vacuum tube anticoagulant,3000 r/min,centrifugal for 5 min,By using the automatic blood coagulation analyzer of beckman·Kurt,Rivaroxaban group, nateglinide group and combined group were separately measured the main pharmacodynamic parameters of Prothrombin time(PT)and Activated partial thrombin time(APTT),International standardization ratio(INR). The pharmacodynamic parameters were carried out by variance analysis.Result: The pharmacodynamic parameters(PT,APTT,INR value) of nateglinide group have no statistical difference( P>0.05).The pharmacodynamics parameter(APTT value) of rivaroxaban group and combination group have no statistical differences(P> 0.05),but the PT and INR values of two groups have significant difference(P<0.05),Rivaroxaban group and combination group, at the same time measured the pharmacodynamics of statistical parameters of PT,APTT,INR values.They have no statistical difference(P> 0.05).Conclusion: After rivaroxaban combined with nateglinide, the rivaroxaban has no significant changes in rats in vivo pharmacodynamicparameters,which showed that up to now the nateglinide has no impact at the pharmacodynamics of rivaroxaban laval in rats. |
PDF Full Text Request