Study On Amlodipine And Venlafaxine And Metabolites UPLC-MS / MS

Two rapid and sensitive ultra performance liquid chromatographic-tandem mass spectrometric (UPLC-MS/MS) methods have been developed for the determination of amlodipne in human plasma and venlafine and its active metabolite O-desmethyl venlafaxine in beagle dog plasma.1、Determination of amlodipine in human plasma and its applicationA rapid and sensitive ultra performance liquid chromatographic-tandem mass spectrometric method for the determination of amlodipine in human plasma has been developed, and has been applied to evaluate the bioequivalence of two formulations of amlodipne. Followed by liquid-liquid extraction from 500μL plasma sample, chromatographic separation was performed on a ACQUITY UPLCTM BEH C18(50 mm×2.1 mm,1.7μm) column with the mobile phase of acrtonitrile-water (0.2% formic acid) by gradient elution. Electrospray ionization (ESI) source was used and operated in the positive ion mode by multiple reaction monitoring (MRM) mode with the transitions of m/z 409.0→238.1 and m/z 260.2→116.1 to quantify amlodipne and the internal standard, respectively. The linear range of amlodipine in human plasma was 0.150-15.0 ng·mL-1, LLOQ was 0.150 ng-mL"1. The intra-day RSD at three QC levels were 11%,8.5% and 7.6%, respectively, and the inter-day RSD were 9.6%,11% and 9.4%, respectively. Accuracy was within 98.0%-102.2%. The extraction recovery of amlodipine was more than 77.4%.The method was used to determine amlodipine in human plasma after an oral administration of test formulation and reference formulation containing 10 mg amlodipine to 18 healthy volunteers. The main pharmacokinetic parameters were as follow:Tmax were (6.2±0.9) and (5.9±1.2) h, Cmax were (6.24±1.73) and (6.06±1.56) ng·mL-1, t1/2 were (40.1±9.8) and (40.4±6.7) h, AUC0-t were (276.34±97.22) and (279.09±82.82) ng·h·mL-1, AUC0-∞were (300.98±108.08) and (304.36±92.76) ng·h·mL-1, respectively. The relative bioavailability of test formulation of amlodipine was (99.4±23.4)%. According to the results of statistical analysis, the test and reference formulations of amlodipine are bioequuivalent.2、Determination of venlafaxine and its active metabolite O-desmethyl venlafaxine in plasma and its applicationA sensitive and rapid ultra performance liquid chromatographic-tandem mass spectrometric method for the determination of venlafaxine and its active metabolite O-desmethyl venlafaxin in beagle dog plasma have been developed, and have been applied to pharmacokinetics of two formulations of venlafaxine in beagle dogs. Followed by protein precipitation from 100μL plasma sample, chromatographic separation was performed on ACQUITY UPLCTM BEH C18(50 mm×2.1 mm,1.7μm)column with the mobile phase of acetonitrile-water (containing 0.1% formic acid). Electrospray ionization (ESI) source was used and operated in the positive ion mode by multiple reaction monitoring (MRM) mode with the transitions of m/z 278.1→58 for VEN and m/z 264.1→58 for ODV, and m/z 446.3→321.2 for internal standard, respectively. The linear range of VEN and ODV in dog plasma were 1.00-500 ng/mL, LLOQ were 1.00 ng/mL. The intra-day RSD at three QC levels were 6.9%,8.4% and 6.4% for VEN and 3.6%, 8.5% and 5.8% for ODV, and the inter-day RSD were 12%,3.9% and 9.2% for VEN and 13%, 6.7% and 5.7% for ODV, respectively. Accuracy were within 94.4%-104.6%. The extraction recovery of VEN and ODV were more than 82.9%.The method was used to determine VEN and ODV in plasma after an oral administration of sustained release capsules containing 75 mg VEN to 4 beagle dogs. The main pharmacokinetic parameters were as follow:Tmax were (6.0±1.9) and (3.5±1.5) h; Cmax were (129.32±31.96) and (17.19±3.10) ng-mL-1, t1/2were (6.2±3.2) and (18.4±10.6) h; AUC0-twere (1280.25±245.79) and(118.34±11.88) ng·h·mL-1,AUC0-∞were (4392.60±3181.11) and (259.13±116.18) ng·h·mL-1, respectively.