Determination Of Valsartan And Amlodipine In Canine Plasma By LC-MS/MS And Its Application To A Pharmacokinetic Study

Objective: To establish a HPLC-MS/MS method for the determination of valsartan and amlodipine in the canine plasma.Methods:①The determination of valsartan in the canine plasma. After the addition of warfarin(internal standards, IS), the canine plasma was achieved by protein precipitation using methanol. The analytes were performed using a Venusil XBP Phenyl column(100mm×2.1 mm, 5 μm) at a flow rate of 0.35 mL/min. The mobile phase was consisted of 1% formic acid water solution(containing 2 mM ammonium acetate)- 1% methyl alcohol methanoic acid(30:70, V/V), using isocratic elution, and injection volume wad 5 μL. The pronated ions of the analytes were detected in positive ionization in Multiple Reaction Monitoring( MRM) mode. The mass transition pairs of m/z 436.4→291.2 and 309.1→163.2 were used to detected valsartan and warfarin, respectively.②The determination of amlodipine in the canine plasma. After the addition of terbinafine(internal standards, IS), the canine plasma was achieved by protein precipitation using methanol. The analytes were performed using a Venusil XBP Phenyl column(100mm×2.1 mm, 5 μm) at a flow rate of 0.30 mL/min. The mobile phase was consisted of 1% formic acid water solution(containing 2 mM ammonium acetate)- 1% methyl alcohol methanoic acid(35:65, V/V), using isocratic elution, and injection volume wad 5 μL. The pronated ions of the analytes were detected in positive ionization in Multiple Reaction Monitoring(MRM)mode. The mass transition pairs of m/z 409.2→238.0 and 292.2→141.2 were used to detected amlodipine and terbinafine, respectively.③According to the chemical preparation before clinical pharmacokinetic study guidelines,the study of bioequiavailability between of Compound valsartan tablet and Reference preparation by the way of double cycle cross delivery,Results: ①The determination of valsartan in the canine plasma. The calibration curve was linear over a concentration range of 2.5 to 5000 ng?mL(r=0.9978). The intraand inter- day relative standard deviation was less than 8 %. The recovery was 96.69 %,100.83 %, 99.78 % at high, middle and low concentrations.②The determination of amlodipine in the canine plasma. The calibration curve was linear over a concentration range of 0.5 to 500 ng?mL-1(r=0.9978). The intra- and inter- day relative standard deviation was less than 10 %. The recovery was 90.26 %, 101.35 %, 99.63 % at high, middle and low concentrations.③Pharmacokinetic study:The results showed that the compound valsartan tablet and reference preparation were not bioequiavailability.Conclution: The samples were treated with methanol to precipitate the protein sample when the sample was pretreated. This method operation is simple and quick, than reported in the literature of liquid-liquid extraction, solid-liquid extraction method.And it is more easy to operate.The method is simple convenient accurate and sensitive, and suitable for the determination of valsartan and amlodipine.