Concentration determination of atorvastatin calcium and pioglitazone hydrochloride in Beagle dog plasma by LC-MS/MS
Dang Hong-wan · Yaowu fenxi zazhi · 2013
Objective: To establish an LC-MS /MS method to determine the concentrations of atorvastatin calcium and pioglitazone hydrochloride in Beagle dog plasma,and to verify the method.Methods: The drugs were extracted by precipitating protein,with diazepam as an internal standard.The Shim-pack XR-ODS(2.0 mm × 100 mm,2.2 μm) column at 40 ℃ and the Shim-pack GVP-ODS(2.0 mm ×5 mm,2.2 μm) pre-column were used.The mobile phase consisted of phase A(5 mmol.L-1 ammonium acetate,pH 5.55) and phase B(acetonitrile),the phase B accounted for 10% of the total mobile phase ratein the first 0.6 min,then changed to 90% from 0.6 min to 1.2 min,and kept at 90% until 3.5 min,then returned to 10% from 3.5 min to 4.1 min.The analysis was stopped until 5.5 min,the total mobile phase rate was 0.3 mL.min-1,injected volume was 20 μL.Electrospray ion source was applied in mass spectrometry,and quantitative analysis was undertaken in multiple reaction monitoring.Results: Atorvastatin calcium and pioglitazone hydrochloride had a good linear relation between 0.05-50 ng.mL-1,0.5 1000 ng.mL-1,respectively.The intra-and inter-day precision RSD were both less than 15%(n =5).Drugs in dog plasma were stable at room temperature for 24 h,and at 4 ℃ for 24 h after being extracted,even after freezing and thawing three times and stored at-70 ℃ for two months.Conclusion: The developed method is simple and accurate,which can be used to determine the concentration and the pharmacokinetics of atorvastatin calcium and pioglitazone hydrochloride in Beagle dogs.