Determination of metformin, pioglitazone and active metabolites of pioglitazone in human plasma by HPLC-MS/MS / 中国药学杂志

ABSTRACT

OBJECTIVE: To establish an LC-MS method to determine the concentrations of metformin, pioglitazone and the active metabolites of pioglitazone(ketopioglitazone M-III and hydroxylpioglitazone M-IV) in plasma after administration of compound metformin and pioglitazone tablets. METHODS: Pioglitazone and the internal standard carbamazepine were extracted from plasma with acetonitrile. The concentrations of pioglitazone and its active metabolites were analyzed on Ultimate C18 column(2.1 mm×150 mm, 5 μm) with mobile phase consisting of acetonitrile-5 mmol·L-1 ammonium acetate(55:45) at a flow rate of 0.3 mL·min-1. The column temperature was 35°C. Metformin and the internal standard memantine were extracted from plasma with acetonitrile and analyzed on Ultimate XB-CN column(2.1 mm×150 mm, 5 μm) with mobile phase consisting of acetonitrile-0.1% formic acid(containing 10 mmol·L-1 ammonium acetate)(73:27) at a flow rate of 0.3 mL·min-1. RESULTS: The liner ranges were 5.08-1016.0 μg·L-1, 2.45-490.0 μg·L-1, and 4.20-840.0 μg·L-1 for metformin, pioglitazone, ketopioglitazone(M-III)and hydroxylpioglitazone(M-IV)respectively. The limits of quantitation were 6.0, 5.08, 2.45, and 4.2 μg·L-1, respectively. The extraction recoveries were more that 89.67%, while the intra- and inter-day precisions(RSD) were less that 15%. CONCLUSION: This assay is accurate, reliable and suitable for pharmacokinetic studies of metformin, pioglitazone and its active metabolites in human plasma.