An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deprotei...An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deproteinated with 10% （v/v） perchloric acid. Separation was achieved on a UltimateTM AQ-C18 column （250 mm×4.6 mm, 5 μm） with a mobile phase （pH 5.05） composed of acetonitrile-water （31：69, v/v, containing 0.002 M sodium dodecyl sulfate, 0.0125 M potassium dihydrogen phosphate, 0.015 M triethylamine） at a flow rate of 1.0 mL/min. The calibration curve was linear （r〉0.994） between 7.5 and 4000 ng/mL. The lower limit of quantification （LLOQ） was 7.5 ng/mL. The precision was validated and the relative standard deviation was in the range of 1.87% to 15.70%; the accuracy was between 93.98%-106.89%. The mean recoveries were 95.40% and 95.31% for metformin and IS, respectively. The relative error （RE） of stability at different storage conditions was within ±9.00%. This method was used to determine the concentration-time profile of metformin in diabetic rat plasma following an oral administration of metformin at the dose of 10 mg/kg. Our results indicated that ion-pair HPLC-UV method using UltimateTM AQ-C18 column was effective for the pharmacokinetic studies of high polarity compounds like metformin.展开更多
A rapid, sensitive and selective UPLC-MS/MS method was developed to determine paeoniflorin and astragaloside IV, This method was validated via a pharmacokinetic study using rat plasma. The internal standard was clarit...A rapid, sensitive and selective UPLC-MS/MS method was developed to determine paeoniflorin and astragaloside IV, This method was validated via a pharmacokinetic study using rat plasma. The internal standard was clarithromycin. A simple one-step deproteinization procedure was used to prepare plasma samples. Separation was achieved on a CAPCELL CORE ADME CI8 column with a gradient mobile phase consisting of solution A （water containing 0.1% formic acid） and solution B （acetonitrile） at a flow rate of 0.3 mL/min. Multiple reaction monitoring （MRM） was used with an electrospray ionization source （ESI） in positive mode. A good linear response was observed within the ranges of 0.01 to 5.00 ~g/mL for paeoniflorin and 0.000l to 0.05 ~tg/mL for astragaloside IV. The accuracy （RE） was within the range of-3.5% to 6.3%, and the intra- and inter-day precisions （RSD） were within 14.2%. The extraction recoveries were all above 78.9%. The pharmacokinetic study of the two analytes in rats after oral administration of Huangqi Guizhi Wuwu Decoction （HGWD） was successfully completed through this method. The method develooed in this studv will fill a gap in oharmacokinetic studies of HGWD.展开更多
基金National Integrity Innovational Technology Platform of New Drug and Research and Development (Grant No.2009ZX09201-010)Innovation Team of Ministry of Education(Grant No. BMU20110263)
文摘An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deproteinated with 10% （v/v） perchloric acid. Separation was achieved on a UltimateTM AQ-C18 column （250 mm×4.6 mm, 5 μm） with a mobile phase （pH 5.05） composed of acetonitrile-water （31：69, v/v, containing 0.002 M sodium dodecyl sulfate, 0.0125 M potassium dihydrogen phosphate, 0.015 M triethylamine） at a flow rate of 1.0 mL/min. The calibration curve was linear （r〉0.994） between 7.5 and 4000 ng/mL. The lower limit of quantification （LLOQ） was 7.5 ng/mL. The precision was validated and the relative standard deviation was in the range of 1.87% to 15.70%; the accuracy was between 93.98%-106.89%. The mean recoveries were 95.40% and 95.31% for metformin and IS, respectively. The relative error （RE） of stability at different storage conditions was within ±9.00%. This method was used to determine the concentration-time profile of metformin in diabetic rat plasma following an oral administration of metformin at the dose of 10 mg/kg. Our results indicated that ion-pair HPLC-UV method using UltimateTM AQ-C18 column was effective for the pharmacokinetic studies of high polarity compounds like metformin.
文摘A rapid, sensitive and selective UPLC-MS/MS method was developed to determine paeoniflorin and astragaloside IV, This method was validated via a pharmacokinetic study using rat plasma. The internal standard was clarithromycin. A simple one-step deproteinization procedure was used to prepare plasma samples. Separation was achieved on a CAPCELL CORE ADME CI8 column with a gradient mobile phase consisting of solution A （water containing 0.1% formic acid） and solution B （acetonitrile） at a flow rate of 0.3 mL/min. Multiple reaction monitoring （MRM） was used with an electrospray ionization source （ESI） in positive mode. A good linear response was observed within the ranges of 0.01 to 5.00 ~g/mL for paeoniflorin and 0.000l to 0.05 ~tg/mL for astragaloside IV. The accuracy （RE） was within the range of-3.5% to 6.3%, and the intra- and inter-day precisions （RSD） were within 14.2%. The extraction recoveries were all above 78.9%. The pharmacokinetic study of the two analytes in rats after oral administration of Huangqi Guizhi Wuwu Decoction （HGWD） was successfully completed through this method. The method develooed in this studv will fill a gap in oharmacokinetic studies of HGWD.
