Determination of glibenclamide and puerarin in rat plasma by UPLC-MS/MS: application to their pharmacokinetic interaction study.

In the treatment of diabetes mellitus, glibenclamide and puerarin may be co-administered unwittingly or wittingly. An ultra performance liquid chromatography-tandem mass spectrometry method was developed to determine the concentrations of glibenclamide and puerarin in rat plasma for the study of pharmacokinetic interaction between them. Analytes were extracted using liquid-liquid extraction. The separation was achieved on a Waters BEH C18 column using 5 mmol/L ammonium acetate solution (containing 0.1% formic acid) and methanol as mobile phase with a linear gradient program. Electrospray ionization source was applied and operated in the multiple reaction monitoring positive mode. The proposed method was proved simple, specific and reliable. Glibenclamide, Pueraria lobata extract and glibenclamide in combination with P. lobata extract were orally administered to rats, respectively. Pharmacokinetic parameters were estimated by Microsoft Excel software and analyzed by SPSS 12.0 software. Compared with glibenclamide group, pharmacokinetic parameters of glibenclamide in the co-administration group such as area under the curve and mean residence time were increased while clearance was decreased. Pharmacokinetic parameters of puerarin in the co-administration group such as peak concentration and area under the curve were enlarged while clearance and apparent volume of distribution were reduced compared with P. lobata extract group. These changes could enhance drug efficacy, but could also make drug accumulation to increase adverse effects, so it was suggested that the dosage should be adjusted or the drug concentration in plasma should be monitored if glibenclamide and puerarin were co-administered.

Li N ，Deng Y ，Wang D ，Qiao Y ，Li F ... -  《-》

Simultaneous determination of epalrestat and puerarin in rat plasma by UHPLC-MS/MS: Application to their pharmacokinetic interaction study.

In the present study, a simple, rapid and reliable ultrahigh-performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) method was developed and validated to determine simultaneously epalrestat (EPA) and puerarin (PUE) in rat plasma for evaluation of the pharmacokinetic interaction of these two drugs. Both the analytes and glipizide (internal standard, IS) were extracted using a protein precipitation method. The separation was performed on a C18 reversed phase column using acetonitrile and 5 mmol/L ammonium acetate in water as the mobile phase with a gradient elution program. The analytes, including IS, were quantified with multiple reaction monitoring under negative ionization mode. The optimized mass transition ion pairs (m/z) were 318.1 → 274.0 for EPA, 415.1 → 266.9 for PUE and 444.2 → 166.9 for IS. The linear calibration curves for EPA and PUE were obtained in the concentration ranges of 10-4167 and 20-8333 ng/mL, respectively (r > 0.99). The current method was successfully applied for the pharmacokinetic interaction study in rats following administration of EPA and PUE alone or co-administration (EPA 15 mg/kg, oral; PUE 30 mg/kg, intravenous). The results showed that the combination of EPA and PUE could increase t1/2 of EPA and reduce Tmax of EPA. These changes indicated that EPA and PUE might cause drug-drug interactions when co-administrated.

Sun H ，Bo Y ，Zhang M ，Wu X ，Zhou M ，Zhao L ，Xiong Z ... -  《-》

LC-MS/MS method for the determination of a new puerarin derivative and its application in pharmacokinetic studies in rats.

To establish a sensitive and rapid liquid chromatographic-tandem mass spectrometry (LC-MS/MS) method for the quantitative analysis of dehydrated puerarin in rat plasma, and its application for pharmacokinetic studies. A plasma sample was pretreated by one-step protein precipitation by the addition of five volumes of methanol. The chromatographic separation was achieved on a Zorbax SB-C18 column (4.6 mm × 150 mm I.D. 5.0 μm, Agilent, USA) at 40 °C at a flow rate of 0.6 mL·min(-1) by an isocratic elution consisting of 10 mmol·L(-1) ammonium acetate in methanol and water containing 0.1% formic acid in a ratio of 20 : 80 (V/V). Detection was performed on a triple quadrupole mass spectrometer in multiple-reaction monitoring (MRM) mode. An atmospheric pressure chemical ionization (APCI) interface in positive ionization mode was used by monitoring the transitions from m/z 399.1→281.0 (dehydrated puerarin) and m/z 271.0→215.0 (internal standard, IS). Calibration curves were linear in the concentration range from 1.50 to 5400 ng·mL(-1), and the lower limit of quantification (LLOQ) was 1.50 ng·mL(-1) in rat plasma. The accuracy and precision values, which were calculated from three different sets of quality control samples analyzed in sextuplicate on three different days, ranged from 95.73% to 103.18%, and from 4.33% to 7.86%, respectively. The method was successfully applied to assess the pharmacokinetics of dehydrated puerarin after oral administration in rats.

Liu AC ，Zhao LX ，Xing J ，Gao J ，Lou HX ... -  《-》

Determination of puerarin in rat plasma by rapid resolution liquid chromatography tandem mass spectrometry in positive ionization mode.

A highly sensitive and specific method of rapid resolution liquid chromatography tandem mass spectrometry (RRLC-MS/MS) in positive ionization mode has been developed and validated for pharmacokinetic study of puerarin in rat plasma. Chromatography was carried out on a Zorbax XDB C18 reversed-phase column using a mobile phase comprising a mixture of methanol and 0.05% acetic acid in water (35:65, v/v) with a flow rate of 0.3 mL/min from 0 min to 5.4 min and then 0.6 mL/min from 5.41 min to 12 min. The mass spectrometer operated in ESI positive ionization mode. Multiple reaction monitoring (MRM) was used to measure puerarin and tectoridin (internal standard). The method was sensitive with a detection limit of 0.33 ng/mL. A good linear response was observed over a range of 10-2000 ng/mL in rat plasma. The inter- and intra-day precision ranged from 2.97% to 7.52% and accuracy from 93.70% to 101.60%. This validated method was applied successfully to a pharmacokinetic study in rat plasma after intravenous administration of puerarin. The main pharmacokinetic parameters were as follows: AUC(0→t) 45.37±13.19 (mgh/L), AUC(0→∞) 47.03±14.78 (mgh/L), MRT 1.03±0.46 (h), T(1/2) 1.31±0.31 (h), V(ss) 0.09±0.02 (L), V(z) 0.17±0.04 (L), Cl 0.10±0.04 (L/h).

Luo CF ，Yuan M ，Chen MS ，Liu SM ，Huang BY ，Liu XW ，Zhu L ... -  《-》

Metabolites of puerarin identified by liquid chromatography tandem mass spectrometry: similar metabolic profiles in liver and intestine of rats.

Puerarin is a major active ingredient of Pueraria radix. Puerarin may exert its medicinal functions in part via its metabolites. In this study, we identified these metabolites to better understand and elucidate puerarin's metabolic pathway. Puerarin was intravenously administered to rats and then metabolites in plasma samples were identified by rapid resolution liquid chromatography electrospray ionization-collision induced dissociation tandem mass spectrometry (RRLC-ESI-CID-MS/MS). Chromatography was conducted on a Zorbax SB C18 column (2.1x100 mm, 1.8 microm) at 30 degrees C, with a gradient mobile phase consisting of 0.05% formic acid and acetonitrile, a flow rate of 0.2 mL min(-1), and a total run time of 14 min. MS/MS acquisition parameters were as follows: positive ionization mode, dry gas: nitrogen, 10 L min(-1), dry temperature: 350 degrees C, nebulizer: 40 psi, capillary: -3500 V, scan range: 250-800. The autoMS, manual, or multiple reaction monitoring mode was selected as required. Two glucuronidated metabolites of puerarin (M1 and M2) were detected. M1 and M2 are presumed to be puerarin-7-O-glucuronide and puerarin-4'-O-glucuronide, respectively, and M2 likely is suspected to be the major metabolite because it represented the predominate peak. Kinetic studies of metabolites demonstrated that M1 and M2 were detected in rat plasma at 5 min after intravenous administration of puerarin, the levels of M1 and M2 then reached their peaks at 10-15 and 15-30 min, respectively. The metabolic profiles were similar in rat liver and intestine investigated by in situ liver and intestine perfusion, indicating that no metabolic regioselectivity of puerarin occurs in the two organs.

Luo CF ，Yuan M ，Chen MS ，Liu SM ，Ji H ... -  《-》