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ABSTRACT: A highly selective and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for quantitating dextromethorphan (DXM) and its metabolite dextrophan (DXO) in rat plasma using pirfenidone as an internal standard. Protein precipitation with acetonitrile was employed for the sample preparation. Chromatographic separation was achieved on a SB-C18 column at 25 degrees C, with a gradient elution programme of which acetonitrile-0.1% formic acid in water as mobile phase. The flow rate was 0.4 mL/min. Detection is carried out by multiple reaction monitoring (MRM) on a ion-trap LC-MS/MS system with an electrospray ionization interface. The assay is linear over the range 1-500 ng/mL for DXM and 1-250 ng/mL for DXO, with a lower limit of quantitation of 1 ng/mL for both. Intra- and inter-day precision of the assay were less than 9.80% and the accuracy were in the range 96.35-106.39%. The developed method was successfully applied to analyze the drug in samples of rat plasma for pharmacokinetic study.
Pharmazie 06/2012; 67(6):485-9. · 1.01 Impact Factor
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ABSTRACT: A sensitive and selective liquid chromatograpy-mass spectrometry method for the determination of bupropion and its main metabolite, hydroxubupropion, in rat plasma was developed and validated. After addition of carbamazepine as internal standard (IS) and precipitation of protein with acetonitrile, the plasma samples were analyzed on an Agilent Zorbax SB-C18 (2.1 mm x 50 mm, 3.5 microm) column at 30 degrees C, with acetonitrile-0.1% formic acid as mobile phase at a flow rate of 0.4 mL min(-1). The detection was carried out in the selective ion monitoring mode with a positive electrospray ionization interface. The calibration curve was linear over the 10-2000 ng mL(-1) for bupropion and 5-1000 ng mL(-1) for hydroxybupropion in plasma. RSD of inter-day and intra-day precision was less than 7% for bupropion, 9% for hydroxybupropion. The developed method was successfully applied to pharmacokinetic studies after single intragastric administration of bupropion 15 mg kg(-1) to rats.
Pharmazie 12/2011; 66(12):924-8. · 1.01 Impact Factor
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ABSTRACT: A sensitive and selective liquid chromatography mass spectrometry method for determination of curdione in rabbit plasma was developed. After addition of tramadol as internal standard (IS), protein precipitation by acetonitrile was used for sample preparation. Chromatographic separation was achieved on a Zorbax SB-C₁₈ (2.1 × 50 mm, 3.5 µm) column with acetonitrile-0.1% formic acid as mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive-ion mode; selective ion monitoring was used for quantification using target fragment ions m/z 237 for curdione and m/z 264 for the IS. Calibration plots were linear over the range of 20-4000 ng/mL for curdione in plasma. The lower limit of quantification for curdione was 20 ng/mL. Mean recovery of curdione from plasma was in the range 94.3-98.4%. The RSD of intra-day and inter-day precision were both less than 9%. This method is simple and sensitive enough to be used in pharmacokinetic research for the determination of curdione in rabbit plasma.
Biomedical Chromatography 09/2011; 26(5):655-9. · 1.97 Impact Factor
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ABSTRACT: A sensitive and selective liquid chromatography-tandem mass spectrometry method for the determination of piracetam in rat plasma was developed and validated over the concentration range of 0.1-20 µg/mL. After addition of oxiracetam as internal standard, a simplified protein precipitation with trichloroacetic acid (5%) was employed for the sample preparation. Chromatographic separation was performed by a Zorbax SB-Aq column (150 × 2.1 mm, 3.5 µm). The mobile phase was acetonitrile-1% formic acid in water (10:90 v/v) delivered at a flow rate of 0.3 mL/min. The MS data acquisition was accomplished in multiple reaction monitoring mode with a positive electrospray ionization interface. The lower limit of quantification was 0.1 µg/mL. For inter-day and intra-day tests, the precision (RSD) for the entire validation was less than 9%, and the accuracy was within the 94.6-103.2% range. The developed method was successfully applied to pharmacokinetic studies of piracetam in rats following single oral administration dose of 50 mg/kg.
Biomedical Chromatography 03/2010; 24(10):1108-12. · 1.97 Impact Factor
