Quantitation of itraconazole in rat heparinized plasma by liquid chromatography-mass spectrometry.
A liquid chromatographic-mass spectrometric (LC-MS) assay was developed and validated for the determination of itraconazole (ITZ) in rat heparinized plasma using reversed-phase HPLC combined with positive atmospheric pressure ionization (API) mass spectrometry. After protein precipitation of plasma samples (0.1 ml) with acetonitrile containing nefazodone as an internal standard (I.S.), a 50-microl aliquot of the supernatant was mixed with 100 microl of 10 mM ammonium formate (pH 4.0). An aliquot of 25 microl of the mixture was injected onto a BDS Hypersil C18 column (50x2 mm; 3 microm) at a flow-rate of 0.3 ml/min. The mobile phase comprising of 10 mM ammonium formate (pH 4) and acetonitrile (60:40, v/v) was used in an isocratic condition, and ITZ was detected in single ion monitoring (SIM) mode. Standard curves were linear (r2 > or = 0.994) over the concentration range of 4-1000 ng/ml. The mean predicted concentrations of the quality control (QC) samples deviated by less than 10% from the corresponding nominal values; the intra-assay and inter-assay precision of the assay were within 8% relative standard deviation. Both ITZ and I.S. were stable in the injection solvent at room temperature for at least 24 h. The extraction recovery of ITZ was 96%. The validated assay was applied to a pharmacokinetic study of ITZ in rats following administration of a single dose of itraconazole (15 mg/kg).
Department of Metabolism and Pharmacokinetics, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543, USA. ming.yao@bms.com
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Srinivas
D000818:Animals; D000935:Antifungal Agents / Q000097:blood* / Q000493:pharmacokinetics; D001274:Atmospheric Pressure; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017964:Itraconazole / Q000097:blood* / Q000493:pharmacokinetics; D013058:Mass Spectrometry / Q000379:methods*; D010879:Piperazines; D011786:Quality Control; D051381:Rats; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014230:Triazoles / Q000097:blood
D000935:Antifungal Agents; D010879:Piperazines; D014230:Triazoles; D017964:Itraconazole; C051752:nefazodone