title: [LC-MS/MS determination of budesonide in dog plasma].
abstract: A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of budesonide in dog plasma. Budesonide and the internal standard triamcinolone acetonide were separated from plasma by alkalinized liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on a Capcell Pak C18 MG column with the mobile phase consisted of acetonitrile -5 mmol x L(-1) ammonium acetate (60:40, v/v) at a flow-rate of 0.50 mL x min(-1). A tandem mass spectrometer equipped with electrospray ionization source was used as detector and operated in the negative ion mode. Quantification was performed using multiple reaction monitoring (MRM) of the transitions m/z 489 --> m/z 357 and m/z 493 --> m/z 413 for budesonide and the internal standard, respectively. The linear calibration curves were obtained in the concentration range of 25.0-2000 pg x mL(-1). The lower limit of quantification was 25.0 pg x mL(-1). The intra- and inter-day relative standard deviation over the entire concentration range was less than 15%. The accuracy was in the range of -8.1% to -1.7% in terms of relative error. The method was applied to a pharmacokinetic study of budesonide controlled-release capsules in Beagle dogs. Maximal budesonide plasma level was observed after (3.5 +/- 3.3) h and the Cmax was (786 +/- 498) pg x mL(-1) after a single oral administration of 9 mg budesonide capsules, Cmax was increased to (2142 +/- 1515) pg x mL(-1) after multiple oral administration (9 mg x 5 d) of budesonide capsules. This method was selective and rapid, and the sensitivity was sufficient for the purpose of the pharmacokinetic study of budesonide controlled-release formulation.
authors: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
authors: Pan
authors: P
authors: Deng
authors: Xiao-Tao
authors: XT
authors: Duan
authors: Xiao-Yan
authors: XY
authors: Chen
authors: San-Ming
authors: SM
authors: Li
authors: Da-Fang
authors: DF
authors: Zhong
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000097:blood / Q000493:pharmacokinetics; D019540:Area Under Curve; D019819:Budesonide / Q000097:blood* / Q000493:pharmacokinetics*; D002853:Chromatography, Liquid / Q000379:methods*; D003692:Delayed-Action Preparations; D004285:Dogs; D008297:Male; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000893:Anti-Inflammatory Agents; D003692:Delayed-Action Preparations; D019819:Budesonide