Quantification of a cytochrome P450 3A4 substrate, buspirone, in human plasma by liquid chromatography-tandem mass spectrometry

J Chromatogr B Analyt Technol Biomed Life Sci. 2006 Dec 5;844(2):235-9. doi: 10.1016/j.jchromb.2006.07.005. Epub 2006 Jul 27.


A sensitive HPLC-tandem mass spectrometry method was developed for determination of buspirone levels in human plasma. After solid phase extraction and reversed phase HPLC separation, detection of buspirone and the internal standard (prazosin) was performed using eletrospray ionization and selected reaction monitoring in the positive ion mode. Linear calibration curves were established over a concentration range of 0.025-2.5 ng/ml when 0.5 ml aliquots of plasma were used. Satisfactory results of within-day precision (RSD of 1.9-7.7%) and accuracy (% difference of 0.5-6.6%) and between-day precision (RSD of 3.7-11.1%) and accuracy (% difference of 2.2-6.8%) were obtained. The assay has been successfully applied to the analysis of buspirone levels in more than 500 human plasma samples collected from a drug interaction study.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Buspirone / blood*
  • Chromatography, High Pressure Liquid / methods*
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme System / metabolism*
  • Humans
  • Reproducibility of Results
  • Substrate Specificity
  • Tandem Mass Spectrometry / methods*


  • Cytochrome P-450 Enzyme System
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human
  • Buspirone