A rapid and sensitive LC/MS/MS assay for quantitative determination of digoxin in rat plasma

J Pharm Biomed Anal. 2003 Aug 21;32(6):1189-97. doi: 10.1016/s0731-7085(03)00050-5.


Digoxin is a cardiac glycoside that is widely used for the treatment of congestive heart failure. To evaluate pharmacokinetics of digoxin in rats, a sensitive LC/MS/MS assay was developed and validated for the determination of digoxin concentration in rat plasma. For detection, a Sciex API3000 LC/MS/MS with atmospheric pressure ionization (API) mass spectrometry turbo ion spray inlet in the positive ion-multiple reaction monitoring mode was used to monitor precursor-->product ions of m/z 798.6-->651.6 for digoxin and m/z 577.6-->433.3 for oleandrin, the internal standard (IS). The standard curve was linear (r(2)>or=0.999) over the digoxin concentration range of 0.1-100 ng/ml in plasma for digoxin. The mean predicted concentrations of the quality control samples deviated by <5.8% from the corresponding nominal values; the intra-assay and inter-assay precision of the assay were within 8.6% relative standard deviation. At the lower limit of quantitation (LLQ) of 0.1 ng/ml, the mean deviation of predicted concentrations from the nominal value was within 3.7%. The extraction recoveries of digoxin and internal standard were 82.7+/-3.9 and 105.9+/-2.3%, respectively. The present method was successfully applied to characterization of pharmacokinetic profiles of digoxin in rats after oral administration.

MeSH terms

  • Administration, Oral
  • Animals
  • Cardiotonic Agents / administration & dosage
  • Cardiotonic Agents / blood*
  • Cardiotonic Agents / pharmacokinetics
  • Chromatography, High Pressure Liquid / methods*
  • Digoxin / administration & dosage
  • Digoxin / blood*
  • Digoxin / pharmacokinetics
  • Male
  • Mass Spectrometry / methods*
  • Rats
  • Rats, Sprague-Dawley
  • Reference Standards
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Cardiotonic Agents
  • Digoxin