Validation of an LC-ESI-MS/MS method for the quantitation of phosphodiesterase-5 inhibitors and their main metabolites in rat serum and brain tissue samples

J Pharm Biomed Anal. 2012 Nov:70:529-33. doi: 10.1016/j.jpba.2012.04.030. Epub 2012 May 10.

Abstract

This work proposes a liquid chromatography-electrospray ionization ion trap mass spectrometry (LC-ESI-ITMS) method, for the quantification of sildenafil (SDF), tadalafil (TDF) and vardenafil (VDF) and their metabolites N-desmethylSDF, O-desethylSDF and N-desethylVDF, preceded by a sample preparation step based on protein and phospholipid elimination. A C8 column (150 mm × 4.6 mm, 5 μm) with ammonium formate (20mM) and acetonitrile as the mobile phase components have been used. This method has been validated, obtaining limits of quantification ranged from 1 to 2.5 ng/mL and 2 to 5 ng/g in serum and brain tissue respectively, while limits of detection ranged from 0.3 to 0.9 ng/mL in serum and 0.6 to 1.9 ng/g in brain tissue. Assay recoveries for low level QC samples were higher than 83% and the matrix effect ranged between 91% and 108% in serum and between 98% and 107% in brain tissue. The method has been applied to the quantification of these compounds in the serum and brain tissue of rats treated intraperitoneally with 10 mg/kg of SDF, TDF or VDF.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Acetonitriles / chemistry
  • Animals
  • Biotransformation
  • Brain / metabolism*
  • Calibration
  • Carbolines / blood
  • Carbolines / pharmacokinetics
  • Chromatography, Liquid* / standards
  • Dealkylation
  • Formates / chemistry
  • Imidazoles / blood
  • Imidazoles / pharmacokinetics
  • Injections, Intraperitoneal
  • Limit of Detection
  • Male
  • Phosphodiesterase 5 Inhibitors / administration & dosage
  • Phosphodiesterase 5 Inhibitors / blood*
  • Phosphodiesterase 5 Inhibitors / pharmacokinetics*
  • Piperazines / blood
  • Piperazines / pharmacokinetics
  • Purines / blood
  • Purines / pharmacokinetics
  • Rats
  • Rats, Sprague-Dawley
  • Reference Standards
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Sildenafil Citrate
  • Spectrometry, Mass, Electrospray Ionization* / standards
  • Sulfones / blood
  • Sulfones / pharmacokinetics
  • Tadalafil
  • Tandem Mass Spectrometry* / standards
  • Triazines / blood
  • Triazines / pharmacokinetics
  • Vardenafil Dihydrochloride

Substances

  • Acetonitriles
  • Carbolines
  • Formates
  • Imidazoles
  • Phosphodiesterase 5 Inhibitors
  • Piperazines
  • Purines
  • Sulfones
  • Triazines
  • formic acid
  • Vardenafil Dihydrochloride
  • Tadalafil
  • Sildenafil Citrate
  • acetonitrile