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.
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.
Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain.
Nora
N
Unceta
Leire
L
Echeazarra
Mario
M
Montaña
Joan
J
Sallés
Alberto
A
Gómez-Caballero
M Aránzazu
MA
Goicolea
Ramón J
RJ
Barrio
D000097:Acetonitriles / Q000737:chemistry; D000818:Animals; D001711:Biotransformation; D001921:Brain / Q000378:metabolism*; D002138:Calibration; D002243:Carbolines / Q000097:blood / Q000493:pharmacokinetics; D002853:Chromatography, Liquid / Q000592:standards; D003640:Dealkylation; D005561:Formates / Q000737:chemistry; D007093:Imidazoles / Q000097:blood / Q000493:pharmacokinetics; D007274:Injections, Intraperitoneal; D057230:Limit of Detection; D008297:Male; D058986:Phosphodiesterase 5 Inhibitors / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*; D010879:Piperazines / Q000097:blood / Q000493:pharmacokinetics; D011687:Purines / Q000097:blood / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000068677:Sildenafil Citrate; D021241:Spectrometry, Mass, Electrospray Ionization / Q000592:standards; D013450:Sulfones / Q000097:blood / Q000493:pharmacokinetics; D000068581:Tadalafil; D053719:Tandem Mass Spectrometry / Q000592:standards; D014227:Triazines / Q000097:blood / Q000493:pharmacokinetics; D000069058:Vardenafil Dihydrochloride
D000097:Acetonitriles; D002243:Carbolines; D005561:Formates; D007093:Imidazoles; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; C030544:formic acid; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate; C032159:acetonitrile