title: Measurement and stability of FTY720 in human whole blood by high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.
abstract: We report here a validated method for the quantification of a new immunosuppressant drug FTY720, using HPLC-tandem mass spectrometry. Whole blood samples (500 microl) were subjected to liquid-liquid extraction, in the presence of an internal standard (Y-32919). Mass spectrometric detection was by selected reaction monitoring with an atmospheric pressure chemical ionization source in positive ionization mode (FTY720: m/z 308.3-->255.3). The assay was linear from 0.2 to 25 microg/l (r(2)>0.997, n=5). The inter- and intra-day analytical recovery and imprecision for quality control samples (0.5, 7 and 15 microg/l) were 95.8-103.2 and <5.5%, respectively. At the lower limit of quantification (0.2 microg/l) the inter- and intra-day analytical recovery was 99.0-102.8% with imprecision of <7.6% (n=5). The assay had a mean relative recovery of 100.5+/-5.8% (n=15). Extracted samples were stable for 16 h. FTY720 quality control samples were stable at room temperature for 16 h, at 4 degrees C for at least 8 days and when taken through at least three freeze-thaw cycles. In conclusion, the method described displays analytical performance characteristics that are suitable for pharmacokinetic studies in humans.
authors.affiliation: Australian Bioanalytical Services Pty Ltd., Princess Alexandra Hospital, Brisbane, Queensland 4102, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Salm
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Warnholtz
authors.forename: Stephen V
authors.initials: SV
authors.lastname: Lynch
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Taylor
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D000068876:Fingolimod Hydrochloride; D006801:Humans; D011409:Propylene Glycols / Q000097:blood*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000097:blood; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D011409:Propylene Glycols; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine