title: Challenges of developing a bioanalytical method for a macrolide immunosuppressant compound by LC-MS/MS.
abstract: The quantification of tacrolimus in human whole blood was developed by LC-MS/MS for a range of 50.0 to 50,000.0 pg/ml. Different challenges were faced during method development due to ion-suppression, lack of sensitivity and low recovery. The optimization of the extraction procedure played a crucial role as tacrolimus had to be isolated from red blood cells, to which it is strongly bound. Another particular challenge arose from the freeze-thaw stability where the extracted samples from fresh blood always showed a lower recovery. Finally, matrix effect was observed in some matrices over time, which resulted in a failed long-term stability in whole blood. In order to resolve the matrix effect issue, the sample procedure had to be improved. The final assay showed good recovery, low matrix effect, linearity, blood stability and good precision and accuracy.
authors.affiliation: Algorithme Pharma Inc., Laval, Montreal, Quebec, Canada. mptaillon@algopharm.com
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Taillon
authors.forename: Milton
authors.initials: M
authors.lastname: Furtado
authors.forename: Fabio
authors.initials: F
authors.lastname: Garofolo
mesh_terms: D016477:Artifacts; D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods*; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D004868:Equipment Failure; D005615:Freezing; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood*; D057230:Limit of Detection; D016559:Tacrolimus / Q000097:blood*; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D007166:Immunosuppressive Agents; D016559:Tacrolimus