title: Simultaneous determination of cortisol, dexamethasone, methylprednisolone, prednisone, prednisolone, mycophenolic acid and mycophenolic acid glucuronide in human plasma utilizing liquid chromatography-tandem mass spectrometry.
abstract: Chronic combination immunosuppressive regimens are commonly prescribed to renal transplant recipients. To develop an assay method for pharmacokinetic studies and therapeutic drug monitoring of multiple immunosuppressives, a liquid chromatography-tandem mass spectrometry (LC/MS/MS) approach for the simultaneous analysis of several glucocorticoids, mycophenolic acid (MPA) and mycophenolic acid glucuronide (MPAG) was investigated. The resultant method utilized a gradient reverse phase separation over a Symmetry C18 column using an ammonium acetate-methanol mobile phase at pH 3.5. The analytes were detected by coupling the chromatography system via electrospray to a triple quadrupole mass spectrometer. Multiple-reaction monitoring in the negative mode ion (MH-/product) was employed selecting MPA at 319.1/190.9, MPAG at 495.1/191.0, dexamethasone at 391.0/361.0, hydrocortisone at 361.1/331.1, methylprednisolone at 373.1/343.1, prednisone at 357.1/327.2, and prednisolone at 359.1/329.1. The calibration curve concentrations ranged from 3.60 ng/mL to 50 microg/mL with the lowest limit of quantitation for corticosteroids being 3.60-7.20 ng/mL and 0.656-6.75 microg/mL for MPA and MPAG, respectively. The relative standard deviation for quality control intraday variation and interday variation was between 0.76% and 9.57% for all analytes. This assay offers a versatile, unique method for multi-analyte immunosuppressive determinations during combination immunosuppression.
authors.affiliation: School of Pharmacy & Pharmaceutical Sciences, University at Buffalo, Buffalo, NY14260-1200, United States.
authors.forename: Robin
authors.initials: R
authors.lastname: Difrancesco
authors.forename: Valerie
authors.initials: V
authors.lastname: Frerichs
authors.forename: Julie
authors.initials: J
authors.lastname: Donnelly
authors.forename: Colleen
authors.initials: C
authors.lastname: Hagler
authors.forename: Jill
authors.initials: J
authors.lastname: Hochreiter
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Tornatore
mesh_terms: D000893:Anti-Inflammatory Agents / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D003907:Dexamethasone / Q000097:blood; D005938:Glucocorticoids / Q000097:blood*; D020719:Glucuronides / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007166:Immunosuppressive Agents / Q000097:blood*; D008775:Methylprednisolone / Q000097:blood; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000097:blood*; D011239:Prednisolone / Q000097:blood; D011241:Prednisone / Q000097:blood; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D020719:Glucuronides; D007166:Immunosuppressive Agents; C113145:mycophenolic acid glucuronide; D003907:Dexamethasone; D011239:Prednisolone; D009173:Mycophenolic Acid; D011241:Prednisone; D006854:Hydrocortisone; D008775:Methylprednisolone