The Clinical Pharmacokinetics Research Laboratory is specialized in the areas of effect of disease states on drug disposition, pharmacokinetics and pharmacodynamics (PK/PD) modeling, and therapeutic drug monitoring (TDM). Located at the Kingston Campus of the University of Rhode Island, this laboratory is equipped with High Performance Liquid Chromatography (HPLC-UV, Hitachi) and ABI 3200 LC-Tandem Mass Spectrometry (LC-MS/MS, AB Sciex), a Xevo™ TQ MS (LC-MS/MS Waters), and a range of other instruments through RI-INBRE centralized core facility. We have established and validated different analytical methods for determination of immunosuppressive agents (i.e. cyclosporine, tacrolimus, sirolimus and mycophenolic acid) and other medications (listed below). In addition, we specialize in the measurement of free (unbound) drug concentration, either in plasma or oral fluids (saliva), and have established methods for determination of contrast media agents, iohexol or iodixanol, useful for accurate estimation of Glomerular Filtration Rate (GFR).
Concentration of total drug and metabolites in biological fluids for in vitro metabolism studies
Acetaminophen concentration for determination of gastric emptying time
" Acetaminophen glucuronide, sulfate and glutathione metabolites (under development)
" Atorvastatin and metabolites concentrations [atorvastatin (ATV) lactone, o-hydroxy ATV, o-hydroxy ATV lactone, p-hydroxy ATV, p-hydroxy ATV lactone] (LC-MS/MS)
" AZT (3'-azido-3'-deoxythymidine) glucuronidation as probe for UGT2B7 activity (LC-MS/MS)
" Chlorzoxazone hydroxylation as probe for P450 2E1 activity (LC-MS/MS)
" Cortisol metabolite (6 beta hydroxy cortisol) and free cortisol concentration in urine (under development)
" Cyclosporine; total concentration (LC-MS/MS)
" Estradiol-glucuronidation as probe for UGT1A1 activity (HPLC-UV)
" Iodixanol concentration for determination of GFR (HPLC-UV)
" Iohexol concentration for determination GFR (HPLC-UV)
" Midazolam, 1'-OH and 4-OH midazolam determination as probe for P450 3A4/5 activity (LC-MS/MS)
" Mycophenolic acid (MPA) metabolites; concentration of MPAG and Acyl MPAG (HPLC-UV)
" Oseltimivir and oseltimivir carboxylate (LC-MS/MS)
" Prednisolone, prednisone and cortisol and cortisone concentrations (LC-MS/MS)
" Propofol glucuronidation as probe for UGT1A9 activity (HPLC-UV)
" Tacrolimus; total concentration (LC-MS/MS)
" Thyroid hormones, T3 and T4 (LC-MS/MS and ICP-MS)
Unbound (free) concentration of drugs
" Cyclosporine; unbound concentration (equilibrium dialysis using [3H] cyclosporine as tracer)
" Mycophenolic acid, unbound concentration (ultrafiltration followed by LC-MS/MS)
" Prednisolone and cortisol; unbound concentration (ultrafiltration followed direct injection into LC-MS/MS)
" Tacrolimus; unbound concentration (equilibrium dialysis using [3H] tacrolimus as tracer)
Concentration of drugs in saliva
" Cyclosporine; saliva concentration (LC-MS/MS)
" Mycophenolic acid, saliva concentration (LC-MS/MS)
" Tacrolimus levels in saliva (LC-MS/MS)
Pharmacodynamic assays for immunosuppressive agents
" Measurement of inosine 5'-monophosphate dehydrogenase (IMPDH) catalytic activity in peripheral blood mononuclear cells (a PD marker for mycophenolic acid activity; enzymatic reaction followed by HPLC-UV)
" Measurement of intracellular cytokines (IL-2, TNF-alpha, IFN-gamma) expression in mitogen stimulated CD3+ cells (intracellular immunostaining of whole blood followed by flow cytometer)
" B-lymphocyte (CD19+) phenotypic markers (CD54, CD86 and CD95) expression on mitogen stimulated peripheral blood mononuclear cells (immunostaining followed by flow cytometer)
" ImmuKnow test (Cylex Inc): this test detects cell-mediated immunity by measuring the concentration of ATP from CD4+ cells following stimulation.
In vitro characterization of Cytochrome P450 activity in human liver microsomes.
Pharmacokinetics and drug-drug interaction studies in rat.
Isolation and fractionation of lipoproteins from plasma to access plasma distribution of drugs among lipoprotein fractions.
Protein binding studies of new drugs and binding of drugs to different blood cells (i.e. red blood cells and lymphocytes).
Transwell assay using MDCK cell lines transfected with human MDR1 (P-glycoprotein) or MRP2 genes. This assay is employed to characterize drug-drug interaction at transporter level.
Last Updated: Feb 14th, 2013