Measurement of free drug and clinical end-point by high-performance liquid chromatography-mass spectrometry Applications and implications for pharmacokineti and pharmacodynamica studies

摘要

Free drug measurement and pharmacodymanic markers provide the opportunity ofr a better understanding of drug efficacy and toxicity.High-performance liquid chromatography (HPLC)-mass spectrometry (MS)is a powerful analytical technique that could facilitate the measurement of free drug and these markers.Currently,there are very few published methods for the determination of free drug concentrations by HPLC-MS.The development of atmospheric pressure ionisation sources,together with on-line microdialysis or on-line equilibrium dialysis and column switching techniques have reduced sample run times and increased assay efficiency.the availability of such methods will aid in drug development and the clinical use of certain drugs,inclluding anti-convulsants,anti-arrhythmics,immunosuppressants,local anaesthetics,anti-fungals and protease inhibitors.The history of free drug measurement and an overview of the current HPLC-MS applications fro these drugs are discussed.Immunosuppressant drugs are used as an example for the application of HPLC-MS in the measurement of drug pharmacodynamics.Potential biomarkers of immunosuppression that could be measured by HPLC-MS include purine nucleosideucleotides,drug-protein complexes and phosphorylated peptides.At the proteomic level,two-dimensional gel electrophoressi combined with matrix-assisted alser desorption/ionisation time-of-flight (TOF0 MS is a powerful tool for identifying proteins involved in the response to inflammatory mediators.