Determination of simeprevir: A novel, hepatitis C protease inhibitor in human plasma by high-performance liquid chromatography–tandem mass spectrometry

Simeprevir (also known as TMC435 or TMC435350) is a novel hepatitis C protease inhibitor. A validated high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the sensitive and selective quantification of simeprevir in human EDTA plasma is described. During assay development, special attention was given to light instability of the drug in plasma and blood. The method consisted of precipitation of plasma proteins with acetonitrile after which the supernatant was analyzed using electrospray LC–MS/MS. The linearity was confirmed in the concentration range from 2.00 to 2000 ng/mL, with 50-fold dilution extending to 100,000 ng/mL. The precision of this assay, expressed as CV, ranged between 4.4% and 8.5% over the entire concentration range with assay accuracy between −0.3% and 8.5%. The method was applied successfully in many clinical studies to document the pharmacokinetics of simeprevir in plasma from healthy volunteers and patients.