Development of a simple HPLC–UV method for the determination of the hepatitis C virus inhibitor simeprevir in human plasma

A simple high-performance liquid chromatography method for the determination of the hepatitis C virus protease inhibitor simeprevir in human plasma was developed and validated. The method involved a rapid and simple solid-phase extraction of simeprevir using Oasis HLB 1cc cartridges, isocratic reversed-phase liquid chromatography on an XTerra RP18 (150 mm × 4.6 mm, 3.5 μm) column, and ultraviolet detection at 225 nm. The mobile phase consisted of phosphate buffer (pH 6, 52.5 mM) and acetonitrile (30:70, v/v). This assay proved to be sensitive (lower limit of quantification of 0.05 μg/mL), linear (correlation coefficients ≥0.99), specific (no interference with various potentially co-administrated drugs), reproducible (both intra-day and inter-day coefficients of variation ≤8.3%), and accurate (deviations ranged from −8.0 to 1.2% and from −3.3 to 6.0% for intra-day and inter-day analysis, respectively). The method was applied to therapeutic monitoring of patients undergoing simeprevir treatment for hepatitis C and proved to be robust and reliable. Thus, this method provides a simple, sensitive, precise and reproducible assay for dosing simeprevir that can be readily adaptable to routine use by clinical laboratories with standard equipment.