Highly sensitive determination of HCV protease inhibitors boceprevir (SCH 503034) and telaprevir (VX 950) in human plasma by LC–MS/MS

The purpose of this study was to develop a specific and highly sensitive method based on fast sample preparation and LC–MS/MS techniques for the determination of the HCV protease inhibitors boceprevir (SCH 503034) and telaprevir (VX 950) in human plasma. Boceprevir, telaprevir and the internal standard dimethylcelecoxib were separated on a Luna C18 column (150 mm × 2.0 mm I.D., 5 μm particle size) under gradient conditions with a mobile phase A consisting of water/ammonia solution (25%) (100:0.05, v/v) and mobile phase B consisting of methanol/ammonia solution (25%) (100:0.05, v/v) and a chromatographic run time of 11 min. The lower limit of quantification (LLOQ) of boceprevir and telaprevir is 0.25 pg on column (25 pg/mL at injection volume of 10 μL). The method possesses a reliable calibration range of 0.025–2.5 ng/mL. Due to the dilution of real life plasma samples by a factor of 10 during the precipitation process the method is suitable to quantify boceprevir and telaprevir at a concentration range of 0.25–25 ng/mL. Variations in accuracy and intraday and interday precision (n = 6 for each concentration) were <15% over the whole range of calibration. For the first time, a rapid, specific, sensitive, accurate and reproducible LC–MS/MS method in human plasma has been developed and validated. It is suitable to quantify the concentrations of the hepatitis C virus protease inhibitors boceprevir and telaprevir in human plasma.