Development and validation of a rapid LC–MS/MS method for simultaneous determination of netupitant and palonosetron in human plasma and its application to a pharmacokinetic study

• Firstly develope a rapid LC–MS/MS method for simultaneous determination of netupitant and palonosetron in human plasma.
• Validate the LC–MS/MS method.
• Apply the validated method to a pharmacokinetic study.

A simple liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was firstly developed and validated for simultaneous determination of netupitant and palonosetron in human plasma using ibrutinib as the internal standard (IS). Following liquid–liquid extraction, the compounds were eluted isocratically on a Phenomenex C18 column (50mm × 2.0 mm, 3 μm) with the mobile phase consisting of acetonitrile and 10 mM ammonium acetate buffer (pH 9.0) (89:11, v/v) at the flow rate of 0.3 mL/min. The monitored ion transitions were m/z 579.5 → 522.4 for netupitant, m/z 297.3 → 110.2 for palonosetron and m/z 441.2 → 138.1 for IS. Chromatographic run time was 2.5 min per injection, which made it possible to analyze more than 300 of samples per day. The assay exhibited a linear dynamic range of 5–1000 ng/mL for netupitant and 0.02–10 ng/mL for palonosetron in plasma. The values for both within- and between-day precision and accuracy were well within the generally accepted criteria for analytical methods (<15%). Selectivity, linearity, lower limit of quantification (LLOQ), accuracy, precision, stability, matrix effect, recovery and carry-over effect were evaluated for all analytes. The method is simple, rapid, and has been applied successfully to a pharmacokinetic study of netupitant and palonosetron in healthy volunteers.