Development and validation of a UHPLC–MS/MS assay for elvitegravir measurement in human plasma and cerebrospinal fluid

The quantification of the integrase inhibitor, elvitegravir, in cerebrospinal fluid will significantly help understand its effects in the central nervous system. An ultra high performance liquid chromatography with tandem mass spectrometry method was successfully validated to measure elvitegravir in human plasma and cerebrospinal fluid. The biological fluid was diluted with methanol and the clear supernatant was injected into the chromatography system. The calibration was linear from 10.0 to 5000 ng/mL in plasma and 1.00 to 25 ng/mL in cerebrospinal fluid. Inter-day and intra-day variability ranged from 1.46 to 8.34% and accuracy ranged from –8.36 to 7.50% for quality controls in either plasma or cerebrospinal fluid analysis. The method was then applied to the measurement of elvitegravir concentrations in plasma and cerebrospinal fluid samples from an HIV+ patient enrolled in a clinical study who switched medications of Stribild® to Genvoya®. The validated method is suitable for the quantification of elvitegravir in plasma and cerebrospinal fluid.