The development and application of a novel LC–MS/MS method for the measurement of Dolutegravir, Elvitegravir and Cobicistat in human plasma

• Measurement of Dolutegravir, Elvitegravir & Cobicistat in a single assay to 10 ng/mL.
• The effect of anticoagulants (lithium heparin versus EDTA) on dolutegravir analysis.
• The method is in use in ongoing clinical trials.

Dolutegravir and Elvitegravir belongs to a class of integrase inhibitors which has recently been approved by the FDA for the treatment of HIV-infection. Elvitegravir and its co-administered booster drug, Cobicistat, has shown the potential to be a candidate for a one pill once a day regimen and is currently a component of many clinical trials. A sensitive LC–MS/MS method has been developed and validated for the simultaneous determination of these three drugs in human plasma. A liquid- liquid extraction was used as a sample preparation technique using 100 μL of plasma. The method was validated from 10 to 4000 ng/mL for Dolutegravir, Elvitegravir and Cobicistat. Chromatography was performed on XBridge C18 2.1 mm × 50 mm column, using an 80:20 methanol/water mobile phase containing 0.1% formic acid on a gradient program. This method was successfully applied for ongoing clinical trials.