RESUMO
Objective: The present research work aims to develop and validate a selective and highly sensitive method for the determination of apixaban in human plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methods: 200 µl of sodium heparin plasma samples were acidified and clean-up was performed by using solid-phase extraction (SPE). Apixaban 13C D3 was used as an internal standard (deuterated) to lower the relative matrix effects and a single step SPE was employed for sample clean up. 10 µl of SPE eluent was loaded onto Hypersil Beta Basic C18, 100×4.6 mm, 5 µ column for highly selective chromatographic separation using an isocratic mobile phase. 2 mmol ammonium acetate in water and acetonitrile were delivered by using a quaternary low-pressure gradient pump without premixing at a minimum flow rate of 0.50 ml/min. Results: LC-MS/MS method was successfully developed and validated to demonstrate the lowest detection limit of 0.05 ng/ml and a linear dynamic range from 1-250 ng/ml with r2>0.99. Method development and validation results proved that the method is selective and highly sensitive for the determination of apixaban in human plasma using LC-MS/MS. Conclusion: Current method can be applied for both therapeutic drug monitoring (TDM) and pharmacokinetic (PK) study analysis.