Dabigatran etexilate mesylate (DABE), a prodrug, quickly changes into dabigatran (DAB) after its oral administration. Accordingly, detecting DABE in plasma is practically unmanageable. An ultraperformance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) technique was developed and validated to compute free DAB in participants. For the first time, the central composite design, a type of response surface methodology, was applied for optimizing variables affecting the cleavage of glucuronide bond. In addition, the pharmacokinetic parameters of generic medication (okanadab) were determined, and the obtained outcomes were compared with those of the branded drug (pradaxa). The sample preparation was done using methanol as a protein precipitant and the separation was achieved using an ACQUITY UPLC BEH C18 column (2.1 × 50 mm, 1.7 μm). The elution was isocratically conducted using 10 mM ammonium formate:methanol (72:28, v/v) as a mobile phase and the flow rate was 0.25 mL/min. Multiple reaction monitoring and positive electrospray ionization were used. The determination was performed within 1 min, and the calibration growth curve was established over a range of 1.19–475 ng/mL using DAB‐d3 as a tagged internal standard. Bioequivalence research was validated following the US Food and Drug Administration (US FDA) guidelines for bioanalytical procedures and acceptable outcomes were achieved. The outcomes for okanadab and pradaxa did not differ significantly.

This research developed and validated a highly sensitive and selective UPLC–MS/MS approach using a triple quadrupole mass spectrometer for quantifying favipiravir. Moreover, we introduced a study evaluating bioequivalence using two drugs, Favibrivix and Avigan, containing favipiravir. Lean Six Sigma verified the capacity and performance of the process. Protein precipitation extraction was utilized to extract favipiravir from the collected human matrices. We used an Acquity UPLCr BEH HILIC column and valproic acid as an internal standard. Furthermore, we conducted the procedure using an isocratic elution comprising acetonitrile and 0.005% ammonia in water (75:25, v/v), a flow rate of 0.25 ml/min, a temperature controlled at 10°C and an injection volume of 1.0 μl. Our UPLC–MS/MS process has a broad range (50–10,000 ng/ml) with a determination coefficient of 0.9980. We validated the method in line with the US Food and Drug Administration. The findings revealed that the test, Favibrivix 200 mg/tablet, and the reference, Avigan® 200 mg/tablet, were statistically bioequivalent in healthy Egyptian participants.