Simultaneous Determination of Nirmatrelvir and Ritonavir in Human Plasma by HPLC-MS/MS

Introduction. SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus 2) is expected to remain a persistent global threat. Therefore, development of disease 2019 (COVID-19) drugs the most urgent issue. Nirmatrelvir and ritonavir combination an oral antiviral drug with activity against SARS-CoV-2. highly efficacious in reducing risk COVID-19. The study describes validation high-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS) method for simultaneous determination nirmatrelvir human blood plasma. could be applied pharmacokinetic ritonavir. Aim. aim this develop validate HPLC-MS/MS bioanalytical Materials methods. plasma by HPLC-MS/MS. samples were processed acetonitrile protein precipitation. Internal standard: promethazine. Mobile phase: 0.1% formic acid solution water (Eluent A), B). Column: Phenomenex Luna C18 50 × 2.0 mm, 5 μm. Analytical range: 50.00–10000.00 ng/mL nirmatrelvir, 5.00–1000.00 Ionization source ionization: electrospray ionization, positive. Detection conditions: 499.90 → 110.10 m/z, 319.20 m/z (nirmatrelvir), 720.90 426.00 296.20 268.10 197.10 139.90 (ritonavir), 285.15 198.05 (promethazine). Results discussion. This was validated selectivity, matrix effect, calibration curve, accuracy, precision, spike recovery, lower limit quantification, carry-over effect stability. Conclusion. quantitative developed validated. analytical range investigate pharmacokinetics