Development and Validation of RP-HPLC Method for the simultaneous determination of Nirmatrelvir and Ritonavir in bulk and pharmaceutical formulation

Abstract

In this study, a rapid and sensitive stability indicating reversed phase HPLC method was developed for quantitation of Nirmatrelvir and Ritonavir simultaneously in bulk and tablet formulation. Nirmatrelvir and ritonavir were separated on a Thermo C18 column with mobile phase containing 0.01M potassium dihydrogen phosphate buffer and acetonitrile (45:55, v/v). The flow rate was 1 mL/min and detection wavelength was 272 nm. Method linearity was established over a range of 75–225 μg/mL for nirmatrelvir and 50–150 μg/mL for ritonavir. Limit of quantification was 0.694μg/mL for nirmatrelvir and 0.820μg/mL for ritonavir. The recovery (%) was 99.96 to 100.45 (Nirmatrelvir) and 100.25 to 101.35 (Ritonavir). The method precisions were 0.11% (Nirmatrelvir) and 0.33% (Ritonavir). Method was suitable to assay nirmatrelvir and ritonavir in tablet formulation (Paxlovid). Stress degradation studies have shown that this method can be implemented to assay nirmatrelvir and ritonavir in the presence of its degradants.