RELIABLE QUANTIFICATION OF NIRMATRELVIR USING A NOVEL UPLC TECHNIQUE

Abstract

Nirmatrelvir (NMT) is a potent oral antiviral agent approved for the treatment of COVID-19 owing to its inhibitory activity against the SARS-CoV-2 main protease (3CLpro). Considering its therapeutic importance and the limitations of previously reported analytical techniques, the present study aimed to develop and validate a rapid, sensitive, and robust Ultra-Performance Liquid Chromatography method for the quantitative estimation of Nirmatrelvir in bulk drug and pharmaceutical dosage forms. The Phenomenex C18 column with a dimension of (50 × 2.1 mm, 2.1 µm) was used for chromatographic separation using an isocratic mobile phase consisting of acetonitrile and 0.1% triethylamine, which was pH-adjusted to 2.5 with orthophosphoric acid in a 30:70 v/v ratio. The flow rate was maintained at 0.5 mL/min with UV detection at 229 nm, yielding a sharp and symmetric peak with a short retention time of 0.693 min. The developed method was validated according to ICH Q2 (R1) guidelines. Specificity studies confirmed the absence of interference from excipients. The method exhibited excellent linearity over the concentration range of 25–150 µg/mL with a correlation coefficient (R²) ≥ 0.999. Precision studies demonstrated %RSD values below 2%, indicating good repeatability and intermediate precision. Accuracy assessed by recovery studies at 80%, 100%, and 120% levels showed recoveries within 98–102%. The method also demonstrated adequate sensitivity with low limits of detection and quantification. Robustness testing revealed that minor deliberate variations in chromatographic analysis conditionsdid not significantly affect analytical performance. Overall, the validated UPLC method is simple, rapid, and cost-effective, making it suitable for routine quality control, formulation development.