A Review on Development and Validation of RP-HPLC Method for Estimation of Molnupiravir in Bulk and Dosage Form

Molnupiravir, an orally active isopropylester prodrug of β-D-N⁴-hydroxycytidine (NHC), represents a significant therapeutic advancement for managing mild-to-moderate COVID-19. Precise analytical quantification of molnupiravir in bulk drug and pharmaceutical dosage forms is essential for ensuring product quality, regulatory compliance, and patient safety. Reverse-phase high-performance liquid chromatography (RP-HPLC) has emerged as the preferred analytical technique due to its exceptional resolution, sensitivity, reproducibility, and universal regulatory acceptance. This comprehensive review examines fundamental principles of RP-HPLC, including stationary phase optimization (predominantly C18 columns), mobile phase composition strategies, pH control mechanisms, and isocratic elution suitability in molnupiravir analysis. Critical sample preparation methodologies for bulk drug substance and formulated pharmaceutical products are systematically presented. Method validation requirements aligned with ICH Q2(R2) and USP guidelines encompass specificity through forced degradation studies, linearity across analytical ranges (r² ≥ 0.999), accuracy with mean recovery 99–101% (%RSD < 2%), and robustness with excellent system suitability. Applications for routine quality control and stability assessments are highlighted. Overall, RP-HPLC provides a robust, reliable, and cost-effective analytical platform for effective evaluation of molnupiravir throughout pharmaceutical development and commercial manufacture.