Analytical Method Development for the Estimation of Molnupiravir: A Review

Molnupiravir, also known as Lagevrio, is a small-molecule antiviral prodrug of β-D-N4-hydroxycytidine (NHC) that is taken orally and was created to treat mild-to-moderate COVID-19 in adults who are at risk of developing the illness. Numerous research organizations throughout the world have independently developed and validated a wide range of analytical procedures as a result of this regulatory and analytical gap. These reported methods, which include chromatographic techniques Chromatographic techniques (RP-HPLC, HPTLC, UPLC, LC-MS/MS, and UPLC-MS/MS), spectrometric techniques (direct UV and derivatized/extractive visible spectrophotometry), and electroanalytical techniques (differential pulse voltammetry), are systematically compiled, categorized, and critically compared in this review with regard to important validation parameters such as linearity, sensitivity (LOD/LOQ), accuracy, precision, and stability-indicating capability, as well as emerging green analytical chemistry metrics. While LC-MS/MS and UPLC-MS/MS methods offered better sensitivity appropriate for bioanalytical and pharmacokinetic applications, RP-HPLC methods were found to offer a suitable mix of sensitivity and practicality for routine quality control. Differential pulse voltammetry brought a sensitive, low-cost electrochemical option with a wide linearity range, while spectrophotometric techniques, especially oxidation-complexation procedures, provided straightforward and affordable alternatives with reasonably low detection limits. Overall, this review emphasizes the variety and technical value of current molnupiravir analytical techniques while highlighting the ongoing need for a pharmacopeial method that is validated, standardized, and environmentally sustainable in order to support regulatory compliance and consistent quality control for this clinically important antiviral drug.