Novel green UPLC method with life cycle assessment for determination of favipiravir and molnupiravir drugs and environmental water samples

A novel green UPLC–SPE analytical method was developed for the simultaneous determination of Favipiravir (FVP) and Molnupiravir (MPV) in pharmaceutical and environmental water samples. The method was designed to address the analytical gap surrounding concurrent antiviral monitoring given their co-administration while minimizing solvent consumption, waste generation, and environmental impact. Water samples preparation employed a solid-phase extraction strategy optimized through systematic evaluation of sorbent type, conditioning, washing, and elution steps. Chromatographic separation was achieved using a mobile phase consisting of 0.01 M potassium dihydrogen phosphate buffer (pH 3.5) and 50% methanol (85:15, v/v), delivered at a flow rate of 0.2 mL/min with a 10 µL injection volume. This method produced sharp, well-resolved peaks with a total run time of less than 5 min. The method exhibited excellent linearity (r² ≥ 0.999), accuracy (98.56–101.19%), precision (RSD ≤ 1.8%), and recoveries of (98.97- 100.74%) across tap water, Nile River water, and pharmaceutical wastewater. Greenness was assessed using the Multi-Color Assessment (MA) platform, yielding a final whiteness score of 85.7%, which indicates a well-balanced integration of environmental, practical, analytical, and innovative attributes and supports the method’s suitability for routine application. The Analytical Eco-Scale score (77) and AGREE pictogram score (0.84) further confirm the strong environmental compatibility of the proposed method. Life cycle assessment (LCA) revealed substantial reductions in energy consumption and waste generation compared with conventional HPLC methods. Overall, the proposed UPLC–SPE approach, integrated with LCA and comprehensive greenness evaluation, represents a pioneering and environmentally informed strategy for antiviral analysis and provides a sustainable platform for future pharmaceutical residue monitoring.