Recent analytical methodologies for the determination of anti-covid-19 drug therapies in various matrices: a critical review

Since the discovery of the first case infected with severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) in Wuhan, China in December 2019, it has turned into a global pandemic. According to the World Health Organization (WHO) statistics, about 603.7 million confirmed coronavirus cases and 6.4 million deaths have been reported. Remdesivir (RMD) was the first U.S. Food and Drug Administration (FDA) approved antiviral drug for the treatment of coronavirus in pediatrics and adults with different disease severities, ranging from mild to severe, in both hospitalized and non-hospitalized patients. Various drug regimens are used in Covid-19 treatment, all of which rely on the use of antiviral agents including ritonavir (RTN)/nirmatrelvir (NTV) combination, molnupiravir (MLP) and favipiravir (FVP). Optimizing analytical methods for the selective and sensitive quantification of the above-mentioned drugs in pharmaceutical dosage forms and biological matrices is a must in the current pandemic. Several analytical techniques were reported for estimation of antivirals used in Covid-19 therapy. Chromatographic methods include Thin Layer Chromatography (TLC) densitometry, High Performance Thin Layer Chromatography (HPTLC), Reversed Phase-High Performance Liquid Chromatography (RP-HPLC), High Performance Liquid Chromatography Tandem Mass Spectrometry (HPLC-MS/MS) or Ultraviolet detectors (HPLC-UV), Ultra High-Performance Liquid Chromatography (UHPLC-MS/MS) or (UPLC-UV) and Micellar Liquid Chromatography (MLC). In addition to other spectroscopic methods including Paper Spray Mass Spectrometry (PS-MS), UV-Visible Spectrophotometry, and Spectrofluorimetry. Herein, we will focus on the clarification of trendy, simple, rapid, accurate, precise, sensitive, selective, and eco-friendly analytical methods used for the analysis of anti-Covid-19 drugs in dosage forms as well as biological matrices.