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1.
Mikrochim Acta ; 189(3): 125, 2022 03 01.
Article in English | MEDLINE | ID: covidwho-1712245

ABSTRACT

A novel electrochemical sensor is reported for the detection of the antiviral drug favipiravir based on the core-shell nanocomposite of flower-like molybdenum disulfide (MoS2) nanospheres and molecularly imprinted polymers (MIPs). The MoS2@MIP core-shell nanocomposite was prepared via the electrodeposition of a MIP layer on the MoS2 modified electrode, using o-phenylenediamine as the monomer and favipiravir as the template. The selective binding of target favipiravir at the MoS2@MIP core-shell nanocomposite produced a redox signal in a concentration dependent manner, which was used for the quantitative analysis. The preparation process of the MoS2@MIP core-shell nanocomposite was optimized. Under the optimal conditions, the sensor exhibited a wide linear response range of 0.01 ~ 100 nM (1.57*10-6 ~ 1.57*10-2 µg mL-1) and a low detection limit of 0.002 nM (3.14*10-7 µg mL-1). Application of the sensor was demonstrated by detecting favipiravir in a minimum amount of 10 µL biological samples (urine and plasma). Satisfied results in the recovery tests indicated a high potential of favipiravir monitoring in infectious COVID-19 samples.


Subject(s)
Amides/analysis , Antiviral Agents/analysis , Disulfides/chemistry , Molecularly Imprinted Polymers/chemistry , Molybdenum/chemistry , Nanocomposites/chemistry , Nanospheres/chemistry , Pyrazines/analysis , Amides/blood , Amides/therapeutic use , Amides/urine , Antiviral Agents/blood , Antiviral Agents/therapeutic use , Antiviral Agents/urine , COVID-19/drug therapy , COVID-19/virology , Electrochemical Techniques/methods , Humans , Limit of Detection , Oxidation-Reduction , Pyrazines/blood , Pyrazines/therapeutic use , Pyrazines/urine , Reproducibility of Results , SARS-CoV-2/isolation & purification
2.
Molecules ; 26(13)2021 Jun 22.
Article in English | MEDLINE | ID: covidwho-1288957

ABSTRACT

In the current work, a simple, economical, accurate, and precise HPLC method with UV detection was developed to quantify Favipiravir (FVIR) in spiked human plasma using acyclovir (ACVR) as an internal standard in the COVID-19 pandemic time. Both FVIR and ACVR were well separated and resolved on the C18 column using the mobile phase blend of methanol:acetonitrile:20 mM phosphate buffer (pH 3.1) in an isocratic mode flow rate of 1 mL/min with a proportion of 30:10:60 %, v/v/v. The detector wavelength was set at 242 nm. Maximum recovery of FVIR and ACVR from plasma was obtained with dichloromethane (DCM) as extracting solvent. The calibration curve was found to be linear in the range of 3.1-60.0 µg/mL with regression coefficient (r2) = 0.9976. However, with acceptable r2, the calibration data's heteroscedasticity was observed, which was further reduced using weighted linear regression with weighting factor 1/x. Finally, the method was validated concerning sensitivity, accuracy (Inter and Intraday's % RE and RSD were 0.28, 0.65 and 1.00, 0.12 respectively), precision, recovery (89.99%, 89.09%, and 90.81% for LQC, MQC, and HQC, respectively), stability (% RSD for 30-day were 3.04 and 1.71 for LQC and HQC, respectively at -20 °C), and carry-over US-FDA guidance for Bioanalytical Method Validation for researchers in the COVID-19 pandemic crisis. Furthermore, there was no significant difference for selectivity when evaluated at LLOQ concentration of 3 µg/mL of FVIR and relative to the blank.


Subject(s)
Amides/analysis , Amides/blood , Antiviral Agents/analysis , Antiviral Agents/blood , Biological Assay/methods , COVID-19/drug therapy , Chromatography, High Pressure Liquid/methods , Liquid-Liquid Extraction/methods , Pyrazines/analysis , Pyrazines/blood , Acyclovir/analysis , Acyclovir/blood , COVID-19/blood , Calibration , Drug Stability , Freezing , Humans , Reference Standards , Reproducibility of Results , Solvents/chemistry
3.
Magn Reson Chem ; 59(7): 746-751, 2021 07.
Article in English | MEDLINE | ID: covidwho-1182204

ABSTRACT

Favipiravir is an established antiviral that is currently being assessed as an investigational drug for the treatment of COVID-19. Favipiravir is strikingly similar to two molecules that the World Health Organization (WHO) lists as essential medicines, which also consist of a six-membered aromatic N-heterocycle bearing a carboxamide function: the anti-tuberculosis agent, pyrazinamide, and nicotinamide, also known as vitamin B3 . We demonstrate the utility of 1 H nuclear magnetic resonance (NMR) profiling, an emerging pharmacopoeial tool, for the highly specific identification, selective differentiation of congeners, and subsequent detection of drug falsification or adulteration of these medicines. The straightforward comparison of basic 1-D 1 H NMR spectra, obtained with benchtop or advanced NMR instruments alike, offers a rapid identity assay and works independently of physical reference materials. This approach accelerates and advances pharmaceutical quality control measures under situations of increased drug demand and altered economy, such as during a pandemic.


Subject(s)
Amides/analysis , Antiviral Agents/analysis , Drug Contamination/prevention & control , Niacinamide/analysis , Pyrazinamide/analysis , Pyrazines/analysis , Quality Control , Amides/chemistry , Antiviral Agents/chemistry , Niacinamide/chemistry , Proton Magnetic Resonance Spectroscopy , Pyrazinamide/chemistry , Pyrazines/chemistry , World Health Organization
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 249: 119241, 2021 Mar 15.
Article in English | MEDLINE | ID: covidwho-1065570

ABSTRACT

The present work describes development of rapid, robust, sensitive and green spectrofluorimetric method for determination of favipiravir (FAV). Different factors affecting fluorescence were carefully studied and Box Behnken Design was applied to optimize experimental parameters. The proposed method is based on measuring native fluorescence of FAV in 0.2 M borate buffer (pH 8.0) at 432 nm after excitation at 361 nm. There was a linear relationship between FAV concentration and relative fluorescence intensity over the range 40-280 ng/mL with limit of detection of 9.44 ng/mL and quantitation limit of 28.60 ng/mL. The method was successfully implemented for determination of FAV in its pharmaceutical formulation with mean % recovery of 99.26 ± 0.87. Moreover, the high sensitivity of the method allowed determination of FAV in spiked human plasma over a range of 48-192 ng/mL. The proposed spectrofluorimetric method was proved to be eco-friendly according to analytical eco-scale.


Subject(s)
Amides/blood , Antiviral Agents/blood , COVID-19/blood , COVID-19/drug therapy , Pyrazines/blood , Spectrometry, Fluorescence/methods , Amides/analysis , Amides/therapeutic use , Antiviral Agents/analysis , Antiviral Agents/therapeutic use , Blood Chemical Analysis/methods , Blood Chemical Analysis/statistics & numerical data , Humans , Limit of Detection , Pyrazines/analysis , Pyrazines/therapeutic use , SARS-CoV-2 , Sensitivity and Specificity , Spectrometry, Fluorescence/statistics & numerical data
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