Development and Validation of a Method for Quantification of Favipiravir as COVID-19 Management in Spiked Human Plasma

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.

Quantitative analysis of favipiravir and hydroxychloroquine as FDA‐approved drugs for treatment of COVID‐19 using synchronous spectrofluorimetry: application to pharmaceutical formulations and biological fluids

“…[ 2 , 8 ] FPV was lately indicated for the treatment of COVID‐19 infections in various countries, including Russia, Egypt, KSA, UAE, Italy, India, Japan, and Turkey. [ 9 , 10 ] Literature review reveals few reported methods for analysis of FPV such as spectrophotometry, [ 11 ] spectrofluorimetry, [ 3 , 12 ] liquid chromatography, [ 3 , 13 , 14 , 15 , 16 ] and electrochemical methods. [ 17 , 18 ]…”

Favipiravir (SARS‐CoV‐2) degradation impurities: Identification and route of degradation mechanism in the finished solid dosage form using LC/LC–MS method

“…Pyrazine carboxamide is a derivative that exhibits antiviral activity against RNA A literature survey revealed that no stability-indicating method has been reported yet for the quantitative determination of favipiravir impurities. A few analytical methods were found; those various experiments were performed in human plasma using LC-MS/MS and HPLC techniques (Balu & Paresh, 2021;Eryavuz et al, 2021;Hailat et al, 2021;Ibrahim et al, 2021;Katharina et al, 2021;Marzouk et al, 2022;Mikhail et al, 2021;Mohamed et al, 2021;Nakayama & Ryo, 2021;Nazifa Sabir Ali et al, 2021;Nippes et al, 2021;Pallavi & Kamalkishor, 2021;Ramarao & Abhinandana, 2021;Rezk et al, 2021;Srinivas, et al, 2021) (Table 1). The literature does not report any HPLC method that accurately and quantitatively assesses the relative and degradation impurities of favipiravir.…”

Menthol-assisted homogenous liquid-liquid microextraction for HPLC/UV determination of favipiravir as an antiviral for COVID-19 in human plasma

“…A few reported methods were developed for determination of favipiravir in biological matrices. To the best of our knowledge, there is only one reported HPLC/UV method for favipiravir determination in biological samples, but it is not sufficiently sensitive for determining therapeutic levels of favipiravir in plasma due to the limited sensitivity and the high LOQ [35] . The other published methods adopted for favipiravir determination in biological matrices were LC-MS/MS, voltammetry and spectrofluorimetry as indicated in Table 4 .…”

“… LC-MS/MS 100–20000 7.11 100 [13] Human serum Protein precipitation by acetonitrile using 900 µL of serum. LC-MS / MS 48–50000 8.00 48 [35] Human urine None using 500 µL of urine. SW-AdSV 10–100 100–20000 ≤8.80 9.30 76 [36] Human plasma None using 20 µL of plasma.…”