A Stability Indicating RP-HPLC Method for Estimation of Favipiravir in Tablets

Objectives: The focus of this research work was to develop an accurate and validated RP-HPLC technique for analysing Favipiravir (FAVI) drug and interpreting related degradants in drug and its formulation. Materials and Methods: The separation was performed on C18 column (Phenomenex Luna BDS Hypersil) with dimension of 4.6x150 mm and 5 µm of particle size at 40ºC in gradient mode. Two solvents mixture was used for analysis. Solvent A (water and 0.01% 10 mM ammonium acetate) and solvent B (acetonitrile) were used as a mobile phase at a rate of 0.5 mL/min and 323 nm wavelength used for detection. Results: The validated method was developed as per ICH parameters including LOD, accuracy, linearity, range, LOQ, precision and the observations were found to be satisfactory. The method was then processed for different degradation conditions. The FAVI was treated with various circumstances like hydrolysis, oxidation and photolytic stages for determination of degradation products. Retention time (tR) was observed at 3.337±0.01 min for FAVI. After stress testing three degradants were found. The first degradant D1 found at 4.170 min (tR), second D2 at 4.260 min (tR) and third D3 at 3.881 min (tR) were found in basic (1 N NaOH), acidic (1 N HCl) and oxidation (30% H2O2) conditions. All the degradants were interpreted by mass spectra. The molecular ion [M+1] m/z 156.8 was found in positive mode mass spectra. The various ion peaks were found at m/z 153.1, 130.0, 112.0 and 101.0. FAVI was observed to be degraded in all the conditions used. Conclusion: There FAVI drug, its formulations and degradants were identified and interpreted by quadrapole MS/MS system.