RESUMO
Simple, accurate and robust analytical methods have been developed and validated for the determination of favipiravir (FVPR) by RP-HPLC and UV spectroscopy techniques as per the ICH guidelines. In the RP-HPLC method for FVPR determination, the mobile phase was ammonium acetate buffer pH 6.5 in pump Aand methanol in pump B. The C18 (Sunfire) 5 µm, 4.6 × 250 mm column was used as a stationary phase, and the detection wavelength was at 323 nm. Under these conditions, FVPR was eluted as a sharp peak at 2.65 min and the overall time taken for each injection was 10 min. In case of the UV spectroscopy method, standard FVPR solutions were prepared with pure ethanol and scanned from 250 to 400 nm and a flourishing spectrum was obtained at 323 nm. Hence, the wavelength of 323 nm was fixed for the whole process of validation in both techniques. The limit of detection (LOD) and limit of quantification (LOQ) in the RP-HPLC method were 1.0 and 3.5 µg/mL, respectively, and the linearity was established in the 10 to 50 µg/mL range. In the UV spectroscopy method, the LOD and LOQ values were found to be 3.5 and 12 µg/mL, respectively, and the linearity was established within 20 to 60 µg/mL range. The regression coefficient was found to exceed 0.999 in both methods. The proposed RP-HPLC and UV spectroscopy techniques are simple, accurate, rugged and robust.
RESUMO
Simple, novel and selective reverse phase-high performance liquid chromatography (RP-HPLC) and ultraviolet (UV) spectroscopic methods have been developed and optimized for the determination of remogliflozin etabonate (RMZ) in bulk and dosage forms. In the HPLC method, the principal peak and internal standard peak were eluted separately at different retention times (RT) with the chromatographic conditions such as, mobile phase consisting of 0.02 M ammonium acetate buffer (pH was adjusted to 4.0 by 1.0 M ortho phosphoric acid), acetonitrile and tetrahydrofuran in the ratio 50:45:05, respectively (v/v) and the stationary phase used was C18, 5 µm, 4.6 mm x 250 mm kromasil column. The flow rate was 2.0 mL min-1, sample injection volume was 10 µL, and the wavelength of detection was fixed at 228 nm. In case UV spectroscopic method, the RMZ was diluted with pure ethanol. The RMZ showed a maximum absorbance at 228 nm. Hence throughout analysis 228 nm was used for the determination of RMZ. The RT of RMZ and internal standard, atorvastatin (ATST) were 6.2 min and 7.0 min, respectively. The resolution between the peaks was found to be more than 2.0. The total run time was fixed at 10 min. The linearity range for RP-HPLC method was found to be 10 µg mL-1 to 50 µg mL-1, at a fixed concentration of ATST. The linearity range for the UV spectroscopic method was found to be in the range of 100 to 250 µg mL-1. Regression coefficients (R2) were found above 0.999 for both of the techniques. The limit of detection and quantification for RMZ were found to be 1.0 µg mL-1 and 3.5 µg mL-1 respectively, in RP-HPLC method and 10.0 µg mL-1 and 40 µg mL-1, respectively, in UV spectroscopic method. The developed methods were found to be simple, accurate, reproducible, and precise. The RMZ can be analyzed in dual techniques, i.e., chromatographic and UV spectroscopic methods for its routine analysis.
