A Stability Indicating RP-HPLC Method for Simultaneous Estimation of Velpatasvir and Sofosbuvir in its Bulk and Tablet Dosage Form

A Stability indicating isocratic liquid chromatographic method with UV detection at 255 nm is described for simultaneous determination of sofosbuvir and velpatasvir  in its bulk and tablet dosage form. Chromatographic separation of two drugs was achieved on a YMC column (4.6×15mm,5 ) using a mobile phase consisting of a binary mixture of acetonitrile and 0.025M KH2PO4  adjusted to pH3..0 with orthophosphoric acid in ratio 50:50. The developed Liquid Chromatographic method offers symmetric peak shape, good resolution and reasonable retention time for both drugs. Linearity, accuracy and precision were found to be acceptable over the concentration range of 50-250 µg/ml for velpatasvir and 200-1000µg/ml for sofosbuvir and R2 found to be 0.999. Accuracy was measured via recovery studies and found to be acceptable, and the percentage recoveries were found in the range of 97-103%.Method precision results obtained are 0.1%RSD for sofosbuvir and 0.8%RSD for velpatasvir. Forced degradation studies were also conducted, and the drugs were subjected to various stress conditions such as acid hydrolysis, base hydrolysis, oxidative, photolytic and thermal degradation. The proposed method was successfully validated and applied for the quantitative estimation of these drugs in both bulk and tablet dosage forms. The LC method can be used for the quality control of formulated products containing sofosbuvir and velpatasvir.