FORCED DEGRADATION STUDIES DEVELOPMENT AND VALIDATION BY RP-HPLC METHOD FOR THE SIMULTANEOUS ESTIMATION OF COMBINATION DRUGS ELBASVIR AND GRAZOPREVIR IN BULK AND PHARMACEUTICAL DOSAGE FORMS

A Stability-indicating reverse phase – high performance liquid chromatography(RP-HPLC) method was developed and validated for the determination of Elbasvir and Grazoprevir in tablet dosage forms using C18 column Discovery( 250x4.6 mm, 5 µ) with a mobile phase consisting of orthophosphoric acid and methanol (45:55% v/v). The pH was adjusted to 3.8 with dil. NaoH.The mobile phase was sonicated for 10min and filtered through a 0.45µm membrane filter at a flow rate of 1.0 ml/min.The Detection was carried out at 220nm and retention time of Grazoprevir was found to be 2.3min ,and retention time of Elbasvir was found to be 4.8min.Linearity for Grazoprevir was observed from 25-150 µg/ml,coefficient of determination R2 was 0.999, with equation y=6488x+6259.Linearity for Elbasvir was observed from 12.5-75µg/ml ,coefficient of determination R2 was 0.999,with equation y= 9099x+383.3.Elbasvir and Grazoprevir was subjected to stress conditions including acidic,alkaline,thermal,oxidation, photostability,neutral degradation,solution stability and the results showed that it was more sensitive towards acidic and alkaline degradation.The method was validated as per ICH guidelines. Key words: Elbasvir, Grazoprevir, RP-HPLC, stability indicating, validation