Quality-by-design approach to selective stability indicating RP- HPLC method development and validation for estimation of Sofosbuvir in bulk drug

Abstract

By utilizing Quality by design approach a simple, robust and selective Reverse phase liquid chromatography (RP-HPLC) method was developed for the estimation of Sofosbuvir in API. Sofosbuvir is a nucleotide Hepatitis C Virus (HCV) NS5B polymerase inhibitor that has antiviral activity. Analyte target profile of Sofosbuvir was constructed and CAA’s were identified. LC analysis was performed on Agilent LC 1200 equipped with a photodiode array detector (PDA) at 261 nm. Initial method was developed on an Inersil ODS (250 mm x 4.6, 5 micron) 65: 35 Methanol and Water at 261nm witha flow rate of 1 mL/min. The degradation studies of Sofosbuvir were carried out under the stress conditions of hydrolysis (acid, base and neutral), oxidation, photolytic and thermal as per ICH guidelines. The alkali hydrolysis shows more critical impurities which were well resolved from pure drug with the application of DoE. Three method variables were selected and their interaction were studied through central composite design and two method responses like retention time of drug and resolution between degradants and active drug were studied. Based on DoE, the optimized method was developed using 60:40 of Methanol and Water, at pH 4 with a flow rate of 1.2 mL/min which produce satisfactory retention time and resolution. This method has been validated and shown to be linear, accurate, robust, precise and specific.