Gradient High Performance Liquid Chromatography method for determination of related substances in (7-{4-[4-(1-Benzothiophen-4-YL] Butoxy} Quinolin-2(1H)-one) dosage form

A sensitive HPLC method was developed and validated for the estimation of related substances in Brexpiprazole in drug Product. The developed method is found to be specific, reproducible, and stability indicating. Kromasil100-5 C18 (150x4.6mm), 5μ column was used and mobile phase consisted of mixture of phosphate buffer of pH5.2 and ACN in gradient program is used at a flow rate of 1.0mL/min at a wave length of 215 nm. The detector linearity was established from concentrations ranging from LOQ-150% of specification level with a correlation co-efficient of 0.999. The method was also validated for specificity, LOD, LOQ, accuracy, robustness, precision. The method is proved to be robust with respect to change in flow rate, pH, organic phase composition and column temperature. The proposed method is found to be sensitive, precise, rapid, reproducible, and offers good column life. Keywords: RP-HPLC; Stability indicating method; Brexpiprazole; validation.