Development and Validation of a Stability-Indicating RP-HPLC Method for Determination of Darifenacin Hydrobromide in Bulk Drugs

Abstract

An isocratic stability-indicating reversed phase high performance liquid chromatographic method (RP-HPLC) was developed for determination of process related impurities and assay of darifenacin hydrobromide (DRF) in bulk drugs. DRF was subjected to various stress conditions such as hydrolysis (acid, base, and neutral), oxidation, photolysis and thermal degradation as per International Conference on Harmonization (ICH Q1A(R2) and Q1B) prescribed conditions to investigate the stability-indicating ability of the method. Significant degradation was observed during acidic hydrolysis and oxidative stress conditions. The chromatographic separation was accomplished on a Prodigy C 8 column (250 × 4.6 mm, 5 μm) with mobile phase consisting of 0.05 M ammonium acetate (pH adjusted to 7.2 by using ammonia solution) and methanol (36% acetonitrile) in 35:65 v/v ratio in an isocratic elution mode at a flow rate of 1.0 mL/min at 25°C. Detection of analytes was carried out using photo diode array detector at a wavelength of 215 nm. The developed LC method was validated with respect to accuracy, linearity, precision, limits of detection and quantitation and robustness as per ICH guidelines.