Development and validation of stability-indicating HPLC method for solifenacin succinate: Isolation and identification of major base degradation product

Abstract

Stability-indicating HPLC method was developed for determination of solifenacin succinate (SLN) as bulk drug and from pharmaceutical formulation. The HPLC separation of SLN from its degradation products was achieved using Oyster BDS C 8 (250 mm × 4.6 mm i.d., 5 μm particle size) column with a flow rate 0.7 mL min-1 and using a UV detector to monitor the eluate at 210 nm. The mobile phase was composed of 10 mM ammonium formate buffer (adjusted pH 3 with formic acid)-acetonitrile-methanol (52.5:37.5:10, v/v/v). The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.9999 in the working concentration range of 2-100 μg mL-1. The limit of detection (LOD) and limit of quantification (LOQ) were 0.07 and 0.21 μg mL -1, respectively. API and formulation of SLN were subjected to acid and alkali hydrolysis, oxidation, thermal and photodegradation. Standard drug peak was well resolved from the peaks of degradation products with significantly different retention time values. Also, isolation and identification of major base degradation product were carried out. The method is simple, accurate, specific, repeatable, stability-indicating, reduces the duration of the analysis and is suitable for routine determination of SLN in pharmaceutical formulation.