Spectrophotometric Determination of Solifenacin Succinate through Ion Association Complex Formation in Bulk Sample and Pharmaceutical Formulations

Abstract

Simple, sensitive and reproducible spectrophotometric methods (method M₁ and method M₂) for the assay of solifenacin succinate are proposed. These methods are based on the formation of ion-association complex involving tertiary nitrogen of solifenacin and the acidic dye, tropaeolin OOO (TP OOO, lmax 500 nm) (M₁), naphthol blue black (NBB, lmax 624 nm) (M₂). Regression analysis of Beer's law plot showed good correlation in the concentration range of 6-21 μg/mL for method M₁ and M₂, respectively. The molar absorptivities fell with in range of 1.31 × 10⁴- 1.74 × 10⁴ mol^-1 cm^-1. The recoveries range from 99.02-100.16 %.