Development of a differential pulse voltammetric method for the determination of Silymarin/Vitamin E acetate mixture in pharmaceuticals

Differential pulse voltammetric method was developed for determination of Silymarin (SMR)/Vitamin E acetate (VEA) mixture in pharmaceuticals. SMR and VE gave well-resolved diffusion-controlled anodic peaks at +756 and +444 mV, respectively (versus Ag/AgCl) in Britton–Robinson buffer at pH 2.8. The solution conditions and instrumental parameters were optimized for their quantitative determination. The linear response was obtained in the range 0.1–4.0 mg L−1 with a detection limit of 0.03 mg L−1 for SMR and 0.05–4.0 mg L−1 with a detection limit of 0.01 mg L−1for VEA.