Voltammetric Reduction Behaviour and Analysis of Lorazepam In Pharmaceutical Formulations

The voltammetric reduction behaviour of Lorazepam has been studied by using d.c polarography, cyclic voltammetry (CV) and differential pulse polarography (DPP) in Britton-Robinson buffers of the pH ranging from 2.0 to 12.0. DPP has been developed for the quantitative estimation of Lorazepam in different pharmaceutical formulations (Tablets) without any prior separation using standard addition method. A single step reduction wave/peak is found to be irreversible and diffusion controlled. Kinetic parameters such as transfer coefficient, diffusion coefficient and heterogeneous forward rate constant values are evaluated and reported. On the basis of the experimental results, a reduction mechanism is proposed for Lorazepam. Key words: Lorazepam, Reduction behaviour, Mechanism, Analysis, Pharmaceutical formulations