Akademik Veri Yönetim Sistemi
REVISTA DE CHIMIE, cilt.62, sa.4, ss.420-426, 2011 (SCI-Expanded)
In this study, the electrochemical reduction of ezetimibe has been studied by means of square wave voltammetry (SWV) at a hanging mercury-drop electrode (HMDE) in electrolytes of different pH. Ezetimibe gave rise to a single voltammetric peak in the potential interval from -1290 to - 1322 mV depending on ezetimibe concentration within the entire pH range (4.0-10.0) in K(2)HPO(4)-Na(2)B(4)O(7)(25:25) (v/v) buffer. The well-defined peaks were observed at the frequency of 50 Hz, amplitude of 20 mV, potential increment of 3 mV The developed method was validated according to the ICH guideline and found to be linear, sensitive, specific, precise, accurate, rugged and robust. Limit of detection (LOD) and limit of quantification (LOQ) were found 0.099 mu g mL(-1) and 0.30 mu g mL(-1) respectively. The linearity range of ezetimibe was 0.33 - 6.54 mu g mL(-1) under the optimum conditions. The developed method was applied successfully for the determination of ezetimibe in tablet dosage form. Also electrochemical behaviours of ezetimibe were investigated. As a results of cyclic voltammetry (CV) and SWV experiments, the reduction mechanism included 2 electrons and 2 protons, and further more, reduction current of ezetimibe was diffusion controlled and the electrode reaction was found to be irreversible by using CV, chronoamperometry (CA) and choronocoulometry (CC) methods. Using these electrochemical techniques diffusion coefficient (D), rate constant for electron transfer (k(f)) and rate constant of following chemical reaction (k) relating to ezetimibe's reduction reaction was calculated. It was found out that the reduction reaction occured according to EC mechanism and possible reduction mechanism was proposed.