Determination of entacapone by differential pulse polarography in pharmaceutical formulation

摘要

The electrochemical methods, sampled direct current, and differential pulse polarography, were developed successfully and applied to the routine determination of Entacapone in pharmaceutical formulation. Both methods gave rise to three reduction waves or peaks respectively. The irreversibility and the diffusion-controlled of the first reduction were confirmed by cyclic voltammetry. The limiting currents are directly proportional to the concentration of entacapone with a correlation coefficient of 0.99. The within-day coefficients of variation and the day-to-day coefficient of variation were less than 3.5% for entacapone and Comtan((R)). The percentage recovery for entacapone in tablets is satisfactory for both methods. The method is simple without any pretreatment.