Determination of Glimepiride in Pharmaceutical Formulations by Square-Wave Voltammetric Method

In this study a square - wave voltammetric method was developed and validated for the direct determination of glimepiride in bulk form and pharmaceutical formulations. The best results were obtained for the quantitative determination of glimepiride in 0.04 M Britton - Robinson buffer at pH 9.0 at -1160 mV vs. Ag/AgCl reference electrode. The experimental and instrumental parameters affecting the peak current of glimepiride were investigated and optimized. The electrochemical behavior of glimepiride was also investigated by cyclic voltammetry. The monitored peak current was directly proportional to the concentration of glimepiride and it shows a linear response in the range from 0.25 - 7.81 μg mL-1 (r = 0.9998). The accuracy of the proposed method was indicated via the mean recovery of 100.95 ± 0.61 % with RSD of 1.48 % at a concentration level of 4.89 μg mL-1. After validation of the proposed method, the applicability of this voltammetric method was carried out by the determination of glimepiride in its pharmaceutical formulations. Possible interferences by several substances usually present in the pharmaceutical formulations have been also evaluated. No interferences were observed. The results obtained from the developed voltammetric method were compared with those obtained by the reported analytical method in the literature.