Square-wave adsorptive stripping voltammetric determination of candesartan cilexetil in pharmaceutical formulations

A sensitive, simple and rapid square-wave adsorptive stripping voltammetric method was developed and validated for the determination of candesartan cilexetil in pharmaceutical formulations. The proposed method was based on electrochemical reduction of candesartan cilexetil at a hanging mercury drop electrode in phosphate buffer at pH 5.0. A well-defined reduction peak was observed at -1340 mV with 30 s of accumulation time and -1100 mV of accumulation potential. Under these optimized conditions, the square-wave adsorptive stripping voltammetric peak current showed a linear correlation on drug concentration over the range of 0.25-1.34 A mu g mL(-1) with a correlation coefficient of 0.9986 for the proposed method. The detection and quantitation limits for this method were 1 x 10(-2) and 2.5 x 10(-1) A mu g mL(-1), respectively. The results obtained for intra-day and inter-day precision (as RSD%) were between 1.10 and 3.90%. This method was applied successfully for the determination of candesartan cilexetil in its tablet dosage forms with mean recoveries of 101.13 +/- A 0.78% with RSD of 2.06% for 8 mg tablet and 99.84 +/- A 0.89% with RSD of 2.36% for 16 mg tablet. The results obtained from the developed square-wave adsorptive stripping voltammetric method were compared with those obtained by the analytical method reported in the literature.