ABSTRACT:
The differential pulse polarographic behavior and determination of simvastatin (SMV) in pure and pharmaceutical dosage forms were investigated on dropping mercury electrode (DME). The method involves the reduction behavior of SMV has been studied in different supporting electrolytes within the pH range 3–9 at DME by differential pulse polarographic analysis (DPPA). The best definition of the analytical signals was found in sodium acetate buffer at pH 7.5 at -1378 to -1384 mV (vs. Ag/AgCl). Under optimized conditions the peak current (Ip) is linear over the range 0.1256- 8.731 µg.mL-1. The DPPA was used successfully for the determination of SMV in pure form. The relative standard deviation did not exceed 4.6% for the concentration of SMV 0.12556 µg.mL-1. Regression analysis showed a good correlation coefficient (R2=0.9997) between Ip and concentration over the mentioned range. The limit of detection (LOD) and the limit of quantification (LOQ) were to be 0.015 µg.mL-1 and 0.045 µg.mL-1, respectively. The proposed method was validated for linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ), robustness and specificity with average recovery of 99.7-100.7%. The developed method is applicable for the determination of SMV in pure and different dosage forms with assay 99.0-103.0% and the results are in good agreement with those obtained by the HPLC reference method.