Determination of atorvastatin at pharmaceutical tablet using cyclic voltammetry technique

Voltammetric oxidation behavior of atorvastatin (ATOR) was studied using cyclic voltammetry in phosphate buffer at pH3. The glassy carbon electrode was used to accumulate ATOR into its surface to give a well-defined oxidation peak at 0.95V potential in presence of Ag/AgCl reference electrode and Pt auxiliary electrode. The high sensitivity of ATOR determination using cyclic voltammetry, was observed with optimum parameters such as: phosphate buffer, pH3, 30 s accumulation time, 0.0 V accumulation potential and 100 mV s-1 scan rate, so these parameters were chosen for the next experiments. The repeatability, stability, calibration curve and detection limit were studied to evaluate the analytical performance for the CV method. Repeatability of 6х10-5 mol L-1 of ATOR was reported 0.22% relative standard deviation (RSD%) for ten anodic CV measurements. The stability was monitored for 6х10-5 mol L-1 ATOR signal for 90 min, yielded a good stability was recorded for the ATOR determination at the voltammetric period. Calibration curve was studied over the range 1х10-5 — 6 х 10-5 mol L-1 for ATOR drug to be obtained a linear relationship with 0.998 correlation coefficient (r2) for sex measurements (n=6). Detection limit (LOD) was calculated to be 7.25 х 10-8 mol L-1(0.04 ppm). Cyclic voltammetry technique was applied for the determination of ATOR at the commercial tablet