Electrochemical Determination of Minoxidil in Different Pharmaceutical Formulations by Flow Injection Analysis

VALERIA PFAFFEN; PATRICIA I. ORTIZ

JAPAN SOC ANALYTICAL CHEMISTRY

Año: 2006 vol. 22 p. 91 - 91

he electrochemical behavior and amperometric-FIA quantification of minooxidil at glassy carbon electrode in described. The procedure is based on the electrochemical oxidation at 0.800 V (vs Ag/AgCl/NaCl(3 M)) in phosphate buffer solution. Minoxidil is determined over the range 1x 10-7-1 x 10-4. Different analytical parameters and electrode stability were analyzed to obtain the best electrode performance, being the optimal conditions: working potentials 0.800V, flow rate 0.74 mLmin-1 and solution pH 7.0. This system allows a sampling rate of 120 samples per hour without requiring any pre-treatment. The proposed method was used for minoxidil quantification in pharmaceutical preparations with satifactory results. The accuracy of FIA-amperometric was established by comparison with the convetional UV determination technique using paired t-test indicating the absence of systematic errors.