Determination of Minoxidil in Pharmaceutical Formulations Using Permanganometry

The study proposed a classical method for determining minoxidil in pharmaceutical formulations using a redox reaction with KMnO4. Optimal results in permanganometry were achieved with a permanganate concentration of 1.00 x 10^-2 mol L^-1, and minoxidil was used as a titrant at 2.00 x 10^-2 mol L^-1 in a 2.00 mol L^-1 H2SO4 solution. Recovery rates for the method ranged from 94.5% to 95.2% depending on the commercial sample. The method was compared to chromatographic procedures, showing relative errors between -1% and -5.26%. This approach was simple, rapid, and offered an alternative for determining minoxidil in pharmaceutical samples with relatively high drug concentrations.