Separation and kinetic-spectrophotometric determination of ketoconazole from formulations using SDS-coated Al2O3 and KMnO4 in alkaline-SDS micellar medium

A kinetic method for the accurate and sensitive determination of Ketoconazole (KC) has been described. The method is based on the alkaline oxidation of KC with KMnO4 in micellar SDS medium. At a fixed time of 8 min, the formed manganate ion is spectrophotometrically measured at 610 nm. The determination of KC by the fixed-concentration and rate constant methods is feasible with the calibration equation obtained, but the fixed time method proves to be more applicable. The proposed method was successfully used for the quantitative determination of KC in formulations after the complete separation of KC using SDS-coated Al2O3 as a suitable solid-phase extraction system in comparison to liquid-liquid extraction using poisonous organic solvents. Beer's law was obeyed from 0.4 to 28 mug mL(-1) and the RSD% values for tablet, cream and shampoo samples were 1.8, 1.4 and 2.3, respectively. The results obtained agreed with those obtained by the USP method.