الملخص

An indirect simple and sensitive spectrophotometric method has been developed for the determination of carvedilol (CAR), olanzapine (OLP) and domperidone maleate (DOM) in pure and pharmaceutical dosages. The method is based on the oxidation of CAR , OLP and DOM with known excess of potassium permanganate in hydrocholric acid medium and subsequent occupation of unreacted oxidant in bleaching of alkali blue 4B dye and measure the absorbance of residual dye at 594 nm. Calibration curves of residual alkali blue 4B dye in the presence of CAR or OLP and DOM were rectilinear over the ranges 1-12, 1-16 and 1-16 µg ml-1 with molar absorptivity of 4.04×104, 2.13×104 and 3.81×104 l.mol-1.cm-1 for CAR, OLP and DOM respectively. The accuracy (Recovery percentage) was ranged between 99.77 and 100.34 and precision (RSD%) is less than 0.75%. The suggested method was successfully applied for determination of the studied drugs in their dosage forms resulted in a good agreement with certified value, standard British pharmacopeia method and standard addition procedure.