الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The monitoring of the selected drugs is important for quality assurance in preprations and for obtaining optimum therapeutic concentrations in body fluids to minimize the risk of toxicity. Therefore, three spectrophotometric methods (A - C) have been described for the assay of selected drugs (propanolol HCl, bisoprolol fumarate, atenolol and timolol maleate). (Method A), involves the formation of yellow ion-pair complexes between the studied drugs and two different dyes, (such as MO and EBT) in acidic buffer and then measuring the absorbance of extracted ion-pair complexes at the selected wavelength. The other two methods are based on redox reactions by the addition of known excess of potassium permanganate to the studied drugs either in acid or alkaline media, followed by the determination of unreacted permanganate at 520 nm in acid media (Method B) or green color of manganate at 610 nm in alkaline media (Method C). The different experimental parameters affecting the development and stability of the colors species were carefully studied and optimized. The overall methods have been successfully applied to assay of the selected drugs in pharmaceutical formulations