Abstract
Author(s): Afaf Abou-elkheir*, HanaaSaleh, Magda M. El-henawee and Basma El-sayedGhareeb
Direct (A) and indirect (B) spectrophotometric methods are proposed for the assay of TerbinafineHCl, Telmisartan andRamipril in bulk drugs and in their dosage forms using ceric (IV) sulphate and ceric (IV) sulphate-chromatrope 2R as reagents. Method (A) involves the addition of certain amount of ceric (IV) sulphate to drugs in acid medium, followed by determination of the decrease in absorbance measured at 319 nm using the experiment as a blank. Method (B) involves the addition of a known excess of ceric (IV) sulphate to drugs in acid medium followed by the determination of unreacted ceric by reacting with a fixed amount of chromatrope 2R then the decrease in color intensity of C2R was measured spectrophotometrically at λmax 507 nm against the reagent blank.The Beer's law is obeyed in the concentration range of (1-9) μg/ml (A),(1-7) μg/ml (B) of Terbinafine hydrochloride, (1-5) μg/ml(A),(B) of Telmisartan and (10-80) μg/ml (A), (10-60) μg/ml (B) of Ramipril. The validity of these methods have been successfully applied for the determination of the drugs in there pharmaceutical preparations. Good recoveries were obtained and the results were comparablewith those obtained by reference method