QUANTITATIVE ANALYSIS OF SELECTED PHARMACEUTICALS VIA CERIUM (IV)-AMARANTH DYE COUPLED REACTION

Simple, sensitive, accurate, and precise spectrophotometric methods for quantitative determination of drugs, viz., Darifenacin (DAR), Esmolol Hydrochloride (ESM), Montelukast Sodium (MON), Sildenafil citrate (SIL),Terbinafine (TER) and Tramadol Hydrochloride (TRA) were developed. The method of each drug depends upon oxidation of drugs by Ce (IV) (Excess) and estimating the amount of unreacted Ce (IV) by amaranth dye at 523nm. The calibration curves obeyed Beer’s law over the concentration range of 1.4-7.0 µg ml-1 (DAR), 2-14 µg ml-1 (ESM), 2-10 µg ml-1 (MON), 20-70 µg ml-1 (SIL), 3-21 µg ml-1 (TER) & 2-14 µg ml-1 (TRA). The methods have been validated in terms of guidelines of ICH and applied to analysis of pharmaceuticals