Spectrophotometric Determination of Drugs and Pharmaceuticals by Cerium (IV) Amaranth Dye Couple

Abstract

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.

Spectrophotometric determination of Montelukast Sodium in pure form and in its pharmaceutical formulations

“…Solutions Montelukast Na Stock solution (1000 µg/mL): An exactly (0.1000 gm) of (MON) "standard" were dissolved in (100 ml) ethanol. (KBr: KBrO 3 ): prepared by dissolving 1.0gm of potassium bromide, and 0.1000gm of potassium bromate in 100 ml distilled water [19] , then 2.5 ml of this mixure were diluted to 100 ml distilled water in a volumetric flask. Crystal Violet (CV) dye: a concentration of 7.7x10 -5 M was prepared by dissolving 0.0031 gm in 100 ml distilled water.…”