Utility of certain π-acceptors for the spectrophotometric determination of gliclazide and tolazamide

Abstract

The reaction of gliclazide and tolazamide with three selected n-acceptors in acetonitrile -water (9 + 1) at pH 9.0-9.5 was found t o give intensely coloured products. A method based on this reaction is proposed for the determination of trace amounts of both drugs. Quantification was carried out at 445 nm for p-chloranil, 450 nm for p-bromanil and ca. 750 nm for 7,7,8,8-tetracyanoquinodimethane. The molar ratios of the reactants were established and the experimental conditions giving maximum absorption were also studied. The proposed procedures were applied successfully t o the determination of both drugs either in pure samples or in tablets with good accuracy and precision. The results were compared with those obtained by the official USP method.

Determination of Paroxetine in Human Plasma by High-Performance Liquid Chromatography Using 7,7,8,8-Tetracyanoquinodimethane as the Derivatization Reagent

“…[24][25][26][27][28][29] These methods are based on the blue-colored TCNQÁ À radical anion formed by interaction of the drugs (as base) with the reagent in acetonitrile at room temperature. Common derivatization reagents, fluorogenic or chromogenic, used for secondary aliphatic amines react also with primary amines, amino acids, and in some cases, such as dansyl chloride, with phenols as well.…”