Spectrophotometric determination of two N-(4-quinolyl) anthranilic acid derivative (glafenine and floctafenine)

Spectrophotometric methods were developed for the determination of glafenin e and floctafenine. The first method depends upon the determination of glaf enine in raw material and tablets as well as in the presence of its main de gradation product glafenic acid (up to 40%). Differential first derivative spectral response at 245 nm in 0.1 N hydrochloric acid, where the correspon ding degradation product exhibits no contribution in 0.1 N sodium hydroxide . The method allows the determination of 2.5-30 mu g ml(-1). The second met hod depends upon the reaction of floctafenine with 2,3-dichloro 5,6-dicyano -p-benzoquinone (DDQ) in acetonitrile to give highly colored complex that c ould be measured quantitatively at (about) lambda(max) 538 nm. The method p ermits the determination of 40-180 mu g ml(-1) or by measuring the first de rivative spectral response of the color at 610 nm. The method permits the d etermination of floctafenine in presence of thiocolchicoside. The methods m entioned both simplicity and sensitivity, having excellent precision and ac curacy (100.31 +/- 0.63, 100.78 +/- 0.77 and 99.9 0+/-0.56 for glafenine an d floctafenine, respectively). The results were of comparable accuracy and reproducibility with the reported methods. (C) 2000 Elsevier Science B.V. A ll rights reserved.