Original Articles
Abdalla Ahmed Elshanawany, Abd
Abstract
A spectrophotometric method was developed for the determination of six antipsychotic drugs, namely, Ethosuximide (I), Amisulpride (II), Flupentixol (III), Citalopram (IV), Buspirone (V) and Fluoxetine (VI) through charge transfer (CT) complex formation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,5-dichloro-3,6-dihydroxy-1,4- benzoquinone (p-chloranilic acid, CL) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). These π acceptor systemswere found to react with these drugs to produce stable complexes. The formation of such complexes with CL were synthesized and characterized by elemental analysis,FT-IR and UV–VIS measurements. The different experimental parameters that affect the spectrophotometric intensity were carefully studied, at the optimum reaction condition the rectilinear calibration graphs were obtained in the concentration range 0.0005 -50 μg/ml for the investigated drugs.The limits of detection ranged from 0.0002 to 0.016μg/ml. The proposed procedures could be applied successfully for the determination of the investigated drugs in their pharmaceutical dosage forms with a good precision and accuracy compared to official and reported methods. Also they were applied to determine spiked human plasma samples. The Stoichiometry of the CT complexes of DDQ, TCNQ and p-CL with the proposed drugs determined by Job’s method and the stability constants (Kct) for the reported CT complexes were calculated according to the Benesi–Hildebrand equation.