The Spectrophotometric Determination of Antiepileptic Drug in Standard and Pharmaceutical Formulations by Diazotization Coupling Reaction and Some Metals Complexes

Abstract

A rapid, sensitive spectrophotometric method has been proposed for the determination of Gabapentin antiepileptic drug in pure and in pharmaceutical preparations was developed. The method is based on the coupling reaction between Gabapentin with8-hydroxy quinoline in to form an olive colored azo dye which gave maximum absorption at 365nm.The optimum reaction conditions like: pH, Temperature affected and time of reaction were evaluated. The ligand and its complexes were characterized by UV-visible spectroscopy, infrared FT-IR, (C.H.N.) analysis and Molar conductivity. The ratio of (metal: ligand) of all complexes was (1:2) by using molar ratio method and jop’s method. Beer’s law is obeyed for ligand and its complexes with (Cu2+, Ni2+,Cd2+, Co2+ and Zn2+) in concentration ranges ( 2 - 20, 1.5 - 25, 1 - 20, 2 - 25 and 2-30μg ml-) respectively . The molar absorptivity also calculated and it's found to be (1.396×104, 2.0208×104, 2.295×104, 1.684×104 and 1.862×104 L.mol-1.cm-1) for Cu2+, Ni2+,Cd2+, Co2+ and Zn2+complexes respectively. The detection of limit and quantification of limits are also calculated. The stability constant of complexes equal to(3.273×106, 1.695×102, 7.859×106, 1.851×105 and 1.588×102 L2.mol-2) for Cu2+, Ni2+,Cd2+, Co2+ and Zn2+ complexes respectively. The method is successfully used for the determination of Gabapentin in pharmaceutical formulations. Analytical parameters like accuracy and precision for the method have been established and evaluated statistically to assess the application of the proposed method. No interferes observed in the proposed method. The complexion with five ions (Cu2+, Ni2+, Cd2+, Co2+ and Zn2+) were studying. The aim of present work was devoted to investigate the reaction between Gabapentin and 8-hydroxy quinoline to form color Azo dye and use this product in the development of sensitive and simple spectrophotometric method for determination of Gabapentin in its pure and pharmaceutical preparations and spectrophotometric studies of a azo dye formed and it's metal complexes with Cu2+, Ni2+, Cd2+, Co2+ and Zn2+ ions.