Rapid, sensitive and validated spectrophotometric methods for the determination of antiepileptics gabapentin (GAB) in pure forms and in pharmaceutical formulations was developed. The method is based on the formation of complex between drug and the chromogenic reagent 4-Chloro-7-Nitrobenzo-2-Oxa-1,3-Diazole (NBD-Cl) producing complex in methanolic medium which showed an absorption maximum at 576 nm. The optimization of the reaction conditions such as: pH, the volume of buffer, and reaction time were investigated. Beer’s law is obeyed in the concentration ranges 10-60 μg ml-1. The molar absorptivity, detection and quantification limits are also calculated. The correlation coefficients were 0.9996 with a relative standard deviation (RSD%) of 45.87. The method successfully applied to the determination of GAB in pharmaceutical formulation.
Tamadr Omer Mohammed and Abdalla A Elbashir