A New Spectrophotometric Azo-Coupling Method for the Determination of Metoclopramide

This study presents a new, simple, and sensitive spectrophotometric method for the determination of metoclopramide in both pure form and pharmaceutical preparations.The method is based on an azo-coupling reaction between metoclopramide and α-naphthol under optimized experimental conditions.The influence of various factors, such as acid type and concentration, base type, reagent volume, reaction time, solvent, and temperature, was investigated to achieve maximum color intensity and stability of the formed product.The absorbance of the colored complex was measured at 613 nm, and Beer's law was obeyed in the range of 1-12 µg/ml.The molar absorptivity and Sandell's sensitivity were 28840.76L•mol⁻¹•cm⁻¹ and 0.013699 µg/cm², respectively.The detection and quantification limits were 0.0137 µg/ml and 0.0186 µg/ml.The proposed method showed excellent accuracy, precision, and recovery (about 101%), and can be successfully applied for the determination of metoclopramide in pharmaceutical dosage forms.