Spectrophotometric assay of metoclopramide hydrochloride in bulk and in dosage form

Abstract

A simple, reproducible and sensitive spectrophotometric method for assay of metoclopramide hydrochloride is investigated. The method is based on the Schiff's base formation reaction of metoclopramide with 1,2-naphoquinone sulphonate (NQS) as chromogenic reagent in the presence of micellar cetylperidinium chloride (CPC) and sodium carbonate in aqueous solution to give a highly coloured product with maximum absorption at 471 nm. Beer's law is obeyed in the range of 0.1-26 g/ml with a molar absorptivity of 4.124×104 l.mol-1.cm-1 and the limit of detection and quantitation are 0.0416 and 0.1386g/ml respectively. The accuracy (average recovery %) is 100.72 % and the relative standard deviation (RSD) is better than 0.44%. Also, it was found that the product formed was in ratio of 1:1 product with stability constant of 3.2×107 L.mol-1. The method is applied successfully to the assay of metoclopramide hydrochloride in pharmaceutical formulations and is agreed well with its certified value and with those of British pharmacopoeia method.