Spectrophotometric Determination of Metoclopramide Hydrochloride in Pharmaceutical Preparations UsingDiazotization Reaction

Kasim M Al-Abbasi,Lamya A Sarsam,Salim A Mohammed

doi:10.33899/rjs.2011.6509

Abstract

A simple, rapid and sensitive spectrophotometric method has been developed for the quantitative determination of metoclopramide hydrochloride in both pure form and in its pharmaceutical formulations. The method is based on diazotization of primary amine group of metoclopramide hydrochloride with sodium nitrite and nitric acid followed by coupling with 8-hydroxyquinoline in alkaline medium to form a pinkish – red coloured species, which showed a maximum absorption at 528 nm against reagent blank. Beer's law was obeyed over the concentration range of 5-300 µg / 25 ml. with a molar absorptivity 3.1×10 4 l.mol -1 .cm -1 . The method is suitable for the determination of metoclopramide hydrochloride in the presence of other ingredients that are usually present in dosage forms and the recoveries were obtained in the range of 98.9-100.0%. The method does not resort to temperature control or to solvent extraction. The effect of organic solvent on the spectrophotometric properties of the azo dye, the composition and stability constant have been worked out. The method has been successfully applied to the determination of metoclopramide in its pharmaceutical preparations ( tablet, syrup and drop ) .

Highlights

Metoclopramide hydrochloride (MCP), 4-amino-5-chloro-2-methoxy-N-(2diethylamino-ethyl) benzamide, is used as an anti-emetic in the treatment of some forms of nausea and vomiting and to increase gastrointestinal motility
Many analytical methods have been developed for the determination of MCP, the most of them are spectrophotometric methods based on diazotization and coupling with dibenzoylmethane (Revanasiddappa and Manju, 2001), benzoylacetone (Omran, 2005), aniline (Shah et al, 2005), β-naphthol (Patel et al, 2006), impramine hydrochloride (Revanasiddappa and Veena, 2006) and 2,4-dihydroxyacetophenone (Khalil, 2010). other spectrophotometric methods involve iona ssociation complex formation (Abdel-Gawad and El-Guindi, 1995), an oxidative coupling reaction (Al-Talib and Mohammed, 1996; Ahmed and Ali, 2006), charge-transfer complex formation (Al-Gabsha et al, 2004), Redox reaction (Amin and Ragab, 2003), or through formation of the Schiff's base with p(dimethylamino) cinamaldehyde (Moussa, 2000)
The potentiometric method requires about 250 mg of drug, whereas the UV method is liable to interferences from tablets excipients, and requires pre-extraction with chloroform

Summary

Introduction

Metoclopramide hydrochloride (MCP), 4-amino-5-chloro-2-methoxy-N-(2diethylamino-ethyl) benzamide, is used as an anti-emetic in the treatment of some forms of nausea and vomiting and to increase gastrointestinal motility. It was prepared by dissolving 0.20 g of 8hydroxyquinoline reagent (Hopkin and Williams) in 2 ml acetic acid and the volume was completed to 100 ml with distilled water in a volumetric flask. The absorbance of the formed coloured azo dye was measured at 528 nm against the corresponding reagent blank.

Results

Conclusion