Exploiting the Diazotization Reaction of 8-hydroxyquinoline for Determination of Metoclopramide-hydrochloric acid in Pharmaceutical Preparations

Abstract

A sample, fast, precise and accurate spectrophotometric method to the quantitative determination of metoclopramide hydrochloride (MCP) in pure and pharmaceutical preparations, a simple, sensitive and high-purity method has been developed. This method is based on the diazotization of the primary amine group of metoclopramide hydrochloride by reaction hydrochloric acid with sodium nitrite followed by conjugation in an alkaline medium with 8-hydroxyquinoline against the reagent blank. The effect of several acids like hydrochloric, nitric, phosphoric, and sulfuriHc acid. That found hydrochloric acid the most excellent acid, to give the maximum absorption and sensitivity and the best volume NaNO2 solution about 1 and 3 mL of an 8-hydroxyquinoline reagent gives high intensity and stability to the color formed, also azo dye give a maximum absorption and best sensitivity after 10 minutes and the color remains stable about 1-hour. Where the concentration range was 1-20 mg/L, it was found that it obeys law Beer-Lambert correlation coefficient (R2 =0.9997). They have a detection limit LoD (0.274 μg mL-1) and limit of Quantitation LoQ (0.915 μg mL-1), respectively. This method has also been used in many pharmaceutical preparations (capsules, tablets and syrup) to determine the drug metoclopramide.