Flow-injection chemiluminescent determination of metoclopramide hydrochloride in pharmaceutical formulations and biological fluids using the [Ru(dipy)32+]–permanganate system

A flow-injection (FI) methodology using (2,2′-dipyridyl) ruthenium(II) [Ru(dipy)32+] chemiluminescence (CL) was developed for the rapid and sensitive determination of metoclopramide hydrochloride. The method is based on the CL reaction of metoclopramide with Ru(dipy)32+ and KMnO4 in a sulfuric acid medium. Under the optimum conditions, a calibration graph was obtained over the concentration range 0.005–3.5 μg ml−1 with a limit of detection (S/N=2) of 1 ng ml−1. The correlation coefficient was 0.99993 (n=8) with a relative standard deviation of 0.48% for 10 determinations of 1 μg ml−1 of drug. The method was successfully applied to the determination of metoclopramide in pharmaceutical preparations and biological fluids after IP administration of 25 mg kg−1 dose to rats. The elimination half-life was 2.5±0.4 h.