Spectrophotometric Methods for the Determination of Anti-Emetic Drugs in Bulk and in Pharmaceutical Preparations

• Published in: Analytical Sciences 2003, Vol.19(5), pp.747-751
• Main Authors: AMIN, Alaa S., RAGAB, Gamal H.
• Format: Article
• Language: English
• Subjects: Analysis; Antiemetics - analysis; Biological and medical sciences; Chromatography, High Pressure Liquid; Dosage Forms; General pharmacology; Medical sciences; Pharmaceutical Preparations - chemistry; Pharmacology. Drug treatments; Sensitivity and Specificity; Spectrophotometry, Ultraviolet - methods
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.19.747

Four rapid, simple, reproducible and sensitive methods (A-D) for assaying domperidone (I) and metoclopramide (II) in a bulk sample and in dosage forms were investigated. The first and second methods, A and B, are based on the oxidation of I and/or II by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of tris-complex upon reactions with Fe3+-o-phen and/or Fe3+-bipy mixture in an acetate buffer solution of the optimum pH-values was demonstrated. Methods C and D involve the addition of excess Ce4+ and the determination of unreacted oxidant by a decrease of the red color of chromotrope 2R (C2R) at a suitable λmax of 528 nm for method C, or a decrease in the orange pink color of Rhodamine 6G (Rh6G) at a suitable λmax value of 525 nm for method D. A regression analysis of Beer-Lambert plots showed a good correlation in the concentration range of 0.2 - 5.8 μg ml-1. The apparent molar absorptivity, Sandell sensitivity, detection and quantification limits were calculated. For a more accurate analysis, the Ringbom optimum concentration ranges are 0.35 - 5.6 μg ml-1. The developed methods were successfully applied to the determination of domperidone and metoclopramide in bulk and pharmaceutical preparations without any interference from common excipients.