Colorimetric methods for the assay of nomifensine maleate

• Published in: Journal of pharmaceutical and biomedical analysis 1989, Vol.7 (1), p.23-28
• Main Authors: Abounassif, Mohammad A., Mohamed, Mohamed E., Aboul-Enein, Hassan Y.
• Format: Article
• Language: English
• Subjects: Aminosalicylic Acid; Analysis; Biological and medical sciences; Bratton—Marshall reagents; colorimetric determination, diazotisation; Colorimetry; coupling with p-aminosalicylic acid; General pharmacology; Indicators and Reagents; Medical sciences; Nomifensine - analysis; Nomifensine - chemistry; Nomifensine maleate; pharmaceutical analysis; Pharmacology. Drug treatments; Spectrophotometry, Ultraviolet
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/0731-7085(89)80063-9

Two colorimetric methods are reported for the assay of nomifensine maleate. The methods are based on the coupling between the diazotised form of nomifensine maleate and (i) N-(1-naphthyl)-ethylene diamine dihydrochloride (Bratton—Marshall reagent) and (ii) p-aminosalicylic acid (PAS). The optimum conditions for the reactions were investigated. The coupled products exhibit maximum absorbance at 470 and 435 nm for the Bratton—Marshall and PAS reagents, respectively. With PAS, a linear relationship has been established between absorbance ( A max) and concentration of nomefensine maleate over the range 2–12 μg ml −1. Similarly, with the Bratton—Marshall reagent, a linear relationship exists in the concentration range 2–16 μg ml −1. The calculated mean percent recoveries for nomifensine maleate in the commercial capsules (Merital® 25 mg) using the Bratton—Marshall and PAS reagents were 97.53 ± 0.71 and 100.28 ± 1.32, respectively. Similarly, for the added recoveries, the percentage obtained were 99.01 ± 0.46 and 100.03 ± 1.03, respectively.