Determination of local anaesthetics and their impurities in pharmaceutical preparations using HPLC method with amperometric detection

• Published in: Journal of pharmaceutical and biomedical analysis 2005-04, Vol.37 (5), p.913-918
• Main Authors: FIJAŁEK, Zbigniew, BACZYNSKI, Emil, PIWONSKA, Agata, WAROWNA-GRZESKIEWICZ, Małgorzata
• Format: Article
• Language: English
• Subjects: 2,6-Dimethylaniline; Analysis; Analytical, structural and metabolic biochemistry; Anesthetics, Local - analysis; Biological and medical sciences; Chromatography, High Pressure Liquid - methods; Drug Contamination; Electrochemistry; Fundamental and applied biological sciences. Psychology; General pharmacology; HPLC method with amperometric detection; Local anaesthetics; Medical sciences; o-Toluidine; Pharmaceutical Preparations - analysis; Pharmacology. Drug treatments
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2004.09.025

A method for the determination of local anaesthetics and their impurities – 2,6-dimethylaniline and o-toluidine – by high-performance liquid chromatographic method with amperometric detection has been developed. The analysis was performed in an isocratic mode on a reversed phase Luna column 5 μm C-18 (100 mm × 4.6 mm). A mobile phase [0.01 mol l −1 Tris buffer of pH 7.9:acetonitrile (45:55)] was selected for the separation and determination of studied anaesthetics and their impurities. Chromatograms were recorded for 500 s by means of an amperometric detector at a potential of +1.0 V of the glassy carbon electrode versus the reference electrode Ag/AgCl. The proposed liquid chromatographic method was successfully applied to the analysis of commercially available pharmaceutical preparations. The limit of the detection for 2,6-dimethylaniline and o-toluidine was 0.8 ng ml −1. The limit of qantitation, considering a signal to noise ratio was 1.5 ng ml −1. The method developed in this study is sensitive and selective and can be applied to routine studies of pharmaceuticals in the form of cream and injection.