title: Development and validation of an improved HPLC method for the control of potentially counterfeit isometamidium products.
abstract: Isometamidium, a mixture of related substances of which 8-(3-m-amidinophenyl-2-triazeno)-3-amino-5-ethyl-6-phenylphenanthridinium chloride hydrochloride (M&B4180A) is the principal active component, is the only chemical agent available for prophylaxis of veterinary trypanosomiasis. A method for the simultaneous quantitation of the major constituents M&B4180A, 3-(3-m-amidinophenyl-2-triazeno)-8-amino-5-ethyl-6-phenylphenanthridinium chloride hydrochloride (M&B38897), 7-(m-amidinophenyldiazo)-3,8-diamino-5-ethyl-6-phenylphenanthridinium chloride hydrochloride (M&B4250) and 3,8-di(3-m-amidinophenyltriazeno)-5-ethyl-6-phenylphenanthridinium chloride dihydrochloride (M&B4596) is described. The related substances are resolved on a Gemini C18 column (150 mm x 4.6 mm, 5 microm) using a mobile phase composed of a mixture of acetonitrile and 50 mM ammonium formate buffer pH 2.8 (25:75 v/v) at a flow rate of 1 ml/min with UV detection at 320 nm. The method is compatible with electrospray ionisation mass spectrometry and provides a tool for the control of substandard and counterfeit commercial preparations of isometamidium.
authors.affiliation: Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow G4 0NR, United Kingdom.
authors.forename: G J
authors.initials: GJ
authors.lastname: Schad
authors.forename: A
authors.initials: A
authors.lastname: Allanson
authors.forename: S P
authors.initials: SP
authors.lastname: Mackay
authors.forename: A
authors.initials: A
authors.lastname: Cannavan
authors.forename: J N A
authors.initials: JN
authors.lastname: Tettey
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000032:analysis / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004340:Drug Contamination / Q000517:prevention & control; D004996:Ethidium / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D007391:International Cooperation; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D010617:Phenanthridines / Q000032:analysis* / Q000737:chemistry / Q000592:standards; D012044:Regression Analysis; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D014344:Trypanocidal Agents / Q000032:analysis* / Q000737:chemistry; D019155:Veterinary Drugs / Q000032:analysis / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D010617:Phenanthridines; D014344:Trypanocidal Agents; D019155:Veterinary Drugs; C000702:isometamidium chloride; D004996:Ethidium