title: Identification of Furosemide Photodegradation Products in Water-Acetonitrile Mixture.
abstract: The aim of this study was to identify the chemical structure of the photodegradation products of furosemide in a water-acetonitrile mixture (1 : 1). Furosemide solution was irradiated with a D65 fluorescent lamp and the products were isolated by preparative HPLC. The fractions were evaporated to dryness in vacuo. The purity of the photodegradation products was measured by HPLC. The purity of products 1, 3, and 4 was greater than 90%, whereas that of product 2 was 13%, therefore, photodegradation product 2 was unstable. We identified photodegradation products 1 and 3 as 4-chloro-5-sulfamoylanthranilic acid and 4-hydroxy-N-furfuryl-5-sulfamoylanthranilic acid, respectively, by LC/MS and NMR. Additionally, we assumed that photodegradation product 4 was methyl 2-((furan-2-ylmethyl)amino)-4-hydroxy-3-(methyleneamino)-5-sulfamoylbenzoate by LC/MS and NMR. This showed that furosemide underwent hydrolysis and substitution, and reacted with the acetonitrile under the light of a D65 fluorescent lamp. We were furthermore able to determine the elution times of the photodegradation products of furosemide by applying the Japanese Pharmacopoeia chromatographic method for related substances to the isolated products.
authors.affiliation: Research & Development Division, Teva Pharma Japan Inc.
authors.forename: Shinji
authors.initials: S
authors.lastname: Katsura
authors.forename: Nobuo
authors.initials: N
authors.lastname: Yamada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakashima
authors.forename: Sumihiro
authors.initials: S
authors.lastname: Shiraishi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Furuishi
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Ueda
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D005665:Furosemide / Q000737:chemistry*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010782:Photolysis; D014867:Water / Q000737:chemistry; D062367:ortho-Aminobenzoates / Q000032:analysis
chemical_list: D000097:Acetonitriles; D062367:ortho-Aminobenzoates; D014867:Water; D005665:Furosemide; C010554:4-chloro-5-sulfamoylanthranilic acid; C032159:acetonitrile