title: Photodegradation of some quinolones used as antimicrobial therapeutics.
abstract: The photostability of the fluoroquinolones ciprofloxacin (CPX), ofloxacin (OFX), and fleroxacin (FLX) toward ultraviolet irradiation (UVA) and room light was investigated in dilute aqueous solutions. A series of photoproducts was observed by high-performance liquid chromatography (HPLC) for all three drugs. As little as 1 h of exposure to room light was enough for the formation of detectable amounts of CPX photoproducts. The major CPX photoproduct was characterized as a dimer by liquid secondary ion mass spectrometry, but its structure was not determined. Since irradiation of CPX results (as cited in ref/11) in a loss of antibacterial activity and since all substances, parent drugs as well as their photoproducts, are potential candidates for undesired drug effects, quinolone drugs should be strictly protected from all light during storage and administration.
authors.affiliation: Walther-Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: E M
authors.initials: EM
authors.lastname: Tiefenbacher
authors.forename: E
authors.initials: E
authors.lastname: Haen
authors.forename: B
authors.initials: B
authors.lastname: Przybilla
authors.forename: H
authors.initials: H
authors.lastname: Kurz
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D002939:Ciprofloxacin / Q000737:chemistry / Q000528:radiation effects; D016576:Fleroxacin / Q000737:chemistry / Q000528:radiation effects; D008027:Light; D013058:Mass Spectrometry; D015242:Ofloxacin / Q000737:chemistry / Q000528:radiation effects; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D015242:Ofloxacin; D016576:Fleroxacin