title: Determination of photostability and photodegradation products of moxifloxacin in the presence of metal ions in solutions and solid phase. Kinetics and identification of photoproducts.
abstract: Photostability of moxifloxacin (MOXI) after UVA irradiation in solutions and solid phase, with and without participation of Cu(II), Zn(II), Al(III), and Fe(III) was tested. The studies were carried out by the TLC-densitometric method and LC-MS/MS method. Elaborated and validated chromatography-densitometric method was used for assaying. It was shown that the number and type of photoproducts depend on the environment and type of the metal ion. The studied ions enhanced the degradation of MOXI in solutions, and the influence of Cu(II) and Fe(III) ions was higher than that of Zn(II) and Al(III) ions. In solid phase, in contrast to solutions, all metal ions decreased the photodegradation, however the influence of ions, Al(III) and Zn(II), was weaker than that of Cu(II) and Fe(III) ions. Identification of the degradation products performed with LC-MS/MS and (1)H NMR identified them as: 1-cyclopropyl-6-fluoro-7-amino-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, 1-cyclopropyl-6-fluoro-8-methoxy-4-oxo-7-(2-oxo-octahydro-6H-pyrrolo[3,4-b]pyridine-6-yl)-1,4-dihydroquinoline-3-carboxylic acid, 7-[3-hydroxyamino-4-(2-carboxyethyl)pyrrolidin-1-yl]-1-cyclopropyl-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid.
authors.affiliation: Jagiellonian University, Medical College, Pharmaceutical Faculty, Department of Inorganic and Analytical Chemistry, Medyczna 9, 30-688, Krakow, Poland.
authors.forename: Urszula
authors.initials: U
authors.lastname: Hubicka
authors.forename: Jan
authors.initials: J
authors.lastname: Krzek
authors.forename: Barbara
authors.initials: B
authors.lastname: Żuromska
authors.forename: Maria
authors.initials: M
authors.lastname: Walczak
authors.forename: Marek
authors.initials: M
authors.lastname: Żylewski
authors.forename: Daniel
authors.initials: D
authors.lastname: Pawłowski
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D004355:Drug Stability; D024841:Fluoroquinolones; D007700:Kinetics; D008670:Metals / Q000737:chemistry*; D000077266:Moxifloxacin; D010782:Photolysis; D011804:Quinolines / Q000737:chemistry*; D012996:Solutions
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D008670:Metals; D011804:Quinolines; D012996:Solutions; D000077266:Moxifloxacin