ABSTRACT
In the photochemical degradation of ciprofloxacin, 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(piperazinyl)-3-quinolone carboxylic acid, two major decomposition products are formed in acidic solution. The main degradation product, after both artificial and daylight exposure, was 7-amino-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolone carboxylic acid. This product was also the dominating compound after more than 5 h irradiation with a high-pressure mercury lamp in aqueous solutions at pH < or = 2 when the solvent additionally contained water-miscible organic solvent. The structure of the isolated compound was elucidated on the basis of the chemical behaviour in thin-layer and high-performance liquid chromatography, and of information from infrared, ultraviolet, mass and nuclear magnetic resonance spectra.
Subject(s)
Anti-Infective Agents/chemistry , Ciprofloxacin/chemistry , Anti-Infective Agents/radiation effects , Chromatography, High Pressure Liquid , Ciprofloxacin/radiation effects , Hydrogen-Ion Concentration , Light , Magnetic Resonance Spectroscopy , Mass Spectrometry , Photochemistry , Ultraviolet RaysABSTRACT
Ciprofloxacin decomposes photochemically in aqueous solutions at acidic pH forming two major degradation products. One of the products, isolated from irradiated solutions by flash chromatography, was 7-[(2-aminoethyl)amino]-1-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxo-3-quinoline carboxylic acid. The compound was an intermediate in the photochemical process, which degraded after longer exposure with a high-pressure mercury lamp to an aromatic amino-compound, 7-amino-1-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxo-3-quinoline carboxylic acid. The structure of the intermediate was elucidated on the basis of information from ultraviolet, mass and nuclear magnetic resonance spectra.
