K. Torniainen et al., STRUCTURE ELUCIDATION OF A PHOTODEGRADATION PRODUCT OF CIPROFLOXACIN, Journal of pharmaceutical and biomedical analysis, 15(7), 1997, pp. 887-894
In the photochemical degradation of ciprofloxacin, 1 uoro-1,4-dihydro-
4-oxo-7-(piperazinyl)-3-quinolone carboxylic acid: two major decomposi
tion products are formed in-acidic solution. The main degradation prod
uct, after both artificial and daylight exposure, was 7-amino-1 -cycio
plopyl-6-fluoro- 1,4-dihydro-4-oxo-3-quinolone carboxylic acid. This p
roduct was also the dominating compound after more than 5 h irradiatio
n with a high-pressure mercury lamp in aqueous solutions at pH less th
an or equal to 2 when the solvent additionally contained water-miscibl
e organic solvent. The structure of the isolated compound was elucidat
ed on the basis of the chemical behaviour in thin-layer and high-perfo
rmance liquid chromatography, and of information from infrared, ultrav
iolet, mass and nuclear magnetic resonance spectra. (C) 1997 Elsevier
Science B.V.