The qualitative and quantitative determination of quinolones of first and second generation by capillary electrophoresis.

Capillary electrophoresis (CE) was applied to the study of 10 quinolones of first and second generation--nalidixic acid, oxolinic acid, pipemidic acid, cinoxacin, norfloxacin, ciprofloxacin, ofloxacin, pefloxacin, fleroxacin, and flumequine. Separation was performed on a fused silica capillary (75 microm-60 cm) using a phosphate buffer (pH 7.0, 125 mM). Detection was at 214 nm. Only norfloxacin and ciprofloxacin cannot be separated in this way. Because of the specificity of the method, the identification of the individual quinolones by their migration time was possible. The same system has been applied for the quantitative determination of quinolones in tablets and capsules. Excipients do not adversely affect the results. Some parameters (linearity, precision, accuracy) were validated. Especially the possibility of simultaneous quantification and identification of the active ingredient in the finished product is very attractive.