Determination of fluoroquinolone antibacterials in pharmaceutical formulations by capillary electrophoresis

To meet the requirement of quantitative analysis, this work reinvestigated the parameters relevant to the separation of seven fluoroquinolone antibact erials, ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, ofloxacin, pefl oxacin, and sparfloxacin, based on the method developed previously in our l aboratory. With the optimum conditions obtained: electrophoretic media - 65 mM sodium berate, 35 mM sodium dihydrogen phosphate, 60 mM sodium cholate, pH 7.3 / acetonitrile (72 : 28, v/v); fused silica capillary - 50 mu m I.D ., total length 67 cm, detection length 52 cm; hydrodynamic injection 60 mb ar, 3 sec; voltage - 27 kV; temperature - 25 degrees C and detection wavele ngth - 275 nm, the fluoroquinolones were well separated within 8.5 min. Aft er being validated the method was used for the assay of the formulation pro ducts. The assay results were within 95 similar to 105 % of their label cla ims. The method should be applicable to the analysis of these and other sim ilar formulation products containing these drugs.