Determination of minor impurities in temafloxacin hydrochloride by high-performance liquid chromatography

Minor impurities in the antibacterial agent temafloxacin hydrochloride were determined using high-performance liquid chromatography. Manufacturing impurities and degradation products were separated using a reversed-phase system with gradient elution. Detector response was linear for the individual impurities to approximately 50 micrograms/ml which represents 2.5% of the drug concentration. The procedure provides quantitation of impurities to approximately the 0.05% level with precision (relative standard deviations) of 4.7% to 29% in typical bulk drug lots. A variety of reversed-phase columns were evaluated for the assay method with optimum resolution achieved using a 5-microns Nucleosil C18 packing.