HIGH-PRESSURE LIQUID-CHROMATOGRAPHIC METHODS FOR CIPROFLOXACIN HYDROCHLORIDE AND RELATED-COMPOUNDS IN RAW-MATERIALS

High-pressure liquid chromatographic (HPLC) methods were developed for the analysis of ciprofloxacin hydrochloride raw materials. Method A i s for drug content and the determination of related compounds eluting before the drug, including the ethylenediamine analog of ciprofloxacin . Method B may be used for the determination of fluoroquinolonic acid and other related compounds eluting after the drug. Both methods requi re a 5 mu m Inertsil ODS2 column (150 x 4.6 mm), a mobile phase contai ning tetrahydrofuran, acetonitrile and buffer (0.005 M 1-hexane-sulpho nic acid sodium adjusted to pH 3.0 with 0.1 M phosphoric acid): 10:5:8 5 (v/v/v) for method A and 25:15:60 (v/v/v) for method B, and a flow r ate of 1 ml min(-1). Detection for method A is at 254 nm; a programmab le variable wavelength detector is required for method B: 254 nm for 1 2 min, then 220 nm for 23 min. The limit of quantitation of the relate d compounds was 0.05% or less. The precision of the assay method was l ower than 1.0%. Drug content in four raw material samples ranged from 98.7% to 101.6% calculated with reference to the anhydrous substance. The water content in these samples ranged from 5.9% to 7.8%. Total imp urity levels were 1.0% or lower. Levels of ethylenediamine analog and fluoroquinolonic acid were below 0.4%. A second analyst, using a diffe rent HPLC system and a column from a different supplier, repeated the analysis of two raw materials samples and obtained similar results.