Simultaneous Quantitative Determination of Eight Fluoroquinolones by High-Performance Liquid Chromatography with UV Detection using a C18 Monolithic Column

In the present work, an accurate and reliable reversed-phase liquid chromatographic method (RP-HPLC) for the simultaneous quantitative determination of eight fluoroquinolones (enoxacin, norfloxacin, ciprofloxacin, levofloxacin, moxifloxacin, enrofloxacin, sparfloxacin, and marbofloxacin) in bulk form and in pharmaceutical products is described. The optimum separation of the selected pharmaceutical compounds was achieved on a Chromolith® RP-18 endcapped column with a mobile phase consisting of acetonitrile and phosphate buffer (pH 5.5; 15 mM) pumped at 2 mL min-1. UV detection of all compounds was accomplished at 280 nm. The procedure was validated according to the International Conference on Harmonization (ICH) Q2 (R1) guideline. Good linear relationships were obtained (r ≥ 0.996) for all the analytes over their respective concentration ranges. Intra- and inter-day precision were less than 2 %. Recoveries were held in the range of 98 to 102 %. The developed method was successfully applied to the analysis of pharmaceutical products.