Determinação quantitativa de gemifloxacino por cromatografia líquida de alta eficiência e eletroforese capilar

Abstract

Gemifloxacin (GMFLX) is a recently developed fluorquinolone antibacterial agent presenting a broad spectrum of activity. The aim of this study was to develop and validate selective and sensitive methods for quantitative determination of GMFLX in coated tablets by high performance liquid chromatography (HPLC) and capillary zone electrophoresis (CZE). The HPLC method was carried out on a LiChrospher 100 RP-8e, 5μm (125 x 4 mm) column with a mobile phase composed of tetrahydrofuranwater (25:75, v/v) with 0.5% of triethylamine and pH adjusted to 3.0 with orthophosphoric acid. The retention time of GMFLX was 2.3 min. The method showed good linearity (r 0.9989) with good precision (RSD < 0.89%). Accuracy was expressed as percentage recovery (R% ≤ 101.3%). The CZE method was performed using 50 mmoL sodium tetraborate buffer (pH 8.6). Samples were injected hydrodynamicaly (0.5 psi, 5s) and the electrophoretic system was operated under normal polarity, at +20kV and temperature of 18°C. A fused-silica capillary 40.2 cm (30 cm effective length) x 75 μm (i.d.) x 375 μm (o.d.) was used. This method presented a migration time of 2.55 min for GMFLX and 1.66 min for metoprolol (internal standard). The evaluated parameters presented acceptable linearity (r 0.9992), precision (RSD < 4.2%) and accuracy (R%≤ 101.8%). Both, HPLC and CZE method could be interesting and efficient techniques to be applied for quality control in pharmaceutical industries.