Rapid analytical procedure for neomycin determination in ointments by CE with direct UV detection

The purpose of this study was the development of an analytical methodology for the determination of neomycin in a complex pharmaceutical preparation. The simplified methodology consisted of a primary liquid-liquid extraction, employing a mixture of chloroform and water (1.25:1, v/v) and subsequent analysis by CE applying a capillary zone electrophoresis method with a 30 cm (effective length), 50 microm (internal diameter) polyacrylamide-coated silica capillary. The background electrolyte consisted of 35 mM phosphate and 15 mM acetate buffer set at pH 4.7, under normal polarity mode and direct UV detection at 200 nm. The separation of the target analyte from the complex matrix was accomplished in less than 3 min. The analytical method was successfully validated in order to verify its proper selectivity, linearity, accuracy and precision for the goal intended and its further implementation for the quantification of the active compound in the pharmaceutical speciality for quality control.