Simultaneous determination of amoxicillin and clavulanic acid in pharmaceutical preparations by capillary zone electrophoresis

Clavulanic acid enhances the antibacterial spectrum of amoxicillin by rendering most β-lactamase producing isolates susceptible to the drug. A fast, simple and efficient capillary electrophoresis method was developed for the simultaneous determination of amoxicillin and clavulanic acid from complex mixtures. Using a 25 mM sodium tetraborate as background electrolyte at a pH of 9.30, + 25 kV applied voltage, 25 °C system temperature, UV determination at 230 nm; we succeeded in simultaneous separation of amoxicillin and clavulanic acid in approximately 2 minutes. The analytical performance of the method was evaluated in terms of reproducibility, precision, accuracy, and linearity. The optimized analytical method was applied for the determination of the two analytes from combined commercial pharmaceutical preparations. This CE method is fast, inexpensive, efficient, and environmentally friendly when compared with the more frequently used high performance liquid chromatography methods described in the literature.