ABSTRACT:
Electrochemical behavior and differential pulse polarographic determination of flucloxacillin (FLUX) in pure and pharmaceutical dosage forms using drop mercury electrode (DME) has been studied. The method involves the electrochemical behavior of flucloxacillin at DME by differential pulse polarographic analysis (DPPA). Various parameters (electrolyte, pulse time, pulse amplitude, etc.) affecting the FLUX determination were examined. Different buffer solutions were used over a wide pH range (2.5–10.0). The best definition of the analytical signals was found in Britton–Robinson buffer (0.04 M) at pH 4.0. Under the optimum conditions, liner calibration graph, Ip=f(CFLUX) was obtained in the concentration ranges of 1x10-7 M (0.0494 µg.mL-1) to 2x10-5 M (9.8780 µg.mL-1), at -975 to -1000 mV (versus Ag/AgCl) with relative standard deviations (RSD) did not exceed 2.1% for the concentrations of FLUX (0.0494 µg.mL-1). Regression analysis showed a good correlation coefficient (R2=9997) between Ip and concentration over the mentioned range. The limit of detection (LOD) and the limit of quantification (LOQ) were to be 0.0034 and 0.0102 µg.mL-1, respectively. The proposed method was validated for linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ), robustness and specificity. The developed method is applicable for the determination of FLUX in pure and different dosage forms in presence a same amount of amoxicillin (AMOX) with average recovery of 99.8 to 101.2% and the results are in good agreement with those obtained by the HPLC reference method.