Bioavailability and half-life of two preparations of flucloxacillin

The comparative bioavailability of two formulations of 250 mg flucloxacillin sodium capsules in eight fasted healthy volunteers was examined. There were no significant differences in the peak serum concentrations, time to peak concentration or area under the curves with the two formulations indicating that the two batches studied did not differ in bioavailability. The serum elimination half-life of flucloxacillin was 1.31-1.39 hours, and six hours after administration of a single 250 mg dose the serum concentration of flucloxacillin was 0.46 micrograms/ml.