Abstract
The absolute bioavailability (BA) of ciprofloxacin and fleroxacin were evaluated in 19 adult Nigerin male volunteers. Subjects meeting the selection criteria were randomized to recetive treatment either with fleroxacin (200 mg-i.v. and 200 mg oral dose) or ciprofloxacin (200 mg-i.v. and 250 mg oral dose). The i.v./oral or oral/i.v. switch was made after a one week washout period. Blood and nrine samples were collected at pre-determined time intervals over a 72 h period for analysis of drug levels.Following intravenous administration the maximum serum concentration (Cmax) was 2.7±1.06 mg/l for ciprofloxacin and 0.99±0.41 mg/l for fleroxacin; the area under the blood level curve (AUC) was 8.82±3.19 mg·h/l with ciprofloxacin and 8.52±3.83 mg·h/l with fleroxacin. Follwing oral administration the Cmax was 1.52±0.94 mg/l with ciprofloxacin and 0.57±0.08 mg/l with fleroxacin; the AUC was 9.87±4.10 and 7.55±1.42 mg·h/l, respectively. The absolute BA following oral administration was found to be 0.79±0.47 for ciprofloxacin and 1.01±0.78 for fleroxacin. When these BA results were corrected for renal clearance (Clr) and eliminiation half-life (t1/2) the values were reduced to 0.37±0.17 and 0.31±0.18, respectively, for ciprofloxacin and 0.53±0.23 and 0.99±0.38, respectively, for fleroxacin. Only 38% with ciprofloxacin and 59% with fleroxacin, of the administered dose, was excreted unchanged following oral administration.More work, however, needs to be done on ciprofloxacin to support and/or confirm the above findings. Fleroxacin, on the hand, exhibited a different trend from that observed in the literature with respect to Cmax and AUC where the values observed in this study were 3-4 fold lower than expected following identical doses, whilst on the other hand the observed BA profile in this study was consistent with literature trends.
