Table 2

Pharmacokinetic parameters for (+) and (−) enantiomers of gemifloxacin following administration of racemic gemifloxacin mesylate to the rat and the dog

OralIntravenous
(+) Enantiomer(−) Enantiomer(+) Enantiomer(−) Enantiomer
Rat
C max(ng/ml)158  ± 43139  ± 321200  ± 174974  ± 109
T max(h)1.31.3N.A.N.A.
 AUC (ng · h/ml)2-a 715  ± 107640  ± 872240  ± 2551970  ± 269
T 1/2 (h)2.0  ± 0.52.0  ± 0.41.5  ± 0.21.6  ± 0.1
 CLb(l/h/kg)N.D.N.D.1.2  ± 0.11.4  ± 0.2
 Vss (l/kg)N.D.N.D.3.8  ± 0.54.8  ± 0.6
F (%)11  ± 211  ± 2N.A.N.A.
Dog
C max (ng/ml)660  ± 260710  ± 2902480  ± 2402740  ± 320
T max(h)1.51.5N.A.N.A.
 AUC (ng · h/ml)2-a 4760  ± 25904600  ± 26606650  ± 11606770  ± 1210
T 1/2 (h)5.6  ± 1.65.0  ± 2.05.0  ± 0.94.7  ± 0.8
 CLb(l/h/kg)N.D.N.D.0.4  ± 0.10.4  ± 0.1
 Vss (l/kg)N.D.N.D.4.4  ± 1.14.0  ± 0.8
F (%)60  ± 3657  ± 34N.A.N.A.

Racemic gemifloxacin mesylate was administered orally at 30 and 10 mg of fb/kg to the rat and dog, respectively, and intravenously at 10 mg of fb/kg to both species. Data are mean values ± S.D. (n = 3–4) except for Tmax, which are median values.

  • N.A., not applicable; N.D., not determined;Cmax, maximum concentration;Tmax, time to reach maximum concentration;T1/2, apparent terminal phase elimination half-life; CLb, blood clearance; F, bioavailability.

  • 2-a  AUC (0–inf).