[Bone and suppurative lesion distribution of antimicrobial agents (ampicillin and ofloxacin) in experimental infected rabbits].

Using Streptococcus milleri and Bacteroides fragilis in the mandibula of the domestic rabbit, a jaw-bone infected model was prepared; ampicillin (ABPC) a penicillin derivative and ofloxacin (OFLX) a pyridonecarboxylic acid derivative, were administered orally, injected intramuscularly, or infused intravenously; their concentration in the pus, mandibula, supramaxilla, humerus, femur, sternum, ilium and serum were measured. Pharmacokinetic studies compared the penetration. (1) By oral administration, the maximum ABPC concentration in the pus and bone tissues was 5.9 to 34.3% of the serum, by intramuscular injection 10.4 to 27.5% and by i.v. infusion 12.1 to 42.4%. (2) The maximum concentration of orally administered OFLX in the pus and bone tissues was 52.5 to 111.7% of the serum, by intramuscular injection 56.4 to 100.3% and by i.v. infusion 61.2 to 121.8%. (3) When administered orally, injected intramuscularly, or infused intravenously ABPC showed good penetration into the pus, mandibula and ilium, and OFLX into the pus, sternum and ilium. When infused intravenously, OFLX in the pus and bone tissues was higher than the MIC of both strains. (4) When ABPC was administered as under 3 routes, T1/2 was longer in the pus and most bone tissues than in the serum. T1/2 of OFLX was shorter in most bone tissues by all administration routes than in serum, T1/2 was longer for OFLX than for ABPC, except when orally administered. (5) AUC of ABPC was in the order of intravenous infusion, intramuscular injection and oral administration. About the same AUC of OFLX was shown after i.v. infusion and i.m. injection, both values being about double after oral administration. In all administration routes, AUC of pus surpassed AUC of serum and AUC of OFLX greatly surpassed that of ABPC.