[Modelling of rifampicin pharmacokinetics in experimental animals administered the drug intravenously and internally].

Pharmacokinetics of rifampicin on its single intravenous and oral administration to rats in doses of 25 and 50 mg/kg and on its intravenous administration to dogs in doses of 8 and 25 mg/kg was studied. When the antibiotic was administered intravenously to the animals, its pharmacokinetics was nonlinear. The linearity distortion in the rats was lower than in the dogs. However, the pharmacokinetic data relevant to the antibiotic administration in the above doses were satisfactorily described by the biexponential equation. The absolute extent of rifampicin systemic absorption following oral administration to the rats was 60 to 85 per cent. Tissue availability of the antibiotic on its intravenous administration was lower than that on its oral administration.