[Pharmacokinetic studies on micronomicin in rats. Comparison of intramuscular and drip intravenous administration models].

Absorption, tissue distribution and excretion of micronomicin (MCR) were studied in rats after intramuscular or 30 minutes drip intravenous administration (10 mg/kg). Serum levels of MCR were measured by bioassay, enzyme immunoassay and high pressure liquid chromatography. The pharmacokinetic studies of MCR after intramuscular or drip intravenous administration were carried out using one-compartment open model or two-compartment open model, respectively. Among 3 assay methods, similar pharmacokinetic parameters of MCR were obtained. In the simulation of serum levels of MCR, the differences between the measured and calculated serum levels after intramuscular or drip intravenous administration were less than 19% of the former levels. After intramuscular or drip intravenous administration of MCR, similar changes of the organ (kidneys, lungs, spleen and liver) levels were observed. Urinary recovery rates of MCR amounted to 82.3% or 91.6% by 24 hours after intramuscular or drip intravenous administration, respectively. After intramuscular or drip intravenous administration of MCR, no metabolites were found in urine of rats.