Daunorubicin, daunorubicinol and DNA plasma kinetics after I.V. administration of daunorubican-DNA complex in the rabbit.

The pharmacokinetics of daunorubicin and daunorubin-DNA complex were studied in the rabbit after i.v. bolus injection and a 4hr infusion period. The plasma levels of daunorubicin and daunorubicinol were measured by high-pressure liquid chromatography and the DNA plasma levels by means of 125I labelled DNA. The results demonstrated a slower distribution of the complex; however, the more rapid decrease in the plasma levels of daunorubicin than that of DNA suggested that this complex essentially constitutes a "daunorubicin circulating pool" from which the drug diffuses more slowly than after the administration of uncomplexed daunorubicin.