Preclinical pharmacokinetics of the antitumor antibiotic deshydroxy-sparsomycin in beagle dogs.

Sparsomycin (Sm) is a well known inhibitor of protein synthesis with anticancer potential. In order to minimize toxicity of this drug and increase its activity, several analogues were synthesized. Deshydroxy-Sm (dSm) appeared to be a good candidate for further investigations because of its lower toxicity and significantly higher antitumor activity in several ascitic tumors in mice. Pharmacokinetic evaluation in beagle dogs was performed using either single iv bolus or continuous infusion administrations. The drug was eliminated with a terminal t1/2 beta of 0.8 +/- 0.08 hours (48 +/- 5 minutes). The mean volume of distribution was 0.4 +/- 0.06 l.kg-1. The mean total body clearance was 6.4 +/- 0.8 ml.min-1.kg-1. The drug is eliminated mainly by the kidneys (54%). Active tubular secretion and active tubular reabsorption of the drug were observed. The pharmacokinetics was linear until the lethal dose. The results of this study provided additional data useful in selection of potentially useful analogues for further preclinical studies.