[Studies on the metabolic fate of 14C-rokitamycin. IV. Absorption, metabolism and excretion in dogs].

Absorption, metabolism and excretion of rokitamycin (TMS-19-Q), were studied after oral (50 mg/kg), intraduodenal (50 mg/kg) and intravenous (10 mg/kg) administrations of 14C-TMS-19-Q to male dogs. Maximum blood and plasma concentrations of the drug reached at 2 hours after oral administration, and they were 11.1 and 14.3 micrograms/ml, respectively. Maximum blood and plasma concentrations reached at 30 minutes after intraduodenal administration, and they were 10.7 and 12.0 micrograms/ml, respectively. Blood and plasma concentrations at 3 minutes after intravenous administration were 8.4 and 11.1 micrograms/ml, respectively. At 24 hours, they were 0.6 and 1.7 micrograms/ml, respectively. During the first 72 hours period after oral administration, 12.8 and 82.6% of the dose were excreted in the urine and feces, respectively. A total recovery rate was 95.4% of the dose. During the first 72 hours period after intravenous administration, 19.4 and 75.3% of the dose were excreted in the urine and feces, respectively. A total recovery rate was 94.7% of the dose. During the first 24 hours period after intraduodenal administration, 18.0 and 48.3% of the dose were excreted in the urine and bile, respectively. A total recovery rate was 66.3% of the dose. Major metabolic reactions on TMS-19-Q were deacylation and hydroxylation, and the major metabolites of TMS-19-Q found in the plasma urine and bile after intraduodenal administration to dogs were 10"-OH-TMS-19-Q, LM A7, LM V and 14-OH-LM V.