Studies on the Metabolic Fate of ³H-TJN-101 (III) : Absorption, Distribution and Excretion after Multiple Oral Administration to Rats.

Abstract

The absorption, distribution, and excretion of ³H-TJN-101 in male rats were studied following 21-day period of daily oral administration (4 mg/kg/day).
1. The radioactivity level in the blood at 1 and 24hr after oral administration rose as the number of doses increased, and the concentration at 1 and 24hr after the 21st dose was 1.6 and 3.9 times higher, respectively, than those after the first dose. The elimination half-life from 48hr after the 21st dose was 2.9 times longer than that after the first dose.
2. The concentrations of radioactivity in most tissues at 24hr after daily administration rose as the number of doses increased, but the elimination was slower in comparison with that after single dose.
3. Excretion of radioactivity in the urine and feces was almost constant after the 4th dose. One hundred and sixty-eight hr after the 21st dose, 12.9% and 80.6% of the radioactivity administered was excreted in the urine and feces, respectively.