Abstract
The absorption, distribution and excretion of 14C-tulobuterol following daily dermal application at 10 mg/kg for 7 days was examined in rats.
1. Blood radioactivity reached a steady state after the 4th dose. After the final dose, blood radioactivity showed maximum values of 506.1 ng eq./ml at 5 hr and disappeared with T1/2 of 19.4 hr as also noted for T1/2 after a single application (15.7 hr).
2. After the final application, the radioactivity in most tissues was higher than after a single application. Elimination of radioactivity in tissue was basically the same as after a single application.
3. Within 168 hr after the 7th application, urinary and fecal excretion was 53.8 and 36.3% of the dose, respectively. Recovery in urine and feces and from residue in the removed tape was 98.6% of the dose.
