| Popis: |
The absorption, excretion and metabolism of Betaxolol were investigated in male and female dogs after oral or intravenous administration of 14C-Betaxolol.1. After oral administration of 14C-Betaxolol(1mg/kg) to male and female dogs, the plasma levels of radioactivity reached the maxima at 2hr, and then decreased with half-lives of 1.7hr (T1/2α) and 14.7hr (T1/2β) in males, and 2.1hr (T1/2α) and 13.2hr (T1/2β) in females, respectively. Plasma levels of unchanged Betaxolol reached the maxima at 2hr after dosing, and then decreased rapidly with half-lives of 4.Ohr and 4.4hr in males and females, respectively.2. After intravenous administration of 14C-Betaxolol(1mg/kg) to male dogs, the plasma levels of radioactivity decreased rapidly until 15min, and then increased gradually until 3hr after dosing. After that, the plasma levels of radioactivity decreased with half-lives of 3. Ohr and 12.2hr (T1/2β). Plasma levels of unchanged Betaxolol decreased rapidly with half-lives of 1.8min (T1/2α) and 3.8hr (T1/2β).3. After oral administration of 14C-Betaxolol, the radioactivity was readily and almost completely absorbed from the gastro-intestial tract. The systemic bioavailability was about 60%.4. In both male and female dogs, approximately 95% of the administered radioactivity was excreted in urine (81-85%) and feces (11-14%) within 120hr after oral or intravenous administration of 14C-Betaxolol.5. Major metabolic routes of Betaxolol in dogs were 0-dealkylation of cyclopropylmethoxyethyl moiety and N-dealkylation of isopropylaminopropoxy moiety. |
