Studies on the Metabolic Fate of Neutrophil Elastase Inhibitor ONO-5046·Na(4): Feto-Placental Transfer and Excretion into Milk

Abstract

Feto-placental transfer and excretion into milk were investigated in pregnant and lactating female rats after a single intravenous bolus administration of ¹⁴C-ONO-5046·Na.
1. At 30 min after intravenous administration of ¹⁴C-ONO-5046·Na at the dose of 1 mg/kg to pregnant rats on 17 days, the radioactivity in the fetus was 0.004 times of that in plasma, then declined to the level below detection limit at 4 hr after administration.
2. The radioactivity was dete cted in the milk after intravenous administration of ¹⁴C-ONO-5046·Na at the dose of 1 mg/kg to lactating rats. Maximal level of radioactivity in the milk was 349.95 ng eq./ml, lower than plasma level of radioactivity.