A pharmacokinetics study on Oxiracetam in rats (III):Feto-placental transfer and its transfer into milk

Abstract

The distribution of radioactivity of ¹⁴C-labelled Oxiracetam (¹⁴C-CT-848) in the fetus and its transfer into milk were studied after single oral administration at a dose of 10mg/kg to pregnant or lactating rats.
1. On day 12 of gestation, radioactivity was not observed in the fetus 1hr after the dosing. The concentrations of radioactivity in uterus, placenta and fetal membrane were the same as that found in maternal blood.
2. On day 18 of gestation, radioactivity in fetus and fetal membranes was higher than that found on day 12 of gestation. Radioactivity in the plasma and tissues of dams reached C_max at 1hr but the C_max in fetal tissues and amniotic fluid was observed at 6hr. Fortyeight hours after dosing only low levels of radioactivity were observed in amniotic fluid and fetus at 9 ?? 4% of maximum levels.
3. After oral administration of ¹⁴C-CT-848 to lactating rats, radioactivity in milk reached C_max at 4hr and was not observed at 24hr after dosing.