[Rat placental barrier permeability for the new antihistaminic preparation, fenkarol].

As established, following a single introduction of phencarol tagged with tritium in a quinuclidine nucleus perorally to rats on the 13th day of gestation its insignificant amounts gain access to the fetus through the placenta. The maximum concentration of the drug in the maternal blood was recorded 3 hours after its introduction, following 6 hours--in the placenta, with the radioactivity continuing to be constant during the first 6 hours in the embryonal tissues. In 48 hours after introduction the radioactive tag is still demonstrable in the study tissues. It is concluded that the drug is largely retained in the placenta, when introduced on the 13th day of pregnancy; on the 21st day of gestation the barrier functions of the placenta declines. The presence of phencarol and its transformation products in the embryonal tissues is confirmed by the method of thin-layer chromotography.