Pharmacokinetics in maternal-fetal unit after intravenous administration of p-phenyl benzoic acid to rat.

The pharmacokinetics in maternal-fetal unit of 14C-p-phenyl benzoic acid was studied in intact and bile-duct-cannulated pregnant rats following the intravenous administration. The half life of the maternal blood level was shortened by bile duct-cannulation. However, the effect of bile duct-cannulation on the decay curve of fetal blood level was not recognized. There was no difference in the distribution pattern from whole body autoradiogram and tissue binding between mother and fetus. PPBA level in fetal plasma was different from that in maternal central and peripheral compartment based on pharmacokinetic analysis. The glucuronide levels in fetal intestine and amniotic fluid increased with time. The levels of PPBA and its glucuronide in fetal tissues on the 18th day of gestation were lower than the corresponding levels on the 20th day of gestation. The elimination rate of the glucuronide in amniotic fluid was higher on the 18th day of gestation.