Effects of butyl-2[[3-(trifluoromethyl)phenyl] amino] benzoic acid upon the embryogenesis in rabbits

As a non-steroidal anti-inflammatory ointment, 2-[[3-(trifluoromethyl) phenyl]-amino] benzoic acid (HF-264) was administered to pregnant Japanese white rabbits through the oral route, and its teratological effects were examined. In the preliminary experiment, the maximum safe dose was determined to be 120 mg/kg b.wt. With regard to the effects of HF-264 upon the reproductive performance of rabbits, no undesirable influence was found. As to the occurrence of congenital malformations, one fetus with open eyelids and omphalocele was observed in the 30 mg group. In the toxic dose group (240 mg/kg b.wt.), one fetus with spina bifida and one with cephalohematoma and omphalocele were found. But no anomalies were found in the control, 60 mg and 120 mg groups. Accordingly no dose-response relationships were observed in the occurrence of malformed fetuses. As the drug is an ointment, the appliance of the drug for local skin lesions is presumed not to be hazardous from a teratological point of view.