[Toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (1). Single-dose intravenous toxicity studies in rats and dogs].

Single-dose toxicity studies of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, were conducted in Sprague-Dawley (SD) rats and beagle dogs. The rats of both sexes were administered ONO-5046.Na intravenously at a single dose of 150, 300 or 450 mg/kg. The male dogs were also given ONO-5046.Na at a single dose of 75 or 150 mg/kg. In the rat study, hypoactivity, bradypnea and paleness of limbs and pinna were observed at doses of 300 mg/kg and above. In particular, one of six female rats in the 450 mg/kg group showed clonic convulsion and died. In surviving animals, those signs disappeared within 3 hr after administration. No effect on body weight gain was seen in either group. Necropsy findings showed a slight foamy fluid in the bronchus, hemorrhage at the right knee joint muscle, tendon and lung in a dead animal. In the dog study, no effects on clinical signs, body weight, food consumption and blood biochemistry were seen in any animals of the 75 and 150 mg/kg groups. It is concluded that the approximate lethal doses are 450 mg/kg in rats and 150 mg/kg and above in dogs.