Toxicological Studies on N_1-ethoxy Carbonyl-N_2-hydrazinophthalazine Hydrochloride (621-BT)

Toxicological and teratological studies on 621-BT were conducted. The results are summarized as follows. 1. Acute toxicity LD_50 of 621-BT given by various routes to mice, rats and rabbits is shown in Table-1. 2. Subacute and chronic toxicity 621-BT was administered orally to rats (SD-JCL) and rabbits (J. Albino) for 6 months, Fifty-percent mortality was observed within the 1st week in the group of rats receiving 350mg/kg and in the group of rabbits receiving 180mg/kg for 4 weeks. The death may have been due to hypotension caused by the treatment with 621-BT. The body weight gain was restrained in all groups. Slight normocytic anemia was found in the hematological examination. In addition, histological changes were observed in the lung, spleen and kidney within 3 months. However, there were no changes in the examination after 6 months. LE cells were not found at all, and there were no changes suggesting collagenosis.