26-WEEK ORAL TOXICITY STUDY OF BENZALAZINE IN DOGS

The 26-week oral toxicity of benzalazine (2-hydroxy-5-[(4-carboxypheny l) azo]benzoic acid, CAS 64896-26-0), a new agent for the treatment of ulcerative colitis and Crohn's disease of the large intestine, was in vestigated in beagle dogs of both sexes. No change tvas observed in th e 160 mg/kg group. A reduction of the aspartate aminotransferase activ ity was observed from 800 mg/kg b.w./d onwards. In high-dosed dogs (16 00 mg/kg b.w./d) liver weights were increased and substance-related ne utral fat disposition in liver cells was observed. The non-toxic dose was 160 mg/kg b.w./d under these experimental conditions.