MUTAGENICITY STUDIES OF BENZALAZINE

Benzalazine (2-hydroxy-5-[(4-carboxyphenyl) azo] benzoic acid, CAS 648 96-26-0), a new agent for the treatment of ulcerative colitis and Croh n's disease of the large intestine, was studied for genotoxic effects by using the following short-term in vitro and in vivo test: 1. revers e mutation test (Ames method) on Salmonella typhimurium, 2. HGPRT (hyp oxanthine-guanine phosphoribosyl transferase) point mutation test on V 79 hamster cells, 3. in vivo cytogenetic test on Chinese hamster cells , and 4. in vivo sister chromatid exchange test on Chinese hamster cel ls. Benzalazine did not show any positive response in the reverse muta tion test, HGPRT-point mutation test, in vivo cytogenetic and sister c hromatid exchange test.