Benzalazine

Reproductive toxicity studies of benzalazine in rats and rabbits.[Pubmed:7848360]

Arzneimittelforschung. 1994 Dec;44(12):1368-70.

Embryotoxicity studies of Benzalazine (2-hydroxy-5-[(4-carboxyphenyl) azo]benzoic acid, CAS 64896-26-0), a new agent for the treatment of ulcerative colitis and Crohn's disease of the large intestine, were performed in rats and rabbits. Benzalazine elicited no evidence of teratogenicity when administered orally during the fetal organogenesis period to pregnant rats at doses up to 2000 mg/kg b.w./d, or to pregnant rabbits at doses up to 1000 mg/kg b.w./d. Rat fetuses in the 400 and 2000 mg/kg groups exhibited decreased body weights; the placentae weights were decreased in these dose groups, too. Rabbit fetuses in the high-dose group (1000 mg/kg b.w./d p.o.) also showed decreased body weights. Decreased body weight gain and reduced food intake were seen in rat dams in the high-dose group (2000 mg/kg b.w./d p.o.). In rabbit dams a decrease in body weight gain in the high-dose group (1000 mg/kg b.w./d p.o.) and a dose-dependent reduction in food intake from 200 mg/kg b.w./d p.o. onwards were noted. No further disturbances were observed in the behaviour of the rat and rabbit dams. External appearance, faeces, consumption of drinking water and macroscopical inspection during autopsy did not indicate any influence of the test compound. No retardations or malformations were seen even at the highest tested dose levels (rat: 2000 mg/kg b.w./d p.o.; rabbit: 1000 mg/kg b.w./d p.o.).

Mutagenicity studies of benzalazine.[Pubmed:7848359]

Arzneimittelforschung. 1994 Dec;44(12):1366-8.

Benzalazine (2-hydroxy-5-[(4-carboxyphenyl) 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 studied for genotoxic effects by using the following short-term in vitro and in vivo test: 1. reverse mutation test (Ames method) on Salmonella typhimurium, 2. HGPRT (hypoxanthine-guanine phosphoribosyl transferase) point mutation test on V79 hamster cells, 3. in vivo cytogenetic test on Chinese hamster cells, and 4. in vivo sister chromatid exchange test on Chinese hamster cells. Benzalazine did not show any positive response in the reverse mutation test, HGPRT-point mutation test, in vivo cytogenetic and sister chromatid exchange test.

Single and subacute local and systemic toxicity studies of benzalazine.[Pubmed:7848356]

Arzneimittelforschung. 1994 Dec;44(12):1353-6.

Benzalazine (2-hydroxy-5-[(4carboxyphenyl) 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 investigated regarding its toxicological properties following single and subacute local and systemic applications. After single oral application of the maximum dose of 10 g Benzalazine/kg b.w. to rats no pathological findings concerning clinical signs, body weight, food consumption and macroscopical post mortem findings could be observed (LD50 > 10000 mg/kg b.w.). The 24-h LD50 values for Benzalazine after single intraperitoneal application were determined as 755 mg/kg b.w. in female rats and 1200 mg/kg b.w. in male rats. The oral administration of Benzalazine at 2000 mg/kg b.w./d or more for 4 weeks to rats gave rise to slight sedation, a reduction in body weight increase, increased organ weights (heart, kidneys, suprarenal glands, spleen) and dose-related histopathological findings (liver, kidneys, heart, thyroid gland, duodenum, spleen, suprarenal glands, testes). The daily dose of 500 mg Benzalazine/kg b.w. for 4 weeks was without any effects under these experimental conditions. In acute local tolerance studies in rabbits, Benzalazine is to be considered as a mild irritant agent for skin (employing an occlusive patch for 24 h) and eye. After a 10-day intra-rectal application of Benzalazine to rabbits no substance-related changes at the application sites in the colon were observed.

Prospective, randomized, double-blind comparison of benzalazine and sulfasalazine in the treatment of active ulcerative colitis.[Pubmed:2906888]

Digestion. 1988;40(3):173-80.

Benzalazine (salicylazobenzoic acid, SAB), a 5-azo derivative of 5-aminosalicylic acid, has been designed as a new therapeutic agent for the treatment of inflammatory bowel disease which might lack the frequent side effects caused by the sulfapyridine moiety of the sulfasalazine molecule (SASP). Here, we report on a prospective, randomized, double-blind comparison of SAB and SASP in patients with an acute relapse of ulcerative colitis. 43 patients with an acute relapse of ulcerative colitis proven by the pertinent endoscopic-macroscopic and histologic criteria were randomized to receive a 6-week course of either 1 g SASP (n = 21) or the equivalent dose of 0.72 g SAB (n = 22) three times a day. Both groups were comparable with respect to demographic data, previous duration and extension of the disease as well as clinical, endoscopic and histologic severity of the relapse. 1 patient on SASP had to be removed from the study due to side effects, while 3 patients on SAB were removed due to rapid worsening of the disease requiring either surgery (1 patient with toxic megacolon) or additional steroid treatment (2 patients). 2 SAB patients were lost to follow-up after substantial improvement had been observed within the first 3 weeks of treatment. In the remaining patients (20 SASP, 17 SAB), stool frequency, stool consistency and macroscopic appearance as well as histology of the diseased mucosa were improved within 6 weeks, with no significant difference between the two groups with respect to any of the parameters recorded. Side effects were recorded in 5 patients on SASP (3 with nausea, 1 with pruritus and 1 with a generalized exanthema) and in 3 patients on SAB (all nausea and vomiting; difference not statistically significant). We conclude that SAB and SASP in equivalent doses are of similar efficacy in the treatment of active ulcerative colitis.