Support: Letter from (Confidential) to USEPA re: Results in 28-Day Dermal Toxicity Study in Rats with (Confidential), a Quinazolinone, dated 01/08/1999 (Sanitized)

摘要

This letter is to inform you of the results of a recently conducted 28-day dermal toxicity study in rats with this test substance. Four groups of 10 male and 10 female Crl:CDo (SD) ICR BR rats were treated dermally with 100, 500, 1000, or 2000 mg/kg/day for 28 consecutive days. A contro group of 10 male and 10 female rats was similarly treated with deionized water. No deaths occurred during the study. Females in the 1000 and 2000 mg/kg/day groups had decreased total protein due to decreased albumin which was considered to be biologically significant. Hypertrophy of thyroid follicular cells was noted in the 1000 and 2000 mg/kg/day male and female groups. In addition, centrilobular hypertrophy of minimal severity occurred in the liver in the 1000 and 2000 mg/kg/day male groups and in the 500, 1000, and 2000 mg/kg/day female groups. However, these changes were considered to be adaptive, physiologic responses of the liver to exposure to a xenobiotic and not biologically adverse. The incidence of mild erythema, not on the test site, was statistically increased in the 2000 mg/kg/day male and female dosage groups and in the 1000 mg/kg/day male dosage group. The cause of this dermal effect is not known.