1H-Isoindol-1-one, 2,3-dihydro-3,3-bis(4-hydroxyphenyl)-2-phenyl-

Endpoint summary

Description of key information

Female rats dosed orally with the substance at 100, 300 and 1000 mg/kg/day were systemically exposed to the substance. Exposure to the substance, in terms of AUClast and Cmax, was similar at all dosage levels on study day 0, but increased as dosage increased from 100 to 1000 mg/kg/day on gestation day 15. Accumulation ratios were 1.2, 1.6, and 3.0 at 100, 300, and 1000 mg/kg/day, respectively.

Additional information

In an oral reproduction/developmental toxicity screening study systemic exposure to the substance was evaluated in adult female rats, prior to and during gestation. Addititional groups of 8 female rats were administered the test substance at dosage levels of 0, 100, 300, and 1000 mg/kg/day for 14 days prior to pairing through gestation day 15. An additional eight males were assigned to each exposure phase group and were used for breeding purposes only. On study day 0 and gestation day 15, blood samples for determination of plasma drug concentration were collected from females prior to dose administration and at 1, 2, 4, 8, and 24 hours following dose administration. Pregnancy status was determined for each female on gestation day 16.

All female rats dosed orally with the substance were systemically exposed to the substance. Exposure to the substance, in terms of AUClast and Cmax, was similar at all dosage levels on study day 0, but increased as dosage increased from 100 to 1000 mg/kg/day on gestation day 15. On gestation day 15, systemic exposure to the substance increased less than dose-proportionally over the 100 to 1000 mg/kg/day range. Exposure to the substance, in terms of AUClast, was higher on gestation day 15 than on study day 0 at 1000 mg/kg/day, but was similar on both evaluation days at 100 and 300 mg/kg/day. Accumulation ratios were 1.2, 1.6, and 3.0 at 100, 300, and 1000 mg/kg/day, respectively. Peak plasma concentrations were reached at 8, 24, and 8 hours post-dosing on study day 0 and at 8, 4, and 8 hours post-dosing on gestation day 15 at 100, 300, and 1000 mg/kg/day, respectively. Substance concentrations were generally at or near Cmax or fluctuated from 1 through 24 hours post-dosing, except for animals dosed at 100 mg/kg/day on study day 0, where concentrations increased through 8 hours, then decreased through 24 hours post-dosing. Concentration data for the terminal elimination phase was inadequate to determine half-life. Plasma concentrations in control group animals were below the limit of quantitation (BLQ) in all samples collected at all time points on study day 0 and gestation day 15.