Teratogenesis study of N-cyclohexyl-2-pyrrolidone in rats and rabbits

Teratogenesis studies were performed in rats and rabbits given N-cyclohexyl-2-pyrrolidone, an aprotic solvent used in chemical processing. Dosages of 0, 15, 50, 150, or 500 mg N-cyclohexyl-2-pyrrolidone/kg body wt/day were administered by gavage to groups of 25 pregnant Sprague-Dawley rats on Days 6 through 15 of gestation. Dosages of 0, 10, 30, 100, or 300 mg/kg/day were administered by gavage to groups of at least 15 pregnant Dutch-Belted rabbits on Days 6 through 18 of gestation. Animals were killed and subjected to uterine examination on Day 20 of gestation for rats and on Day 29 for rabbits. There were no significant differences between the vehicle control and N-cyclohexyl-2-pyrrolidone-treated groups for implantation numbers or live or dead fetuses, resorptions, and fetal body weight in rats and rabbits. Dam body weight gain during gestation was comparable among groups. External gross visual examination of the fetus as well as examination of skeletal and soft tissues revealed no effects related to treatment with N-cyclohexyl-2-pyrrolidone.