[Reproductive and developmental toxicity study of mofezolac (N-22) (4)--Study by oral administration of N-22 during the perinatal and lactation periods in rats].

peri- and postnatal study of mofezolac (N-22), a new developed analgesic and anti-inflammatory agent, was carried out with Wistar rats. N-22 at dose levels of 0, 25, 50 and 100 mg/kg/day were administered orally to pregnant and subsequent delivered dams from day 17 of gestation through day 21 of lactation. Body weight gains of dams treated with 50 and 100 mg/kg/day were depressed during perinatal period. Prolongation of pregnancy period, low performance of pup care with decrease in body weights and food consumptions were observed in 100 mg/kg/day group. Decrease in number and birth index, increase in number of stillborns and tendency to decrease in viability index on day 4 were found in 100 mg/kg/day group. Other parameters of development, behavior or reproductive capability of F1 animals showed no changes related to administration of N-22. It was suggested that no effect dose levels of N-22 were 25 mg/kg/day for dams viewpoint of general toxicity and that was 50 mg/kg/day for dams on reproductive performance and for offspring on development.