Abstract: BACKGROUND ＆ AIM: To investigate the teratogenicity of erythromycin propionate-N- acetylcysteinate(EPAC) in rats. MATERIAL AND METHODS: SD rats were used in this teratogenicity study. On days 6－15 of pregnancy, SD rats received the drug in three doses of 75, 200, and 400 mg/kg. RESULTS: After oral administration of EPAC, pregnant rats in the groups of 200 and 400 mg/kg doses had signs of anorexia, and decreased activity. The results showed that the body weight gains of pregnant rats on days 10－13 were significantly lower in the groups of the doses of 200 and 400 mg/kg than in the control group, and recovered to normal after the withdrawal of the drug. The fertility of pregnant rats was not different in each group compared with the control group. No morphologic malformation of rat fetuses was observed in each group compared with those in the control group. The body length and tail length of rats were not significantly different in each group. No abnormality was observed in the growth of bones and internal organs in rat fetuses in all groups. CONCLUSION: EPAC in the doses of 200 and 400 mg/kg has maternal toxicity in pregnant rats, characterized by decreased body weight and anorexia, but has no fetal toxicity or teratogenicity.

Key words: erythromycin propionate-N- acetylcysteinate, rat, fetal toxicity, teratogenicity