This study was performed to evaluate repeated-dose toxicities of STB-HO-BM in Sprague-Dawley rats. STB-HO-BM was administered orally to rats at dose levels of 0, 100, 300 and 1,000 mg/kg/day for 13 weeks. In recent study, there were no dose related changes in mortality, clinical signs, body weight changes, food and water consumption, opthalmoscopy, organ weights, urine analysis, hematological findings, and biochemical examination of all animals treated with STB-HO-BM. Gross and histopathological findings revealed no evidence of specific toxicity related to STB-HO-BM. These results suggest that the oral no observed adverse effect level (NOAEL) of STB-HO-BM may be over 1,000 mg/kg in rats.