Abstract: AIM: To evaluate the tolerance of healthy volunteers to ulinastatin (UTI) in different doses and confirm its safety dose in vivo. METHODS: 44 healthy volunteers were randomized into single rising dose groups (100, 200, 400, 600, 800, 1000, 1200 kU) and multiple rising dose groups (900 or 1200 kU, tid for 7 days). RESULTS: The maximal tolerance single-dose was 1200 kU, and the maximal tolerance multiple-dose was 900kU. CONCLUSION: UTI was safe at a dose from 100 to 1200 kU in a single administration or at a dose from 300 to 900 kU in multiple administration.

Key words: ulinastatin, tolerance, safe dose