It is planned to design 11 dose groups within 62.5 mg ~ 4000 mg for single-dose tolerability study. A single-center, randomized, blinded, placebo-controlled, dose escalation trial design is adopted. There are 8 subjects each in 62.5 mg, 125 mg, 3000 mg and 4000 mg dose groups, and 10 subjects each in other groups. Each group consists of half males and half females, including 2 placebo-controlled subjects (1 male and 1 female). The trial is carried out from low-dose group to high-dose group. Each subject only receives one dose of test drug, which is dissolved in 100 mL of 0.9% NS, intravenous drip. During the trial, the adverse events of subjects should be closely followed. The next dose group can be studied only when the observation of the previous dose group is completed and it is confirmed that the drug is safely tolerated. The test should be stopped in case of serious adverse reactions, or when more subjects experience adverse reactions and have reached termination criteria of the trial, even if the maximum dose has not been reached.~In order to investigate possible effect of infusion rate on the tolerability and to ensure the safety of subjects, the infusion time is planned to be 30 min in 62.5 mg, 125 mg and 250 mg low-dose groups; two infusion time, 30 min and 60 min, in 500 mg, 1000 mg and 2000 mg groups. Under the circumstance that subjects can tolerate 60-min infusion, the same dose group at infusion time of 30 min is added to investigate the possible effect of infusion rate on the tolerability. The 3000 mg and 4000 mg dose groups only receive 60-min infusion for investigation of tolerability.
To design 11 dose groups within 62.5 mg ~ 4000 mg for single-dose tolerability study. A single-center, randomized, blinded, placebo-controlled, dose escalation trial design is adopted. 8 subjects each in 62.5 mg, 125 mg, 3000 mg and 4000 mg dose groups, 10 subjects each in other groups, including 2 placebo-controlled subjects. To be carried out from low-dose group to high-dose group. The next dose group can be studied only when the observation of the previous dose group is completed and it is confirmed that the drug is safely tolerated. The test should be stopped in case of serious adverse reactions, or when more subjects experience adverse reactions and have reached termination criteria of the trial, even if the maximum dose has not been reached.~Infusion time is planned to be 30 min in 62.5 mg, 125 mg and 250 mg ; two infusion time, 30 min and 60 min, in 500 mg, 1000 mg and 2000 mg groups. If subjects can tolerate 60-min infusion, the same dose group at infusion time of 30 min is added. The 3000 mg and 4000 mg dose groups only receive 60-min infusion for investigation of tolerability.