RFUS-250

Primary objective: To evaluate the safety and tolerability of RFUS-250 for injection after a single intravenous administration to healthy Chinese volunteers. Secondary objectives: 1) To evaluate the pharmacokinetic characteristics of RFUS-250 for injection after a single intravenous administration to healthy Chinese volunteers; 2) To detect RFUS-250 and its metabolites in the blood, urine and feces of healthy Chinese volunteers, and preliminarily evaluate the excretion pathway. Exploratory objectives: 1) To explore the analgesic efficacy of RFUS-250 for injection after a single intravenous administration to healthy Chinese volunteers; 2) To explore the effect of the blood concentration of the original drug and metabolites (if necessary) on the QTc interval after a single intravenous administration of RFUS-250 for injection to healthy Chinese volunteers.