Liaoning Haisco Pharmaceutical Co., Ltd.

To preliminarily evaluate the efficacy and safety of HSK21542 injection for postoperative analgesia in orthopedic surgery;

Main study objectives: To evaluate the effect of a single intravenous injection of HSK3486 on cardiac repolarization (QTc interval of the electrocardiogram) in healthy subjects. Secondary study objectives: To evaluate the effect of a single intravenous injection of HSK3486 on other ECG parameters in healthy subjects (relative to the positive control moxifloxacin hydrochloride tablets and placebo); To demonstrate the sensitivity of the study by using a single oral dose of 0.4 g moxifloxacin hydrochloride tablets as a positive control; To evaluate the safety and tolerability of a single intravenous injection of HSK3486 in healthy subjects; To evaluate the PK characteristics of HSK3486 and its metabolites (if applicable) in healthy subjects after a single intravenous injection of HSK3486.

Phase I: Research objective: To explore the reasonable dosage range of propofol injection for general anesthesia in pediatric population aged 2-17 years. Phase II: Main research objective: To confirm the effectiveness of propofol injection for general anesthesia in pediatric population aged 2-17 years. Secondary research objective: To evaluate the safety of propofol injection for general anesthesia in pediatric population aged 2-17 years. Exploratory research objective: To evaluate the agitation during the recovery period after general anesthesia of propofol injection in pediatric population aged 2-17 years.