HR-1801

1) Evaluate the safety and tolerability of 24 h intravenous administration of HR1801 LD/CR for injection in healthy Chinese subjects. 2) Evaluate the pharmacokinetic (PK) characteristics of 24 h intravenous administration of HR1801 LD/CR for injection in healthy Chinese subjects. 3) Explore and determine a data- and model-derived HR1801 dosing regimen that is expected to safely achieve postoperative analgesia. 4) Evaluate the safety and tolerability of intravenous administration of ketorolac tromethamine injection in healthy Chinese subjects. 5) Evaluate the PK characteristics of intravenous administration of ketorolac tromethamine injection in healthy Chinese subjects. 6) Preliminary comparison of the PK characteristics of LD/CR intravenous administration of HR1801 for injection with intravenous push administration of ketorolac tromethamine injection every 6 hours (q6h).