CZ1S

Primary objective: Using the Numerical Rating Scale (NRS) pain intensity score as an indicator and ropivacaine hydrochloride injection as a control, evaluate the effectiveness of local infiltration of CZ1S for injection for postoperative analgesia in subjects undergoing total hip replacement. Secondary objectives: 1. To evaluate and compare the safety of local infiltration of CZ1S for injection and ropivacaine hydrochloride for postoperative analgesia in subjects undergoing total hip replacement. 2. To evaluate and compare the pharmacokinetic (PK) characteristics of local infiltration of CZ1S for injection and ropivacaine hydrochloride in subjects undergoing total hip replacement.