RF-16001

Study objectives: Primary objective: To investigate the pharmacokinetic (PK) characteristics of ropivacaine sustained-release microspheres (formulations T and R) produced at two new and old sites in healthy volunteers after a single subcutaneous multiple-point injection of 425 mg, and to evaluate the PK differences between the two preparations; Secondary objective: To evaluate the safety and tolerability of ropivacaine sustained-release microspheres produced at the new site in healthy volunteers after a single subcutaneous multiple-point injection of 425 mg.