Introduction
neurotoxicity, cardiovascular toxicity, muscular toxicity, nerve block
Ropivacaine is an S-enantiomer amide local anesthetic with high pKa and low lipid solubility. Its nerve block effects are similar to those of bupivacaine, but it has lower neurotoxicity, cardiovascular toxicity, and local muscular toxicity [At present, ropivacaine hydrochloride injection is widely used in the clinic. Commonly, the injection is administered subcutaneously at the surgical incision or injected directly at the ganglion for preemptive analgesia before the operation [After single administering ropivacaine hydrochloride solution to the surgical incision, a nerve block is produced; the analgesic duration is less than 8 h, which likely will not meet the needs of postoperative analgesia (i.e., more than 24 h) [To date, more than three slow-release formulations of ropivacaine have been studied. Ropivacaine liposome gels containing infrared photosensitizers and phospholipids can be retained Ropivacaine is insoluble in water and is slowly released from the oil solution. Castor oil and phospholipids were used as carriers to design a ropivacaine suspension formula that could sustainably block nerves for 36 h [Currently, our ropivacaine oily delivery depot (RODD) has been approved for phase I clinical research by the Center for Durg Evaluation of National Medical Products Administration of China. This study evaluated the safety, pharmacokinetics and preliminary efficacy of RODD in healthy subjects.