Evaluating the efficacy and safety of perianal injection of liposomal ropivacaine HR18034 for postoperative analgesia following hemorrhoidectomy: A multicenter, randomized, double-blind, controlled phase II clinical trial

HR18034, composed of the ropivacaine encapsulated in multi-lamellar, concentric circular structure liposomes as the major component and a small amount of free ropivacaine, has performed well in animal experiments and phase I clinical trials. This trial was to investigate the efficacy, safety, pharmacokinetic profile and the minimum effective dose of HR18034 for postoperative analgesia after hemorrhoidectomy compared with ropivacaine.