Efficacy and safety of HR18034 for analgesia after hemorrhoidectomy: a multi-center, randomized, double-blind, positive and placebo controlled phase III trial

INTERVENTION: Experimental group:HR18034 380mg local infiltration;Positive control group:Ropivacaine 75mg local infiltration ;Placebo control group:0.9% sodium chloride injection local infiltration ; CONDITION: Postoperative pain PRIMARY OUTCOME: NRS pain intensity scale; SECONDARY OUTCOME: Pain Relief Score;Analgesia Satisfaction Evaluation;Sleepiness scores;Electrocardiogram (ECG);Heart rate, pulse;blood pressure;Pharmacodynamics; INCLUSION CRITERIA: 1. Before the trial, understand the nature, significance, possible benefits, possible inconveniences and potential risks of the trial in detail. Be able to understand the procedures and methods of this study, be willing to strictly follow the clinical trial protocol to complete this trial, and voluntarily sign the informed consent; 2. Patients with grade III‐IV internal hemorrhoids or external hemorrhoids or mixed hemorrhoids are to undergo external dissection and internal ligation under subarachnoid anesthesia, and the expected total length of the incision is greater than or equal to 3cm; 3. Age >= 18 years old, gender is not limited; 4. 18 kg/m^2 <= BMI <= 28 kg/m^2; 5. American Society of Anesthesiologists (ASA) grades I to II; 6. female subjects of childbearing potential had a negative blood pregnancy test within 7 days before randomization and were not lactating. Women of childbearing potential had to consent to use highly effective contrace