Efficacy and Safety of KHN702 Tablets in Moderate to Severe Post-operative Pain Subjects

Inclusion criteria

• Subjects between the ages of 18 and 75 years, inclusive.
• Body mass index (BMI) of 18.0 to 30.0 kg/m2, inclusive.
• Patients scheduled for surgery.
• According to the researcher's medical judgment, American Society of Anesthesiologists (ASA) classification≤Grade II.
• The subject can understand and comply with the study procedures and requirements, and can provide written informed consent prior to any study procedures.
• NRS ≥ 4 points within 6 hours after surgery.

Exclusion criteria

• Participants experiencing acute or chronic pain unrelated to the surgical site, which the investigator deems may confound the participant's assessment of postoperative pain.
• History or evidence of any of the following conditions prior to screening:

• History of significant cardiovascular or cerebrovascular disease;
• Severe respiratory disease history;
• Severe Neurological and Psychiatric disease History;
• Active peptic ulcer disease, significant vomiting, chronic diarrhea, ileus, malabsorption, or other known conditions that significantly affect drug absorption, distribution, metabolism, or excretion;
• Subjects at high risk of bleeding who are deemed unsuitable for this trial by the investigator;
• Long-term use of opioids or nonsteroidal anti-inflammatory drugs within the past 30 days prior to screening, or discontinuation of medications affecting analgesic efficacy assessment (except those permitted by the protocol) less than 5 half-life prior to randomization.
• Subjects with a history of opioid allergy, or those with a history of allergy to the intraoperative medications specified in the protocol, postoperative rescue analgesics, or known allergies to the investigational drug or its excipients.
• Subjects who underwent major surgery within 3 months prior to screening and the investigator determined that it would affect postoperative pain assessment.
• Any of the following infectious diseases were present during screening: Hepatitis B surface antigen (HBsAg) positive, hepatitis C virus antibody (HCV Ab) positive, human immunodeficiency virus antibody (HIV Ab) positive, or serum treponema pallidum antibody (TPAb) positive.
• History of substance abuse or alcohol abuse within the three months prior to screening .
• History of blood donation within the past three months prior to screening.
• Individuals who have participated in any clinical research within the past three months prior to screening .
• Pregnant or lactating women; women or men of reproductive potential who are unwilling to use contraception throughout the study period; or subjects (including male subjects) planning to conceive within 3 months after study completion.
• Subjects with intraoperative blood loss exceeding 1000 mL or those experiencing other severe complications during surgery;
• Subjects requiring intensive care following surgery;
• Other circumstances deemed unsuitable for participation in this trial by the investigator.