A Clinical Trial Evaluating the Efficacy and Safety of HSK21542 in PONV

Inclusion Criteria: 1. Age ≥18 and ≤75 years old, male or female; 2. The American Society of Anesthesiologists (ASA) Class I-III; 3. 18 kg/m2 ≤ BMI ≤ 40 kg/m2; 4. Hospitalized subjects scheduled to undergo elective laparoscopic abdominal or gynecological surgery under general anesthesia for an expected anesthetic time of ≥ 1 h; 5. Subjects with intermediate or high risk (score ≥ 2 points) experiencing PONV judged by the investigator using the Apfel simplified risk score; 6. Subjects who agree to participate in the trial and voluntarily sign the Informed Consent Form (ICF); Exclusion Criteria: Prior and concomitant diseases 1. History or evidence of any of the following diseases prior to screening: 1. Respiratory diseases: severe chronic obstructive pulmonary disease, acute exacerbation of chronic obstructive pulmonary disease, severe airway stenosis, large pharyngolaryngeal mass, (broncho) tracheoesophageal fistula or airway tear, and serious respiratory tract infection within 2 weeks prior to screening; 2. Central nervous system disorders: subjects with epilepsy, Parkinson's disease, or other central nervous system diseases causing nausea and vomiting, such as craniocerebral injury, intracranial space-occupying lesions, intracranial aneurysms, etc.; 3. Cardiovascular diseases: subjects with uncontrolled hypertension \[systolic blood pressure (SBP) ≥170 mmHg and/or diastolic blood pressure (DBP) ≥105 mmHg without treatment with antihypertensive medication, or SBP ≥160 mmHg and/or DBP ≥100 mmHg after treatment with antihypertensive medications\], serious cardiac insufficiency ( the New York Heart Association \[NYHA\] Grade III-IV), unstable angina pectoris, acute myocardial infarction, severe arrhythmia, history of tachycardia/bradycardia requiring medical treatment, Grade II-III atrioventricular block (excluding pacemaker use) within 6 months prior to screenin; 4. Digestive disorders: subjects with intestinal obstruction or other digestive diseases that may cause nausea and vomiting as judged by the investigator; 5. Patients with a confirmed diagnosis of vestibular function disorder, excluding travel sickness (including but not limited to peripheral vestibular syndrome, central vestibular syndrome, etc.); 6. Subjects with a history of significant and chronic dizziness. Prior and concomitant medications 2. Any of the following medications or treatments have been used at screening: 1. Subjects who have received antiemetics/medications with antiemetic effects within 24 h before the start of surgery or who have used antiemetics/drugs with antiemetic effects before the start of surgery for no more than 5 half-lives (calculated as the longest time); 2. Subjects with neoplasm malignant treated with chemotherapy within 4 weeks prior to screening; Laboratory and other tests 3. Laboratory test indicators at screening meet the following criteria: 1. White blood cell count \< 3.0 × 109/L; 2. Platelet count \< 80 × 109/L; 3. Hemoglobin\< 70 g/L; 4. Prolongation of prothrombin time (PT) exceeding the upper limit of normal for 3 seconds; 5. Prolongation of activated partial thromboplastin time (APTT) exceeding the upper limit of normal for 10 seconds; 6. Alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) \> 3 × ULN; 7. Total bilirubin \> 2 × ULN; 8. Blood creatinine \> 2 × ULN; 9. Fasting serum glucose≥ 11.1 mmol/L; Other conditions 4. Subjects anticipated to require continued endotracheal intubation after the end of surgery; 5. Subjects anticipated to require the insertion of nasal or oral gastric tubes after the end of surgery; 6. Subjects with a history of serious drug allergies or those allergic to the investigational drugs specified in the protocol; 7. Subjects with a history of drug abuse, drug addiction, or alcoholism within 3 months prior to screening, where alcoholism is defined as consuming \> 2 units of alcohol on average daily (1 unit = 360 mL of beer with 5% alcohol, 45 mL of liquor with 40% alcohol or 150 mL of wine); 8. Subjects with nausea, retching, or vomiting within 24 h prior to induction of anesthesia (except for those caused by bowel preparation); 9. Subjects who have participated in any investigational trial (defined as receiving investigational drug or placebo) within 3 months prior to screening; 10. Female subjects who are pregnant or breastfeeding; female or male subjects of child-bearing potential are unwilling to use contraception throughout the entire study period and for 3 months after the study completion; 11. Subjects judged by the investigator to be unsuitable for participating in this clinical trial for any other factors.