Clinical Research Directory

Inclusion Criteria: 1. Able and willing to provide a written informed consent. 2. Scheduled for elective abdominal surgery (excluding hepatic surgery) under general anesthesia, with an expected operative duration of 1-4 hours. 3. Male or female adults aged between 18 and 65 years， 4. Meet the weight standard：18.5 kg/m²≤BMI≤30 kg/m² 5. Conform to the ASA Physical Status Classification：classification I II. Exclusion Criteria: 1. Not suitable for nasal spray 2. Having received general anesthesia within 28 days prior to randomization 3. Subjects with a history of myocardial infarction or unstable angina pectoris 4. Subjects with heart rate\<60beats/min at screening, or a history of severe arrhythmia such as second degree type II or higher atrioventricular block, or a history of cardiac insufficiency 5. Subjects with a history of ischemic stroke or transient ischemic attack 6. Subjects with poor blood pressure control after medication 7. Subjects with abnormal clotting function 8. Subjects with a history of mental illness and a history of cognitive impairment epilepsy 9. Subjects with a history or possibility of a difficult airway 10. Subject with a history of substance abuse and drug abuse 11. Adrenoceptor agonists or antagonists were used before randomization：Phase 1: Subjects who have received α2-adrenergic receptor agonists or antagonists within 14 days prior to randomization. Phase 2: Subjects who have received selective α2-adrenergic receptor agonists or antagonists within 14 days prior to randomization; 12. Uncontrolled hepatic or renal dysfunction 13. Thyroid dysfunction 14. Allergic to a drug ingredient or component 15. Pregnant or nursing women 16. No birth control during the specified period of time 17. Participated in clinical trials of other drugs (received experimental drugs) 18. The investigators determined that other conditions were inappropriate for participation in this clinical trial