A Phase I Study in Healthy Participants

Inclusion Criteria: 1. Healthy adult males or females aged 18-45 years; 2. Male body weight ≥45 kg, male body weight ≥50 kg, and body mass index (BMI): 19.0-26.0 kg/m2 (both inclusive), BMI =body weight (kg)/height 2 (m2); 3. The subjects voluntarily participate in the study and sign an informed consent form before the study. Exclusion Criteria: 1. Subjects who participated in any clinical studies of drugs or took study drugs within 3 months prior to the administration of study drug; 2. Subjects who have undergone surgery within 3 months prior to screening or who plan to undergo surgery during the study or who have undergone surgery that would affect the absorption, distribution, metabolism, and excretion of drugs; subjects with a previous history of diseases of cardiovascular system, blood and lymphatic system, respiratory system, urinary system, endocrine, immune, mental and nervous system (such as epilepsy) that are clinically significant; 3. Subjects with a history of respiratory system diseases, such as acute exacerbation of chronic obstructive pulmonary disease, pulmonary fibrosis, pulmonary hypertension, pulmonary edema, pulmonary interstitial disease, bronchial asthma, paradoxical bronchospasm, or throat ulcer and edema, or subjects with previous surgery of throat, trachea/bronchi and lung, or subjects with upper and lower respiratory tract infection and acute sinusitis caused by virus or bacteria within the 4 weeks prior to the use of study drug that are clinically significant or render them unsuitable to participate in the study in the opinion of the investigator; 4. Subjects with ocular diseases or thyroid-related diseases that are clinically significant or render them unsuitable to participate in the study in the opinion of the investigator; 5. Subjects with a history of drug allergy (antibiotics, interferon products, etc.), or a specific history of allergy (asthma, urticaria, eczema, etc.), or allergic constitution (such as allergy to two or more drugs, food, pollen, etc.); 6. Subjects who cannot tolerate aerosol inhalation; 7. Subjects who have used any prescription drugs, over-the-counter drugs, Chinese herbal medicines, or vitamins within14 days prior to screening; 8. Subjects who have received vaccine within 4 weeks prior to the first dose, or subjects who plan to receive vaccine within 4 weeks after the last dose; 9. Subjects who have had non-physiological blood loss of ≥300 mL within 3 months before the first dose (including trauma, blood collection, blood donation); or subjects who plan to donate blood during the study or within 30 days after the last dose; 10. Subjects who have had a history of drug use or abuse within 6 months prior to screening; 11. Subjects who have smoked within 3 months prior to screening, or who cannot stop using any tobacco products during the study; 12. Subjects who have consumed more than 14 glasses of alcohol per week (1 glass =150 mL wine, or 360 mL beer, or 45 mL spirits) within 3 months prior to screening; 13. Subjects who cannot tolerate venipuncture for blood collection or have potential blood collection difficulties, or subjects who feel dizzy and sick at the sight of blood or needle; 14. Subjects who have special requirements for diet and cannot follow a standardized diet; 15. Subjects who have a birth plan, or are unable to voluntarily take effective contraceptive measures, or have a sperm/egg donation plan during the study period and within 3 months after the last dose; female subjects who are pregnant or lactating; 16. Subjects with clinically significant abnormalities on physical examinations, electrocardiograms, vital signs, chest X-rays, lung function, and laboratory tests (as judged by the clinician); 17. Pulmonary function test: subjects with measured/predicted FEV1 ≤80% or FVC≤ 80% of expected value; 18. Subjects who have positive urine nicotine test results; 19. Subjects who have positive urine drug test results; 20. Subjects who have positive alcohol breath results; 21. Subjects who cannot use aerosol device correctly or who do not pass the aerosol dosing training; 22. Subjects who cannot complete this study due to other reasons, or subjects who are unsuitable to participate in this clinical study due to other various reasons;