Inclusion Criteria:

1. Fully understand the study procedures and methods, volunteer to participate in this study, and sign the written informed consent form.
2. Healthy adult participants, male or female, aged 18 to 50 years (inclusive).
3. Body Mass Index (BMI) ≥ 18 and < 28 kg/m²; body weight ≥ 50.0 kg and < 90.0 kg for males, and ≥ 45.0 kg and < 90.0 kg for females.
4. Medically healthy as determined by the investigator, based on the absence of clinically significant abnormalities in physical examinations, laboratory tests, vital signs, chest X-ray, and electrocardiogram (ECG).
5. Able to use the inhalation device correctly and effectively.
6. Agree to use effective contraceptive measures throughout the study period. Female participants of childbearing potential must agree to use effective contraception from the screening period until 6 months after the last dose. During this period, female participants must agree to have no plans for pregnancy or egg donation/harvesting; male participants must agree to have no plans to father a child or donate sperm. Their male or female partners of childbearing potential must also agree to use effective contraceptive measures during this period.

Exclusion Criteria:

1. History of any clinically significant disease (including past and current history), including but not limited to respiratory, cardiovascular, gastrointestinal, hematological, endocrine, immunological, dermatological, malignant tumor, neuropsychiatric, ear/nose/throat (ENT), or metabolic diseases; or any other condition that, in the opinion of the investigator (or sub-investigator), makes the participant unsuitable for the study.
2. Major surgery within 6 months prior to dosing, planned surgery during the study, or previous surgery that may significantly affect the pharmacokinetics or safety evaluation of the study drug.
3. Current oral diseases that may affect the study, as judged by the investigator (e.g., oropharyngeal candidiasis, oral ulcers, oral mucosal lesions).
4. Fever (body temperature > 37.5°C) or symptomatic respiratory infection within 1 month prior to dosing; any infection requiring systemic antibiotics or antivirals within 3 months prior to screening; or a history of recurrent infections.
5. Positive test results for Human Immunodeficiency Virus (HIV), Hepatitis B surface antigen (HBsAg), Treponema pallidum (syphilis) antibody, or Hepatitis C Virus (HCV) antibody.
6. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), or total bilirubin exceeding the upper limit of normal (ULN) at the screening or baseline visit.
7. Forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) < 80% of the predicted value, or FEV1/FVC < 0.7, or arterial oxygen saturation < 95% at the screening or baseline visit.
8. Smoking (including e-cigarettes) within 6 months prior to dosing, or a positive smoking (nicotine/cotinine) test.
9. History of drug abuse within 3 months prior to screening, or a positive urine drug screen.
10. Participation in any drug or medical device clinical trial within 3 months prior to screening.
11. Blood donation or blood loss ≥ 400 mL within 3 months prior to dosing.
12. Difficulty in venous blood sampling, intolerance to venipuncture, or a history of needle or blood phobia (vasovagal syncope).
13. Known allergy to the study drug or any of its ingredients.
14. Female participants who are pregnant or lactating, or who plan to become pregnant from the time of the study through 6 months after the last dose.
15. Any condition that, in the opinion of the investigator, makes the participant unsuitable for participation in the study.