To evaluate the safety, tolerability and pharmacokinetic characteristics of TQC3721 suspension for inhalation in single/multiple administration(s) in healthy subjects; to evaluate the safety,tolerability and efficacy TQC3721 suspension for inhalation in multiple administrations in patients with Chronic Obstructive Pulmonary Disease（COPD）and asthma.

Inclusion Criteria:

• Sign the informed consent form before the trial, fully understand the content, process and possible adverse reactions of the test;
• Able to complete the study according to the requirements of protocol;
• Aged between 18 and 65 years old, both men and women;
• For healthy subjects: Male ≥50kg, female ≥45kg,body mass index(BMI)=weight (kg)/height 2 (m2), BMI is 18-28 kg/m2 (including the critical value); For patients: BMI is 18-28 kg/m2 (including the critical value), and body weight is ≥45kg.
• For healthy subjects: normal or abnormal vital signs, physical examination, laboratory examination, electrocardiogram, and imageological examination have no clinical significance;
• For healthy subjects: FEV1 and forced vital capacity(FVC) are at least 90% of the predicted values;
• Subjects (including male subjects) have no pregnancy plan and have voluntarily taken effective contraceptive measures for at least 1 month after being screened to the last use of the study drug;
• For patients: Vital signs range: systolic blood pressure 90 to 140mmHg, diastolic blood pressure 50 to 90 mmHg, heart rate 50 to 90 bpm;
• For patients: 12-lead electrocardiogram with QT interval corrected ≤450 msec (males) or ≤470 msec (females), QRS interval ≤120 msec, PR interval ≤200 msec and no morphologic and other clinical significant abnormalities (such as left band branch block, atrioventricular node dysfunction, ischemic ST segment abnormalities);
• For patients: Ability to perform acceptable and reproducible spirometry;
• For patients: According to the diagnostic criteria of 2018 Practical Edition of Guidelines for the Diagnosis and Treatment of COPD, the patient was diagnosed with COPD for at least 1 year;Post-bronchodilator spirometry at screening must demonstrate FEV1/FVC ratio of ≤0.70 and FEV1 must be ≥40 % to ≤80% of predicted normal;
• For patients: mMRC Scoring at screening ≥2;
• For patients: Clinically stable COPD in the previous 4 weeks;
• For patients: Capable of withdrawing long acting bronchodilators until the end of the treatment period, and short acting bronchodilators for 8 hours prior to administration of study medication;
• For patients: Current and former smokers with a smoking history of ≥10 pack years（smoking at least 20 cigarettes a day for 10 years or at least 10 cigarettes a day for 20 years）;
• For patients: beta agonists are currently used only "when needed";
• For patients: Never smoked or An ex-smoker for ≥6 months；

Exclusion Criteria:

• Preexisting or existing the neuropsychiatric system, respiratory system, cardiovascular system, digestive system, hemo-lymphatic system, immune system, liver and kidney dysfunction, endocrine system, musculoskeletal system, or other disease that the investigator assesses that may affect drug metabolism or safety.
• For healthy subjects: Have a history of fainting needles, fainting blood.
• For healthy subjects: Known allergy to the study drug and their metabolites or any of the excipients of the formulation.
• For healthy subjects: Those who smoked more than 5 cigarettes per day during the 3 months before the trial.
• A history of alcohol abuse in the past 6 months (14 units of alcohol consumed per week: 1 unit =360 ml of beer or 45 ml of 40% alcohol spirits or 150 ml of wine).
• For healthy subjects: Donated blood or had substantial loss of blood (more than 400 mL) within 2 months before the test.
• For healthy subjects: Had taken any prescription, over-the-counter, vitamin product or herbal medicine within 1 month prior to the use of the study drug.
• Participated in other clinical trials within 3 months prior to this study.
• Positive for hepatitis (including hepatitis B and C), human immunodeficiency virus（HIV） or syphilis at screening.
• Women who are pregnant or breast-feeding.
• Positive test for alcohol.
• For healthy subjects: Blood collection is difficult or cannot tolerate venipuncture blood collection.
• For healthy subjects: The subject is unable or can not comply with ward management regulations.
• For healthy subjects: The subject is unable to complete the study due to personal reasons.
• For healthy subjects: Any circumstances that the investigator considers to pose a safety risk to the subject during the study or may interfere with the conduct of the study.
• For patients: Intolerance to salbutamol, tiotropium, or this product or prior exposure to Ensifentrine (RPL554).
• For patients: Use of any medicine within 4 weeks prior to initiation of the study drug, including non-prescription medications and herbs, except vitamins.
• For patients: Physical examination findings that researchers consider clinically significant at the time of screening.
• For patients: A history of cardiovascular disease (including arrhythmias) or active hyperthyroidism.
• For patients: History of malignancy of any organ system, treated or untreated within the past 5 years, with the exception of localised basal cell carcinoma of the skin.