This is a phase 4, randomized, double-blind, multicenter clinical trial to evaluate the efficacy and safety of YMC026 in respiratory disease patients with cough and sputum as the main symptoms

The study has planned 4 visits during 2 weeks period (1 week of screening period, 1 week of treatment period). All subjects who agree to participate in the study and voluntarily give written informed consent are assessed by inclusion and exclusion criteria at the screening visit. After the screening period, the final eligibility of the subjects will be assessed at the randomization visit. Subjects who are determined to be appropriate for this study will be allocated to experimental group(YMC026) or control group(placebo) randomly in a 1:1 ratio. Subject will be administered the investigational product daily for 6 days. The safety for the subjects will be assessed at Day 3 and Day 6 visit, and the efficacy evaluation will be assessed at Day 6 visit.

Inclusion Criteria:

1. Both gender, 15 years ≤ age < 75 years
2. Patients with BSS(Bronchitis Severity Score) ≥ 5point at screening visit and randomization visit
3. Written consent voluntarily to participate in this clinical trial

Exclusion Criteria:

1. Patients with severe respiratory disease
2. Patients with severe pulmonary disease
3. Patients who has history for drug hypersensitivity or allergic reaction in component of investigational product or similar drug
4. Patients with pregnant and/or have breast feeding
5. Patients who were treated with monoamine oxidase inhibitor, antihistamines, anti-viral drugs and glucocorticoids within 2 weeks prior to administration of investigational product
6. Patients who were treated with β2-agonist and anticholinergic drug within 1 weeks prior to administration of investigational product
7. Patients who were treated with secretolytics, mucolytics and bronchodilators within 1 day prior to administration of investigational product
8. Patients who are participating in another trial within 30 days prior to screening visit
9. Patients who investigators determines not appropriate to take part in this clinical study