Budesonide/Formoterol Inhalation Powder in Adults With Asthma

The goal of this clinical trial is to evaluate whether budesonide/formoterol powder for inhalation (II) manufactured by Shanghai New Huanghe Pharmaceutical Co., Ltd. is non-inferior to the active comparator, Symbicort® Turbuhaler® (AstraZeneca), in the treatment of adult bronchial asthma, and to assess its safety profile in this population. The main questions it aims to answer are: Does the test product (budesonide/formoterol 160 μg/4.5 μg) show non-inferior efficacy compared to the reference product (Symbicort® Turbuhaler® 160 μg/4.5 μg) in improving lung function, as measured by the change from baseline in trough FEV1 after 42 days of treatment? What is the safety profile of the test product in adult patients with asthma? Researchers will compare participants receiving the test product plus placebo of the comparator to those receiving the active comparator plus placebo of the test product, to see if the test product is non-inferior to the reference product in terms of efficacy, with comparable safety. Participants will: Be randomized to receive either the test product (budesonide/formoterol 160 μg/4.5 μg, 2 inhalations twice daily) plus placebo of the comparator, or the active comparator (Symbicort® Turbuhaler® 160 μg/4.5 μg, 2 inhalations twice daily) plus placebo of the test product, for 6 weeks of treatment Perform daily morning and evening PEF measurements and record them, along with rescue medication use and any adverse events, in a diary card Attend regular clinic visits for pulmonary function tests, ACQ-5 and AQLQ questionnaires, safety assessments (vital signs, physical and oropharyngeal examinations, laboratory tests, and 12-lead ECG), and drug accountability