The primary objective will be to compare the formulations regarding their impact on the pulmonary function of persistent asthma patients and the secondary objective will be the clinical control of the disease's symptoms.
Primary endpoint: Forced expiratory volume in 1 second (FEV1) at the final visit.
Secondary endpoints: Expiratory Flow Peak (EFP), symptoms score, FEV1 throughout the study, use of rescue medication, compliance with inhaler use, inhaler acceptance and preference, and frequency of the observed adverse events.
