Mild Asthma

The primary objectives of the study are: Part 1: to characterize the potency and variability of dose response on efficacy (Provocative concentration of methacholine causing at least a 20% fall in forced expiratory volume (FEV1) \[PC20\]) of salbutamol administered via MDI with salbutamol HFA-134a or salbutamol HFA-152a in participants with mild asthma. Part 2: to compare the comparative dose response on efficacy (PC20) of salbutamol when administered via MDI with salbutamol HFA-134a or salbutamol HFA-152a in participants with mild asthma.

The goal of this observational study is to better understand how asthma affects the lungs in young adults (ages 17-35) with mild asthma. The main questions it aims to answer are: * Can advanced imaging detect abnormal airway function in people with mild asthma? * Do changes in ventilation imaging correlate with asthma symptoms or quality of life? Researchers will compare hyperpolarized xenon-129 MRI and Technegas (Tc-99m) imaging to see if these techniques reveal more detailed lung abnormalities than standard lung function tests. Participants will: * Complete a single 2-hour visit * Undergo two types of lung imaging: Hyperpolarized xenon-129 MRI (to visualize how air moves in the lungs), Technegas (Tc-99m) imaging (to assess airflow using nuclear medicine) * Perform spirometry and other breathing tests * Answer questionnaires about asthma symptoms and quality of life This study is designed to improve our understanding of subtle changes in lung function that may not be detected by standard tests in people with mild asthma. The findings may lead to better diagnostic tools and more personalized treatment strategies in the future.

The objective of this study is to evaluate the pharmacodynamic (PD) bioequivalence (BE) of albuterol inhalers, test formulation: Albuterol Sulfate HFA inhalation aerosol 108 mcg (equal to albuterol base 90 mcg) per actuation and reference formulation: ProAir HFA (albuterol sulfate) or FDA authorized generic: Albuterol Sulfate HFA (Teva Pharmaceutical USA, Inc.) Inhalation Aerosol 108 mcg (equal to albuterol base 90 mcg) per actuation manufactured by two different manufacturers using methacholine bronchoprovocation challenge test in patients with stable mild asthma.

This is a pharmacodynamic bioequivalence bronchoprovocation study using single-dose, double-blind, double-dummy, randomized, study consisting of four study treatments (zero dose \[Placebo\], E.Q. 90 mcg Base dose of R inhalation aerosol, E.Q. 180 mcg Base dose of R inhalation aerosol, E.Q. 90 mcg Base dose of T inhalation aerosol) and four Periods (Period 1 to Period 4). Randomization procedure at Period 1 will assign any one study treatment to be administered in each Period in a cross-over manner. By the end of Period 4, a subject who completes dosing in all four Periods would have administered all four treatments in the study. The efficacy variable, post-dose PC20 obtained during each Period is the provocative concentration of the methacholine challenge agent required to reduce the FEV1 by 20% following administration of differing doses of albuterol (or placebo) by inhalation. The 20% reduction in FEV1 is determined as compared to post-saline FEV1 measured before the Placebo or Albuterol administration. The pharmacodynamic equivalence will be based on the dose-scale method of analysis of the post-dose PC20 If the 90% confidence interval for the relative bioavailability (F) falls within 67.00% -150.00% then it will be considered that pharmacodynamic equivalence is established.

The purpose of this registry aims is to collect a large number of patients with mild and moderate asthma in a real-word conditions for a perspective observation of epidemiological evolution of the disease in relation to the therapeutic interventions available currently and in the near future.