A Trial to Evaluate the Safety and Efficacy of HL231 Solution for Inhalation in Patients with COPD

This study is a randomized, single-dose, multi-center, two-part, crossover, dose-ranging study of HL231 in the treatment of subjects with COPD. This study is divided into 2 parts. Part A is a 5 treatment period single dose study. Each treatment period will be separated by a washout period of at least 14 days. The primary comparison for bronchodilation was between HL231 doses vs Ultibro or placebo in COPD patients. Part B is a 3 treatment period single dose study. Each treatment period will be separated by a washout period of at least 14 days. The primary comparison for pharmacokinetic profile was between HL231 vs Ultibro in COPD patients.