A single-dose, randomized, open-label, two-period, two-sequence, two-treatment, single-centre, two-way crossover bioequivalence study of Albuterol Sulfate inhalation aerosol 108mcg per actuation (equivalent to 90mcg of Albuterol) and Proair HFA (albuterol sulfate) Inhalation Aerosol 90mcg per actuation was carried out under fasting conditions in healthy adults, aged 20-60 years. For each period, 60 subjects were planned to receive a single dose of albuterol inhalation aerosol (2 puffs) according to the pre-determined randomization scheme. Venous blood of each subject was drawn 22 times over the period of 24 hours. Plasma samples were collected and analysed for albuterol concentrations by LC-MS/MS. For each subject, there were 2 dosing periods, separated by a 14-day washout period. During the study, standardized meals were provided to all subjects when institutionalized.
The primary objective of the study was to assess the bioequivalence between the test product (Albuterol Sulfate inhalation aerosol 108mcg per actuation) and the reference product (Proair HFA [albuterol sulfate] Inhalation Aerosol 90mcg per actuation) under fasting conditions. Bioequivalence would be demonstrated if the 90% confidence interval for the ratios of geometric means for AUC(0-t), AUC(0-inf), and Cmax between test products and reference products were completely contained within the FDA defined acceptance range of 80.00%-125.00%.