A Single Dose, Randomized, Open‐Label, Cross‐Over Bioequivalence Study of Budesonide Pressurized Metered‐Dose Inhaler in Healthy Chinese Subjects

Budesonide is a first-line inhaled glucocorticoid (ICS) for asthma treatment in adults and children. The purpose of this study was to compare the pharmacokinetics and assess the bioequivalence between two budesonide pressurized metered-dose inhalers (pMDIs, 200 μg/actuation × 1 actuation) in healthy Chinese subjects. The study was conducted in 32 healthy Chinese subjects using a single-center, randomized, open-label, four-period and crossover design with a 3-day washout between periods. Blood samples were collected up to 16 h post-dose. Plasma concentrations of budesonide were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Reference-scaled average bioequivalence (RSABE) or average bioequivalence (ABE) method was applied to evaluate the bioequivalence, on the basis of the within-subject standard deviation (S_WR) of the reference product (Budiair), and the safety was also assessed. Eventually, 31 subjects completed this study. For the maximum concentration (C_max) (within-subject standard deviation, S_WR ≥ 0.294), the RSABE method showed a geometric mean ratio (GMR) of 97.13% with a 95% upper confidence bound of < 0. For the area under plasma concentration-time curve from time zero to the last measurable concentration (AUC_0-t) and the area under plasma concentration-time curve extrapolated to infinity (AUC_0-∞) (S_WR < 0.294), ABE yielded GMRs of 104.81% and 104.61%, with 90% confidence intervals (CIs) of 99.98%-109.86% and 99.81%-109.63%, respectively. All adverse events (AEs) were mild to moderate and transient, with no serious adverse events (SAEs) reported. The two budesonide pMDIs (200 μg) were bioequivalent and well tolerated in healthy Chinese subjects. Trial Registration: Chinese Clinical Trial Registry, Registration No. CTR20244600; ClinicalTrials.gov identifier: NCT06924190.