Pharmacokinetics and safety comparison of cycloserine capsules and their generic counterpart: a randomized, open-label, two-period, two-sequence, single-dose crossover bioequivalence study in healthy Chinese subjects.

INTRODUCTION: Cycloserine is a broad-spectrum antibiotic and clinically important second-line anti-tuberculosis agent. This study assessed the bioequivalence of a test cycloserine formulation versus its reference formulation under fasted and fed conditions. METHODS: Using a randomized, open-label, two-period, two-sequence crossover design, 64 healthy Chinese participants were enrolled (63 completed). Subjects received a single 250-mg oral dose of both formulations. Bioequivalence was evaluated using plasma concentration-time profiles and key pharmacokinetic (PK) parameters. Statistical analysis employed the Average Bioequivalence (ABE) method. Geometric mean ratios (GMRs) and 90% confidence intervals (90% CIs) for Cmax, AUC0-t and AUC0-∞ fell entirely within the predefined range (80.00-125.00%) under both conditions. RESULTS: Both formulations exhibited comparable safety profiles. DISCUSSION: Bioequivalence was established between the test and reference cycloserine capsules under fasted and fed states. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (www.chinadrugtrials.org.cn) as (CTR20233940).