Comparative pharmacokinetics study of two tablet formulations of delpazolid, a novel oxazolidinone class antibiotic

Delpazolid is an oxazolidinone-class antibiotic under development for treating diseases caused by antimicrobial-resistant gram-positive bacteria. This study compared the pharmacokinetics (PK) and safety of two formulations of delpazolid 400 mg with distinct excipient compositions: Batch No. 3183817R (test drug) and Batch No. 1650006 (reference drug). A randomized, open-label, single-dose, two-way crossover study was conducted. The participants received a single oral dose of delpazolid 400 mg (test or reference) in each period, with serial blood samples collected up to 12 hours post-dose. The PK parameters of delpazolid were calculated using a noncompartmental method. The geometric mean ratios (GMRs) and its 90% confidence intervals (CIs) of the test drug to the reference drug were estimated for the maximum plasma concentration (C_max) and area under the plasma concentration-time curve from time zero to the last observation (AUC_last). Safety assessments were also conducted. Twenty-four participants completed the study as planned. The PK profiles of delpazolid were similar between the test and reference drugs. The GMRs (90% CIs) of the test to the reference for C_max and AUC_last were 1.1265 (0.8666-1.4644) and 1.0290 (0.9402-1.1261), respectively. The result of AUC_last met the bioequivalence criteria (0.8-1.25), but the 90% CI for C_max exceeded the upper limit of 1.25. Both drugs were safe and well tolerated. The two different delpazolid formulations showed comparable PK and safety profiles, indicating that the test drug is an appropriate alternative to the reference drug.

Trial registration: ClinicalTrials.gov Identifier: NCT04939779.