Objectives: This study aimed to develop and validate a physiologically based pharmacokinetic (PBPK) model of Pretomanid to provide a mechanistic understanding of its pharmacokinetics, incorporating CYP3A4-mediated metabolism and tissue-specific distri...
Objectives: This study aimed to develop and validate a physiologically based pharmacokinetic (PBPK) model of Pretomanid to provide a mechanistic understanding of its pharmacokinetics, incorporating CYP3A4-mediated metabolism and tissue-specific distribution, particularly in the lungs.
Methods: Based on published clinical pharmacokinetic data encompassing single oral doses ranging from 50 to 1000 mg a whole-body PBPK model was constructed using PK-Sim® (version 12). External validation employed independent datasets from multiple clinical studies. Critical parameters, including oral bioavailability, hepatic clearance, and plasma protein binding, were optimized using the Levenberg–Marquardt algorithm. Model performance was assessed through goodness-of-fit analysis, visual predictive checks, and geometric mean fold error (GMFE) calculations of drug exposure across multiple dosing regimens.
Results: The PBPK model accurately reproduced Pretomanid plasma concentration–time profiles across multiple doses (50–1000 mg). GMFE values for AUC, Cmax, and half-life ranged from 1.05–1.66, all within the acceptable predictive range (0.5–2). The predicted lung concentrations were comparable to plasma exposure (AUC_lung/plasma ≈ 1.0), consistent with literature reports. The model demonstrated robust external validity across independent datasets.
Conclusions: The model enables prediction of lung tissue exposure, assessment of CYP3A4-mediated interactions, and rational design of clinical dosing regimens. Future refinement incorporating disease- specific physiology will further enhance translational application.