SimBiology model for Target-Mediated Drug Disposition (TMDD)

SimBiology model for Target-Mediated Drug Disposition (TMDD) implements mechanistic simulations in MATLAB to characterize and predict the nonlinear pharmacokinetics of drugs exhibiting high-affinity binding to pharmacologic targets (e.g., enzymes, receptors, transporters), including receptor-mediated endocytosis.

Key Features:

• Mechanistic Basis: Describes target-mediated kinetics allowing detailed representation of drug–target interactions and their effects on distribution and elimination.
• MATLAB/SimBiology implementation: Implemented using MATLAB SimBiology for mechanistic PK simulation and analysis.
• Polyexponential Plasma Concentration Profiles: Predicts polyexponential plasma concentration–time profiles with steeper distribution phases at lower doses and similar terminal phases across doses.
• Dose-Dependent Parameters: Captures dose-dependent changes in noncompartmental parameters such as volume of distribution at steady state (Vss) and dose-dependent clearance (CL(D)), and shows apparent clearance decreases only when binding contributes to elimination.
• Application to Therapeutic Agents: Applied to agents including the aldose reductase inhibitor imirestat, the endothelin receptor antagonist bosentan, and recombinant human interferon-beta 1a to reproduce time-course concentration behavior across doses.

Scientific Applications:

• Drug Development: Inform design and optimization of dosing regimens for drugs with target-mediated disposition by predicting dose-dependent PK behavior.
• Pharmacokinetic Studies: Provide a framework to analyze PK data exhibiting nonlinear kinetics due to target binding and receptor-mediated processes.
• Mechanistic Insights: Elucidate how drug–target interactions (including receptor-mediated endocytosis) drive distribution and elimination to support therapeutic strategy decisions.

Methodology:

Computer simulations in MATLAB/SimBiology using mechanistic parameters representing drug–target interactions (including receptor-mediated endocytosis) to predict plasma concentration–time profiles and dose-dependent PK behaviors.