Module232025

09/05/2025

Introduction key concepts

What is a model in this context?

• a representation of a system or phenomenon using mathematical equations, to describe its behavior, analyzeits properties, and make predictions

• Examples: a regression (y=a*x+b); a differential equation dy/dx = f(x)

• Here “x” is an independent variable (dose; concentration) and “y” is a dependent variable (AUC; time) Models are built for purpose (context of use)

What do we want to know?

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• How certain do we need to be? What are we willing to assume?

• Possibilities are a function of the quantity, quality and mechanistic understanding of data available

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Introduction key concepts

General PK/PD model types Quantitative Systems Pharmacology (QSP ) • informed and constrained by best understanding of the biology and need to be interconnected • Compartments are cells, organs, and subcellular compartments • intervention with mechanistic pharmacodynamics Physiology based models (bottom-up) • physiologiccompartmental structure withsystem-related (e.g. blood flows, organ volumes) and drug-related (e.g. log P, intrinsic metabolic clearance) parameters • Physiologicalplausibilityof parameter estimatesmustbe assessed • Includes in vitro-in vivo extrapolation (IVIVE) methods (e.g. enzyme activity)

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