PBPK Model
A comprehensive whole-body physiologically based pharmacokinetic (PBPK) model serves as the foundation for complex calculations. This model accounts for the physiological intricacies of the entire body.
Teoreler incorporates a detailed representation of compartments, each reflecting specific anatomical and physiological aspects. The structural framework of these compartments is elucidated to facilitate a nuanced understanding of the model's simulation dynamics in the figure below. This approach ensures a thorough exploration of pharmacokinetic processes, considering diverse bodily regions.
The utilization of a whole-body PBPK model not only enhances precision in computations but also enables a more accurate representation of the intricate interplay between drug dynamics and the multifaceted physiological environment. The current model has a few assumptions and limitations*:
- The oral model assumes complete drug dissolution in the stomach under fasted conditions when a simple absorption model is used.
- There is no reabsorption from the large intestine.
- The distribution model is blood flow limited.
- Organs/tissue compartments exhibit instantaneous and uniform drug distribution.
- First-order kinetics govern drug release from intramuscular and subcutaneous depot sites.
- The existing PBPK models consist of a human adult (18–60 years) model, a child/adolescent (2–18 years) model, a rat model, and a mouse model. These models are currently applicable for simulating drugs unaffected by transporters.
* The models will be updated in the future to address these current limitations.