Biokinetic

Biokinetic is the study of how living organisms process substances, focusing on the rates and pathways of absorption, distribution, metabolism, and elimination. The term covers a broad range of chemicals and compounds, including nutrients, pharmaceuticals, pesticides, environmental contaminants, and radionuclides. Biokinetic analysis seeks to describe the fate of a substance in a biological system and to explain how biological factors influence its concentration in different tissues over time.

A core goal of biokinetics is to quantify ADME processes through mathematical models. Common approaches range from simple compartment models, which treat the body as interconnected pools, to physiologically based pharmacokinetic (PBPK) models that incorporate organ sizes, blood flow, enzyme activities, and transport mechanisms. These models help predict tissue concentrations, exposure risks, and dose metrics under various scenarios. While pharmacokinetics is a key subfield focused on drugs, biokinetics has a broader remit that includes non-therapeutic chemicals and radionuclides, as well as complex mixture exposures.

Applications span drug development, clinical dosing, toxicology, environmental health, and radiological protection. In medicine, biokinetic modeling informs dose selection, efficacy, and safety assessments. In environmental health and risk assessment, it supports predictions of body burdens from inhalation, ingestion, or dermal contact. In radiation protection, biokinetic models describe the retention, distribution, and clearance of radionuclides to estimate organ doses.

Challenges in biokinetics include variability between individuals and species, differences in exposure routes, and limitations of experimental data to validate models. Continuous refinement of models and parameters is essential for accurate risk assessment and decision-making.