absorption
Definition
Absorption is the pharmacokinetic process by which a drug molecule moves from its site of administration into the systemic circulation. This process is governed by physicochemical properties including lipophilicity, molecular weight, ionization state, and formulation characteristics. Absorption rate and extent determine drug bioavailability and influence therapeutic efficacy. Key factors include route of administration (oral, transdermal, subcutaneous), membrane permeability, first-pass metabolism, and transporter-mediated uptake. For orally administered drugs, absorption primarily occurs in the small intestine through passive diffusion or active transport mechanisms. Understanding absorption mechanisms is critical for drug design, dose optimization, and predicting drug-drug interactions that may alter bioavailability and clinical outcomes.
Visualize absorption in Nodes Bio
Researchers can map absorption-related networks connecting drug molecules to membrane transporters (SLC, ABC families), metabolizing enzymes (CYP450s), and anatomical absorption sites. Network visualization reveals how genetic variants in transporter genes affect drug uptake, identifies potential absorption-based drug interactions, and traces causal pathways from formulation properties through cellular mechanisms to systemic exposure endpoints.
Visualization Ideas:
- Drug-transporter interaction networks showing SLC and ABC family members affecting intestinal absorption
- Multi-scale pathway maps connecting drug physicochemical properties to absorption mechanisms and systemic exposure
- Comparative absorption networks across species showing transporter expression differences in preclinical models
Example Use Case
A pharmaceutical team developing an oral kinase inhibitor discovers poor bioavailability in clinical trials. Using network analysis, they map the compound's interactions with intestinal efflux transporters (P-glycoprotein, BCRP) and metabolizing enzymes (CYP3A4). The visualization reveals that the drug is a substrate for multiple efflux pumps, explaining limited absorption. By analyzing structural analogs in the network, they identify chemical modifications that reduce transporter affinity while maintaining target potency, improving oral bioavailability from 12% to 45%.