Absorption Parameters

Absorption Parameters

Figure 1 below shows the absorption parameters of Aspirin

Caco-2 Permeability

• Definition: Prediction of permeability using a human colon adenocarcinoma cell line model.

• Importance: Correlates with intestinal absorption potential. Higher permeability indicates better absorption.

• Expected Range: Aspirin shows high Caco-2 permeability due to its moderate lipophilicity (Figure 1).

P-glycoprotein (P-gp) Inhibitor/Substrate

• Importance: P-gp is an "efflux pump" in cells (like in the intestine and blood-brain barrier) that actively pushes foreign substances (like drugs) out of the cell.

• P-gp Substrate: If a drug is a substrate, the pump will eject it, reducing its absorption and concentration. This is generally undesirable.

• P-gp Inhibitor: If a drug is an inhibitor, it can block the pump. This can increase its own absorption but can also cause dangerous drug-drug interactions by preventing other drugs from being pumped out. This is also often undesirable.

• Desirable Range: Non-substrate and Non-inhibitor. 

• Aspirin: Predicted as Non-substrate and Non-inhibitor.

Human Intestinal Absorption (HIA)

• Definition: Prediction of fraction absorbed through the intestinal epithelium.

• Importance: Determines oral bioavailability potential. Poor absorption may necessitate alternative administration routes.

• Desired Range: >80% is considered high absorption. Aspirin shows excellent absorption (>90%) due to its appropriate physicochemical properties.