Site of absorption studies are conducted early in development with different formulations of a given drug to determine which has the highest absorption at distinct locations of the GI track (jejunum, ilium, colon) or which formulation releases drug at the optimal location in the GI track for maximum absorption and bioavailability.
Scientific & PK Considerations of Site of Absorption Studies
Site of absorption studies rely on pharmacokinetics following release of drug at specific locations of the GI track. The PK parameters determined from release in areas of the small intestine (jejunum, ilium) or large intestine (colon) are compared and used to evaluate the optimal formulation for additional clinical trials.
When to Execute Site of Absorption Studies in Development Programs
The timing around execution of a site of absorption study depends on multiple factors including interactions with regulatory authorities, funding, investor expectations, exit strategies, and overall clinical development plans to support future studies or de-risk the continued development of a drug.