Which term best describes the process of movement from the GI tract into the bloodstream?

• A. Disintegration
• B. Drug absorption
• C. Dissolution
• D. Metabolism

Answer: (B)

Absorption is the movement of a drug from the GI tract into the bloodstream. When a drug is taken orally, it begins in the gut lumen and must cross the intestinal lining to reach systemic circulation, where it can circulate to tissues. This step is what makes the drug available to produce its effects.

Think of the journey in stages: disintegration breaks the dosage form into smaller pieces, and dissolution brings those pieces into solution in GI fluids; once dissolved, the molecules can be absorbed across the gut mucosa. Metabolism, on the other hand, refers to chemical changes the body makes to the drug (primarily in the liver and gut wall), which often occurs after absorption and can modify activity or lead to inactivation.