Absorption of Drugs Definition: Movement of drug from administration site to systemic circulation. Steps: Disintegration → Dissolution → Membrane passage. Mechanisms: Passive diffusion, Facilitated diffusion, Active transport, Endocytosis.

1. Absorption of Drugs
Department of Pharmaceutics
Maharaja Sayajirao University

2. Introduction
e process by which a drug enters the bloodstream from its site of

3. Definition
e movement of drug from the site of administration into the syst

4. Steps Involved
1. Disintegration
2. Dissolution
3. Passage across membranes

5. Factors Affecting Absorption
1. Physicochemical properties
2. Dosage form
3. Route of administration
4. pH and pKa
5. Surface area and blood flow

6. Mechanisms of Absorption
1. Passive diffusion
2. Facilitated diffusion
3. Active transport
4. Endocytosis and filtration

7. Sites of Absorption
r site: Small intestine due to large surface area and good blood su

8. First-Pass Effect
of drug in liver before reaching systemic circulation reduces its b

9. Summary
t, intensity, and duration of drug action. Influenced by physicoche