Absorption_of_Drugs_Presentation_Fully_Safe.pptx

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 Absorption is the process by which a drug enters the bloodstream from its site of administration.

3. Definition It is defined as the movement of drug from the site of administration into the systemic circulation.

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 Major site: Small intestine due to large surface area and good blood supply.

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

9. Summary Absorption determines onset, intensity, and duration of drug action. Influenced by physicochemical and biological factors.