Absorption of Drugs and Factors Affecting Drugs Absorption

Absorption of drugs
mechanism of absorption of drugs
factors affecting the absorption

1. Topic of
presentation
Absorption of drugs
Factors affecting
drugs absorption
Mechanism of drugs
absorption
Submitted to:
Dr. Sadaf Sarfaraz
Submitted by:
Roll no. 140

2. Absorption of drugs
definition
The transport of drug from the site of
administration to the systemic circulation is
called drug absorption

3. Sites of drug administration
and absorption
Oral and drug reaches into the GIT
Buccal
sublingual
•Intra-dermis
Sub-cutaneous
Intra-muscular
Through inhaler into the
lungs
Transport of drug
circulation

4. Mechanism of drug
absorption
1.Passive transport
2. Active transport

5. 1. Passive transport
I.Simple diffusion
a.Trans-cellular
b.Para-cellular
2. Facilitated diffusion
It requires some carrier-proteins like channels for
example aquaporins

6. Passive transport of drug

7. 2. Active transport of drug
i. By pump transporter
ii. By the process of pinocytosis
(endocytosis and exocytosis )

8. Factors affecting drug
absorption
1.Factors related to drug
Particle size
Chemical stability
solubility
Drug concentration

9. HA(aq) A (aq) + H (aq).
⇌ ⁻ ⁺
Acidic and basic nature of drug
Weak acid
Weak base
 B(aq) +H BH (aq)
⁺ ⇌ ⁺

10. 2. Factors related to patient
For example decrease absorption in hypovolemic
shock
Blood flow to the absorption site
total Surface area
For example in coeliac disease villi of small
intestine is damaged resulting in decrease surface
area and absorption

11. •Contact time
Diarrhea

constipation
For example in
•P-glycoprotein

12. thank
You… .