absorption of drugs through various routes

definition, mechanism of drug absorption, factors affecting it, first pass effect of liver, various pathway of drug absorption, sites of drug administration, active and passive transport, simple and facilitated diffusion, pinocytosis and active transport, and thanks slide

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… .