Bioavailabilitu

1. Absorption and Bioavailability
Prepared by
Rawand Sirwan Izzaddin
Department of Pharmaceutics
College of pharmacy/HMU

2. Absorption Definition
The most important principle in pharmacokinetics
theory is drug absorption which is defined as the
transportation of the unmetabolized drug from the site of
administration to the body circulation system.
• chemical composition of a drug
• environment of the drug inside the body
work together to determine the rate and extent of
drug absorption.

3. Absorption

4. Absorption
There are three important point which
determine the absorption of the drug :-
1. Physicochemical properties of the drug
2. Formulation
3. Route of drug administration

5. Routes of Drug Administration

6. Pharmacokinetics

23. Bioavailability
• Bioavailability is defined as a rate and extend of
absorption of unchanged drug from its dosage form
and become available at the site of action .
• Bioavailability of drug depend on 3 points
1. Pharmaceutical factors
2. Patient related factors
3. Route of administration

24. Absolute Bioavailability
When a systemic availability of a drug when
given orally is determined in comparison to its
intravenous administration , is called absolute
bioavailability .

25. Relative bioavailability
Relative bioavailability measures the
bioavailability of a formulation (A) of a certain
drug when compared with another formulation
(B) of the same drug .