Transcript Biopharmaceutics - Fakultas Farmasi UNAND

Introduction of
Biopharmaceutics
and
Pharmacokinetics
Dr. Muslim Suardi, MSi., Apt.
Faculty of Pharmacy
University of Andalas
2008
Biopharmaceutics
“The study of the in vitro impact of the
physicochemical properties of the drug
& drug product on drug delivery to the
body under normal or pathologic
conditions”
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Pharmacokinetics
The study of the absorption,
distribution, biotransformation and
elimination of xenobiotics.
Pharmacodynamics
The study of the biochemical &
physiological effects of xenobiotics
& their mechanisms of actions
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Pharmacodynamics
Biopharmaceutics
Pharmacologic effect
Drug in dosage
form
Release
Disolution
Peripheral
Tissues
GI
Absorption
Metabolism
Excretion
Distribution
Pharmacokinetics
BIOPHARMACEUTICS
Drug in dosage form
Release
Drug particles in GIT fluids
Dissolution
Drug in solution
GI
Degradation
Absorption
Presystemic metabolism
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PHARMACOKINETICS
Peripheral
Tissues
GI
Absorption
Liver /Metabolism
Excretion
Distribution
Central Compartment
Free  Bound
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DETERMINANTS OF
PHARMACOLOGIC EFFECT
Drug therapy is the major intervention
available for the amelioration & palliative
care of disease. The predominant role of
pharmacotherapy in the management &
prevention of disease necessitates a clear
understanding of factors that influence the
response to xenobiotics.
XENOBIOTICS
• Any compound to which the body is
exposed but which is foreign to the
body.
• This could be a drug or environmental
chemical. Importantly, those
principles that govern the disposition
of & response to chemicals are the
same with which we are concerned as
it relates to drugs.
PRIMARY MEANS TO
QUANTIFY DRUG EFFECT
• ONSET
• DURATION
• INTENSITY
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Evaluation of the onset,
duration and intensity of
xenobiotics leads to the
observation of an important
reality about
pharmacologic effect:
VARIABILITY !
CRITICAL NATURE OF THE
CONCENTRATION-EFFECT RELATIONSHIP
Hardman et.al (eds), 1996.
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The figure below illustrates the variability in response to IM 0.02 mg/kg
in a group of 27 subjects (Smith & Rawlins, 1973)
50 to 60
Change in
Heart Rate
30 to 40
10 to 20
-10 to 0
0
5
10
Number of Subjects
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What conclusion do we draw
from these facts?
Variability in drug
concentration makes a
major contribution to the
observed variability in
pharmacologic effect.
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Important Facts Related to Drug Effect
• There is significant variability in drug
response
• Pharmacologic response is dependent, in
large measure, on the concentration of
drug achieved at the site of action
• There is significant variability in the drug
concentration achieved after a standard
dose of a drug