Transcript week01.1.biopharm

Definitions
drug - any substance that affects the structure or functioning of an
organism
pharmaceutics - the area of study concerned with the formulation,
manufacture, stability, and effectiveness of dosage forms
pharmacology - the science of the properties of drugs and their effects
on the body
pharmacokinetics - the study of the kinetics of absorption, distribution,
metabolism, and excretion of drugs and their corresponding
pharmacologic response in animals/man
clinic - a facility or area where ambulatory patients are seen for special
study and treatment
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PHARMACEUTICAL INDUSTRY
Drug Discovery
- natural sources, synthesis/modification
biological properties
Preclinical Studies
- pharmacology, pharmacokinetics
preformulation
- chem/phys properties
- analytical assays
Formulation
development of dosage form
 large-scale manufacturing

Clinical Trials
Approval for Distribution
Post-Marketing Surveillance
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INTRODUCTION
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drugs seldom administered alone
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objective of dosage form design
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given as a formulation
» contain additional ingredients called excipients
achieve a predictable therapeutic response to a drug
included in a formulation which is capable of large scale
manufacture with reproducible product quality
must consider physical, chemical, biological
properties of all components
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Excipients
Purpose
Example
pH control
citric acid, NaCO3
preservative
NaBenzoate, phenol
antioxidant
surfactant
ascorbic acid,
NaBisulfite
alcohol, sterilized
water
cetyl alcohol
ointment base
petrolatum, PEG
flavor
peppermint oil,
menthol
solvent
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Need for Dosage Forms
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provide safe and accurate delivery of given dosage
protect drug from environmental degradation
protect drug from GI degradation
conceal bitter, salty taste, offensive odor
allow for administration of poorly soluble drug
provide rate-controlled action
allow for admin. by desired route
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Routes of Administration
Route
dosage form
oral
tablets, capsules, solutions,
suspensions, powders,
emulsions, gels, lozenges
ointments, creams, pastes,
lotions, gels, solutions
injections (i.v., s.c., i.m., i.p.,
i.t., i.a, …)
ointments, creams, lotions,
patches, infusion pumps
solutions, suspensions
topical
parenteral
transdermal
intraocular
/nasal/aural
pulmonary
rectal
vaginal
urethral
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aerosols
solutions, ointments,
suppositories
solutions, ointments,
suppositories, gels, foams
solutions, suppositories
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Drug Action
QuickTime™ and a
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Biopharmaceutics
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Bioavailability

extent of absorption and the rate at which an
administered dose reaches systemic circulation in
its active form
tissue, lymph
intravenous
drug in
dosage form
oral
liver
blood plasma
bound  free
excretion
metabolism
site of
action
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example of oral administration plasma
concentration time profile
absorption
phase
elimination phase
plasma
conc’n
time after administration
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Therapeutic Window

therapeutic response is dependent on drug
achieving an adequate plasma concentration
plasma
conc’n
Cp
time after administration
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Pharmacodynamics
not all individuals respond in same manner
no. of individuals
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minimum dose for response
(mg/kg)
therapeutic index (TI)
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TI =
TD50
ED50
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absolute bioavailability
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any drug delivered extravascularly has the potential of being
bound or eliminated before reaching bloodstream
amount of drug reaching bloodstream is equal to the area
under the Cp vs t curve, AUC
absolute bioavailability =
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relative bioavailability
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some drugs cannot be given by iv
bioavailability determined by comparison to standard dosage
form
relative bioavailability =
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AUC extra
AUC IV
AUC test
AUC s tandard
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Bioequivalence
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comparison of amounts of same drug that are absorbed from
2 different formulations of the same dosage form (generics)
the two formulations are considered equivalent if there is no
significant difference between any of Cmax, Tmax, AUC
Cp
time
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