NUR601-Pharm.Intro.
determines the onset, duration, and in-
tensity of a drug's effect.
sometimes described as what the body
does to a drug, refers to the movement
Pharmacokinetics
of drug into, through, and out of the
body—the time course of its absorption,
bioavailability, distribution, metabolism,
and excretion.
described as what a drug does to the
Pharmacodynamics body, involves receptor binding, post re-
ceptor effects, and chemical interactions.
Weak organic Bases--Un-Ionized Lipid Soluble-(Lipophilic)
Low Lipid Solubility-high water solubili-
ty-(Hydrophilic)
Weak Organic Bases---Ionized
High electrical Resistance thus cannot
penetrate the Cell membrane easily.
most absorption occurs in the small in-
Small Intestine testine because the surface area is larg-
er and membranes are more permeable
Certain molecules with low lipid solubil-
ity (eg, glucose) penetrate membranes
more rapidly than expected.
One theory is facilitated passive diffu-
sion: A carrier molecule in the mem-
brane combines reversibly with the sub-
strate molecule outside the cell mem-
brane, and the carrier-substrate complex
diffuses rapidly across the membrane,
Facilitated Passive Diffusion
releasing the substrate at the interior sur-
face.
In such cases, the membrane transports
only substrates with a relatively specific
molecular configuration, and the avail-
ability of carriers limits the process.
The process does not require energy ex-
penditure, and transport against a con-
centration gradient cannot occur.
Active transport
, NUR601-Pharm.Intro.
Active transport is selective, requires en-
ergy expenditure, and may involve trans-
port against a concentration gradient.
Active transport seems to be limited to
drugs structurally similar to endogenous
substances (eg, ions, vitamins, sugars,
amino acids). These drugs are usually
absorbed from specific sites in the small
intestine.
In pinocytosis, fluid or particles are en-
gulfed by a cell. The cell membrane in-
vaginates, encloses the fluid or particles,
then fuses again, forming a vesicle that
Pinocytosis
later detaches and moves to the cell
interior. Energy expenditure is required.
Pinocytosis probably plays a small role in
drug transport, except for protein drugs.
refers to the extent and rate at which the
active moiety (drug or metabolite) enters
systemic circulation, thereby accessing
the site of action.
Bioavailability of a drug is largely deter-
mined by the properties of the dosage
Bioavailability
form, which depend partly on its design
and manufacture. Differences in bioavail-
ability among formulations of a given
drug can have clinical significance; thus,
knowing whether drug formulations are
equivalent is essential.
indicates that drug products contain the
same active compound in the same
Chemical Equivalence amount and meet current official stan-
dards; however, inactive ingredients in
drug products may differ.
indicates that the drug products, when
Bioequivalence given to the same patient in the same
dosage regimen, result in equivalent
determines the onset, duration, and in-
tensity of a drug's effect.
sometimes described as what the body
does to a drug, refers to the movement
Pharmacokinetics
of drug into, through, and out of the
body—the time course of its absorption,
bioavailability, distribution, metabolism,
and excretion.
described as what a drug does to the
Pharmacodynamics body, involves receptor binding, post re-
ceptor effects, and chemical interactions.
Weak organic Bases--Un-Ionized Lipid Soluble-(Lipophilic)
Low Lipid Solubility-high water solubili-
ty-(Hydrophilic)
Weak Organic Bases---Ionized
High electrical Resistance thus cannot
penetrate the Cell membrane easily.
most absorption occurs in the small in-
Small Intestine testine because the surface area is larg-
er and membranes are more permeable
Certain molecules with low lipid solubil-
ity (eg, glucose) penetrate membranes
more rapidly than expected.
One theory is facilitated passive diffu-
sion: A carrier molecule in the mem-
brane combines reversibly with the sub-
strate molecule outside the cell mem-
brane, and the carrier-substrate complex
diffuses rapidly across the membrane,
Facilitated Passive Diffusion
releasing the substrate at the interior sur-
face.
In such cases, the membrane transports
only substrates with a relatively specific
molecular configuration, and the avail-
ability of carriers limits the process.
The process does not require energy ex-
penditure, and transport against a con-
centration gradient cannot occur.
Active transport
, NUR601-Pharm.Intro.
Active transport is selective, requires en-
ergy expenditure, and may involve trans-
port against a concentration gradient.
Active transport seems to be limited to
drugs structurally similar to endogenous
substances (eg, ions, vitamins, sugars,
amino acids). These drugs are usually
absorbed from specific sites in the small
intestine.
In pinocytosis, fluid or particles are en-
gulfed by a cell. The cell membrane in-
vaginates, encloses the fluid or particles,
then fuses again, forming a vesicle that
Pinocytosis
later detaches and moves to the cell
interior. Energy expenditure is required.
Pinocytosis probably plays a small role in
drug transport, except for protein drugs.
refers to the extent and rate at which the
active moiety (drug or metabolite) enters
systemic circulation, thereby accessing
the site of action.
Bioavailability of a drug is largely deter-
mined by the properties of the dosage
Bioavailability
form, which depend partly on its design
and manufacture. Differences in bioavail-
ability among formulations of a given
drug can have clinical significance; thus,
knowing whether drug formulations are
equivalent is essential.
indicates that drug products contain the
same active compound in the same
Chemical Equivalence amount and meet current official stan-
dards; however, inactive ingredients in
drug products may differ.
indicates that the drug products, when
Bioequivalence given to the same patient in the same
dosage regimen, result in equivalent
