W7 - Absorption Flashcards
What does the a of ADME stand for
Absorption
what is pharmacokietics
How much of the drug that is given to the patient which reaches the target organ, where it goes and how long it stays in the body for
What are some factors which are desirable for a drug
Has a stable form which is amenable to introduction to body
pass into the body
reaches its target
remains in the body long enough to achieve therapeutic effect
not produce harm while in the body
exit the body when its job is done
what are the two most important factors relating to absorption
lipophilicity
hydrophilicity
What does lipophilic mean
The substance is insoluble in aqueous media, it binds to strongly to plasma proteins and can distribute into lipid bilayers
What does hydrophilic mean
inability to cross plasma membrane
What is log p
it is a value to measure how hydrophilic or lipophilic a molecule is
Describe how size changes the way a molecule crosses the membrane
a small molecule can move through the membrane via diffusion
a larger molecule will require an aqueous channel to pass through
a large molecule will require a carrier protein to pass through the membrane
what is ionisation
protonation or deprotonation resulting in a charged molecule
why is ionisation important
Ionized ions cant cross the lipid bilayer we must take it into account
What 4 administration methods are described as enteral
oral
sublingual
rectal
inhalation
what does enteral mean
involves or passes through the intestines
what is a topical administration
application to epithelial surfaces e.g. skin
what 4 administration methods are described as parenteral
subcutaneous
intramuscular
intravenous
intrathecal
what is parenteral
any route that is not enteral
