12: Nanoparticles Flashcards
list some challenges of standard drug therapy with conventional dosage forms
Low water solubility Poor absorption Short biological life Non-specificity Non-selectivity Adverse effects and toxicity Low cellular uptake
<1nm is classified as
molecular
1nm-0.5um is classified as
colloidal
all colloids are ____
nanomeds
> 0.5um are classifed as
coarse
what are some common nanodelivery systems
lipid based nanocarriers polymer based nanocarriers inorganic nanocarriers viral nanoparticles drug conjugates
why are solubilizing agents like cremophor and tweens not used
toxicity
what to use instead of cremophor and tweens
liposomes
what are 4 reasons to use drug targeting
difficulty in accessing site of action + maintaining stability all the way there
unwanted drug effects
lower required dose
describe first order targeting
target to diseased organ or tissue
describe second order targeting
target to cells in tissue or organ
describe third order targeting
target intracellular organelles
a nanomedicine targets T cells in the lymph nodes. what order targeting is this
second
3 approaches for drug targeting
magic bullet
magic shotgun
prodrug approach
what is the magic bullet approach
bio active agents that are both potent and selective to a particular target in the body
preparation of pharmacologically inactive substances that become active at site of action describes the ___ approach
prodrug
what is the magic shotgun approach
using macromolecule carriers that direct the drug to specific sites in the body
what is required to use the prodrug approach of targeting?
the enzyme or chemical process involved in its transformation to be present at the active site
when a drug is in a carrier, the fat of the drug in vivo will be governed by the
physiochemical properties of the carrier
taking advantage of normal physiological conditions describes _____ targeting
passive
blood capillaries are divided into 3 types
continuous
fenestrated
sinusoidal
how big does your molecule have to be to not pass through continuous endothelium
> 2nm
how big are the cell junctions between fenetrated capillaries
20-80nm
why is there enhanced permeability in tumors
leaky vasculatur and disorganized tissues
why is there an enhanced retention effect at tumor tissues
collapsed lymph drainage system = no way to get out
what is active targeting
taking advantage of overexpression of receptors to get increased cell uptake or specific cell attachment
what is physical targeting
taking advantage of environmental factors in organs
designing a drug to go to an area with low pH is an example of _____ targeting
environmental
if a drug is released very slowly from the liposome, the PK of the drug reflects the PK of the
carrier
if a drug is released rapidly from a liposome, then the PK of the drug reflects the
PK of the drug
when a liposome has a coating that prevents recognition by the phagocytic system, it is called a
stealth liposome
what are some side effects of doxil or caelyx
increased mucositis and hand-foot syndrome
the toxicity profile of caelyx vs free doxorubicin is similar to ______ vs_________
continuous infusion vs bolus injection
why is the drug irinotecan administered in a liposome
poor water solubility otherwise
what is the difference between nanocapsules and nanospheres
nanocapsules = one big reservoir system nanosphere = many tiny bubbles of drug in the particle
what is abraxane and what are its perks
an injectable suspension of paclitaxel and albumin, the serum albumin solubilizes and carries the drug = reduction in acute toxicity = can be more aggressively dosed
T or F: abraxane’s lowered toxicity is due to being cremophor free
T
what are the 3 nanodispersed systems for transdermal drug delivery
liposomes
nanoemulsion
lipid nanoparticle
what is the difference between a nanoemulsion and a lipid nanoparticle
nanoemulsion = liquid lipid core
lipid nanoparticle = solid lipid core
what is a lipid bilayer enclosing an aueous core
liposome
what is PNKP
DNA repair enzyme that phosphorylates 5 and dephos 3’ to allow DNA ligase to rejoin the strands
a target for anticancer drugs
if PNKP is inhibited, cells should become sensitive to
IR and TOPI inhibitors
