12: Nanoparticles

Question 1

list some challenges of standard drug therapy with conventional dosage forms

Answer 1

Low water solubility  
Poor absorption  
Short biological life  
Non-specificity  
Non-selectivity  
Adverse effects and toxicity  
Low cellular uptake

Question 2

<1nm is classified as

Answer 2

molecular

Question 3

1nm-0.5um is classified as

Answer 3

colloidal

Question 4

all colloids are ____

Answer 4

nanomeds

Question 5

> 0.5um are classifed as

Answer 5

coarse

Question 6

what are some common nanodelivery systems

Answer 6

lipid based nanocarriers
polymer based nanocarriers
inorganic nanocarriers
viral nanoparticles
drug conjugates

Question 7

why are solubilizing agents like cremophor and tweens not used

Answer 7

toxicity

Question 8

what to use instead of cremophor and tweens

Answer 8

liposomes

Question 9

what are 4 reasons to use drug targeting

Answer 9

difficulty in accessing site of action + maintaining stability all the way there
unwanted drug effects
lower required dose

Question 10

describe first order targeting

Answer 10

target to diseased organ or tissue

Question 11

describe second order targeting

Answer 11

target to cells in tissue or organ

Question 12

describe third order targeting

Answer 12

target intracellular organelles

Question 13

a nanomedicine targets T cells in the lymph nodes. what order targeting is this

Answer 13

second

Question 14

3 approaches for drug targeting

Answer 14

magic bullet
magic shotgun
prodrug approach

Question 15

what is the magic bullet approach

Answer 15

bio active agents that are both potent and selective to a particular target in the body

Question 16

preparation of pharmacologically inactive substances that become active at site of action describes the ___ approach

Answer 16

prodrug

Question 17

what is the magic shotgun approach

Answer 17

using macromolecule carriers that direct the drug to specific sites in the body

Question 18

what is required to use the prodrug approach of targeting?

Answer 18

the enzyme or chemical process involved in its transformation to be present at the active site

Question 19

when a drug is in a carrier, the fat of the drug in vivo will be governed by the

Answer 19

physiochemical properties of the carrier

Question 20

taking advantage of normal physiological conditions describes _____ targeting

Answer 20

passive

Question 21

blood capillaries are divided into 3 types

Answer 21

continuous
fenestrated
sinusoidal

Question 22

how big does your molecule have to be to not pass through continuous endothelium

Answer 22

> 2nm

Question 23

how big are the cell junctions between fenetrated capillaries

Answer 23

20-80nm

Question 24

why is there enhanced permeability in tumors

Answer 24

leaky vasculatur and disorganized tissues

Question 25

why is there an enhanced retention effect at tumor tissues

Answer 25

collapsed lymph drainage system = no way to get out

Question 26

what is active targeting

Answer 26

taking advantage of overexpression of receptors to get increased cell uptake or specific cell attachment

Question 27

what is physical targeting

Answer 27

taking advantage of environmental factors in organs

Question 28

designing a drug to go to an area with low pH is an example of _____ targeting

Answer 28

environmental

Question 29

if a drug is released very slowly from the liposome, the PK of the drug reflects the PK of the

Answer 29

carrier

Question 30

if a drug is released rapidly from a liposome, then the PK of the drug reflects the

Answer 30

PK of the drug

Question 31

when a liposome has a coating that prevents recognition by the phagocytic system, it is called a

Answer 31

stealth liposome

Question 32

what are some side effects of doxil or caelyx

Answer 32

increased mucositis and hand-foot syndrome

Question 33

the toxicity profile of caelyx vs free doxorubicin is similar to ______ vs_________

Answer 33

continuous infusion vs bolus injection

Question 34

why is the drug irinotecan administered in a liposome

Answer 34

poor water solubility otherwise

Question 35

what is the difference between nanocapsules and nanospheres

Answer 35

``` nanocapsules = one big reservoir system nanosphere = many tiny bubbles of drug in the particle ```

Question 36

what is abraxane and what are its perks

Answer 36

an injectable suspension of paclitaxel and albumin, the serum albumin solubilizes and carries the drug = reduction in acute toxicity = can be more aggressively dosed

Question 37

T or F: abraxane's lowered toxicity is due to being cremophor free

Answer 37

T

Question 38

what are the 3 nanodispersed systems for transdermal drug delivery

Answer 38

liposomes nanoemulsion lipid nanoparticle

Question 39

what is the difference between a nanoemulsion and a lipid nanoparticle

Answer 39

nanoemulsion = liquid lipid core | lipid nanoparticle = solid lipid core

Question 40

what is a lipid bilayer enclosing an aueous core

Answer 40

liposome

Question 41

what is PNKP

Answer 41

DNA repair enzyme that phosphorylates 5 and dephos 3' to allow DNA ligase to rejoin the strands a target for anticancer drugs

Question 42

if PNKP is inhibited, cells should become sensitive to

Answer 42

IR and TOPI inhibitors