Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmaceutics > Stability > Flashcards

Stability Flashcards

1
Q

what is drug stability

A

extent a product retains the same properties and characteristics ti possessed at time of manufacture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are 3 areas of concern for drug stability

A

chemical
physical
sterility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

degradation of the active may result in ?

A

inaccuracy in dosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the 5 ways of chemical degradation

A 
hydrolysis 
oxidation 
photolysis 
racemization 
dehydration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is hydrolysis

A

decomposition of drug through reaction with water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the most common functional group involved?

A

carboxyl derivatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the functional groups subject to hydrolysis

A 
amide - acetaminophen
lactam- penicillin
ester-atropine
lactone-warfarin
acetal- erythromycin
imine- diazepam
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how are drugs degraded by oxidation

A

spontaneously atmospheric oxygen is added or loss of hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how are the products of oxidation different

A

more conjugated

color/aroma changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the functional groups subject to oxidation

A 
phenol-steroid
catchol-isoproterenol 
ether- PEG
thiol- methimazole
thioether-chlopromazine 
aldehyde-paraldehyde
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does photolysis degrade drugs

A

light provides energy for initiation of oxidative process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the four things that may occur when electromagnetic radiation is absorbed by a molecule

A

molecule decomposes
energy retained =chemical change
energy converted to heat
emit light of diff wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does dehydration change drug stability

A

loss of water molecule changes the crystal habit (pseudopolymorphism) which may change solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is racemization

A

change in optical activity - changes biological activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what forms a schiff base

A

primary amine and aldehyde functional groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what forms a maillard reaction

A

amine and hydroxyl group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

give an example of racemization

A

dextromethorphan is a cough suppressant

levomethorphan is an opiod analgesic

18
Q

what does a blactam group and amino group result in

A

inactive amide

19
Q

what are the 4 ways of physical degradation

A

polymorphism
vapourization
aging
adsorption

20
Q

what is polymorphism

A

differences in crystal structures that results in solubility and stability differences

21
Q

how does vapourization cause instability

A

drugs with high vapour pressure are lost through vapourization

22
Q

what properties changes with aging

A

dissolution and disintegration

23
Q

why does adsorption affect drug stability

A

may lose drug to the pachaging of material or in PVC plastic of IV bgs

24
Q

what is t90

A

shelf life, time when the initial concentration of active has decreased by 10%

25
Q

how is the order of a reaction determined

A

experimentally

26
Q

what is a first order reaction

A

loss of drug proportional to the concentration remaining with respect to time

27
Q

what is a zero order reaction

A

loss of drug independent of concentration and constant with respect to time

28
Q

how does temperature affect reaction rate

A

increasing temp increases rate

29
Q

what is a catalyst

A

substance that increases the rate constant of a reaction without being transformed or consumed

30
Q

a v shaped pH rate profile is what type of substrate? what does the bottom of the v represent

A

a non ionizable substrate

bottom v is slowest reaction so best place to buffer

31
Q

what does a sigmoid shaped curve on a ph rate profile indicate

A

ionizable substrate

32
Q

what are some solvents that can be used to solubilize a drug

A

alcohol
propylene glycol
glycerol
PEG

33
Q

how does increasing the solvent polarity affect the rate of reaction

A

if a charge is developed the rate increases

if there is less charge the rate decreases

34
Q

why does formulating drugs as suspensions stabilize a drug

A

reduced solubility decreases amount of drug available for reaction
decomposes through apparent zero order kinetics

35
Q

how can you prevent hydrolysis

A 
exclusion of water 
buffer to optimal ph 
store at reduced temperature 
change solvent composition 
formation of complexes 
formulate as suspension
36
Q

how can you prevent oxidation

A

protect from light
exclude oxygen
add antioxidants
ph of 3-4

37
Q

how can you protect a drug from light

A

amber glass

opaque plastic

38
Q

what are antioxidants

A

more easily oxidized than the product

39
Q

what is a chelatin agent

A

consume trace amounts of metal ions which can function as catalysts

40
Q

whats an example of a chelating agent

A

EDTA

Pharmaceutics (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions