10+11: Drug Stability and Expiration Date

Question 1

when drugs are repackaged or handled, what happens to their shelf life?

Answer 1

shortened

Question 2

a sterile eye drop is repackaged from a multiple dose dropper into a minum, what is the new shelf life

Answer 2

24h

Question 3

a sterile solution is repackaged from a large vial into a unit dose syringe, it must be used within

Answer 3

24hrs

Question 4

the shelf life of a product is the time period in which it must remain within its approved specification under recc conditions. what is approved specification

Answer 4

90% of labeled quantity

Question 5

path for dosage form manufacturing

Answer 5

bulk drug
manufacturing
pharmaceutical company
pharmacy patient possession

Question 6

how long can eyedrops be used after opening the dropper

Answer 6

1 month

Question 7

list the 5 types of instability

Answer 7

physical
chemical 
microbial
therapeutic
toxicological

Question 8

what are the 3 most vulnerable dosage forms to physical instability

Answer 8

emulsions
semisolids
suspensions

Question 9

what is a common sign of physical instability in tablets

Answer 9

fog or liquid droplets, crystal formation in package, swelling, fusion between tablets

Question 10

what is a common sign of instability in suppositories

Answer 10

softening or hardening, oil stains

Question 11

describe polymorphic transformation

Answer 11

crystalline structure to amorphous structure or crystalline structure to another crystalline stucture

Question 12

polymorphic transformation happens due to

Answer 12

heat, pressure, humidity

Question 13

a tablet looks the same as before, but with lower solubility, what instability may have happened

Answer 13

polymorphic transformation

Question 14

what is pseudopolymorphism

Answer 14

solvated to nonsolvated form- drug loses crystalline water in their structure

Question 15

what is aging in physical instability

Answer 15

changing in disintegration/ dissolution of dosage forms

Question 16

what is the most common cause of precipitation

Answer 16

change in pH

Question 17

list 4 reasons for precipitation

Answer 17

change in pH
dilution of cosolvent during storage
complexation
salting out by addition of electrolytes

Question 18

stability in aq solution varies with ___ (3 things)

Answer 18

concentration
solution
container

Question 19

how to slow down physical instability

Answer 19

production
packaging
storage conditions

Question 20

what is buffer capacity

Answer 20

ability o fbuffer to resist change in pH

Question 21

what is buffer capacity and how can we increase it

Answer 21

ability of buffer to resist change in pH

greater the concentration, greater the resistance

Question 22

oxidation results in a loss of

Answer 22

electrons

Question 23

list some methods to prevent oxidation

Answer 23

light resistant packaging
film coating
tablets
insert gases
chelating agents
antioxidants

Question 24

how to reduce the risk of hydrolysis

Answer 24

determine the pH of max stability and use a buffer to keep it there

Question 25

what is the pH range for acetate buffer

Answer 25

3.6-5,6

Question 26

besides, adding a buffer, what else can we do to reduce the risk of hydrolysis

Answer 26

``` add nonaqueous solvents add surfactants convert to less soluble salts formulate as a suspension choose solid dosage forms ```

Question 27

oxidation of catalyzed by

Answer 27

metabolic elements

Question 28

products of oxidation are usually ________ and may be promoted by ________

Answer 28

coloured | light (photooxidation)

Question 29

list 3 antioxidants

Answer 29

oygen scavengers chain terminators reducing agents

Question 30

name an aqueous and an oil system antioxidant

Answer 30

ascorbic acid | ascorbyl palmitate

Question 31

tocopherol is a

Answer 31

oil system antioxidant

Question 32

what drugs / FGs are susceptible to photolysis

Answer 32

aromatic hydrocarbon groups, heterocyclic analogs, aldehydes, ketones

Question 33

drugs that absorb light <280nm decompose in _____ while drugs that absorb light >400nm decomposed in _______

Answer 33

sun light | sunlight and room light

Question 34

what is the difference between chemical and physical dehydration

Answer 34

physical dehydration = lose water from drug crystals | chemical = lose water from drug structure

Question 35

T or F: racecmization can change ADME

Answer 35

T

Question 36

racemization is usually catalyzed by

Answer 36

acid or base

Question 37

a drug becomes racemized and has a long half life, what will this affect

Answer 37

stability

Question 38

a drug is racemized and has a short half life, what will this affect

Answer 38

stability and pharmacology

Question 39

T or F: drug excipient incompatibilities may occur

Answer 39

T

Question 40

a solution of acids in a clear bottle has changed from clear to yellow tinged. What is likely the degradation process

Answer 40

chemical- oxidation

Question 41

zero order reactions rates are _____ of concentration

Answer 41

independent

Question 42

what type of formulations have zero order degradation kinetics

Answer 42

suspensions

Question 43

what types of formulations have first order degradation kinetics

Answer 43

solutions

Question 44

in the hydrolysis of ampicillin, why is the rate not also dependent on water? making it a second order reaction?

Answer 44

water is so much in excess it doesn't matter

Question 45

rate of a second order reaction depends on

Answer 45

concentrations of both reactants

Question 46

what are some additives that would affect degradation rate

Answer 46

buffers surfactants antioxidants chelating agents

Question 47

with a 10C increase in temperature, we see a ____ times increase in reaction rate

Answer 47

2-3x

Question 48

what are accelerated tests of stability

Answer 48

studies designed to increase the rate of chemical degradation or physical change using exaggerated storage conditions

Question 49

2 methods for accelerated tests of stability

Answer 49

arrheanius method | amirjahed method

Question 50

how to do the arrheanius method

Answer 50

see degradation of drug at different temps, then plot the graph and calculate k plot a second graph of logK vs temp and extrapolate to wanted temp for k

Question 51

find drug % decline at different temperatures, plot days to 90% vs temperature and extrapolate describes which method

Answer 51

amirjahed

Question 52

for approximation purposes, what is Q10

Answer 52

3