Biopharmaceutical Exam

Question 1

What are three factors decreasing GI absorption of protein drugs?

Answer 1

1. size limits epithelial permeability
2. chemical hydrolysis
3. enzymatic proteolysis

Question 2

What are two factors affecting protein toxicity (safety)?

Answer 2

1. dose-related pharmacological activity

2. off-target toxicity related to immunogenicity of protein

Question 3

When does aggregation occur?

Answer 3

denaturing leads to exposed hydrophobic residues that can associate with other protein molecules

Question 4

What are four (4) processes that can cause denaturation?

Answer 4

1. temperature
2. surface interaction
3. agitation
4. foaming

Question 5

Name five (5) excipients used in biopharmaceuticals?

Answer 5

1. Tween 80
2. albumin
3. sucrose
4. EDTA
5. TRIS

Question 6

Why is Tween 80 used in biopharmaceuticals?

Answer 6

surfactant and stabilizer against aggregation

Question 7

Why is albumin used in biopharmaceuticals?

Answer 7

protein and stabilizer against surface-mediated aggregation

Question 8

Why is sucrose used in biopharmaceuticals?

Answer 8

diasaccharide used to stabilize lyophilized protein formulations

Question 9

Why is EDTA used in biopharmaceuticals?

Answer 9

metal ion chelator used to protect against oxidative instability

Question 10

Why is TRIS used in biopharmaceuticals?

Answer 10

buffer used to control pH

Question 11

What is the major limitation of using prokaryotic cells for protein production rather than eukaryotic cells?

Answer 11

prokaryotic cells are incapable of post-translational protein modification (e.g. glycosylation)

Question 12

Why are protein drug substances frozen?

Answer 12

Bulk protein drug substance are frozen to stabilize before final drug product formulation.

Question 13

What are the pros and cons of freezing (frozen liquid) vs freeze-drying?

Answer 13

1. Freezing is less time-consuming
2. Freezing is less costly
3. Freeze-drying provides greater stability.

Question 14

What are two (2) reasons protein drug substanced are lyophilized [freeze-dried]

Answer 14

1. protect against hydrolysis [chemical]

2. protect against physical instability from solutoin [physical]

Question 15

List seven (7) sources of biopharmaceutical contamination

Answer 15

1. particulates
2. leachables
3. bacteria
4. mycoplasma
5. virus
6. pyrogens
7. endotoxins

Question 16

List the advantages and disadvantages of live attenuated vaccines

Answer 16

1. adv: possibility of life-long immunity

2. disadv: revert to virulent form

Question 17

List the advantages and disadvantages of inactivated (killed) vaccines

Answer 17

1. adv: no risk of reversion

2. disadv: require booster administration and adjuvants

Question 18

List five (5) types of vaccines

Answer 18

1. subunit vaccine
2. polysaccharide
3. recombinant
4. live-attenuated
5. inactivated

Question 19

List an example of a subunit vaccine

Answer 19

Pertussis

Question 20

List two (2) examples of a polysaccharide vaccine

Answer 20

1. streptococcal pneumonia

2. typhoid

Question 21

List two (2) examples of a recombinant vaccine

Answer 21

1. hepatitis B

2. HPV (papilloma)

Question 22

List eighth (8) examples of live-attenuated vaccines

Answer 22

1. oral polio
2. measles
3. mumps
4. rubella
5. influenza
6. smallpox
7. typhoid
8. anthrax

Question 23

List five (5) examples of inactivated vaccines

Answer 23

1. cholera
2. pertussis
3. inactivated polio
4. influenza
5. hepatitis A

Question 24

What is the antigen production host for a viral vaccine?

Answer 24

1. Cell cultures

2. Eggs (chicken)

Question 25

What is the antigen production host for a bacterial vaccine?

Answer 25

1. bacterial fermentation | 2. yeast fermentation

Question 26

What are two (2) reasons adjuvants are used in vaccine formulations?

Answer 26

enhance immune response by: 1. increasing antigen uptake 2. inducing the production of cytokines and complements

Question 27

What is thimerosal?

Answer 27

mercury-containing microbial preservative that has historically been used in vaccines

Question 28

What are the safety concerns for thimerosal?

Answer 28

potential toxicity in children

Question 29

From what vaccines was thimerosal removed?

Answer 29

Vaccines recommended for children -- single-dose vaccines.

Question 30

In what vaccines does thimerosal remain?

Answer 30

Multi-dose vaccines, including influenza.

Question 31

What is the function of gelatin in vaccinations?

Answer 31

stabilize vaccine against physical instability

Question 32

What are the safety concerns of gelatin?

Answer 32

one in 2 million children experience hypersensitivity reaction to gelatin

Question 33

What three (3) amino acids are basic?

Answer 33

1. Arginine 2. Lysine 3. Histidine 4. terminal amines

Question 34

What two (2) amino acids are acidic?

Answer 34

1. Aspartic acid 2. Glutamic acid 3. terminal acids

Question 35

What amino acids are susceptible to oxidation?

Answer 35

1. Methionine | 2. Cysteine

Question 36

What amino acids are susceptible to carbonyl amine reactions (e.g. glycation)?

Answer 36

1. Lysine | 2. Terminal amines

Question 37

What amino acids are susceptible to deamidation?

Answer 37

1. asparagine | 2. glutamine

Question 38

How does a second structure in a region of "susceptible to degradation" affect rate of degradation?

Answer 38

Secondary structure decreases rate of degradation.

Question 39

What is the primary structure?

Answer 39

Sequence of amino acids

Question 40

What is secondary structure?

Answer 40

Alpha helices and Beta-sheets -- amino acid configuration; weak interactions.

Question 41

What is tertiary structure?

Answer 41

three dimensional globular sturcture, native and denatured conformations

Question 42

What is quaternary structure?

Answer 42

intermolecular interactions such as aggregation and association (dimers, hexamers, polymers)

Question 43

Describe the general trend of protein solubility?

Answer 43

Proteins tend to be ionized at extreme pH. There is a certain pH that is the "isoelectric point," at which net charge is zero and solubility is at minimum.

Question 44

What are three benefits of directions of use in protein pharmaceuticals?

Answer 44

1. avoid aggregations/precipitations problems (temperature, surface interaction, foaming, agitations etc.) 2. avoid chemical instability 3. avoid incompatibilities

Question 45

What are three (3) strategies for preventing proteins from degrading?

Answer 45

1. refrigeration 2. freeze-drying 3. placing a nitrogen headspace over a drug in a tightly sealed container

Question 46

What are four (4) examples of physical instability?

Answer 46

1. insolubility 2. foaming 3. catastrophic aggregation 4. gelation

Question 47

Does dissolving a protein in D5W increase protein stability?

Answer 47

No.