PS400 exam 3

Question 1

for ph profile, when is the max stability of a drug?

Answer 1

at pka, drug segregation rate is lowest

formulate ate aka or a little above

Question 2

what is best selling drugs for the years:
2012-2020
2021-23
23-24
24

Answer 2

humira (anti TNF a antibody)
cominrnaty (covide 19 mrna)
keytrude (anti PD1)
ozemspic & Wegovy

Question 3

what are features of small molecule drugs?

Answer 3

low MW
organic or chemical synthhesis
fewer steps
well characterized
known structure
homogenous
not immunogenic

Question 4

what are properties of biologics?

Answer 4

high MW
made w/ live cells or organisms
critical steps
less easily characterized
may or may not be defined
heterogenous
immunogenic

Question 5

what can cause precipitation in plasma products?

Answer 5

ethanol, salt, pH, temp, centrifuge

Question 6

what are peptide products?

Answer 6

calcitonin
oxytocin
vasopressin

Question 7

what is the general mechanism of peptide production?

Answer 7

deprotection of chains

coupling of growing chain with new aa

cleavage of peptide chain

on a large scale, produced by recombinant DNA technology

Question 8

why are protein therapeutics more complicated than small molecule therapeutics??

Answer 8

large and more complex

Question 9

how are protein therapeutics produced?

Answer 9

recombinant by living organisms

challenging to characterize, require many analytical methods

Question 10

what is affect of protein therapeutics for immunogenicity and why?

Answer 10

potential for immunogenicity, due to endotoxins

Question 11

what happened during hGh testing??

Answer 11

developing fevers due to endotoxins

they must be removed by methods including ion-exchange chromatography

Question 12

what is primary, secondary, and tertiary and quaternary structure?

Answer 12

primary: sequence of a chain

secondary: local folding of polypeptide into helices or sheets

tertiary: 3d folding pattern of protein

quaternary: protein consisting more than one amino acid

Question 13

what is the process of endotoxin removal?

Answer 13

ion exchange chromatography

mix aa–>
binding of negative aa with cations to immobilize–>
separation of negative charged aa

Question 14

how are protein therapies produced??

Answer 14

isolate gene of interest

introduce gene into an expression vector

transform/ transfect vector into host cells

grow cells

isolation and purify protein from cells

formulate protein product

Question 15

what is the general structure of antibodies?

Answer 15

4 polypeptide chains connected by disulfide bonds between cysteine residues

2 heavy: Fab
2 light: fc

Question 16

how do Herceptin antibodies work?

Answer 16

immune cells targeting cancerous cells bound by Herceptin

dimersed HER2 receptors signal tumor cells to proliferate

Question 17

what does Herceptin do?

Answer 17

binds to HER2 tumor cells and flag them for destruction by immune system

blods downstream HER2 signaling to inhibit proliferation

Question 18

how does neonatal Fc receptor recycling work?

Answer 18

FcRn binds IgG in acidified endosome

sorting of complexes

some are recycled and IgG disassociate at physiological pH

OR
non receptor proteins are degraded in lysosome

Question 19

how does ADCC and CDC work?

Answer 19

ADCC:
-antibodies bind antigens
-NK cells recognize cell bound antibodies
-cross linking degranulation into lytic synapse
-die via apoptosis

CDC:
same process except for step 2
recruits complementary proteins that form membrane attack complex

Question 20

what are the 5 classes of antibodies?

Answer 20

IgM
igA
igD
igG
igE

Question 21

what is the most common subclass of IgG?

Answer 21

IgG1 and IgG2 & 4 r common

Question 22

what is fucosylations?
what does it do?

Answer 22

adding focose sugar units to a molecule

on Fc domain of antibody adds bulk–> weakens binding to Fc-y receptors for ADCC

Question 23

what is deamination degradation pathways?
what is rate affected by?

Answer 23

Asn & Gln

faster for Asn than Gln

N+1 residue (asn-gly is fastest)

reduces potency and leads to aggregation

Question 24

what is the process for oxidation?
what is it caused by?
what happens to trp?
when does it occur faster?

Answer 24

met, trp, cys

caused by chemical reagents (excitants,surfactant ) UV light

oxidation of trp by light can become yellow

reduces potency and less to aggregation

occurs faster at higher temp

Question 25

what are two other protein degradation pathways?

Answer 25

peptide bonde hydrolysis (asp-pro)

glycation (lys)

Question 26

what is disulfide reshuffling:
between what residues
occurs at what ph
what is it faster than

Answer 26

between cys residues

occurs at high pH

faster than formation or reduction of disulfide

Question 27

when is aggregation favored and when can it occur?

Answer 27

at pH near isoelectir point of protein & when protein is shake a lot

during freezing

Question 28

stressors : what happens to water in cyro concentration? to protein? what happens to osmolarity?
what causes unfolding?

Answer 28

water freezes first and interacts with itself bc of hydrophobic interactions

protein concentrating and can aggregate due to increased interactions

increase osm

interacts between ice surface & protein can lead to unfolding

Question 29

freeze drying proteins:
what is lyophilization?

Answer 29

freezing a protein solution to form ice

then by sublimation from solid phase to gas phase

lyophilize products are more stable

Question 30

what are barriers to protein and peptide delivery?

Answer 30

poor bioavailability due to acidic environment in the stomach & presence of protein degrading enzymes

rapid elimination in circulation due to protein degrading enzymes in blood & renal elimination

immogenicity due to immune system developing anti drug (ADA) against drug, which eliminate drug from circulation

Question 31

what was developed to tackle immongenicity, rapid elimination and poor bioavailability?

Answer 31

nanomedicne, but not always effective

Question 32

peptide delivery: lipidatioin
what is chain covalently & non covalently attached to?
how does it increase half life?
what does it form?

Answer 32

lipid chain is covalently attached to to peptide

noncovalently with albumin

statically hindering proteolytic enzymes from interacting with the peptide by binding to albumin & enabling FcRN recycling

increases size–> reducing kidney filtration

micelles at injection site sustaining release & slowing absorption

Question 33

peptide delivery strategies:
PLGA formulation
what can be altered to control drug release?
what does it do in the kidney?

Answer 33

size, porosity, polydispesity, shape, surface,

increases size–> reducing kidney filtration

Question 34

peptide delivery strategy:
PEGylation
what Chains attach to peptide
how does it increase half life and reduce kidney filtration?

Answer 34

hydrophilic polymer attaches (inc solubility)

sterilely hindering protelyic enzymes from interaticing w peptide

increase size, red kidney filtration

Question 35

peptide delivery strategies:
fusion proteins
what does Fc & albumin fusion attach to ?
how does it inc half life and reduct kidney filtration?

Answer 35

attach FC domain to peptide,
albumin fusions attach albumin

steriacally hinders proteolytic enzymes from intreating w the peptide & enables FcRN recycling

increase size red kidney filtration

Question 36

what does PEGylation and fusion proteins affect?

Answer 36

pharmacokinets and pharmacodynamics

Question 37

what is GLP1?
why is it rapidly eliminated?

Answer 37

involved in triggering insulin secretion

for type 2 diabetes

renal clearance and metabolism by dipeptidyl peptidase 4

Question 38

what are strategies to extend half life of GLP1?

Answer 38

change aa sequence to reduce Dpp4 cleavage

lipid attachment: lira & semaglutide

albumin
Fc fusion
PLGA
implant
oral
inhaled