Surfactants, Polymers, and Chelation (Classes 16-18)

Question 1

What is the difference between cohesion and adhesion?

Answer 1

Cohesion is attraction between like molecules; adhesion is attraction between dissimilar molecules

Question 2

When water beads up on a waxed car, is that an example of increased cohesion or adhesion?

Answer 2

cohesion

Question 3

Is surface tension the result of cohesion or adhesion?

Answer 3

cohesion

Question 4

How do you calculate surface tension?

Answer 4

1/2rhpg

Question 5

What are the most toxic surfactants?

Answer 5

cationic

Question 6

What are the safest surfactants?

Answer 6

non-ionic

Question 7

How does a surfactant affect surface tension?

Answer 7

Lowers it

Question 8

Are high surface activity compounds better at raising or lowering surface tension?

Answer 8

Lowering

Question 9

What’s the relationship between solubility and surface activity?

Answer 9

Inversely related (Any factor that tends to decrease solubility of a surfactant will increase surface activity; Increasing hydrocarbon chain will increase surface activity)

Question 10

What does HLB stand for?

Answer 10

Hydrophilic Lipophilic Balance

Question 11

What does a higher HLB value mean?

Answer 11

Higher HLB -> more hydrophilic; more dominant polar head

Question 12

What does a lower HLB value mean?

Answer 12

Lower HLB -> more lipophilic; longer carbon chains

Question 13

When CMC is reached, what happens?

Answer 13

Micelles form

Question 14

How does HLB value correlate to CMC?

Answer 14

Higher HLB = Higher CMC

Question 15

Addition of 1 methylene group to a surfactant chain does what to the CMC?

Answer 15

decreases it 3-fold.

Question 16

What mixture killed michael jackson?

Answer 16

Propofol and lorazepam

Question 17

What are some properties of polymers?

Answer 17

crystallinity, solubility, polydispersity, glass transition temperature, chain entanglement

Question 18

Describe crystallinity

Answer 18

The degree to which polymer strands will align in rigid, uniform lines. Less order = amorphous.

Question 19

Properties of a polymer depend on what 2 things?

Answer 19

Size and shape

Question 20

Reactivity of a polymer depends on what 2 things?

Answer 20

Chemistry and assembly of units

Question 21

What is a substance of high molecular weight consisting of repeating monomers called?

Answer 21

polymer

Question 22

What repeating unit is used in teflon?

Answer 22

CF2

Question 23

For a polymer to be perfectly monodisperse, what does the PI need to be?

Answer 23

1

Question 24

What must the polydispersity index be for a polymer to be considered monodisperse?

Answer 24

between 1 and 1.1

Question 25

What does polydisperse mean?

Answer 25

multiple chains of varying length

Question 26

When a polymer is placed in temps below its Tg, what are some characteristics of the polymer?

Answer 26

hard, stiff, glassy

Question 27

When a polymer is placed in temps above its Tg, what are the characteristics of the polymer?

Answer 27

Weak, flexible, ductile

Question 28

Do short polymer chains have a higher or lower Tg than cross-linked polymer chains?

Answer 28

lower

Question 29

In polystyrene vs a milk jug, which polymer would have the lower Tg? Which polymer would have shorter chains?

Answer 29

polystyrene. Polystyrene

Question 30

What factors decrease dissolution rate of a polymer?

Answer 30

Increased molecular weight, crystallinity, cross-linking

Question 31

A drug encapsulated in a polymer must diffuse through what extra layer before it reaches the diffusion layer?

Answer 31

gel layer

Question 32

What type of drug delivery system exploits the properties of osmosis?

Answer 32

Oros

Question 33

What are 4 types of copolymers?

Answer 33

alternating, random, graft, block

Question 34

Name 4 uses of polymers in pharmacy.

Answer 34

Drug delivery systems, film coatings, IV Admin sets, Membranes & filters, Thickening agents, Tablet excipients (binders, disintegrants), meshes

Question 35

If you wanted to make a chewable quality polymer, Tg should be about what?

Answer 35

Body temperature

Question 36

What are some factors that decrease the dissolution rate of a polymer?

Answer 36

Increased molecular weight, increased crystallinity, increased crosslinking

Question 37

What are some examples of nanocarriers?

Answer 37

liposomes, nanospheres, nanoparticles, nanofibers, nanotubes, nanosuspensions, nanogels

Question 38

What are 2 types of adsorption?

Answer 38

physical & chemisorption

Question 39

According to langmuir's isotherm, what is formed by molecules that adsorb to a solid surface?

Answer 39

monolayer

Question 40

Give an example of a therapy that uses adsorption?

Answer 40

activated charcoal

Question 41

Give an example of a therapeutic chelation agent?

Answer 41

EDTA

Question 42

Give two examples of chelation agents found naturally?

Answer 42

heme & chlorophyll

Question 43

Do cyclic structures increase or decrease chelate stability?

Answer 43

increase

Question 44

Is a high log k value associated with greater or less stability?

Answer 44

greater

Question 45

What is the chelate effect predominantly the effect of?

Answer 45

entropy

Question 46

What is denticity?

Answer 46

the number of atoms in a single ligand that bind to a central atom in a coordination complex

Question 47

What needs to be chelated in Wilson's disease and what is a chelation agent to do it?

Answer 47

Copper; Penicillamine

Question 48

Tetracycline is used for Rocky mountain spotted fever. What does Tetracycline chelate within the diet?

Answer 48

Milk, iron, antacids

Question 49

Why do we not give tetracycline to children less than 8?

Answer 49

It will chelate with the teeth