Phar 323 - Terminologies And Important Points For Midterm 1 (Part 2)

Front 1

What are the steps of PLA Synthesis?

Back 1

Lactide is mixed with Tin Octanol and added Heat and Time

Front 2

What is a Number Average Molecular Weight (Mn)?

Back 2

The number represents the average number of repeating subunits in a polymer

=sum of (frequency of A x size of A)/ total number

Front 3

What is the structure of an Amorphous Polymer?

Back 3

Polymer chains making up the solid mass are completely randomly arranged

Front 4

What is the strucutre of a SemiCrystalline Polymer?

Back 4

Solid mass is composed of randomly arranged chains in some areas and chains which are arranged in an orderly but short range fashion in other areas

Front 5

Polymer can be completely Crystalline. True or False?

Back 5

FALSE

Front 6

What are the comparisons of General properties of Amorphous and Semicrystalline Polymers?

Back 6

1. Amorphous:

-High free volume

-Possesses a glass transition temp(Tg)

2. Semicrystalline:

-Low free volume

-Possesses both a glass transition temp(Tg) and a melting temp(Tm)

Front 7

What is a Tg?

Back 7

Glass Transistion Temp, which is specific to polymers. Above this temperature a polymer goes from hard brittle glass like material to a soft and felxible, rubber like material.

Front 8

What determines Tg?

Back 8

1. Backbone flexibility lowers Tg

2. Bulky pendent groups increases Tg by acting like an anchor (but can also decrease Tg by increasing free volume)

Front 9

PDLLA is a completely amorphous while PLA is semicrystalline. True or False?

Back 9

TRUE

Front 10

PGA is amorphous. True or False?

Back 10

False, PGA is Semicrystalline

Front 11

EVA is amorphous. True or False?

Back 11

TRUE

Front 12

What is the relationship between MW and Viscosity of the Polymer Solution?

Back 12

The higher the MW, the longer the polymer chains the more viscous the polymer solution.

Front 13

What is a Star Polymer?

Back 13

Polymeric biomaterials which has a central core from which 3 or more arms branch

Front 14

What is a Dendrimer?

Back 14

Polymeric biomaterials which is a near spherical shape and used for microencapsulation and drug delivery

Front 15

What are the shapes of Network Polymers?

Back 15

Either ladder or Semiladder Shape

Front 16

What are Supramolecular Polymers?

Back 16

Molecular superstructures are held together by non covalent bonds

Front 17

What is a Comb Polymer?

Back 17

Very high numbers of side chains, all of similar length

Front 18

"The spoons in the food court with the words 'biodegradeable' on them are made from ____"

Back 18

PLA

Front 19

What are the steps of Hydrolytic degradation of the biodegradeable polyesters?

Back 19

1. Uptake of water from aqueous tissue fluids into polymer.

2. Random cleavage of ester bonds by water bonds.

3. Long polymer chains are broken up into shorter chains or oligomers.

4. Oligomers dissolve in water because they are smaller.

5. Polymer begins to erode and there is mass loss

Front 20

What factors affect the rate of degradation of biodegradeable polymers?

Back 20

1. Composition: more hydrophilic the polymer the faster it degrades.

2. Molecular Weight: more MW leads to slower degradation rate.

3. Morphology: Amorphous polymer degrades faster than semicrystalline.

4. Surface Area of Polymer: increased surface area to volume ratio increases porosity increases degradation.

5. Site of Administration: Site of implantation can affect the degradation rate.

6. pH: more acidic /more basic promotes degradation.

7. Bond Stability

Front 21

How do Acidic/ Basic conditions compare for polymer degradation?

Back 21

1. Acidic conditions accelerate hydrolysis and H+ is retained so it acts as a catalyst.

2. Basic conditions accelerate hydrolysis but the OH- is used up and hydrolysis stops.

Front 22

Rank the following in bond stability: Alkane, Ester, Ether, Amide and Anhydride

Back 22

Alkane>Ether>Amide>Ester>Anhydride

Front 23

What are the steps of O/W emulsion technique?

Back 23

1. Polymer + Drug are dissolved in a common, organic water immiscible solvent (Chloroform) 2. Slow addition to stirred aqueous solution often containing a stabilizer to form O/W emulsion

3. Solvent diffuses out of the polymer/drug droplets leading to hardening of the droplets into solid polymer spheres entrapping drug

4. Collection of microspheres by centrifugation and filtering by washing to remove remaning solevent.

Front 24

What are the steps of W/O/W emulsion technique?

Back 24

1. Polymer + Drug are dissolved in aqueous solution, then emulsion formed when they are dissolved in water immisicble organis solvent. 2. The primary W/O emulsion is then added to a stirring aqueous solution to form a W/O/W emulsion.

3. Solvent diffuses out of the polymer/drug droplets leading to hardening into a solid polymer sphere entrapping the drug.

4. The microspheres are collected by centrifugation or filtration followed by washing to remove remaining solvent

Front 25

What physical characterisitc of microspheres are prepared by W/O/W emulsion?

Back 25

They are characterized by pores in the internal structure, where the sizes of the pores is proprtional to the amount of water used in the primary emulsion.

Front 26

What are the factors influencing the properties of Microparticles and Nanoparticles?

Back 26

1. Properties of Materials

2. Parameters of the dispersed phase

3. Operating conditions of the steps

Front 27

Which solvent makes the best disperse phase for small drug molecules?

Back 27

Acetone

Front 28

Which solvent makes the best disperse phase for most drug molecules?

Back 28

Chloroform

Front 29

Where do 1um large microspheres end up after IV injection?

Back 29

Liver, Spleen and Lungs

Front 30

What are the general methods of preparing Implants?

Back 30

1. Solvent Casting

2. Electrospinning

3. Melt Press/Melt Extrude

Front 31

Which drugs would you deliver with electrospun mats?

Back 31

Any drugs that is used with patches (Fentanyl, Scopalamine, etc)

Front 32

Which polymers can be used with the technique of melt extrusion?

Back 32

PLLA, PGA and PDLLA

Front 33

What are the mechanisms of Drug Release from Polymers?

Back 33

1. Diffusion of Drug

2. Degradation and Erosion of Polymer

Front 34

What are the differences between Reservoir Systems and Matrix Systems?

Back 34

In the Matrix System:

-Diffusion takes place through pores and the diffusion distance INCREASES as time increases.

In the Reservoir System:

-Diffusion takes place across a barrier and the diffusion distance is constant throughout

Front 35

Which of the Controlled Relase Systems are Biodegradeable?

Back 35

Diffusion Controlled Systems: Matrix, Reservoir Systems

Front 36

Which of the Controlled Relase Systems are NOT Biodegradeable?

Back 36

Chemically Controlled Systems: Biodegradeable Microspheres, Drug-Polymer Conugates

Front 37

What factors influence Drug Release from Matrix Polymers?

Back 37

1. Nature of Polymer: More hydrophilic releases faster.

2. Polymer Molecular Weight: higher MW releases drug slower.

3. Polymer Crystallinity: More crystalline polymers result in decreased drug release rate

4. Drug Loading in Polymer: Increased drug loading results in faster release

5. Surface Area

Front 38

What are the 3 phases of a high MW polymer triphasic drug release profile?

Back 38

1) Burst Phase

2) Primary Diffusion

3) Polymer Degradation/Erosion

Front 39

Why do we coat stents in Polyvinyl Pyrollidine?

Back 39

Keeps away moisture, for storage purposes

Front 40

What is PDMS and what are its applications?

Back 40

Poly DiMethyl Siloxane:

1) Used in cosmetics and heat transfer fluids

2) Used to be used as filler in breast implants but now as a joint [knuckle] replacement

3) In Silicon Oil form for ophtalmology applications

Front 41

What is Pharmaceutical Stability ?

Back 41

The extent to which a product retains the same properties and characteristics that it possessed at the time of manufacture.

Front 42

What are the three components of pharmacuetical stability?

Back 42

1. Physical Stability

2. Chemical Stability

3. Microbiological Stability

Front 43

Which components of pharmaceutical stability effect drug stability and drug efficacy?

Back 43

All of them!!

Front 44

What are examples of Physical Instability of Drugs?

Back 44

Coalescence, Creaming, Flocculation, Breaking, Capping, Chipping and Cracking

Front 45

What are examples of Chemical Instability of Drugs?

Back 45

Acetaminophen chemical structure decomposes into different structures due to water or oxygen

Front 46

What are examples of Microbiological Instability of Drugs?

Back 46

Growth of Microbiological growth

Front 47

What factors influence pharmaceutical stability?

Back 47

1. Nature of the active ingrediants and excipients 2.interactions between the drug and excipients

3. the manufacturing process

4.Packaging

5.Storage

Front 48

What specifications define the stability of a pharmaceutical product?

Back 48

1. Active Ingrediant Content: HPLC >90% of labeled dose.

2. Impurity Content: HPLC <2% of the total dose. 3. Appearance of the product

Front 49

How can a a pharamacist help ensure product stability?

Back 49

1. Observe expiration dates and rotate stock.

2. Store under recommended conditions.

3. Patient Education

4. Observe for evidence of instability

Front 50

What type of pharmaceutical Instability was the cause of the Glenn Chin case?

Back 50

Microbiological Instability:

Since he used expired products to make steroid injections for his patients.