Dispersed Systems: Colloids

Description

1. To understand the definition of colloids. 2. To understand the unique properties of colloids 3. To get familiar with the classifications of colloidal systems. 4. To identify colloidal dosage forms and their methods of compounding or preparation: - Gels - Magmas - Nano/Micro delivery systems 5. To Understand important physical properties of colloids.
Crystal Yu
Quiz by Crystal Yu, updated more than 1 year ago
Crystal Yu
Created by Crystal Yu over 6 years ago
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Resource summary

Question 1

Question
Solutions are known as [blank_start]molecular dispersions[blank_end] in which the size of the internal phase is [blank_start]< 1 nm[blank_end].
Answer
  • molecular dispersions
  • < 1 nm

Question 2

Question
Molecular dispersions can pass through [blank_start]ultrafilters[blank_end] and semi-permeable membranes. They undergo rapid [blank_start]diffusion[blank_end] and are invisible under an [blank_start]electron microscope[blank_end].
Answer
  • ultrafilters
  • diffusion
  • electron microscope

Question 3

Question
Most pharmaceutical suspensions and emulsions are [blank_start]coarse[blank_end] dispersions in which the size of the internal phase is [blank_start]> 500 nm[blank_end].
Answer
  • > 500 nm
  • coarse

Question 4

Question
Coarse dispersions are visible under a [blank_start]light microscope[blank_end] and do not [blank_start]diffuse[blank_end]. Particles can be separated via [blank_start]filtration[blank_end].
Answer
  • light microscope
  • diffuse
  • filtration

Question 5

Question
Colloids are also known as [blank_start]fine dispersions[blank_end]. Examples of colloids include [blank_start]micelles[blank_end] and [blank_start]microemulsions[blank_end].
Answer
  • fine dispersions
  • micelles
  • microemulsions

Question 6

Question
Colloids are dispersed systems in which the size of the internal phase is between [blank_start]1 nm[blank_end] and [blank_start]500 nm[blank_end].
Answer
  • 1 nm
  • 500 nm

Question 7

Question
Colloids are visible through [blank_start]electron microscopes[blank_end], they diffuse [blank_start]slowly[blank_end], and are separated by ultrafiltration or [blank_start]dialysis[blank_end]
Answer
  • electron microscopes
  • slowly
  • dialysis

Question 8

Question
Particle shape of colloids will depend on the phase of the medium. This will affect the [blank_start]viscosity[blank_end].
Answer
  • viscosity

Question 9

Question
There are three different classifications of colloids: 1. [blank_start]Lyophilic[blank_end] colloids 2. [blank_start]Lyophobic[blank_end] colloids 3[blank_start]. Association[blank_end] colloids
Answer
  • Lyophilic
  • Lyophobic
  • . Association

Question 10

Question
Lyophilic colloids: [blank_start]Large organic[blank_end] molecules capable of being [blank_start]solvated[blank_end] or [blank_start]associated[blank_end] with the molecules of the continuous phase. (example: acacia or gelatin)
Answer
  • Large organic
  • solvated
  • associated

Question 11

Question
Lyophilic colloids are prepared by [blank_start]simple mixing[blank_end]. They are thermodynamically [blank_start]stable[blank_end] and reconstitution is possible.
Answer
  • simple mixing
  • stable

Question 12

Question
Lyophilic colloids [blank_start]increase[blank_end] the viscosity of the medium and has two different phases the gel and solution phase
Answer
  • increase

Question 13

Question
The solution-gel transition in a lyophilic colloid is dependent on the [blank_start]critical gelation concentration[blank_end] and [blank_start]temperature[blank_end]
Answer
  • critical gelation concentration
  • temperature

Question 14

Question
[blank_start]Lyophobic colloids[blank_end] are thermodynamically unstable and reconstitution is not possible.
Answer
  • Lyophobic colloids

Question 15

Question
Lyophobic colloids require stabilization to prevent [blank_start]coalesence[blank_end].
Answer
  • coalesence

Question 16

Question
[blank_start]Association[blank_end] colloids are amphiphilic compounds such as micelles and vesicles.
Answer
  • Association

Question 17

Question
Colloidal dosage forms include: A) [blank_start]Gels[blank_end] B) [blank_start]Magma[blank_end] C) [blank_start]Nano-delivery[blank_end] systems
Answer
  • Gels
  • Magma
  • Nano-delivery

Question 18

Question
A gel is a solid or semisolid system of at least two constituents: a [blank_start]condensed mass[blank_end] enclosing or interpenetrated by [blank_start]water[blank_end]
Answer
  • condensed mass
  • water

Question 19

Question
[blank_start]Jelly[blank_end]: when liquid is present. [blank_start]Xerogel[blank_end]: When liquid is removed from a gel and only the framework remains. Examples include gelatin sheets, tragacant ribbons, and acacia tears.
Answer
  • Jelly
  • Xerogel

Question 20

Question
[blank_start]Imbibition[blank_end]: Taking up liquid without a change in size [blank_start]Swelling[blank_end]: Taking up liquid with a change in size [blank_start]Synersis[blank_end]: Loss of liquid
Answer
  • Imbibition
  • Swelling
  • Synersis

Question 21

Question
Gels: One phase systems - [blank_start]Macromolecules[blank_end] bond together with van der Waals forces to form [blank_start]amorphous[blank_end] or [blank_start]crystalline[blank_end] regions (Ex. tragacant and carboxymethylcellulose)
Answer
  • Macromolecules
  • amorphous
  • crystalline

Question 22

Question
Gels: Two phase systems - [blank_start]Floccules[blank_end] of small particles form and create a network - Not always stable - [blank_start]Thixotropic[blank_end] - Examples of this are aluminum hydroxide gel, bentonite magma, and magnesium magma
Answer
  • Floccules
  • Thixotropic

Question 23

Question
In gels, two phase systems are usually [blank_start]inorganic[blank_end] and single phase systems are usually [blank_start]organic[blank_end],
Answer
  • inorganic
  • organic

Question 24

Question
Examples of [blank_start]Hydrogels[blank_end]: Pectin paste, tragacanth jelly, and methylcellulose
Answer
  • Hydrogels

Question 25

Question
Examples of [blank_start]Organogels[blank_end]: Petrolatum, mineral oil/polyethylene gel, and cocoabutter
Answer
  • Organogels

Question 26

Question
With the acrylic acid-based polymer [blank_start]carbomer[blank_end], maximum viscosity will happen at pH [blank_start]7[blank_end].
Answer
  • carbomer
  • 7

Question 27

Question
Carbomers Are very [blank_start]hygroscopic[blank_end], so should be kept in tight containers before use, or they will get sticky.
Answer
  • hygroscopic

Question 28

Question
A commonly used gelling agent known as [blank_start]Alginic acid[blank_end] is taken from seaweed. It needs [blank_start]calcium salts[blank_end] to form the gel.
Answer
  • Alginic acid
  • calcium salts

Question 29

Question
A commonly used gelling agent known as [blank_start]methyl cellulose[blank_end] slowly hydrates in hot water and is then stirred with cold water to prompt dissolution
Answer
  • methyl cellulose

Question 30

Question
A commonly used gelling agent known as [blank_start]hydroxyethylcellulose[blank_end] hydrates and swells in cold water. It makes thinner gels that are compatible with water and alcohol.
Answer
  • hydroxyethylcellulose

Question 31

Question
A commonly used gelling agent known as [blank_start]hydroxypropylcellulose[blank_end] hydrates and swells in water and hydroalcoholic solvents. Good for high amount of drugs and makes thin gels.
Answer
  • hydroxypropylcellulose

Question 32

Question
The only true example of an organogel is [blank_start]plastibase[blank_end] or [blank_start]jelene[blank_end]. This gel can be heated to about 60 degrees without loss of consistency.
Answer
  • plastibase
  • jelene

Question 33

Question
[blank_start]Aluminum hydroxide[blank_end] gel is an antacid and may cause constipation. May interfere with the bioavailability of [blank_start]tetracycline[blank_end] by [blank_start]chelating[blank_end].
Answer
  • Aluminum hydroxide
  • tetracycline
  • chelating

Question 34

Question
[blank_start]Milk of Magnesia[blank_end] is an antacid with anti-constipating effects. It does not cause constipation.
Answer
  • Milk of Magnesia

Question 35

Question
Gels should be kept in tight containers and should be observed for: - [blank_start]Shrinkage[blank_end] - Separation of liquid - [blank_start]Discoloration[blank_end] - [blank_start]Microbial growth[blank_end]
Answer
  • Shrinkage
  • Discoloration
  • Microbial growth

Question 36

Question
If the particle size in a two-phase system is large, the gel is referred to as a [blank_start]magma[blank_end]
Answer
  • magma

Question 37

Question
[blank_start]Microemulsions[blank_end] are thermodynamically stable, optically transparent mixtures of a biphasic o/w or w/o system stabilized with [blank_start]surfactants[blank_end].
Answer
  • Microemulsions
  • surfactants

Question 38

Question
Microemulsions are prepared using surfactants with an HLB range of [blank_start]15[blank_end] - [blank_start]18[blank_end] such as polysorbate 60 and 80
Answer
  • 15
  • 18

Question 39

Question
Microemulsions are swollen micelles. The surface area is very [blank_start]high[blank_end] in these microemulsions, therefore [blank_start]interfacial tension[blank_end] has become very low.
Answer
  • high
  • interfacial tension

Question 40

Question
Microemulsions are used to enhance [blank_start]oral absorption[blank_end], [blank_start]transdermal delivery[blank_end] as well as targetting anticancer agents
Answer
  • oral absorption
  • transdermal delivery

Question 41

Question
[blank_start]Liposomes[blank_end] are used to provide sustained release of some drugs. Provides drug solubilization and protection, sustained and controlled release, [blank_start]targeted delivery[blank_end], and drug internalization.
Answer
  • Liposomes
  • targeted delivery

Question 42

Question
Depending on the process used for their preparation, two types of nanoparticles can be formed. - [blank_start]Nanocapsules[blank_end] - [blank_start]Nanoparticles[blank_end]
Answer
  • Nanocapsules
  • Nanoparticles

Question 43

Question
Nanocapsules coats the drug in a manner that is similar to that of an [blank_start]egg[blank_end] Nanoparticles have drug dispersed throughout similar to that of a [blank_start]cookie[blank_end]
Answer
  • cookie
  • egg

Question 44

Question
[blank_start]Polymeric micelles[blank_end] are better for encapsulating hydrophobic drugs than liposomes because they can leak
Answer
  • Polymeric micelles

Question 45

Question
[blank_start]Tyndall effect[blank_end]: Scattering may be described in terms of Turbidity which is the fraction decrease in light intensity due to scattering to all directions.
Answer
  • Tyndall effect

Question 46

Question
Bigger particles = [blank_start]Lower[blank_end] diffusion coefficient = [blank_start]slow[blank_end] rate of diffusion
Answer
  • Lower
  • slow
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