Quiz
Dispersed Systems: Colloids
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1Solutions are known as [blank_start]molecular dispersions[blank_end] in which the size of the internal phase is [blank_start]< 1 nm[blank_end].
- Amolecular dispersions
- B< 1 nm
2Molecular 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].
- Aultrafilters
- Bdiffusion
- Celectron microscope
3Most 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].
- A> 500 nm
- Bcoarse
4Coarse 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].
- Alight microscope
- Bdiffuse
- Cfiltration
5Colloids 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].
- Afine dispersions
- Bmicelles
- Cmicroemulsions
6Colloids 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].
- A1 nm
- B500 nm
7Colloids 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]
- Aelectron microscopes
- Bslowly
- Cdialysis
8Particle shape of colloids will depend on the phase of the medium. This will affect the [blank_start]viscosity[blank_end].
- Aviscosity
9There 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- ALyophilic
- BLyophobic
- C. Association
10Lyophilic 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)- ALarge organic
- Bsolvated
- Cassociated
11Lyophilic colloids are prepared by [blank_start]simple mixing[blank_end]. They are thermodynamically [blank_start]stable[blank_end] and reconstitution is possible.
- Asimple mixing
- Bstable
12Lyophilic colloids [blank_start]increase[blank_end] the viscosity of the medium and has two different phases the gel and solution phase
- Aincrease
13The solution-gel transition in a lyophilic colloid is dependent on the [blank_start]critical gelation concentration[blank_end] and [blank_start]temperature[blank_end]
- Acritical gelation concentration
- Btemperature
14[blank_start]Lyophobic colloids[blank_end] are thermodynamically unstable and reconstitution is not possible.
- ALyophobic colloids
15Lyophobic colloids require stabilization to prevent [blank_start]coalesence[blank_end].
- Acoalesence
16[blank_start]Association[blank_end] colloids are amphiphilic compounds such as micelles and vesicles.
- AAssociation
17Colloidal dosage forms include:
A) [blank_start]Gels[blank_end]
B) [blank_start]Magma[blank_end]
C) [blank_start]Nano-delivery[blank_end] systems- AGels
- BMagma
- CNano-delivery
18A 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]- Acondensed mass
- Bwater
19
[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.- AJelly
- BXerogel
20[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- AImbibition
- BSwelling
- CSynersis
21Gels: 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)- AMacromolecules
- Bamorphous
- Ccrystalline
22Gels: 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- AFloccules
- BThixotropic
23In gels, two phase systems are usually [blank_start]inorganic[blank_end] and single phase systems are usually [blank_start]organic[blank_end],
- Ainorganic
- Borganic
24Examples of [blank_start]Hydrogels[blank_end]: Pectin paste, tragacanth jelly, and methylcellulose
- AHydrogels
25Examples of [blank_start]Organogels[blank_end]: Petrolatum, mineral oil/polyethylene gel, and cocoabutter
- AOrganogels
26With the acrylic acid-based polymer [blank_start]carbomer[blank_end], maximum viscosity will happen at pH [blank_start]7[blank_end].
- Acarbomer
- B7
27Carbomers
Are very [blank_start]hygroscopic[blank_end], so should be kept in tight containers before use, or
they will get sticky.- Ahygroscopic
28A 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.
- AAlginic acid
- Bcalcium salts
29A 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
- Amethyl cellulose
30A 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.
- Ahydroxyethylcellulose
31A 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.
- Ahydroxypropylcellulose
32The 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.
- Aplastibase
- Bjelene
33[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].
- AAluminum hydroxide
- Btetracycline
- Cchelating
34[blank_start]Milk of Magnesia[blank_end] is an antacid with anti-constipating effects. It does not cause constipation.
- AMilk of Magnesia
35Gels 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]- AShrinkage
- BDiscoloration
- CMicrobial growth
36If the particle size in a two-phase system is large, the gel is referred to as a [blank_start]magma[blank_end]
- Amagma
37[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].
- AMicroemulsions
- Bsurfactants
38Microemulsions 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
- A15
- B18
39Microemulsions 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.
- Ahigh
- Binterfacial tension
40Microemulsions are used to enhance [blank_start]oral absorption[blank_end], [blank_start]transdermal delivery[blank_end] as well as targetting anticancer agents
- Aoral absorption
- Btransdermal delivery
41[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.
- ALiposomes
- Btargeted delivery
42Depending on the process used for their preparation, two types of nanoparticles can be formed.
- [blank_start]Nanocapsules[blank_end]
- [blank_start]Nanoparticles[blank_end]- ANanocapsules
- BNanoparticles
43Nanocapsules 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]- Acookie
- Begg
44[blank_start]Polymeric micelles[blank_end] are better for encapsulating hydrophobic drugs than liposomes because they can leak
- APolymeric micelles
45[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.- ATyndall effect
46Bigger particles = [blank_start]Lower[blank_end] diffusion coefficient = [blank_start]slow[blank_end] rate of diffusion
- ALower
- Bslow
Informationen
- Beschreibung
- 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.
- Autor
- Crystal Yu
- Sprache
- English
- Aufrufe
- 150
- Schlagwörter
- Bewertung
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