Final Flashcards
1
Q
What is a dispersion?
A
One substance which is dispersed in another
2
Q
A true solutions is a ________ molecular dispersion.
A
Homogenous
3
Q
The dispersed phase is ______ distinguishable from dispersion medium
A
Physically
4
Q
TF: Dispersions are found in a large number of dosage forms
A
True
5
Q
Which one of the choices describes a dispersed phase component?Select all that apply
A. Termed the external Phase
B. Termed the internal phase
C. Termed the non continuous phase
D. Termed the Continuous phase
A
B
C
6
Q
What are dispersed systems classified by?
A
Phase
Particle size
7
Q
What type of dispersion is small (0.1-1000nm)?
A
Colloidal dispersion
8
Q
TF: Coarse dispersions are in the micrometer range
A
True
9
Q
What are the three types of colloidal dispersion types?
A
Lyophilic
Lyophobic
Association
10
Q
What does lyo refer to?
A
Solvent or medium
11
Q
TF: Lyophilic means solute has a low affinity for the medium?
A
False
Strong affinity
12
Q
Lyophilic colloids have ____ regions from ionizable functional groups.
A. Polar
B. non polar
A
Polar (allows hydration in aqueous environments)
13
Q
Which one of the following is not a lyophilic colloid?
A.Proteins
B.Natural gums
C. Glucose
D. Cellulose derivatives
A
C. Glucose
14
Q
Some hydrophilic (lyophilic) colloids may exist in both _____ and ____ state.
A
Solid
Gel
15
Q
In gel state of lyophilic colloids, molecules form connected networks resulting in _____ viscosity.
A
Increased (make more thick and less freely moved)
16
Q
In the solid state, lyophilic colloids move _____ in a solution
A
Freely
17
Q
How is xanthan gum made?
A
Fermenting corn sugar with a bacteria
18
Q
What is Xanthan Gum used for?
A
Emulsifier
Thickening agent
19
Q
Lyophobic colloids lack ____ groups the give them surface hydrophilicity?
A
Polar
20
Q
What are some examples of lyophobic colloids?
A
Milk
Lipid emulsions
Nanocrystal suspensiom
21
Q
What is the major problem with hydrophobic colloids?
A
Their tendency to aggregate
22
Q
What protein predominates in the plasma?
A
albumin
23
Q
How are association colloids formed?
A
By association of dissolved particles into a substance in the colloidal size range
24
Q
What are surfactant micelles and liposomes are made of?
A
Amphipiles
25
Interactions of association colloid result in _____ contact between the lipophilic portions of the _____ and water.
Minimal
Amphiphile
26
What are microemulsions?
Dispersion oil in water or water in oil
27
What is the difference between a homogenous and heterogenous dispersion?
Homogenous - molecular dispersion
Heterogenous - Physically distinguishable
28
What are the two components of a dispersion?
Dispersed phase
Dispersed medium
29
TF: Dispersed phase is termed the external or continuous region
False
It is the internal or continuous phase
30
How are dispersions classified?
By phase or particle size
31
What are the three phases of dispersions?
Solid
Liquid
Gas
32
What are three examples of solid dispersion?
Suppositories
Gels
Solid foam
33
What are three examples of liquid dispersion?
Crystal suspension
Emulsions
Foams
34
What are two examples of gas dispersions?
Smoke/spray powder
Mist
35
What are two types of dispersions based on particle size?
Colloidal dispersion
Coarse dispersion
36
What is the size range for a colloidal dispersion?
0.1-1000 nm
37
What is the size range for coarse dispersions?
1-200 um
38
Lyophilic colloids have _____ regions from ionizable functional groups.
Polar
39
What do polar groups enable for lyophilic dispersions?
Enables hydration in aqueous environments
40
What are three types of lyophilic dispersions and some examples of each?
Proteins-albumin
Polysaccharides-natural gums, cellulose derivative
41
TF: Polysaccharide dispersions may be in the solid or gel form
True
42
Lyophobic dispersions lack ____ groups to give them surface hydrophilicity.
polar
43
What are some examples of lyophobic dispersions?
Milk
Lipid emulsions
Nanocrystal suspensions
44
What is the major problem with hydrophobic colloids?
Their tendency to aggregate
45
In what size range are association dispersions?
Colloidal
46
What is the predominate plasma protein?
Albumin
47
The pressure exerted by blood against the wall of a capillary is called ____ ____ pressure.
Capillary hydrostatic pressure
48
TF: Capillary hydrostatic pressure is the same as capillary blood pressure
True
49
Capillary hydrostatic pressure is the force that drives fluid ____ of capillaries and ____ tissues.
Out of caps
Into tissues
50
As fluid exits a capillary and moves into tissues, the hydrostatic pressure in the interstitial fluid correspondingly RISES/DECREASES
rises
51
What is another name for oncotic pressure?
Colloid osmotic-pressure
52
What is oncotic pressure induced by?
Proteins (albumin) in the plasma
53
Where do water molecules move back into the circulatory system due to oncotic pressure?
Lower venous pressure end of capillaries
54
Tf: Oncotic pressure has opposing effects of both hydrostatic blood pressure and interstitial colloidal osmotic pressure?
True
55
What does hydrostatic pressure do?
push water and small molecules out of the blood and into interstitial spaces within the arterial end of capillaries
56
What effect will administering hypertonic solution have on intracellular and extracellular volume?
It will increase extracellular volume
Decrease intracellular volume
57
What effect will adminstering hypotonic solution have on intracellular and extracellular volume?
Increase both extracellular and intracellular volume
58
What effect will administering isotonic solution have on intracellular volume and extracellular volume?
Will increase extracellular volume but not effect intracellular volume
59
What effect will administering colloidal dispersions have on intravascular volume?
It will increase intravascular volume
60
TF: Administering colloidal dispersions will decrease interstitial and intracellular volume?
False there is not effect
61
Surfactant micelles will form ________ when CMC is reached 2-5 nm
Spontaneously
62
Microemulsions are oil in ____ or water in ____ dispersions.
Water
Oil
63
TF: Microemulsions are thermodynamically stable and often formed with co-surfactants
True
64
Which association colloid is more complex bilayer structures and can become large enough to exceed colloidal size range?
Association
65
What is brownian motion?
Random, irregular movements of particles
66
What is brownian motion caused by?
Bombardment of particles by the molecules of the dispersion media
67
What affects particle movements?
Particle size
Viscosity of medium
temperature
68
What factors decrease effects of brownian motion?
Decrease in temp (less movements)
Increase in viscosity (thicker so less easy to move)
Increase in particle size (more bulky and less freely movable)
69
TF: colloidal particles are not kept suspended by brownian motion due to their small size?
False
Particles are small enough that brownian motion keeps them suspended
70
TF: colloidal particles can counteract gravitational forces
True
71
Dispersions (except colloids) are affected by gravitational forces in a ______ manner
Predictable
72
TF: Particle sediment is going down only
False
it can go up or down
73
What type of emulsion will sediment up?
Oil in water (creaming)
74
Particles will sediment based on _____ Law
Stokes
75
The interfacial molecules will have _____ binding energy with interior molecules and this creates _____ surface energy
Lower
Postitive
76
What does magnitude of the surface energy depend on?
The collective cohesive and adhesive forces within a particular system
77
As particle size decreases,
Surface area is _____
More molecules are in contact with dispersion _____
Free surface energy _____
Results in _____ and dispersion stability is ______
Increased
Media
Rises
Aggregates; Impaired
78
What determines if aggregation occurs or does not occur within a particular system?
Forces surrounding particle interactions
79
What is the DVLO Theory?
Two primary forces (potentials) determine whether aggregation in a suspension will occur
80
What are the two primary forces that determine whether aggregation in a suspension will occur?
Van der Waals attraction potential
Electrostatic repulsion potential
These happen simultaneously to differing degrees
81
Van der Waals attraction and electrostatic repulsion potential approach zero as distance between particles increases/decreases
Increases
82
What are the two non-dvlo forces?
Hydration forces
Steric Forces
83
Hydration forces occur with _____ colloids
hydrophilic
84
What is the net result in hydration forces?
Repulsion which keeps the colloidal particles apart
85
What do steric forces do?
Coat particles with polymeric materials
Creates a physical barrier that prevents van der Waal attractive forces
86
What is Ostwald Ripening?
Creation of large particles at the expense of smaller ones
87
When adding particles to a solution, smaller particles will undergo dissolution ____ faster than larger particles. The solutes from smaller particles diffuse toward and deposit on ____ particles.
Faster
Larger
88
TF: temperature increase will increase the rate of dissolution and increase ripening
True
89
What are van der waals forces?
Attractive forces between molecules created from fluctuations in electron density
90
Van der Waals Forces creates what type of interactions?
Dipole-induced dipole
91
What does electrostatic forces depend on?
Magnitude of surface charge
92
What does magnitude of surface charge come from?
Ionizable groups on particle molecules (depends on pH of medium and pKa of particle molecules)
Adsorption of ions from solution onto uncharge particle surface
93
What is the shear plane?
Boundary between the diffuse layer and the dispersion medium surrounding the particle
94
What is the zeta potential?
The net electric charge at the outer diffuse layer and occurs at the shear plane
95
The greater the zeta potential, the more _____ between particles is present
Repulsion
96
What do salts do when adding to a suspension?
Add counterions to the diffuse layer
This will reduce the electrostatic barrier (repulsion)
Creates floccules which are easily resuspended
97
What is a flocculated suspension?
A suspension in which particles have undergone flocculation
98
What is the rate of sedimentation for flocculated suspensions?
The rate of sedimentation is high
99
What is the volume of sedimentation in flocculated suspensions?
High
100
Flocculated suspensions form porous/non-porous sediments
Porous
101
How can the re-dispersion of sediment be easily done in flocculated solutions
By agitation
102
What are the three factors affecting adsorption from solution?
Solubility
pH
Temperature
103
How does solubility affect adsorption from a solution
Higher the solubility the lower the solubility
104
TF: unionized forms will be more adsorbent than ionized species
True
105
Adsorption is an _______ process
Exothermic
106
Decreasing/increasing temperature will enhance the adsorption process
Decreasing the temperature
107
Critical Micelle Concentration is reach as surface is saturated/unsaturated
Saturated
108
What are micelles?
Aggregates of surface active agents
109
Micelles will always be in equilibrium with _____
Monomers
110
Critical micelle concentration _____ as hydrophobic groups on surfactant increases
Decreases
111
TF: Ionic surfactants have a much lower CMC than non ionic surfactants even with identical hydrophobic groups
False
They have a much lower CMC than non ionic surfaces
112
CMC increases/decreases with electrolytes in solution because electrolytes reduce repulsion between micelles
Decreases
113
What is hydrophile-lipophile balance?
A number that describes the hydrophilic-lipophilic nature of the surface active molecule
114
What is the HLB scale?
An arbitrary scale that made it possible to organize information about surface active agents
115
What is the use of zwitterionic as surfactants ?
Co-surfactant to boost foaming properties
116
TF: Depending on pH of the medium they are in zwitterions can be anionic cationic or zwitterionic
True
117
Non ionic surfaces are/are not affected by prescence of salts or by pH
Not affected
118
What is the difference between SPAN and TWEEN?
SPAN- sorbitan fatty acid esters are water in oil emulsions
TWEEN-polyoxyethylene sorbitan in fatty acid esters- are oil in water emulsions
119
What are the uses of non ionic surfactants?
Pharmaceuticals, cosmetic, foam stablizers, viscosity enhancers, food industry, dishwashing detergents and shampoos
120
What are the uses of cationic surfactants
Bacteriocidal
Adsorb to negative charged surfaces
Fabric softeners
Hair conditioners
121
What are cationic surfactants compatible with?
Non ionic and zwitter ionic surfactants
122
What are the uses of anionic surfactants
Toothpaste
Shampoos
Cosmetics
fabric detergents
Cleansers
123
What are anionic surfactants compatible with?
Non ionic and zwitterionic surfacts
124
Surfactants are _______
amphiphiles
125
Surfactants will move _____ to interfaces
Spontaneously
126
What combination will tell the spreading coefficient
Surface tension inherent to particle
Surface tension inherent to liquid
Interfacial tension between the particle and liquid
127
What is the spreading coefficient
How well liquid will spread over solid particle
128
What is the measure of spreading coefficient
Contact angle
129
In pharmaceuticals, we often try to _____ surface tension to obtain a positive spreading coefficient
Decrease
We do this by decreasing the contact angle
130
What forces affect surface (interfacial) tension?
Cohesive
Adhesive
131
What is cohesion?
The energy needed to create new surfaces
132
What is adhesion?
The work needed to separate two immiscible liquids
