(Midterms) PhyPharm Lec Quiz 3 Flashcards
1
Q
Suspensions in which the suspended particles are LARGER than molecules but too small to drop out of the suspension due to gravity
A
Colloids
2
Q
Particle size of Colloids
A
10-2000 Angstrom
Note: 1 Angstrom = 0.1 nm
3
Q
Father of Physical Chemistry
A
Thomas Graham
4
Q
Two separate phases of colloidal system
A
- Dispersed Phase (Internal phase)
- Continuous Phase (Dispersion medium)
5
Q
Dispersed Phase AKA?
A
Internal Phase
6
Q
Continuous Phase AKA?
A
Dispersion Medium
7
Q
What shows in suspension and colloid but does not show in solution
A
- Brownian motion
- Tyndall Effect
8
Q
Give the 6 shapes of colloidal particles
A
a. Spheres and globules
b. Short rods and prolate ellipsoids
c. Oblate ellipsoids and flakes
d. Long rods and threads
e. Loosely coiled thread
f. Branched threads
9
Q
Homogenous mixture is also called: (give 5)
A
- Colloidal System
- Colloidal Solution
- Colloidal Dispersion
- Colloidal Emulsion
- Colloidal Foam
10
Q
Type of Colloid:
DP - Liquid
DM - Gas
A
Liquid Aerosol
11
Q
Type of Colloid:
DP - Solid
DM - Gas
A
Solid Aerosol
12
Q
Type of Colloid:
DP - Gas
DM - Liquid
A
Foam
13
Q
Type of Colloid:
DP - Liquid
DM - Liquid
A
Emulsion
14
Q
Type of Colloid:
DP - Solid
DM - Liquid
A
Sol (colloidal dispersion or suspension)
15
Q
Type of Colloid:
DP - Gas
DM - Solid
A
Solid foam
16
Q
Type of Colloid:
DP - Liquid
DM - Solid
A
Gel
17
Q
Type of Colloid:
DP - Solid
DM - Solid
A
Solid suspension
18
Q
Lyophilic Colloids AKA
A
Emulsoids
19
Q
Lyophobic Colloids AKA
A
Suspensoids
20
Q
Dispersed phase has GREAT ATTRACTION for the dispersion medium
A
Lyophilic Colloids (Emulsoids)
21
Q
Dispersed phase does not precipitate easily
A
Lyophilic Colloids (Emulsoids)
22
Q
Sols are quite stable
A
Lyophilic Colloids (Emulsoids)
23
Q
Sol can be reconstituted by simply remixing with the dispersion medium, these sols are called?
A
Reversible Sols
24
Q
Dispersed phase has little affinity for the dispersion medium
A
Lyophobic Colloids (Suspensoids)
25
Easily precipitated on the addition of small amounts of electrolytes by heating or by shaking
Lyophobic Colloids (Suspensoids)
26
Sols are not stable
Lyophobic Colloids (Suspensoids)
27
Solvent-Loving
Lyophilic Colloids (Emulsoids)
28
Solvent-Hating
Lyophobic Colloids (Suspensoids)
29
Classification of colloids based on types of particles of the dispersed phase. Give the 3
1. Multimolecular colloids
2. Macromolecular colloids
3. Associated colloids
30
Aggregates of atoms or small molecules with molecular size less than 1nm.
Multimolecular Colloids
31
Formed when on dissolution in a suitable solvent
Macromolecular Colloids
32
Example of naturally occuring macromolecules:
Starch, protein, cellulose
33
Examples of Man made macromolecules
Polymers such as polyethylene and polystyrene
34
Colloids which behave as normal strong electrolytes at low concentrations but exhibit colloidal properties at higher concentrations due to the formation of aggregated particles
Associated Colloids (Amphiphilic)
35
The aggregated particles thus formed are called what?
Micelles
36
How many molecules does Micelles have
more than 100
(it also has a lyophilic and lyophobic part, that's why it's amphiphilic)
37
On dilution, these colloids revert back to individual ionns
Associated colloids
38
Colloid system wherein the colloid particles are dispersed in water
Hydrocolloids
39
True or False: Hydrocolloids can be either irreversible (single-state) or reversible
True
Example: Agar, can be solid, can be gel
40
What hydrocolloid is extracted from seaweed
Carrageenan
41
What hydrocolloid is extracted from citrus peel and apple pomace
Pectin
42
What hydrocolloid is extracted from bovine and fish origins
Gelatin
43
Hydrocolloid-based medical dressing used for wound treatment and for acne
Duoderm
44
What are the properties of Colloids
1. Optical property
2. Kinetic property
45
When light is scattered, the solution appears turbid what is this?
Tyndall Effect
46
Capable of yielding pictures of the actual aprticles
Electron microscope
used to observe the size, shape, and structure of colloidal particles
47
Useful in estimating particles size, shape, and interactions. Widely used for determining the molecular weight of colloids
Light-scattering
48
Studying this property of colloid is useful in obtaining information regarding the: shape, size, structure, and molecular weight of colloids
Optical Property
49
What are the 4 Kinetic property of Colloids
a. Thermally-induced motion
b. Gravitationally induced - sedimentation
c. Applied externally - viscosity
d. Electrically induced
50
What are the 3 Thermally-induced motion
1. Brownian Motion
2. Diffusion
3. Osmosis
51
Colloidal particles are subject to random collision with the molecules of the dispersion medium with result that each particle shows erratic motion results from the bombardment of the particles by molecules of the dispersion meddium
Brownian motion
52
Occurs spontaneously from a region of high concentration to low conc. until uniform
Diffusion
53
Passage of SOLVENT into a solution through a semipermeable membrane
Osmosis
54
As the viscosity increases, the force required to make it flow, increase or decrease?
Increases
55
Forms dispersion of low viscosity
Spherocolloids
Linear particles = more viscous
56
movement of a charged surface with respect to an adjacent liquid phase
Electrokinetic Phenomena
1. Electrophoresis
2. Electroosmosis
57
Phenomenon of movement of colloidal particles under an applied electric field
Electrophoresis
if particles accumulate near negative electrode = positive
if near positive electrode = negative
58
Phenomenon in which dispersion medium is allowed to move under the influence of an electrical field, whereas colloidal particles are not allowed to move
Electro-osmosis
59
Impurities that can be removed by filtration method
Insoluble impurties
60
Impurities that can be removed by means of membrane with pore openings smaller than the colloidal particles
Soluble impurities
61
Purification of sols can be accomplished by three methods, what are these 3 methods?
1. Dialysis
2. Electrodialysis
3. Ultrafiltration
61
If the low molecular-weight impurities to be removed
are electrolytes
Electrodialysis
62
A technique of separation of colloidal particles from molecular particles, uses a semipermeable membrane, the pore size of which will prevent the passage of colloidal
particles but will permit small particles or molecules such as urea, glucose, sodium chloride
Dialysis
63
the dialysis can be speeded
up by applying an electric potential to the sol which
produces
Electrolysis
64
When a sol is placed in a compartment closed by a dialysis membrane and pressure is applied, the liquid and small molecules are forced through the membrane while the colloidal particles are retained
Ultrafiltration
65
Colloids used in the treatment of cancer
Colloidal copper
66
2 Properties of Suspended particles:
1. Floculate
2. Aggregate
66
a coarse dispersion in which insoluble solid particles are dispersed in a liquid medium
Suspensions
66
3 Types of Coarse dispersions
1. Suspensions
2. Emulsions
3. Semisolids
67
3 CLASSIFICATIONS OF PHARMACEUTICAL
SUSPENSIONS
1. Orally administered mixtures
2. Externally applied suspensions
3. Injectable preparations
68
Particles settle rapidly do not form a cake, and are easily resuspended
Flocculate
69
particles settle slowly and eventually form a sediment in which aggregation occurs with the resultant formation of a hard cake that is difficult to resuspend
Aggregate
70
Particles held together by stronger forces.
Aggregate
71
Formation of light, fluffy conglomerates that are held together by weak Van der Waals forces.
Flocculate
72
Factors that Influence the Velocity of Sedimentation:
a.) Theory of Sedimentation Stokes Equation
b.) Effect of Brownian Movement
c.) Sedimentation of Flocculated Particles
73
Pseudoplastic or plastic in nature, act by entrapping the particles so that, ideally, no
settling occurs
Structured vehicles
74
Suspension qualities:
a.) Flow readily from the container
b.) Possess a uniform distribution of particles in each dose.
75
What angle should you observe that the powder makes
with the surface of the liquid
90 degrees
(Wetting of Particles)
76
What can be added to enhance wettability
Surfactants
77
defined as the condition in which the particles do not aggregate and in which they remain uniformly distributed throughout the dispersion.
Physical stability of suspensions
78
Stability of Suspension may be reduced by:
a.) Particle aggregation
b.) Particle growth
c.) Interaction with excipients
78
Methods determining the type of Emulsions:
small quantity of a water-soluble dye such as methylene blue or brilliant blue may be dusted on the surface of the emulsion.
Dye Method
79
Enumerate the types of Emulsions
a. Oil-in-water emulsion
b. Water-in-oil emulsion
(a.) Oil-in-water emulsion – the oil phase is dispersed as
globules throughout an aqueous continuous phase.
b.) Water-in-oil emulsion – the oil phase serves as the
continuous phase.)
79
thermodynamically unstable system consisting of at least two immiscible liquid phases, one of which is dispersed as globules (dispersed phase) in the other liquid phase (continuous phase), stabilized by the presence of an emulsifying agent
Emulsions
80
METHODS OF DETERMINING THE TYPE OF EMULSIONS
a.) Dye Method
b.) Dilution Test Method
c.) Conductivity Test Method
81
Methods determining the type of Emulsions:
If o/w type – the dye will dissolve and uniformly diffuse throughout the water.
If w/o type – the particles of dye will lie in clumps on the surface.
Dye Method
82
Methods determining the type of Emulsions:
If the emulsion mixes freely with the water, it is o/w type.
Dilution Test Method
83
Methods determining the type of Emulsions:
If o/w type, a current will pass through the emulsion.
If w/o type, the emulsion fails to carry the current
Conductivity Test Method
84
involves the change of emulsion type from o/w to w/o or vice versa.
Phase inversion
85
formation of lumps
Flocculation
86
lack of uniformity of drug distribution.
Creaming
87
If the dispersed phase is less dense than the continuous phase, which is generally the case of o/w emulsions, the velocity of sedimentation becomes negative, this is a?
upward creaming results
88
particles gather together
Coalescence
89
If the dispersed phase is heavier than the continuous phase, the globules settle – common in w/o emulsions – known as
creaming in a downward direction.
90
Which is reversible, and which is irreversible: Creaming and Breaking
Creaming - reversible
Breaking - irreversible
91
A moderately coarse dispersion of uniformed-size particles have the best stability.
TAKE NOTE OF THAT!!!
92
Viscosity alone does not produce stable emulsions; however, viscous emulsions may be more stable than mobile ones by virtue of the retardation of flocculation and coalescence.
TAKE NOTE OF THAT!!!
93
Gels may contain water
Hydrogels
94
is a solid or semisolid system of at least two constituents, consisting of a condensed mass enclosing and interpenetrated by a liquid
Gel
95
the product when the coherent matrix is rich in liquid.
Jelly
95
Gels containing organic liquids
Organogels
96
when the liquid is removed and only the framework remains.
Xerogel
97
the liberation of oil or water from ointment bases results from a deficient gel structure rather than from the contraction involved in syneresis.
Bleeding
97
the taking up of liquid by a gel with an increase in volume. The opposite of syneresis
Swelling
97
the phenomenon when a gel stands for sometime, it often shrinks naturally, and some of its liquid is pressed out.
Syneresis
98
gels taking up a certain amount of liquid without a measurable increase in volume
Imbibition
