Module 7 Flashcards
(113 cards)
1
Q
are composed of solid particles with spaces between the particles that contain a gas (most often
air).
A
Powders
2
Q
A material is generally considered a powder when
particle size is less than _____.
A
40 microns
3
Q
A _________ is a small compact particle of a substance.
A
granule
4
Q
A material is generally considered a granule when
particle size is greater than _____.
A
40 micron
5
Q
A physical state of a single chemical substance or single drug.
A
POWDERS IN PHARMACEUTICALS
6
Q
A _______ is a mixture of finely
divided drugs or chemicals in dry form meant for internal or external use.
A
pharmaceutical powder
7
Q
Raw materials (_________) are typically
processed as powders.
A
API and excipients
8
Q
The presence of molecular
forces produces a tendency
for solid particles to stick
to themselves (__________)
and to other surfaces
(________).
A
cohesion; adhesion
9
Q
Other interparticle
interactions may be due to:
i. __________
between adsorbed liquid
layers at the particle surfaces
ii. ____________ arising
from contact or frictional
charging
A
Surface tensional forces; Electrostatic forces
10
Q
Powder and granular systems must be considered as a _______ whose behavior is a function of both the fundamental properties and the external factors.
A
multiphase continuum
11
Q
The ___________ of the powder and
individual particles (for example size, shape, surface
texture and moisture content)
A
fundamental properties
12
Q
Such as humidity temperature and
consolidation history.
A
external factors
13
Q
Powder behavior is generally related to _________.
A
interparticle interactions
14
Q
Physical property: Powders are ______ particles while granules are small _________.
A
fine; grains
15
Q
Physical property: Powders are acted upon by _________ forces while granules are acted upon by ____________ forces.
A
adhesion and frictional; gravitational
16
Q
Powders has _______ flow while granules flow _________.
A
poor; well
17
Q
Powders have ______ compressibility while granules have _________ compressibility.
A
poor; better
18
Q
Rheological properties of powders and granules include:
A
Flow and compressibility
19
Q
Powders are _____ stable due to ______ surface area.
A
less; higher
20
Q
Granules are _________ stable due to having ______ surface area.
A
more; less
21
Q
Powders are _______ to caking while granules are ________ to harden and cake.
A
prone; less likely
22
Q
Powders have ______ wettability while granules are _________ wetted.
A
low; easily
23
Q
Powders are ______ to dust formation while granules have ______ dust formation.
A
prone; less
24
Q
Powders have a high chance of ___________ dosing while granules have better _________.
A
non-uniform; unifomity
25
Powders need a _________ method of processing while granules involves ________ processing, exposure to ________ and ___________.
simpler; more; heat; solvents
26
________ are objectively better as a material, yet _________ are used more often from R&D to manufacturing of drugs.
Granules; powders
27
Granules perform better than powder in
flow, compressibility, stability, caking tendencies, wettability, dust formation, and uniformity
28
Powder performs better than granules in
Physical property and processing
29
Understanding of the properties and behavior of powders and
granular media is essential for
industrial applications because of
pneumatic transport and tableting processes.
30
Variance in particle properties
can create handling challenges
that impact the ability of the
powder to move around the
manufacturing process using
hoppers and silos
31
Correctly _________ a
powder can provide a good understanding of powder
behavior which can help improve processing techniques.
characterizing
32
_______ are tested for properties such as composition,
particle size, morphology, etc. while _________ is
evaluated via material density, flowability, electrostatic
properties, blend stability, and so on.
Individual particles; Bulk powder behavior
33
__________ has traditionally been considered
to affect powder behavior, but there are other particle
properties that influence the overall behavior o f the powder.
PARTICLE SIZE & SHAPE
34
POWDER BEHAVIOR IN BULK
1 . Mixing
2 . Flowability
3 . Compressibility
4 . Dissolution
35
________ in its simplest definition means “ to put together in one mass .”
MIXING
36
________ means to mix smoothly and inseparably together
during which a minimum energy is imparted to the bed.
BLENDING
37
Physical property in mixing that shows if components are of different densities, the denser one will sink through the lighter one.
MATERIAL DENSITY
38
Physical property in mixing that shows the difference in particle sizes of components is the
main cause of segregation in blends and mixes.
PARTICLE SIZE
39
Physical property in mixing that shows the more the particle deviates from a spherical
shape, the greater the difficulty of mixing.
PARTICLE SHAPE
40
Why do we mix? To achieve ________.
homogeneity
41
Define for the application
considered what means "homogeneous" and
"inhomogeneous".
HOMOGENEITY
42
Standards on determining homogeneity of a mixture are set by the industry, the customers, or an external regulation.
INDUSTRY SPECIFIC
43
INDUSTRY SPECIFIC standards for food industry sampling size.
serving
44
INDUSTRY SPECIFIC standards for pharmaceutical sampling size.
dose
45
Occurs when there are high concentration of orange particles in one area and others of high concentration of blue particles.
Segregation
46
If there is a high coefficient of variation, then the mixture is ____ homogeneous.
less
47
_________ occurs when the motion of individual
particles is biased according to their characteristics.
SEGREGATION
48
In the absence of such bias in particle characteristics,
individual motion invariably leads to __________.
homogenization
49
Segregation limits the ______ in a mixer. All mixtures will undergo ________.
extent of homogeneity; de - mixing
50
__________ can be classified
depending on the physical
characteristics and flow conditions subjected to the mixture.
SEGREGATION OF GRANULAR
MATERIALS
51
Three types of segregation of granular materials.
trajectory, percolation, fluidization
52
Factor that is main cause of segregation.
Particle size
53
Tendency to segregate is higher the larger the disparity in component _______.
particle size
54
For non-aerated samples, gentle vibration of a sample may encourage smaller particles to move ______, and larger particles to ________ to the surface.
downward; rise
55
If we have a very narrow particle size distribution, segregation is due to ____ and _____.
Material density; particle shape
56
If the denser particles form the lower layer: the degree of mixing _________ gradually until an equilibrium is attained (not necessarily complete mixing).
increases
57
If the denser particles form the lower layer : the degree of mixing increases to a maximum, then _______ as the _____ component falls through the _______ one.
drops to equilibrium; denser; lighter
58
T/F: The order of addition of components to the mixer is crucial!
True
59
According to shape, ___________ particles are easily mixed but also easily segregates.
Spherical
60
According to shape, particles of ________ shape are difficult to segregate if mixing has been achieved.
irregular
61
For particle shape, spheres interact by _______; cubes by _____________; and 3D cross by ________.
tangent, face to face, interlock
62
_______ is a property that defines an ability of a powdered material to flow.
Flowability (powder flow)
63
Flowability is the ratio of the __________ holding the
particles together vs the _______ trying to pull them apart.
cohesive forces; gravity forces
64
_____ is a measure of the amount of strength the material retains at a stress-free surface following consolidation to a stress level.
Flow function (ff)
65
Flow function (ff) describes _________ as a function of _______.
cohesive strength; compaction pressure
66
Factor of flowability that states that the presence of molecular forces produces a
tendency for solid particles to stick to themselves and to other surfaces.
COHESION & ADHESION
67
_________ particles have better flow. ________ surfaces have tendencies to interlock, thus have poorer flow.
Spherical; Rough
68
Fine particles with very high surface to mass ratios are more ______ than coarser particles which are influenced more by _______
forces. More cohesion means _______ flow.
cohesive; gravitational; less
69
Other factors that may affect cohesive forces between particles (e.g., moisture, electrostatic charges, impurities).
ALTERATION OF SURFACE FORCES
70
Classification of flowability testing methods
Flow rate
Density ratio
Angle of repose
Shear cell
Others
71
The reduction in the volume of a powder bed due to the application of stress.
Compression
72
The transformation of powder into an intact compact with measurable strength and defined shape by the application of a compression pressure.
Compaction
73
__________ is the
process of the gaseous
phase displacement
from granules or
powders.
Compression
74
__________ is the
process of consolidation
of particles, with
compression being a part
of this process.
Compaction
75
Compressibility is a measure of the _______ change a sample undergoes when
pressure is applied.
relative volume
76
Compressibility describes the relationship of _______ to ______.
bulk density; applied pressure
77
Bulk density is the ratio of
Split mass to volume after compression (g/ml)
78
Compressibility index is the ratio of
Density after compression to conditioned bulk density
79
Particle size exerts a greater
influence on _________ of
powders compared to particle
shape.
compressibility
80
Compressibility is an identifier
of _________.
powder flow behavior
81
_________ is the fraction of the
space filled by the figures making up the packing.
Packing density
82
Packing density is equal to
Bulk density * weight fraction / specific gravity
83
Moisture increases the _______ of the powder bed and decreases ______, promoting ________.
tensile strength; density variation; inter-particulate bond formation
84
In general, the presence of moisture enables powder
compaction to operate at a lower _______ requirement.
pressure
85
Compressibility behavior improves the higher the ________ but a shift occurs in the trend once ___________ is achieved.
moisture content; optimum moisture
86
Compaction leads to an increase in average surface
________.
temperature
87
With a faster compaction, the __________ the temperature increase.
higher
88
Compaction leads to an increase in temperature primarily due to the increasing degree of ________ (volume reduction) and the effect of _________ (wall friction) .
powder deformation; interparticle interaction
89
In pharmaceuticals, temperature rise in the compressed powder can affect
physiochemical properties of the powder, such as ______ degradation and
change in _________.
thermal; crystallinity
90
Compression may lead to
_________.
polymorphism
91
T/F: Each polymorph form has its own set of physical properties – one form may have poor compressibility, while another form has superb compressibility .
True
92
The process in which a substance forms a solution.
DISSOLUTION
93
The dissolution of a drug is important in determining
its ________ and ________.
bioavailability; therapeutic effectiveness
94
________ correlates the dissolution rate of a drug with particle characteristics and properties.
Noyes –Whitney equation
95
The ________ of the powder in the dissolution medium
highly influences the dissolution performance of the drug.
solubility
96
Solubility changes depending on ___________ characteristic.
solid - state
97
Considering particle size, the dissolution rate of a material depends on its _________.
specific surface area
98
General rule: with ______ particle sizes, there is ______specific surface area and thus________________ dissolution.
smaller; larger; faster
99
__________ are legally binding
collection of standards and quality specifications for drugs.
Pharmacopoeias
100
Pharmacopoeias include
Standard tests for identification, purity, strength, dosage, and other performance characteristics
Formulation and drug preparation
Analytical methods, dissolution
testing, stability, microbial purity
101
The ________ is the
constant, three -dimensional angle (relative to the horizontal base) assumed by a cone -like pile of material formed by any of several methods.
angle of repose
102
Step 1 in getting the angle of repose: Form the angle of repose on a fixed base with a
_________ to retain a layer of powder on the base. The base should be free of _______.
retaining lip; vibration
103
Step 2 in getting the angle of repose: Vary the height of the __________ to carefully build up
a symmetrical cone of powder. Care should be
taken to prevent ________ as the funnel is moved.
funnel; vibration
104
The funnel height should be maintained approximately __________ from the top of the powder
pile as it is being formed to minimize the impact
of _____ on the top of the cone.
2-4 cm; falling powder
105
Determine the angle of repose by measuring the
height of the cone of powder and calculating the
angle of repose, using the following equation:
tan(alpha) = height/0.5/base
106
The _________ has been proposed as an indirect measure of bulk density, size and shape, surface
area, moisture content, and cohesiveness of materials because all of these can influence the observed
compressibility.
compressibility index
107
The ______ and the _______are
determined by measuring both the bulk volume and the
tapped volume of a powder.
compressibility index; Hausner ratio
108
Compressibility index is computed by
100 x (V_o-V_f)/V_o
109
Hausner ratio is computed by
Vo/Vf
110
The CI and HR are not _______ properties of the powder and
as such depend a lot on the methodology.
intrinsic
111
Considerations of the following are important on the CR and HI:
- Diameter of the cylinder used
- Number of time the cylinder is tapped
- Mass of material used in the test
- Rotation of sample during tapping.
112
_____ is used for powder surface investigation with a probe scanned over a surface.
ATOMIC FORCE MICROSCOPY (AFM)
113
Analytical techniques for powder characterization
ATOMIC FORCE MICROSCOPY (AFM)
PARTICLE SIZE ANALYZERS
Surface Electron Microscopy
