MICROMERITICS Flashcards
MICROMERITICS
came from the greek word ____
micros
MICROMERITICS
micros means
small
- the science and technology of small particles
- cover particles 100nm to 100mm
micromeritics
MICROMERITICS
covers particles ____ to ____
100nm - 100mm
- focuses on particles in the size range of 1nm to ⁓5mm
- has three categories: colloidal dispersions, coarse dispersions, pharmaceutical powders
PHARMACEUTICAL MICROMERITICS
PHARMACEUTICAL MICROMERITICS
focuses on particles in the size range of ____ to ____
1nm to approx 5mm
PHARMACEUTICAL MICROMERITICS
3 categories
colloidal dispersions (& nanoparticles)
coarse dispersions
pharmaceutical powders
PHARMACEUTICAL MICROMERITICS
SIZE:
colloidal dispersions & nanoparticles
< 1,000 nm
PHARMACEUTICAL MICROMERITICS
SIZE:
coarse dispersions
1 - 50um
PHARMACEUTICAL MICROMERITICS
SIZE:
pharmaceutical powders
50um
PHARMACEUTICAL MICROMERITICS
the only dispersion not covered
molecular dispersion
how many micromeritic properties
7
MICROMERITIC PROPERTIES
ANALYTICAL TECHNIQUE:
* laser diffraction
* dynamic light scattering
REOPRTED PARAMETER:
* D-value
SIZE
MICROMERITIC PROPERTIES
ANALYTICAL TECHNIQUE:
* imaging
* scanning electron microscopy
REPORTED PARAMETER:
* high-resolution images
* circularity
SHAPE
MICROMERITIC PROPERTIES
ANALYTICAL TECHNIQUE:
* electrophoretic light scattering
REPORTED PARAMETER:
* zeta potential
CHARGE
MICROMERITIC PROPERTIES
ANALYTICAL TECHNIQUE:
* atomic force microscopy
* rheometry
REPORTED PARAMETER:
* elasticity
* stiffness (Young’s modulus)
MECHANICAL
MICROMERITIC PROPERTIES
ANALYTICAL TECHNIQUE:
* gas adsorption method
REPORTED PARAMETER:
* surface area
* pore size
SURFACE
MICROMERITIC PROPERTIES
ANALYTICAL TECHNIQUE:
* differential sanning calorimetry
REPORTED PARAMETER:
* percentage of crystallinity
INTERNAL MICROSTRUCTURE
MICROMERITIC PROPERTIES
ANALYTICAL TECHNIQUE:
* bulk density
* tapped density
REPORTED PARAMETER:
* hausner ratio
FLOWABILITY & COHESIVENESS
- shape, surface area of each paritcle, size range and number, weight and volume must be considered
- cannot be describe by a single dimension
PARTICLE SIZE
particles cannot be described by a ____
single dimension
PARTICLE SIZE
a size of a spherical particle is characterized by its ____
diameter
PARTICLE SIZE
a size of a non-spherical particle is characterized by its ____
equivalent spherical diameter
PARTICLE SIZE | EQUIVALENT SPHERICAL DIAMETER
- the diameter of a circle that has the same projected area as the particle
- imaginary circle that covers 2 points of the particle
PORJECTED
PARTICLE SIZE
absence of measurable diameter with irregularly shaped particles
equivalent spherical diameter
PARTICLE SIZE
- for non-spherical/asymmetrical particles
- approximate particle size based on diameter of sphere
equivalent spherical diameter
PARTICLE SIZE | EQUIVALENT SPHERICAL DIAMETER
- the diameter of the particle at the point that divides a randomly oriented particle into two equal projected areas
MARTIN’S
PARTICLE SIZE | EQUIVALENT SPHERICAL DIAMETER
commonly used in particle sizing
MARTIN’S
FERET’S
PARTICLE SIZE | EQUIVALENT SPHERICAL DIAMETER
not used in particle sizing because of variations
PROJECTED
PARTICLE SIZE | EQUIVALENT SPHERICAL DIAMETER
- the distance between imaginary parallel lines tangent to a radomly oriented particle and perpendicular to the ocular scale
FERET’S
- represents the number of particles in each size present in a given sample
- represented as frequency curve or cumulative percentage over/under a particular size curve
- particles in a group could either be: monodisperse, polydisperse
PARTICLE SIZE DISTRIBUTION
PARTICLE SIZE DISTRIBUTION
collection of particles of uniform size
MONODISPERSE
PARTICLE SIZE DISTRIBUTION
collection of particles of more than one size
POLYDISPERSE
PARTICLE SIZE DISTRIBUTION
is represented as ____ or ____ over/under a particular size curve
frequency curve or cumulative percentage
METHODS OF DETERMINING PARTICLE SIZE DISTRIBUTION
number of particles
optical microscopy
electron microscopy
METHODS OF DETERMINING PARTICLE SIZE DISTRIBUTION
weight of particles
sieving
sedimentation
centrifugation
METHODS OF DETERMINING PARTICLE SIZE DISTRIBUTION
light scattering by particles
photon correlation spectroscopy
METHODS OF DETERMINING PARTICLE SIZE DISTRIBUTION
volume of particles
coulter counter method
particle shape analysis is carried out using ____
imaging techniques
it affects:
* solubility
* packing properties
* flowability
* bulk powder properties
* surface area
PARTICLE SHAPE
carried out using imaging techniques
PARTICLE SHAPE ANALYSIS
PARTICLE SHAPE
measure of deviation from roundness;
- if AR = 1, the particle is a perfect sphere
ASPECT RATIO
PARTICLE SHAPE
expresses the radius of cuvature of the particle corners
- if roundness = 1, the particle is circular
(roundness of corners)
ROUNDNESS
PARTICLE SHAPE
measures the closeness to a perfect sphere
* if sphericity = 1, the particle is sphere
(roundess as a whole)
SPHERICITY
PARTICLE SHAPE
representative of local surface textures between corners
* if roughness decreases, the particle surface has more concavities
ROUGHNESS
SURFACE AREA & SPECIFIC SURFACE
what is the relationship between the asymmetry of the particle to the specific surface
DIRECTLY PROPORTIONAL
defined as the surface area per unit volume or per unit weight
SPECIFIC SURFACE
SURFACE AREA & SPECIFIC SURFACE
what is the relationship of the particle size to the surface area
inversley proportional
materials with high specific area may have cracks and ____ that adsorb gases & vapors into their interstices
PORES