Podcast
Questions and Answers
The science and technology of small ______ is called Micromeritics.
The science and technology of small ______ is called Micromeritics.
particles
The physical, chemical, and pharmacologic properties of drugs can be related in a significant way to the ______ and hence surface area of a particle.
The physical, chemical, and pharmacologic properties of drugs can be related in a significant way to the ______ and hence surface area of a particle.
size
Smaller the ______ of the particle, better the physical stability of the dosage form.
Smaller the ______ of the particle, better the physical stability of the dosage form.
size
Good flow properties of granules & powders are important in the manufacturing of ______ & capsules.
Good flow properties of granules & powders are important in the manufacturing of ______ & capsules.
Signup and view all the answers
Higher ______ area allows intimate contact of the drug with the dissolution fluids in vivo & increases the drug solubility & dissolution.
Higher ______ area allows intimate contact of the drug with the dissolution fluids in vivo & increases the drug solubility & dissolution.
Signup and view all the answers
Particle ______ and surface area influence the drug absorption & subsequently the therapeutic action.
Particle ______ and surface area influence the drug absorption & subsequently the therapeutic action.
Signup and view all the answers
The ______ diameter is the diameter of a sphere having the same surface area as the particle.
The ______ diameter is the diameter of a sphere having the same surface area as the particle.
Signup and view all the answers
The ______ diameter is the diameter of a sphere having the same volume as the particle.
The ______ diameter is the diameter of a sphere having the same volume as the particle.
Signup and view all the answers
The ______ diameter is the projected diameter of a sphere having the same observed area as the particle.
The ______ diameter is the projected diameter of a sphere having the same observed area as the particle.
Signup and view all the answers
The Stokes diameter, dst, is the diameter which describes an equivalent sphere undergoing sedimentation at the same rate as the asymmetric ______.
The Stokes diameter, dst, is the diameter which describes an equivalent sphere undergoing sedimentation at the same rate as the asymmetric ______.
Signup and view all the answers
It very rarely occurs that all particles in a sample are of the same size (______).
It very rarely occurs that all particles in a sample are of the same size (______).
Signup and view all the answers
There is usually a mix of different sizes present (______).
There is usually a mix of different sizes present (______).
Signup and view all the answers
Frequency distribution curve is also known as ______ distribution curve.
Frequency distribution curve is also known as ______ distribution curve.
Signup and view all the answers
Microscopy measures particle size in the range of ______ - 100µm.
Microscopy measures particle size in the range of ______ - 100µm.
Signup and view all the answers
At least ______ particles should be measured for good representation in microscopy.
At least ______ particles should be measured for good representation in microscopy.
Signup and view all the answers
Sieve analysis is performed using a nest or stack of sieves where each lower sieve has a smaller ______ size than that of the sieve above it.
Sieve analysis is performed using a nest or stack of sieves where each lower sieve has a smaller ______ size than that of the sieve above it.
Signup and view all the answers
Sieve method is used to find ______ size distribution and average diameter.
Sieve method is used to find ______ size distribution and average diameter.
Signup and view all the answers
Error causing variables in sieve method include sieve ______ duration and intensity of agitation.
Error causing variables in sieve method include sieve ______ duration and intensity of agitation.
Signup and view all the answers
Cumulative frequency curve is a graph of particle ______ versus size
Cumulative frequency curve is a graph of particle ______ versus size
Signup and view all the answers
The ______ frequency curve shows the total number of particles below a certain size
The ______ frequency curve shows the total number of particles below a certain size
Signup and view all the answers
The size range 40-45 has a ______ frequency of 7
The size range 40-45 has a ______ frequency of 7
Signup and view all the answers
The median of the given data is approximately ______ mm
The median of the given data is approximately ______ mm
Signup and view all the answers
The upper class boundary of the size range 50-55 is ______ mm
The upper class boundary of the size range 50-55 is ______ mm
Signup and view all the answers
A cumulative percentage curve is a graph of percentage vs ______
A cumulative percentage curve is a graph of percentage vs ______
Signup and view all the answers
The cumulative undersize curve is compared with the cumulative ______ curve
The cumulative undersize curve is compared with the cumulative ______ curve
Signup and view all the answers
Microscopy measures particle size in the range of ______ - 100µm
Microscopy measures particle size in the range of ______ - 100µm
Signup and view all the answers
At least ______ particles should be measured for good representation in microscopy
At least ______ particles should be measured for good representation in microscopy
Signup and view all the answers
Sieving can cause ______________ of granular materials.
Sieving can cause ______________ of granular materials.
Signup and view all the answers
The sedimentation method measures the size of particles by measuring their ______________ velocity of settling.
The sedimentation method measures the size of particles by measuring their ______________ velocity of settling.
Signup and view all the answers
In the sedimentation method, the density of the particle is represented by ______________.
In the sedimentation method, the density of the particle is represented by ______________.
Signup and view all the answers
The gravitational sedimentation method is not applicable to colloidal formulations because of ______________.
The gravitational sedimentation method is not applicable to colloidal formulations because of ______________.
Signup and view all the answers
In a Coulter counter, the powder is suspended in an ______________ solution.
In a Coulter counter, the powder is suspended in an ______________ solution.
Signup and view all the answers
The amplitude of the peak in the resistance of the system is proportional to the particle ______________.
The amplitude of the peak in the resistance of the system is proportional to the particle ______________.
Signup and view all the answers
The distance of fall in time t is represented by ______________.
The distance of fall in time t is represented by ______________.
Signup and view all the answers
The viscosity of the medium is represented by ______________.
The viscosity of the medium is represented by ______________.
Signup and view all the answers
The acceleration due to gravity is represented by ______________.
The acceleration due to gravity is represented by ______________.
Signup and view all the answers
Void volume (v) is the volume of space ______ particles
Void volume (v) is the volume of space ______ particles
Signup and view all the answers
True density () is the density of the actual ______ material
True density () is the density of the actual ______ material
Signup and view all the answers
Granule density ( g) is the mass of particles divided by the ______ (including intra-particle pore volumes)
Granule density ( g) is the mass of particles divided by the ______ (including intra-particle pore volumes)
Signup and view all the answers
Bulk density ( b) is the mass of a powder divided by the ______ volume
Bulk density ( b) is the mass of a powder divided by the ______ volume
Signup and view all the answers
Cumulative curves are another way to express ______ size distributions
Cumulative curves are another way to express ______ size distributions
Signup and view all the answers
The volume of space ______ particles is known as void volume
The volume of space ______ particles is known as void volume
Signup and view all the answers
The ______ density is the density of the actual solid material
The ______ density is the density of the actual solid material
Signup and view all the answers
Particle size distribution is often expressed in terms of ______ curves
Particle size distribution is often expressed in terms of ______ curves
Signup and view all the answers
The ______ volume is the volume of a powder in a densely packed state
The ______ volume is the volume of a powder in a densely packed state
Signup and view all the answers
Study Notes
Micromeritics
- Micromeritics is the science and technology of small particles, focusing on the size and surface area of particles and their impact on physical, chemical, and pharmacologic properties of drugs.
Particle Size
- Particle size influences physical stability, dose uniformity, release and dissolution, and absorption and drug action in pharmaceuticals.
- Smaller particles have better physical stability, better flow properties, and increased drug solubility and dissolution.
- Particle size is usually expressed as diameter or volume, but diameter is more commonly used.
Measuring Particle Size
- Particle size can be measured using microscopy, sieving, sedimentation techniques, and other methods.
- Microscopy measures particle size in the range of 0.2-100µm, but only measures two dimensions and requires counting 300-500 particles for accurate representation.
- Sieving method uses a nest of sieves to separate particles by size and determines weight size distribution and average diameter.
- Sedimentation method measures particle size by measuring terminal settling velocity in a gravitational or centrifugal environment.
Particle Size Distribution
- Particle size distribution can be expressed as a frequency distribution curve, which is usually polydisperse (having a mix of different sizes).
- Cumulative curves can be used to represent particle size distributions, including cumulative frequency curves, cumulative percentage curves, and cumulative weight curves.
Powder Properties
- Porosity of powders can be measured using void volume (v) or porosity (ε).
- True density (ρ) is the density of the actual solid material, while granule density (ρg) is the mass of particles divided by the volume, including intra-particle pore volumes.
- Bulk density (ρb) is the mass of a powder divided by the bulk volume.
Median
- The median is the middle value of a particle size distribution, which can be determined from a cumulative frequency curve.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Understanding the science and technology of small particles in pharmaceuticals, including particle size and its impact on physical, chemical, and pharmacologic properties.
