Particle Size in Medicine Formulation

Why is the appropriate size of particulate solids important in medicine formulation?

What is determined when a drug is synthesized and formulated?

How does particle size impact medicine formulation?

Why is interference with the uniformity of fill volumes in tablets and capsules a concern?

How do powders with different particle sizes impact encapsulation or tablet compression?

Why is it important to define and control the particle sizes of drugs and powders during formulation?

What is the impact of reducing the particle size of a drug on its dissolution rate?

How does reducing the particle size of a low solubility drug like griseofulvin affect its dissolution rate?

What impact can an increased rate of dissolution due to reduced particle size have on drug handling by the body?

Why is reducing the particle size of nitrofurantoin not always beneficial?

What is the impact of reducing particle size to improve dissolution rate?

Why is knowledge and control of particle size important for drug products?

What is the median size for fine powder?

What is the median size for micronized powder?

What is the median size for very fine powder?

Coarse powder has a median size greater than 355 μm.

The median size for very fine powder is 125 μm or less.

Micronized powder has a median size less than 10 μm.

What is the term used to describe the diameter of a hypothetical sphere representing an approximation to the true size and shape of a particle?

Why is the dimension representing the size of a particle referred to as the equivalent sphere diameter?

What property of a particle is measured and related to a sphere to determine its equivalent diameter?

What is the projected area diameter based on?

What is the perimeter diameter based on?

What is the purpose of generating more than one sphere equivalent to an irregular particle shape?

What does Feret’s diameter measure?

What does Martin’s diameter represent?

What factors influence Feret’s and Martin’s diameters?

Particle size can be determined based on factors such as volume, surface area, sieve aperture, and sedimentation characteristics.

Equivalent sphere diameter is based on factors such as volume, surface area, sieve aperture, and sedimentation characteristics.

It is not possible to determine the equivalent sphere diameters of particles based on factors such as volume, surface area, sieve aperture, and sedimentation characteristics.

What is the term used to describe a particle population with spheres of the same diameter?

What is the term for particles with a range of different equivalent diameters?

How are particles with a range of different equivalent diameters described?

What can be presented in the form of a histogram plotted from data to interpret particle size distribution?

What does a histogram enable to be determined about particles with a given equivalent diameter?

What does a histogram allow to be compared?

What is the alternative to a histogram for representing particle size distribution?

What does a cumulative percent undersize value represent in particle size analysis?

How can two or more particle populations be compared?

Mode and median are measures of central tendency used to represent a single value near the middle of the size distribution.

The mode represents the most frequently occurring particle size in the distribution.

The median is the arithmetic average of all the particle sizes in the distribution.

Is the three point size distribution based on the diameters below which 90%, 50% and 10% of the particles lie?

The values for the diameters may be written as X90, D90, d 90, or D [ X50, D50, d 50, or D [0.50]; and X10, D10, d 10, or D [

Is the median size for very fine powder 125 μm or less?

True or false: The IQCS can take any value between −1 and +1. If the IQCS is 0, then the size distribution is practically symmetrical between the quartile points.

True or false: A median size of 125 μm or less is considered very fine powder.

True or false: The median size for micronized powder is less than 10 μm.

Arithmetic means are obtained by summation of a particular parameter for all the individual particles in a sample and division of the value obtained by the total number of particles.

Means can be related to the diameter, surface area, volume or mass of a particle.

The median is the arithmetic average of all the particle sizes in the distribution.

What is the most widely used technique for powder classification?

What property does sieving method rely on for particle size analysis?

What is the typical range of analysis achievable using sieves?

Sieving analysis is usually performed with powders in the dry state only.

Wet sieving can be used for powders in liquid suspension or those which agglomerate during dry sieving.

Sieving analysis cannot be used for powders in liquid suspension or those which agglomerate during dry sieving.

What material is often used to make the mesh for sieve analysis?

How many sieves does a typical sieve stack usually comprise?

What is the arrangement of mesh sizes from top to bottom in a sieve stack?

Mesh size refers to the number of openings in one linear inch of a screen.

A 36 mesh screen will have 150 openings.

Sieves can only be referred to by their aperture size.

What is the diameter of a particle measured by a sieve?

What type of plot is used to analyze particle size distribution after sieving?

What happens to the powder during sieving analysis?

What is the recommended sieving time for dry sieving?

When using standard sized sieves (200 mm diameter), when is it recommended to stop sieving?

Why is it important to define and control the sieving times?

What is a key advantage of the sieving technique?

Why is the sieving technique considered an accepted alternative to other analysis methods?

What type of materials is the sieving technique well adapted for?

Is the sieving technique well adapted for bulk materials?

Is the possibility to separate the particle size fractions an advantage of the sieving technique?

Are the investment costs for the sieving technique high?

Is it problematic if the material has much fine material below 100 μm, unless specialized micro sieving equipment is available?

Is it problematic if the particles are fragile?

Is it problematic if the particles are in the form of elongated needles?

What makes the sieving technique problematic for particles in the form of elongated needles?

Why is the sieving technique problematic for materials that easily acquire an electrostatic charge?

What is a disadvantage of the sieving technique when dealing with hygroscopic materials?

What is a problematic characteristic for particles when using the sieving technique?

Why is the sieving technique problematic for materials that easily acquire an electrostatic charge?

What is a known problem of reproducibility associated with the sieving technique?

Is the sieving technique problematic if the material easily acquires an electrostatic charge?

Is the sieving technique problematic for particles in the form of elongated needles?

Is the sieving technique labor-intensive?

What distinguishes air jet sieving from conventional mechanically vibrated sieve analysis?

What is a potential advantage of air jet sieving over conventional mechanically vibrated sieve analysis?

What issue can arise with finer particles in air jet sieving?

Air jet sieving is often more efficient and reproducible than conventional mechanically vibrated sieve analysis.

Agglomeration is not a problem with finer particles in air jet sieving.

Air jet sieving uses a complete nest of sieves.

Light microscopy is relatively inexpensive and requires small sample sizes

Light microscopy can only detect 3D shapes of particles

Light microscopy provides a permanent record photograph of the examined particles

What is an advantage of light microscopy for particle examination?

What is a benefit of light microscopy in terms of sample size requirement?

What is a feature of light microscopy that aids in record-keeping?

What is a disadvantage of the sieving technique when dealing with particle shape?

What is a potential issue associated with the sieving technique's throughput?

What is a concern related to sizing operator bias when using the sieving technique?

What is a key advantage of scanning electron microscopy (SEM)?

What is a disadvantage of scanning electron microscopy (SEM)?

When is scanning electron microscopy (SEM) particularly appropriate?

What is the lower limit of particle sizing by the gravitational sedimentation method?

What is the particle size range mostly applied to centrifugal sedimentation?

What are the effects that can be overcome by centrifuging the suspension in sedimentation techniques?

What is the Andreasen Pipette Technique primarily known for?

What distinguishes the Andreasen Pipette Technique from beaker decantation?

What is the key advantage of the Andreasen Pipette Technique over beaker decantation?

What is the method used to determine size distribution?

What happens to particles greater than a critical size during the settling process?

What type of sample does each collected suspension sample represent, except for particles greater than a critical size?

How is the concentration of solid in a sample expressed as a percentage?

What does the concentration expressed as a percentage of the initial concentration give?

How is the corresponding Stokes' diameter obtained?

What is a disadvantage of sedimentation analysis for particle size measurement?

Why is careful temperature control necessary for sedimentation analysis?

What is an advantage of the sieving technique for particle size analysis?

Is sedimentation analysis relatively simple and inexpensive to perform?

Is it necessary to carefully control temperature to suppress convection currents during sedimentation analysis?

Are particles required to be completely insoluble in the suspending liquid for sedimentation analysis?

Is the Coulter Counter method used to measure particle volume based on the diameter of a sphere that has the same volume as the particle?

Does the Coulter Counter method determine the number and size of particles suspended in an electrolyte by causing them to pass through an orifice immersed with an electrode?

Do changes in electric impedance as particles pass through the orifice in the Coulter Counter method generate voltage pulses proportional to the volumes of the particles?

What does the Coulter Counter method measure?

What does the diameter of a sphere representing the volume of a particle indicate?

What generates voltage pulses in the Coulter Counter method?

What is the Coulter Principle (Electrical Sensing Zone method) used for?

What does the voltage pulse measured in the Coulter method represent?

What property of particles does the Coulter method of sizing and counting particles NOT depend on?

True or false: The Coulter Principle is based on measurable changes in electrical resistance produced by conductive particles suspended in an electrolyte?

True or false: The Coulter method of sizing and counting particles is dependent on particle shape, color and density?

True or false: The Coulter method allows the system to count and size particles for an exact reproducible volume?

Is the Coulter method suitable for measuring particle diameter from approximately 0.5-400μm?

Does the Coulter method require the medium to be an electrolyte?

Is the Coulter method suitable for measuring high particle concentration?

What is a disadvantage of the sedimentation method for particle size analysis?

What is a challenge associated with the Coulter method for particle size measurement?

What is a key advantage of the sieving technique for particle size analysis?

What method relates obscuration of light source to particle size?

Which technique involves particles passing through a laser beam and the light scattered by them being collected over a range of angles in the forward direction?

What is the advantage of laser diffraction technique over sedimentation analysis?

Particle size range for Laser Diffraction Particle Size Analysis is 0.02 - 2000µm

Laser Diffraction measures the distribution of scattered light intensity to yield particle size distribution

The angles of diffraction in Laser Diffraction are directly related to the particle size

Is laser diffraction a non-intrusive technique?

Is laser diffraction a fast technique?

Is laser diffraction typically uses a low power laser beam?

What is a key advantage of laser diffraction for particle size analysis?

Why is careful temperature control necessary for sedimentation analysis?

What is a potential advantage of air jet sieving over conventional mechanically vibrated sieve analysis?

What should govern the choice of particle size analysis method?

What might constrain the selection of a particle size analysis method?

What is a key factor in selecting a particle size analysis method?