52 Questions
What factors affect flowability?
Both material and equipment characteristics
How can powder flowability vary?
Different powders can flow differently in the same hopper
Is powder flowability a simple concept
False
What is the definition of powder flowability?
The ability of a powder to flow in a specific piece of equipment
What are flow properties?
Properties that affect the flow of a powder
What are some of the flow properties mentioned in the passage?
bulk density ,permeability, cohesive strength, and wall friction
How do flow properties arise in a powder?
From the collective forces acting on individual particles
Which of the following is NOT an example of flow properties?
Solubility.
What are some forces that affect the flow properties individual of powder?
Van der Waals, electrostatic, surface tension, interlocking, friction
How does uneven powder flow affect high-speed tableting conditions?
It reduces capping and lamination risks
Which of the following describes the purpose of reproducible filling of tablet dies and capsule dosators?
A+B
How can excess fine particles in a powder affect its flowability?
Increase particle die wall friction
How does excess fine particles in a powder affect its flowability?
lubrication problems and increases the risk of dust contamination during powder transfer
What is the importance of flowability in the production of pharmaceutical dosage forms?
d. All of the above
Why is it important to have uniform flow from bulk storage containers or hoppers into the feed mechanisms of tableting or capsule filling equipment?
To maintain tablet weight uniformity
Which of the following flow properties is of critical significance in operations such as:
All of the above
All of the following is correct powders flow properties are measured using a number of parameters except:
blending
What department is responsible for determining flow properties and other derived and intrinsic properties in the preformulation stage?
Research and Development department
What is cohesion?
The occurrence between like surfaces, such as the same component particles in bulk solid
What is adhesion?
The presence of molecular forces between two different objects.
What are adhesive and cohesive forces mainly composed of?
Short-range non-specific van der Waals forces.
What provides a useful method of characterizing the drag or frictional forces within a powder bed?
Cohesion
Which type of forces arise from contact or frictional charging?
Electrostatic forces
Which of the following is NOT an attractive force contributing to interparticulate adhesion and cohesion?
Magnetic forces
What are flow properties used for in the formation of stable tablets?
Ensuring continuous and uniform flow of granules
True or False: Flow properties are employed as the flow measurements of the effect that the interparticulate forces acting at once.
True
Which of the following is flow properties powders are classified?
A+B
Which factors can affect flow properties ?
all of above
Flow properties of solids have a great impact on the tableting and encapsulation process.
True
What can be affected by the uniform & rapid flow of powders?
Weight variation
All of the following is correct flow property Interparticulate forces are of several types except ?
Adhesive and cohesive forces
What does the term hygroscopicity describe in the pharmaceutical Sciences?
The ability of a solid to take up and retain water.
How can hygroscopicity be defined?
The rate and extent of water vapor uptake by a solid at certain RH values and temperatures.
What are some physicochemical properties that can affect hygroscopicity?
Morphology, crystallinity, specific surface area, crystal structure, and state of hydration.
What are some possible outcomes of water uptake by a hygroscopic material?
Deliquescence and hydrate formation.
What can deliquescence formation result in?
Both a and b
When water exists as a hydrate, it usually results in:
Both a and b
What types of interactions can water molecules have with the components of a dosage form?
A+B
Which of the following is an example of a salt with water of crystallisation?
Green vitriol (FeSO4·7H2O)
Which salt has the formula CuSO4·5H2O?
Blue vitriol
Which compound has the formula Na2CO3·10H2O?
Washing soda
When does water of crystallisation get lost?
A+D
Water of crystallisation:a certain fixed number of water molecules
True
How do efflorescent substances differ from deliquescent substances?
Efflorescent substances transform into a powdery mass after losing water molecules
What is the phenomenon called when hydrated crystals lose water molecules on exposure to air at normal temperature?
Efflorescence
Which of the following is an example of an efflorescent substance on exposure to air at ordinary temperature?
Na2SO4·10H2O
What is the phenomenon called when some crystalline salts absorb moisture from the air and dissolve in it to form an aqueous solution?
Deliquescence
True or False: Deliquescent substances always contain water of crystallization.
False
Which of the following is an example of a deliquescent substance?
B+C
What is hygroscopicity?
The tendency of a material to absorb moisture from the atmosphere and reach a dynamic equilibrium with water in the atmosphere
What is a deliquescent substance?
A substance that absorbs moisture from the atmosphere and can be liquefied by partially or wholly forming a solution
What is an efflorescent substance?
A substance which loses water to form a lower hydrate or become anhydrous
Study Notes
Factors Affecting Flowability
- Powder flowability can be affected by various factors, including excess fine particles.
Definition of Powder Flowability
- Powder flowability refers to the ability of a powder to flow smoothly and consistently.
Flow Properties
- Flow properties are characteristics that describe the flow behavior of a powder.
- Examples of flow properties include:
- Cohesion (interparticle attraction)
- Adhesion (particle-to-particle or particle-to-surface attraction)
- Frictional forces
- Drag forces
Importance of Flowability
- Uniform flow is crucial in pharmaceutical production, as it affects the quality of tablets and capsules.
- Flowability is critical in high-speed tableting conditions to ensure consistent and accurate filling of tablet dies and capsule dosators.
Adhesion and Cohesion
- Adhesion: attraction between unlike particles or surfaces
- Cohesion: attraction between like particles
- Both adhesion and cohesion are composed of van der Waals forces, electrostatic forces, and hydrogen bonding.
Measuring Flow Properties
- Flow properties are measured using various parameters, such as angle of repose and compressibility.
Interparticulate Forces
- Interparticulate forces arise from contact or frictional charging between particles.
- Examples of interparticulate forces include van der Waals forces, electrostatic forces, and hydrogen bonding.
Hygroscopicity
- Hygroscopicity: the ability of a substance to absorb water vapor from the air.
- Physicochemical properties that can affect hygroscopicity include surface area, particle size, and surface chemistry.
- Hygroscopic materials can undergo deliquescence (dissolution in absorbed water) or efflorescence (loss of water of crystallization).
Water of Crystallization
- Water of crystallization: water molecules incorporated into a crystal lattice.
- Examples of salts with water of crystallization include CuSO4·5H2O and Na2CO3·10H2O.
- Water of crystallization can be lost on exposure to air or heat.
Deliquescent and Efflorescent Substances
- Deliquescent substances: absorb moisture from the air and dissolve in it to form a solution.
- Efflorescent substances: lose water of crystallization on exposure to air.
- Examples of deliquescent substances include NaNO3 and KNO3.
- Examples of efflorescent substances include Na2CO3 and CuSO4.
This quiz covers the importance of flowability in the production of pharmaceutical dosage forms, including reasons for producing free-flowing pharmaceutical powders and their impact on tablet weight uniformity and filling processes.
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