T1 - Week 6 Flashcards
What is the USP defintion of powders?
A single solid or mixture of solids in a finely divided state
What is a powder?
A dry substance composed of finely divided particles
How is powder pharmaceutically prepared?
- A medicated powder
- Limited use in therapeutics
What are granules?
Prepared agglomerates of powdered material
Define micromeritics
The study of small particles
Describe the characteristics of powders
- Bulk volume of a powder (Vbulk)
- True volume
- Void= (Vbulk-V)/Vbulk
- Porosity
What is true volume?
The space occupied by the powder exclusive of the intramolecular space
Excluding void volume
What is envelope density?
Includes pore volume but not interparticle spaces
What is bulk density?
Includes pore volume and interparticle spaces
What is porosity?
Measure of void volume
What variables does micromeritics study?
- Partical size
- Shape
- Angle of repose
- Porosity
- True volume
- Bulk volume
- Apparent density
- Bulkiness
What are some methods of determining particle sizes?
- Sieving
- Microscopy
What are USP’s descriptive terms for particle size of powder?
- Very coarse (Sieve #8)
- Coarse (Sieve #20)
- Moderately coarse (Sieve #40)
- Fine (Sieve #60)
- Very fine (Sieve #80)
How are granule particle analysized?
- Typically fall within the range of 4 - to 12-sieve size
- Sometimes 12- to 20-sieve range are used in tablet making.
What are the roles of particle size?
- Stability
- Drug Absorption
- Side Effects
- Manufacturing aspects (Mixing, compression, wetability, flow)
What is comminution?
Reduction of the particle size of a solid substance to a finer state
What are the methods of reducing particle size on a small scale?
- Rough surface (as a porcelain mortar) result in a finer grinding action than a smooth surface (as a glass mortar).
- Grinding a drug in a mortar to reduce its particle size is termed trituration or comminution.
What are the methods of reducing particle size on a large scale?
Mills and pulverizers
What is levigation?
Used in small-scale preparation of ointments and suspensions to reduce the particle size and grittiness of the added powders.
A mortar and pestle or an ointment tile may be used.
What are the steps of levigation?
- A paste is formed by combining the powder and a small amount of liquid (the levigating agent) in which the powder is insoluble.
- The paste is then triturated, reducing the particle size.
- Mineral oil and glycerin are commonly used levigating agents.
- The levigated paste may then be added to the ointment base and the mixture made uniform and smooth by rubbing them together with a spatula on the ointment tile.
What is the angle of repose?
Technique for estimating the flow properties of a powder
How is the angle of repose achieved?
- Done by allowing the powder to flow through a funnel and fall freely onto a surface.
- The height and diameter of the resulting cone are measured and the angle of repose is calculated.
What are the different methods of powder blending?
- Spatulation
- Trituration
- Sifting
- Tumbling
How would we make blended powder?
Reducing the particle sizes of each powder to make it more uniform
What is spatulation?
Blending small amounts of powders by movement of a spatula through them on a sheet of paper or an ointment tile.
Why isn’t spatulation suitable for large quantities of potent drugs?
Because homogenous blending may not be ascertained
Can this be used to incorporate potent drugs into diluent powder?
No
What is trituration?
Used to both comminute and mix powders
What is used for trituration?
Glass mortar
What is sifting?
Mixing powders by passing through sifters
What is tumbling
Mixing powders in a rotating chamber but time-consuming
Describe geometric dilution method
- Used with a small amount of a poten substance is to be mixed with a large amount of diluent
- Done by placing the potent drug with an approximately equal volume/amount of the diluent in a mortar and is mixed thoroughly by trituration.
- Process continued by adding an equal volume of diluent to the powder mixture.
What is segregation?
Undesirable separation of the components of the blend, occurred by sifting, air entrapment, and particle entrapment
What are advantages of medicated powders for internal use?
The doses of some drugs are too bulky to be formed into tablets or capsules of convenient size, so they may be administered as powders.
What are disadvantages of medicated powders for internal use?
Undesirable taste of the drug
What is bulk powder?
- Reasonably dosed with inaccurate measuring devices
- Susceptible to degradation
What is oral powder?
- Bulk or Divided Powders (accurate single dose)
- Effervescent granules
- Granules for suspension
What is dusting powder?
- Topical use
- Medicated, Protectant, Absorbent, Astringent, Coolant
What is douche powder?
- Powders to add to solution
- Enhanced portability Usually acidic
What is insufflation?
Fine powders introduced to body cavities by mechanical means
What is inhalation powder for?
Delivery to lungs
What is efflorescent powder?
Drugs or chemicals that contain water of hydration that may be released when the powders are manipulated or are stored under conditions of low relative humidity
What is hygroscopic powder?
Solid drugs or chemicals that absorb moisture from the air
What is deliquescent powder?
Hygroscopic powders that may absorb sufficient moisture from the air to dissolve and form a solution.
What is pharmaceutical eutectic mixture?
A mixture of two or more solid substances that may liquefy when intimately mixed at room temperature
What are the components of hard gelatin capsules
- Size 000 - 5
- 1.4 mL - 0.13 mL
How are capsules closed?
- Hard Gelatin Capsule Closures
- Coni-snap
- Capsule seals
What are the powders that require special handling?
- Efflorescent powder
- Hygroscopic powder
- Deliquescent powder
- Pharmaceutical eutectic mixture
What goes in a capsule?
- Powder or granule
- Pellet
- Paste
- Capsule
- Tablet
What are the types of capsule fillings?
- Manual
- Tablet mold
What is the process of industry’s filling capsules?
Ingredients go into the milling/sieving → Blending → Powder blend go into the capsule filler → Capsule inspection screen → Capsule check-weighing system → Finished capsules → Packaging
What are soft gelatin capsules?
- More moisture than hard gelatin capsules
- Often have preservatives like methyl and propyl paraben
- Designed to hermetically seal
What does in soft gelatin capsules?
- Liquid
- Paste
- Powder
- Tablets
What is direct compression?
- For Blends with good flow and compressibility
- Simple, time-effective and cost-effective process
- Conformity of low dose actives is a problem
- High-dose actives are difficult to process
- Segregation can occur
- Static Charge can occur due to lack of moisture
What is wet granulation?
- Can densify materials
- Improved flow and compressibility
- Improves content uniformity
- Reduces fine particles and electrostatic charge
- Can process drugs susceptible to high shear
What are the disadvantages of wet granulation?
- Multiple process step
- Expensive
- Time consuming
- Not good for heat
- Moisture sensitive
What is dry granulation?
- Can densify materials
- Improved flow and compressibility
- Can process moisture sensitive materials
- Less time and cost effective than direct compression
- Can not process drugs susceptible to high shear
- Process creates dust and fine particles.
What are examples of compression testing?
- Tablet Hardness (crushing strength)
- Disintegration Testing
- Friability (mechanical shock)
- Weight Variation
- Content Uniformity
- Assay of API
What are the types of capping defects?
- Top of tablet is broken
- Trapped air on compression
What are the types of lamination defects?
Layering of particles instead of bonding together
What are the types of picking and sticking defects?
- Logos, lettering, imprint codes
- Particles stick to machinery
What are types of coating defects?
- Logo bridging and filling
- Picking and Sticking
- Twinning- tablets sticking together
- Orange peel – roughness of coating
- Color Variation
- Cratering
- Cracking
- Core Erosion- core breaks down
- Edge Chipping
What are compressed tablets?
- Any shape or size
- Scored or unscored
What are multi-compressed tablets?
Tablet with a tablet or multi-layer
What is multi-compressed tablets used for?
- Overcoming imcompatibilities
- Altering drug release
- Unique appearance
What are film-coated tablets?
- Thin polymer coat
- More durable, less time-consuming, less bulky than sugar coating
- Designed to rupture at the desired location in GI tract
What are sugar-coated tablets?
- Mask taste
- Protect formulation
- Makes imprinting easier
- Improves appearance
- Bulky- adds 50% to weight of tablet.
- Difficult coating process
What are gelatin-coated tablets?
- Gelatin Coat over compressed tablet
- Provides smaller dosage form than filling a capsule of same amount of ingredients
- Facilitates swallowing
- More tamper evident
What are enteric-coated tablets?
- Delayed release properties
- Designed to pass through stomach unchanged
- Drug release in small intestine
What is an enteric coat used for?
- Stomach degrades API
- API is irritating to stomach lining
- Enhance absorption of drug
What are chewable tablets?
Chewable and dissolves quickly
What are effervescent tablets?
Dissolves in water prior to administration
What are chewable dispersible tablets?
Can be swallowed, chewed or dispersed prior to administration
What are other types of tablets?
- Rapidly Disintegrating Tablets (Orally Disintegrating Tablets) (RDT, ODT)
- Vaginal Tablets
What are the characteristics of molded tablets?
- Base is lactose
- Combinations with sucrose, dextrose, and/or mannitol are commonly used.
- Small tablets usually around 1 grain (65 mg)
- Very soluble in water
- Good for buccal and sublingual delivery
- Usually potent drugs
What occurs when molded tablets have too much liquid?
- Hamper cohesion
- Extend drying time
- Cause creeping of API to surface
