Powders + Granules Flashcards
What are granules?
Agglomerates of powdered material
Which is more soluble, amorphous or crystalline?
Amorphous
Polymorphs exist in the (solid/liquid/gas) phase and never exists in _____
Exists as solid
Never exists in solution
Formation of polymorphism is dependent on what?
Crystallization conditions such as temperature, solvent, etc
What is polymorphism?
Ability of a SOLID material to exist in more than one form (not at the same time)
Particle size reduction (increases/decreases) surface area
increase
Increased surface area tends to (increase/decrease) dissolution rate
increase
What is dissolution rate?
TIME it takes for RX to dissolve
(T/F) Increasing dissolution rate has no effect upon the extent of solubility of a solute
True
Acidic RX are absorbed where?
Stomach
Basic RX are absorbed where?
Intestines
How long do RX remain in the stomach?
2-4 hrs
How long do RX remain in the intestines?
4-10 hours
What is micrometrics?
Science of small particles
Powder particle size ranges where what?
Coarse (1cm) to extremely fine (1 micrometer)
How is sedimentation rate determined?
Measuring particle settling viscosity in a liquid medium via Stokes Law
What is an excellent flow property value?
Angle of Repose = 25-30
What is a horrible flow property value?
Angle of Repose = >66
What is a passable flow property value?
Angle of Repose = 41-45
What is the angle of repose?
Estimates powder flow properties
Generally, flow is a problem with particle sizes _____
<100 micrometers
Powders with low angle flow (freely/poorly)
Freely
Powders with high angle flow (freely/poorly)
Poorly
Bulk vs Tapped density
Includes pore, air and voids
Bulk
Bulk vs Tapped density
Density increases
Tapped
Bulk vs Tapped density
Particles pack more efficiently
Tapped
Packing (for porosity’s case) is dependent on what?
Particle shape and spaces between particles
Small-scale trituration includes…
Grinding w/ mortar and pestle
Large-scale trituration includes…
Mills and pulverizers
When is sifting not acceptable?
Incorporation of potent drugs into a diluent powder
When demixing of powders occur, what is it usually caused by?
Particle size variations or densities
What are hygroscopic powders?
Absorb moisture from air
What are deliquescent powders?
Absorb moisture from air + partially/completely liquefy
To minimize hygroscopic and deliquescent powders, where can store them in?
Tight containers w/ desiccant packs
What are efflorescent powders?
Crystalline powders that contain water that is liberated during processing/low humidity
What’s the problem with efflorescent powders?
It may become sticky or even liquefy
How can you minimize the problem associated w/ efflorescent powders?
- Use anhydrous form of RX
2. Minimize friction
What is an eutectic?
- Powder becomes sticky or liquefies when mixed together
2. Melting point reduced when two powders mixed
How can you minimize the problem associated w/ eutectics?
- Mix material w/ bulkuy absorbent powder
2. Avoid compression (use spatula instead of mortar/pestle)
What kind of agents can EXPLODE when mixed??
Oxidizing and reducing agents
What kind of individuals prefer oral powders?
Peeps w/ difficulty swallowing solid dosage form
What are the advantages and disadvantages of oral powders?
+ = faster dissolution and absorption over solid dosage forms
- = Undesirable taste
What is insufflation?
Blowing something into a body cavity
When are aerosol powders particularly useful?
Anti-infectives w/ a WIDE therapeutic index
What is the particle size range of aerosol powders?
1 to 6 micrometers
(T/F) Powders dispensed in bulk is only limited to non-potent substances
True
When are powder papers used?
Limited to institutional practice
What are the advantages of granules?
- Better flow than small powders
- May be swallowed directly in food or H2O
- May be compacted into tabs/caps
What are the main methods of forming granules?
- Wet granulation
2. Dry granulation
What are the disadvantages of granules?
Time and labor investment
What kind of dosage form is preferred for reconstitution?
Granules
What do effervescent granulated salts release when in contact with water?
CO2
What kind of dosage form requires strict control of humidity and temperature conditions (10% RH + 20-25C)?
Effervescent Granulated Salts
What are the advantages of effervescent formulations?
- Protects low pH sensitive material in the stomach
- Assist delivering large doses
- Enhanced absorption
- Masks unpleasant tastes
(T/F) Effervescent Granulated can be swallowed directly
Nope, dissolve in H2O first
Tartaric and citric acids are used together in a __:__ ratio for effervescent granulated salts
2:1
If you just used tartaric acid alone for effervescent granulated salts, what would happen?
Chalky taste, crumbes
If you just used citric acid alone for effervescent granulated salts, what would happen?
Produces a sticky material
Effervescent granulated salts are prepared in (high/low) humidity and in _____ resistant, stainless steel vessels
low humidity + acid resistant