PHA 327 - Exam 2 - Powders 2

  1. Describe the method of obtaining bulk density (as described for tapped density in Preformulation):
    • 50 cc of powder is passed through sieve #20 and places in a 100cc volumetric cylinder
    • The cylinder is dropped at a 2 second interval 3 times from 1inch above a wooden surface
    • The weight of powder is divided by the final volume
  2. What does the angle of repose measure in terms of pharmaceutical properties?
    Flow property
  3. You can measure the flow property of a drug by measuring what parameter?
    The angle of repose
  4. A small angle of repose indicates what relative level of Flow?
  5. A large angle of repose indicates what relative level of Flow?
    Very poor
  6. What are the five advantages of powders discussed in class?
    • Better stability than solutions
    • Large doses can be administered
    • Wide range of ingredients and doses can be used
    • Rapid dispersion of the drug in the stomach (vs. compressed forms)
    • Can be dispersed in liquid for administration
  7. Solutions or powders are more stable?
  8. What are the disadvantages of powders as discussed in class?
    • Not good for bad tasting drugs
    • Not good for drugs that deteriorate easily in the atmosphere
  9. What type of drugs deteriorate rapidly in the atmosphere and thus should not be used in powder formulations?
    Ferrous iron salts
  10. Ferrous iron salts should be administered in what form?
    Coated tablets because they oxidize easily
  11. What four ways of mixing powders were mentioned in class?
    • Triturating
    • Spatulation
    • Sifting
    • Tumbling
  12. Trituration, spatulation, sifting and tumbling are methods for doing what?
    Mixing powders
  13. Describe trituration:
    Mortar and pestle
  14. What powder mixing technique uses a mortar and pestle?
  15. What is trituration used for?
    • Mixing
    • Pulverizing
  16. What types of mortar an pestles are commonly used?
    • Wedgewood
    • Glass
  17. What is the Wedgewood mortar and Pestle commonly used for?
    Pulverizing due to the rough inner surface
  18. What are glass mortar and pestles commonly used for?
    Simple mixing
  19. What type of mortar and pestle would you use for simple mixing?
  20. What type of mortar and pestle would you use for pulverizing course material?
  21. Describe Spatulation:
    A spatula is used to mix powders on a pill tile
  22. What powder mixing method uses a spatula and a pill tile?
  23. What situations are ideal for spatulation:
    • Small quantities of powder
    • Powders being mixed have the same densities
  24. If you have a small amount of powder with similar densities, which powder mixing technique might you use?
  25. Relatively how much drug would you expect to loss during transfer after performing spatulation?
  26. For powders that resist mixing by trituration, what other method would you use?
  27. What type of drugs are ideal for sifting?
    very light powders
  28. What mixing technique works very well for magnesium oxide and charcoal?
  29. What type of sieve is used for powder sifting?
    • Standard prescription sieve
    • Flour sifters
  30. What is tumbling?
    Mixing powders together by shaking or rotating them in a closed container
  31. What type of powder mixing process includes shaking or rotating in a closed container?
  32. When would you use tumbling to mix powders?
    When two or more extremely light powders are to be combined
  33. What type of mixing would you choose for crystalline salts?
    Trituration with a Wedgewood mortar
  34. If the surface of a wedgewood mortar becomes smooth, what an you do to remedy the problem?
    triturate with a little pumice powder or sand
  35. When would you triturate with pumice powder or sand?
    If you wedgewood mortar becomes too smooth
  36. What is electrification?
    Substance repel each other due to resistance of admixture or electrical charges
  37. When substances repel each other due to the resistance to admixture electrical charges what do we call it?
  38. How can you remedy electrification?
    Moisten slightly with a few drops of alcohol or mineral oil
  39. In what situation would you moisten your powder mixture slightly with a few drops of alcohol or mineral oil?
    When electrification occurs
  40. How can you avoid packing when triturating?
    triturate as lightly as you can and frequently scrape the edge of the mortar with a spatula
  41. How can you minimize Physical Immiscibility?
    • Separately, triturate two powders to a fine state
    • Then, sift or tumble the two powders together
Card Set
PHA 327 - Exam 2 - Powders 2
PHA 327 - Exam 2 - Powders 2