PHA 327 - Exam 2 - Preformulation 3

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PHA 327 - Exam 2 - Preformulation 3
2013-04-19 11:26:32
PHA 327 Exam Preformulation

PHA 327 - Exam 2 - Preformulation 3
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  1. The dissolution rate of a drug substance provides insights into absorption on its own (T/F)?
    False, the dissolution rate when combined with solubility, partition coefficient and pKa provide insight into its potential for absorption
  2. What chemical forms of a drug can alter the dissolution rate?
    • Acid
    • Base
    • Salts
  3. What ways can you alter a drug chemically to alter the dissolution rate?
    • Alter the form:
    • Acid
    • Base
    • Salt
  4. Which Crystal form has a greater dissolution rate?
    The metastable form (compared to the stable form)
  5. Do smaller or larger particles have a greater dissolution rate?
    Smaller particles
  6. Why do smaller particles have a greater dissolution rate?
    They have a greater surface area
  7. What surface properties effect the dissolution rate of a drug?
    Surface energy
  8. A high surface energy (i.e. microionized powder may result in what two things that effect the dissolution rate?
    Poor wetability and agglomeration
  9. What is deaggregation?
    The breakdown of Granules or aggregates into fine particles
  10. What is the term for the breakdown of granules or aggregates to fine particles?
  11. After the drug has been dissolved, what process can occur to remove it from solution?
  12. What are the steps in the process of breaking down tablets?
    Tablet to granules/aggregates to fine particles to drug in solution
  13. What is polymorphism?
    The existence of at least 2 different crystal structures of the same chemical substance
  14. What is the term that describes at least two different crystal structures of a single chemical?
  15. Polymorphs are different ion their crystal structures, but identical in what ways?
    They liquid and vapor states
  16. What physical differences do polymorphs have?
    • solubility
    • melting point
    • density
    • hardness
    • crystal shape
    • optical properties
    • electrical properties
    • vapor pressure
  17. Why are polymorphs important to pharmaceuticals?
    They have different absorption rates and therapeutic responses
  18. Name four examples of polymorphic drugs (as discussed in class):
    • Progesterone
    • Theobromide oil
    • Nicotinamide
    • Tobramycin
  19. What methods are available for characterization of polymorphic drugs?
    • Thermal analysis (DSC, TGA, Thermomicroscopy)
    • IR
    • X-ray diffractometry
  20. Why is it important to characterize the melting point of a drug?
    Helps in detection of impurities