PHA 327-Bioavailability

  1. What are the disadvantages of Concentration time plots?
    • Limited utility
    • Do not describe the actual drug movement
  2. What are the methods for determining Area Under the Curve?
    • Calculus integration
    • Cut and way paper
    • Trapezoid method
  3. What is the equation for the area of a trapezoid?
    1/2(base1 + base2) x height
  4. How do you use the trapezoid method for determining the area under the curve?
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  5. Approximate the linear function and then use teh equation:
    1/2(base1 + base2) x height
  6. What are the units for an AUC of a concentration time curve?
  7. What does the area under the curve for a concentration time plot mean?
    The total drug exposure
  8. What is the Area under the curve affected by?
    All drug processes and movements
  9. What can the AUC be used for?
    Comparing drug products and dosage forms
  10. How is Bioavailability usually reported?
    As a percentage of the total drug given
  11. Is Bioavailability a measure of drug action and effects?
    • Is somewhat interpreted that way, assumed to be related
    • Though, is not really
  12. What is the Equation for Bioavailability?
    F = AUCa/AUCb
  13. What is the critical determining factor for Bioavailability?
    The denominator
  14. What is the denominator of Bioavailability?
    The Reference material
  15. What is Relative Bioavailability?
    A comparison between two dosage forms, where one form becomes the denominator
  16. What is the absolute Bioavailability?
    A comparison of the amount of drug that reaches circulation to the amount that was given
  17. What is the reference/denominator for Absolute Bioavailability?
    The AUC following IV administration
  18. What are the assumptions of Bioavailability?
    • Patient sample is representative
    • Absorption is the universal and unchanging
  19. What is Pharmaceutical Equivalence?
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    • Contains the same active ingredient(s)
    • Same dosage form/Route of administration
    • Identical in strength or concentration
    • May differ in shape, scoring configuration, release mechanisms, packaging, excipients, expiration time
  20. What is Pharmaceutical Alternatives?
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    • Contain the same therapeutic moiety
    • Different salts, esters, or complexes of that moiety, or are different dosage forms or strengths
    • Different dosage forms and strengths and extended-release products within a product line by a single manufacturer are pharmaceutical alternatives
  21. What is Therapeutic Equivalent?
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    • They are pharmaceutical equivalents and can be expected to have the same clinical effect and safety profile
  22. Who conducts Bioequivalence studies?
    Generic drug manufacturers
  23. What are FDA pivotal parameters for Bioequivalence?
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    • AUC
    • Cmax
    • tmax (subjective)
    • All should be 80-120% of the reference product
  24. What are the limits on AUC, Cmax and tmax of a generic drug compared to a reference drug?
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    • Need to be within 80-120% of the reference drug
  25. What are bioavailability studies used for usually?
    To compare different routes of administration
  26. What are Bioequivalence studies used for usually?
    Compare new drugs to a known drug product
  27. What are the units for Salt factor?
    Unit less
  28. What are the units of Bioavailability?
    Unit less
  29. What is the salt factor?
    The fraction of the dose that is bioavailable and is active
  30. What is the Amount available of a drug?
    The dose times the bioavailability times the percent that is in an active form (the salt factor)
  31. How do you calculate Bioequivalence?
    SxFxD = SxFxD
  32. What drugs are concerning to give bioequivalents of?
    • Drugs that:
    • have a small therapeutic range
    • require high doses
    • are not well absorbed
    • studies show different products have different effects
  33. What is Bioavailability?
    The rate and extent to which the AI is absorbed and available at the site of action
  34. What is a Bioequivalent drug product?
    • Pharmaceutical equivalent or alternative products with comparable bioavailability
    • May sometimes be demonstrated using an in vitro bioequivalence standard, especially when such an in vitro test has been correlated with human in vivo bioavailability data.
Card Set
PHA 327-Bioavailability
PHA 327-Bioavailability