Bioavailability and Bioequivalence

  1. established non-propritary common name of active ingredient (acetaminophen)
    generic name
  2. used by organic chemists; indicates structure (p-hydroxyacetaniline)
    chemical name
  3. privately owned trade name of a drug
    • brand name
    • an example is tylenol
  4. This is a reference to the rate and extent to which a drug is absorbed.

    Remember, F and ka are direct measures of bioavailability but are too variable to be useful for this purpose for the plasma observations.
  5. From an oral Cp vs time curve, the ____, _____, and _____ are used as indirect measures to determine the bioavailability of a drug.

    *Also describe what each blank measures.
    Cmax is a measure of rate and extent of absorption.

    tmax is a measure of rate of absorption.

    AUC is a measure of the extent of absorption.
  6. Urine Observations

    If absorption is greater for one drug product than another, then more of the ______ drug product should appear in the urine.

    For most drugs elimination is what order?

  7. Urine Observations

    Enough time should be allowed for the collection of the amount of absorbed drug in the urine-about how many t 1/2's?
  8. Au infinity is what?

    What does it measure?
    the total amount of absorbed drug that is ultimately excreted unchanged

    A measure of the extent of drug absorption.
  9. This compares the extent of absorption of t test product (generic drug) with a standard or reference product.

    The systemic availability of a drug in a given drug product relative to its availability in a standard formulation(Reference Listed Drug).
    Relative Bioavailability
  10. A high relative bioavailability means two products may be what?
    What does it not mean?
    It means two products may be bioequivalent but doesn't mean that either product is well absorbed.
  11. Absolute Bioavailability requires what?
    2 routes of administration
  12. A reference to the fraction of the oral dose that is absorbed.
    Absolute Bioavailability

    • 2 Routes of Administration
    • Compares oral to i.v.
  13. Bioavailability Studies contribute to assure that standards of _______ and _________ of a drug such as identity, strength, purity are met.
    safety and effectiveness
  14. For new generic products and new formulations of old drugs the FDA requires that _______ and ________ are met.
    in vitro/in vivo studies of bioavailability and pharmacokinetic parameters such as t1/2, rates of absorption, excretion, metabolism
  15. Data from bioavailability studies helps determine ______________.
    appropriate dose regimens
  16. Bioequivalent products show similar ____________ when studied under similar conditions.
  17. This is demonstrated by establishing that no statistical difference exists among Cmax, tmax, and AUC for the test and reference products.
  18. For bioequivalence, ANOVA or analysis of variance is a commonly used test where the level of probability must be ______ and a power of _____% certainty.

    The average parameter value of the test product should be within ______% of that of the reference product.
    • <0.05
    • 80%

  19. The rate and extent of absorption of the test drug do not show a significant difference from the rate and extent of absorption of the reference drug when administered at the same molar dose of therapeutic ingredient under similar experimental conditions in either a single dose or multiple doses.
    This shows bioequivalence.
  20. There is no difference in the extent of absorption in the test and reference products but a significant difference in ____________.

    This means the test and reference products are bioequivalent.
    rate of absorption, refelected in the label and is medically insignificant
  21. Bioequivalence studies are typically ____ dose, following what, ____ treatment, _______ design.

    When is the plasma sample taken?

    What other studies are sometimes performed to determine bioequivalence?
    • single
    • two
    • randomized cross-over design

    Plasma sample taken just before dose at at regular intervals thereafter

    Food intervention studies and multiple dose studies are sometimes performed
  22. For a Latin square Bioequivalence Study, each subject receives each drug how many times? with sufficient time between product administrations to allow for: 1.____________ and 2. ______________

    • full description of Cmax, tmax, and AUC
    • elimination of product of drug from the body
  23. For a replicated cross over design in bioequivalence studies, estimates within subject variance for ____ products.

    The FDA recommends this study be _____periods, ____sequences, and ______ formulation design.
    two products

    • four
    • two
    • two
  24. Dispensing an unbranded product or a different brand in place of a prescribed product.
    Generic substitution
  25. Same ________, same _________ but different __________ for a generic substiution.
    • dosage form
    • active ingredient
    • manufacturer
  26. What substitutions can be done using the orange book?
    generic substitutions

    • A is therapeutically equivalent
    • B shows inadequate evidence of bioequivalence
    • Two letter codes are used
  27. Same therapeutic entity but presented as different salts, complexes or esters. Also different dosage forms (elixirs, capsules, and tablets) and strengths by a single manufacturer.
    Pharmaceutical Alternative
  28. Same active ingredient, same amount of it, same dosage form for the same route of administration. Must meet same uniformity, disintegration, and dissolution rates where applicable. May differ in features such as packaging, shape, color, release mechanism, excipients and same labeling details.
    Pharmaceutical Equivalents
  29. The process of dispensing ___________ in place of a prescribed product. Needs prescriber approval.
    Pharmaceutical alternatives
  30. Different active ingredients, share same indications, and used for same therapeutic objectives. Ibuprofen instead of ASA.
    Therapeutic alternatives
  31. Pharmaceutic equivalents that are expected to have the same clinical effect and safety profile.
    Therapeutic equivalents
  32. Therapeutic subsitution involves the use of a _______________.
    therapeutic alternative
  33. For the drug review process NDA's require what?

    ANDA's require what?
    NDA's require animal and clinical data along with bioavailability data.

    ANDAs only need bioequivalence data.
  34. The biopharmaceutics classification system is used to predict what?

    in vivo absorption based of solubility and permeability characteristics

    • Jw=drug flux (mass/area/time)
    • Pw=permeability of membrane
    • Cw=drug concentration at intestinal membrane surface
Card Set
Bioavailability and Bioequivalence