Bioavailability and Bioequivalence in Pharmacokinetics

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Questions and Answers

What does bioavailability provide an estimate of?

The relative fraction of the administered dose that is absorbed into the systemic circulation (correct)

The absolute fraction of the administered dose that is absorbed into the systemic circulation

The concentration of the drug in the systemic circulation

The total amount of unchanged drug that reaches the systemic circulation

How is bioavailability most often assessed for systemically available drug products?

By assessing the volume of distribution of the drug

By calculating the elimination rate constant of the drug

By measuring the peak concentration of the drug in the plasma

By determining the area under the drug plasma concentration-versus-time profile (AUC) (correct)

What does absolute bioavailability compare?

The total amount of unchanged drug following different routes of administration

The absolute concentration of the drug following different routes of administration

The bioavailability of the active drug following intravenous administration with that following oral administration (correct)

The bioavailability of different drugs within the systemic circulation

Why is intravenous drug administration considered 100% absorbed?

Because it bypasses first-pass metabolism Signup and view all the answers

What route of administration is considered for extravascular administration in absolute bioavailability?

Inhaled, intramuscular, oral, rectal, subcutaneous, sublingual, topical, transdermal, etc. Signup and view all the answers

What does absolute bioavailability measure?

The AUC of the extravascularly administered drug product divided by the AUC of the drug product given intravenously Signup and view all the answers

What is the absolute bioavailability of a drug given by the intravenous route?

100% (Fabs = 1.0) Signup and view all the answers

In a relative bioavailability study, what is compared?

The systemic exposure of a drug in a designated formulation with that of the same drug administered in another formulation Signup and view all the answers

What is a multi-source drug product?

A drug product that contains the same active drug substance in the same dosage form & is marketed by more than one pharmaceutical manufacturers Signup and view all the answers

Why does it take years for innovator products to be released into the market?

They require extensive safety testing Signup and view all the answers

Which of the following is not a topic covered in the main course outline of Biopharmaceutics and Pharmacokinetics?

Reaction kinetics Signup and view all the answers

In the context of biopharmaceutics and pharmacokinetics, hepatic elimination refers to the:

Metabolism of drugs by the liver Signup and view all the answers

What type of study compares the bioavailability of a drug product to a reference standard, often the innovator product?

Bioequivalence study Signup and view all the answers

According to the course outline, which book would be a relevant reference for learning about controlled release medications?

Applied Biopharmaceutics and Pharmacokinetics, 7th edition Signup and view all the answers

What does pharmacogenetics primarily focus on in the context of drug therapy?

Individual genetic variability in drug response Signup and view all the answers

What does biopharmaceutics study?

Factors influencing the therapeutic effectiveness of drug products Signup and view all the answers

What does pharmacokinetics study?

The kinetics of drug absorption, distribution, metabolism, and excretion Signup and view all the answers

What is bioavailability defined as?

The process of movement of drug from its site of administration to the systemic circulation Signup and view all the answers

Where is the site of action usually located?

In the extravascular tissues Signup and view all the answers

What is elimination defined as?

The process that tends to re Signup and view all the answers

Study Notes

Bioavailability and Absorption

Bioavailability provides an estimate of the fraction of an administered dose of a drug that reaches the systemic circulation.
Bioavailability is most often assessed for systemically available drug products by comparing the area under the curve (AUC) of a drug concentration vs. time plot after administration via different routes.

Absolute Bioavailability

Absolute bioavailability compares the bioavailability of a drug product administered via a non-intravenous route to the bioavailability of the same drug product administered via the intravenous route.
Intravenous drug administration is considered 100% absorbed because the entire dose enters the systemic circulation directly.
In absolute bioavailability, the extravascular route of administration is considered, such as oral, sublingual, or topical administration.
Absolute bioavailability measures the fraction of the dose that reaches the systemic circulation after administration via a non-intravenous route.

Relative Bioavailability

In a relative bioavailability study, the bioavailability of a drug product is compared to a reference standard, often the innovator product.

Biopharmaceutics and Pharmacokinetics

A multi-source drug product is a product that is marketed by multiple manufacturers.
Innovator products take years to be released into the market due to the need for extensive research, development, and regulatory approval.
Hepatic elimination refers to the process by which the liver removes drugs from the bloodstream.
Biopharmaceutics studies the relationship between the physical and chemical properties of a drug and its biological effects.
Pharmacokinetics studies the movement of a drug within the body, including its absorption, distribution, metabolism, and elimination.
Bioavailability is defined as the fraction of an administered dose of a drug that reaches the systemic circulation.
The site of action is usually located at the target receptor or tissue where the drug exerts its therapeutic effect.
Elimination is defined as the removal of a drug from the body, including processes such as metabolism, excretion, and transport.

Additional Topics

Pharmacogenetics primarily focuses on the genetic factors that influence an individual's response to drug therapy.
Controlled release medications are discussed in the book "Pharmaceutics: The Science of Dosage Form Design".

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Description

Test your knowledge of bioavailability and bioequivalence in pharmacokinetics through this lecture 11 quiz. Explore concepts such as relative and absolute availability, and the estimation of the fraction of the administered dose absorbed into the systemic circulation.