Bioavailability & Bioequivalence, Generic & Biosimilar Part 1

Vocabulary flashcards covering the fundamental concepts of branded and generic medicines, bioavailability parameters, factors affecting drug absorption, and routes of administration.

Branded or Innovator Medicines

New medicines developed through research and development of a new chemical molecule, known by both a generic name and a brand name assigned by the developer.

Generic Medicine

A copy of a branded medicine that contains the same active ingredients, dosage form, strength, and route of administration, and is proven to be bioequivalent, safe, and effective.

Bioequivalence

A condition where two medicinal products containing the same active substance are pharmaceutically equivalent and their bioavailabilities lie within acceptable predefined limits after administration in the same molar dose.

Bioavailability

The extent and rate at which the active moiety is delivered from a pharmaceutical form and becomes available in the systemic circulation.

Area Under Curve (AUC)

A bioavailability parameter derived from the plasma drug concentration vs time curve that measures the rate and extent of absorption.

$$C_{max}$$

A bioavailability parameter representing the maximum plasma concentration, used to measure the extent of absorption.

$$T_{max}$$

A bioavailability parameter representing the time to reach maximum concentration, used to measure the rate of absorption.

True Dose

The amount of the drug that is actually available at the site of action to exert its therapeutic effect, rather than simply the amount swallowed.

Pharmaceutical Factors

Physicochemical properties of the drug (such as particle size, salt form, and crystalline structure) and formulation variables (such as disintegration time) that affect bioavailability.

Patient Related Factors

Physiologic conditions (such as GI fluid pH, gastric emptying rate, and intestinal motility) and external interactions (such as food or alcohol) that affect bioavailability.

ADME

An acronym representing the four processes of pharmacokinetics affected by the route of administration: Absorption, Distribution, Metabolism, and Excretion.

Enteral Route

A category of drug administration where medications enter the body through the digestive system, including oral ($PO$), per rectum ($PR$), and sublingual routes.

Parenteral Route

A category of drug administration where medications enter the body by means other than the digestive system, including intravenous ($IV$), intramuscular ($IM$), and subcutaneous ($SC$) routes.

First-pass Metabolism

A process occurring in the gut wall or liver during absorption where a drug is extensively metabolized, leading to variable bioavailability and exposure.

Active Pharmaceutical Ingredient (API)

The key ingredient in a medicine; generic versions must contain the same strength of this ingredient as the original branded product.