Definition of Bioavailability
Bioavailability is defined as the fraction (F) of an administered drug dose that reaches systemic circulation in an unchanged form and is available for therapeutic action. It includes both:
Extent of drug absorption (how much drug reaches systemic circulation)
Rate of absorption (how quickly the drug reaches systemic circulation)
Objectives of Bioavailability Studies
Bioavailability studies are conducted to:
Compare Different Drug Formulations – Ensure consistency between different formulations of the same drug.
Evaluate Drug Absorption – Assess how much drug enters the bloodstream after administration.
Determine Optimal Dosage Forms – Choose the best formulation (tablet, capsule, solution, etc.).
Assess the Impact of Food or Other Factors – Understand how food, pH, or metabolic variations affect drug absorption.
Establish Therapeutic Equivalence – Ensure generic formulations provide the same therapeutic effect as brand-name drugs.
