Bioequivalence (BE)
Bioequivalence ensures that two drug formulations have similar pharmacokinetic properties, leading to the same safety and efficacy when administered under identical conditions.
It is a subset of therapeutic equivalence, focusing on rate and extent of drug absorption.
Types of Equivalence
Pharmaceutical Equivalence – Same active ingredient, dosage form, strength, and route of administration.
Therapeutic Equivalence – Pharmaceutical equivalents with comparable safety and efficacy.
Bioequivalence – Pharmaceutical equivalents with similar pharmacokinetic profiles (AUC, Cmax, Tmax).
Bioequivalence Studies
Bioequivalence studies compare a test drug (generic) to a reference drug (brand-name) to confirm similar in-vivo performance and ensure the generic provides the same therapeutic effect.
Objective of BE Studies
Demonstrate comparable pharmacokinetics between test and reference products.
Compare AUC (Area Under the Curve), Cmax (Maximum Concentration), and Tmax (Time to Cmax) to assess absorption similarity.
Types of BE Studies
In-Vitro Studies – Dissolution testing under lab conditions to predict in-vivo behavior.
In-Vivo Studies – Compare AUC, Cmax, Tmax in humans or animals to assess drug absorption and bioavailability.
Methods of Bioequivalence Testing
Pharmacokinetic Studies – Measure AUC, Cmax, Tmax in healthy volunteers.
Pharmacodynamic Studies – Compare drug effects (used for topical or inhaled drugs).
Clinical Trials – Rarely used, required for drugs with complex effects.
In-Vitro Dissolution Testing – Used when IVIVC is established.
Regulatory Criteria (FDA, EMA)
AUC & Cmax must fall within 80-125% of the reference drug (90% confidence interval).
Ensures therapeutic equivalence between generic and brand-name drugs.
