Related Experiment Video
Updated: Jul 3, 2026
07:25
In Vitro Methods for Comparing Target Binding and CDC Induction Between Therapeutic Antibodies: Applications in Biosimilarity Analysis
Published on: May 4, 2017
Including information on the therapeutic window in bioequivalence acceptance
Tom Jacobs1, Filip De Ridder, Sarah Rusch
1Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Universiteit Hasselt, and Katholieke Universiteit Leuven, Belgium, Agoralaan 1, B3590 Diepenbeek, Belgium. tom.jacobs@uhasselt.be
Pharmaceutical Research
|July 19, 2008
Summary
A new bioequivalence limit is proposed, considering the therapeutic window. This approach adjusts limits for narrow-window drugs and highly variable drugs, improving drug safety and efficacy assessments.
Area of Science:
- Pharmacokinetics and Drug Development
- Regulatory Science
- Pharmaceutical Analysis
Background:
- Bioequivalence studies are crucial for generic drug approval.
- Current bioequivalence limits may not adequately account for drug-specific therapeutic windows.
- Narrow therapeutic index drugs require stringent evaluation due to potential safety risks.
Purpose of the Study:
- To propose a novel bioequivalence limit that incorporates the therapeutic window.
- To enhance the assessment of drug products, particularly those with narrow therapeutic ranges.
- To refine regulatory standards for generic drug evaluation.
Main Methods:
- Introduction of the therapeutic range, defined by maximum tolerated dose/therapeutic dose (MTD/D) and therapeutic dose/lowest effective dose ratios.
- Comparative analysis of the proposed acceptance range against established methods (Schuirmann and Karalis).
- Retrospective application of the method to pharmacokinetic data from three drugs with narrow therapeutic windows: phenytoin, theophylline, and digoxin.
Main Results:
- Simulations demonstrate that the novel bioequivalence limits are narrower for drugs with narrow therapeutic indices.
- The proposed limits are expanded for highly variable drugs possessing a wide therapeutic window.
- Results indicate similarity to classical bioequivalence limits for less variable drugs with broad therapeutic ranges.
Conclusions:
- The proposed bioequivalence approach offers a more tailored assessment by narrowing acceptance ranges for drugs near therapeutic window boundaries.
- It provides wider acceptance ranges for products characterized by a broad therapeutic window, accommodating variability.
- This method enhances the safety and efficacy evaluation of generic drugs by considering their specific therapeutic characteristics.
Related Concept Videos
01:16Bioequivalence Data: Statistical Interpretation
The statistical interpretation of bioequivalence data is a significant aspect of pharmaceutical research. Bioequivalence refers to the absence of any significant difference in the rate and extent to which the active ingredient in pharmaceutical products becomes available at the site of drug action when administered at the same molar dose under similar conditions. This helps determine if different drug products have similar absorption rates, ensuring their interchangeability.Statistical...
01:09Bioequivalence of Drugs: Drugs with Multiple Indications
The concept of therapeutic equivalence (TE) in drugs with multiple indications is complex. A generic drug may be therapeutically equivalent to a brand-name product for one specific indication, but this doesn't necessarily mean it's equivalent for all other indications. Evidence of TE in one patient group and bioequivalence shown in healthy volunteers can support—but not confirm—TE for other indications. However, definitive proof requires individual clinical studies for each indication due to...
01:16Bioequivalence: Overview
Pharmaceutical equivalents, by definition, are drug products with the same active ingredient in the same quantities, encapsulated in identical dosage forms, and intended for the same administration routes. These pharmaceutical equivalents are deemed bioequivalent if the bioavailability of the active entity in the drug preparations is similar. Moreover, pharmaceutical equivalents demonstrating bioequivalence are also regarded as therapeutically equivalent. This means that when used as directed,...
01:13Bioequivalence studies: Biowaivers
In certain scenarios, in vitro dissolution tests can replace in vivo bioequivalence studies. This is particularly true when a drug product, though available in varying strengths, maintains proportional similarity in its active and inactive ingredients. In such cases, the need for in vivo bioequivalence studies for lower strength variants may be waived, provided dissolution tests and in vivo studies on the highest strength yield satisfactory results.Bioequivalence can be indicated through...
01:17Equivalence: In Vitro and In Vivo Bioequivalence
Bioequivalence studies are crucial in evaluating whether new drugs can match an approved one regarding pharmacological effects and clinical performance. These studies test if drugs, despite different dosage forms, share identical plasma concentration-time profiles. Three types of equivalence are central to these studies: chemical, pharmaceutical, and therapeutic. Chemical equivalence indicates that two or more drug products contain identical active ingredients in equal amounts. Pharmaceutical...
01:13Therapeutic Index
The therapeutic index of a drug is a key parameter in pharmacology that quantifies the relative safety of a drug by calculating the ratio between the dose that causes toxicity in half the population (50%) to the dose that proves to be effective for half the population (50%). It provides a spectrum of doses for a particular drug ranging from effective to potentially toxic. To illustrate, consider an anticoagulant agent like warfarin. It possesses a narrow window within its therapeutic index to...