Bioequivalence bioavailability


Convex team has extensive experience in the conduct of bioequivalence and bioavailability studies. We can work along with you in the process of study design and conduct. Our dedicated team of experts ensures that all studies are performed in compliance with Good Clinical Practice (GCP) guidelines and regulatory requirements.

BE studies play an important role in drug development as well as during post-approval period for both pioneer and generic drugs. They serve as bridging studies in the presence of formulation or manufacturing changes to provide supportive evidence for safety and efficacy of a drug product.

Two drug products are considered bioequivalent if they are pharmaceutical equivalents or pharmaceutical alternatives whose rate and extent of absorption do not show a significant difference when administered at the same molar dose of the active moiety under similar experimental conditions, either single dose or multidose.

Acceptable BE between a test and reference product is among the criteria by regulatory agencies for approval of new generic drug products. Therapeutically equivalent drug products can be substituted with the full expectation that the substituted (test) product will produce the same safety effect and safety profile as the originally prescribed (reference) product.

Our Study Design and Conduct Capabilities


Subject Database

  • Crossover and Parallel Design
  • Single Dose and Multi Dose
  • Healthy Subject and Patient Population
  • Administered Dose
  • Sampling
  • Parent Drug and Metabolites
  • Enantiomers and Racemates
  • Endogenous Compounds
  • Food-Effect BA study
  • Fast Fed BE study
  • Drug-drug interaction studies
  • Fasting studies
  • Food intervention studies
  • Parallel group design
  • Cross over study design
  • Two period cross over design
  • Replicated study design
  • Non replicate parallel study designs
  • Scaled average bioequivalence design
  • Multiple dose steady state study design
  • Latin square design
  • Balance incomplete block designs
Cinical studies

We have been involved in studies examining the bioequivalence between highly variable drugs, liposomal drug products, drug products acting locally, topical drug products, orally inhaled drug products (powder inhalers and metered dose inhalers), and nasal drug products.

Clinical Investigational Team


Our clinical investigational team consists of experienced professionals who are committed to delivering high-quality results:

  • 1 Principal Investigator: Pharmacology specialist
  • 5 Sub-Investigators: Cardiology, Neurology, Endocrinology specialist
  • 14 Study Nurses
  • 3 Lab Technicians
  • 3 Study Coordinators
  • 1 Clinical Research Manager

Understanding Bioequivalence and Bioavailability


What is bioequivalence (BE)?

The absence of a significant difference in the rate and extent to which an active ingredient or active moiety in pharmaceutical equivalents or pharmaceutical alternatives become available at the site of action when administered at the same molar dose under the same conditions in an appropriately designed study.

BE between a test and reference product is established in order to demonstrate therapeutic equivalence. Therapeutically equivalent drug products can be substituted with the full expectation that the substituted (test) product will produce the same safety effect and safety profile as the originally prescribed (reference) product.

What is bioavailability (BA)?

The absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutical equivalents or alternatives becomes available at the site of drug action when administered at the same molar dose under similar conditions in an appropriately designed study.

Ethical Considerations in Phase 1 Trials

What is the difference between BE and BA?

The difference between BE and BA lies in the study goals, hence the study designs and statistical analysis of the study outcomes. The BA studies can be employed to assess the pharmacokinetics and performance of a drug product related to the absorption, distribution and elimination of the drug in vivo.

In contrast, BE studies are primarily utilized for formulation comparisons and thus data analysis focuses on the release of active ingredient or moiety from the drug product and subsequent absorption into the systemic circulation. Drug products are considered as pharmaceutical equivalents when they are identical dosage forms and contain identical amounts of the identical active drug ingredient.

Clinical Application and Population Bioequivalence


For physicians and patients, bioequivalent drug products can and should be used interchangeably to achieve a similar therapeutic effect. Bioequivalence studies, in fact, serve as surrogates for clinical trials in evaluation of therapeutic equivalence in efficacy and safety between the innovator product and its generic copies.

However, when a physician has the possibility of administering a generic drug product, he or she needs to consider the anticipated therapeutic effect that may be obtained from the patient. If a new patient has just begun a drug regimen, the physician does not have any information about the patient’s therapeutic response to any of the different formulation that he or she could prescribe.

As a result, the only relevant information that the physician could have is the comparison of the marginal distributions for some pharmacokinetic responses or metric between the generic and innovator drug product from a population of subjects.

If the marginal distributions follow an approximate normal distribution, the equivalence can be evaluated through inferences on population parameters, such as average and intrasubject variability. This concept is referred to as the population bioequivalence. Given the information about population parameters, the physician can determine whether to prescribe an innovator drug product or its generic copies to a new patient who just begins to receive the drug regime.

On the other hand, suppose a patient with a chronic disease, such as hypertension or diabetes, has been well controlled under long-term administration of an innovator drug product. In other words, the concentration of its active ingredients has been titrated to an efficacious and safety level within the patient’s individual therapeutic window. For more information please contact us at: info@convex.bg