What are bioequivalence studies?
Bioequivalence studies (BE) are a specific type of clinical study designed to demonstrate that two medicinal products — most commonly a reference (original) drug and a generic drug — are equivalent in terms of the rate and extent of absorption of the active substance into the body. This means that, when the same dose is administered, both products achieve comparable concentrations of the active substance in the blood and should therefore have a similar therapeutic effect and safety profile.
Bioequivalence studies are one of the most important elements in the registration process for generic medicines. They eliminate the need to repeat full efficacy and safety studies that have already been conducted for the reference product. If bioequivalence is demonstrated, it can be concluded that the two products will behave comparably in the body.
Bioequivalence studies are most commonly conducted in healthy volunteers. This helps minimize the influence of disease on the results and allows the pharmacokinetic properties of the investigational product to be assessed more precisely. Participants receive both the test product and the reference product, usually during two separate study periods, according to a so-called cross-over design. An appropriately long wash-out period is used between administrations to prevent the first treatment from affecting the results of the second period.
During the study, multiple blood samples are collected at precisely defined time points. Based on the results, the concentration of the active substance in the blood is determined, and key pharmacokinetic parameters are calculated, such as maximum concentration (Cmax), time to reach maximum concentration (Tmax), and the area under the concentration-time curve (AUC), which reflects the overall exposure of the body to the drug.
Bioequivalence studies are conducted in accordance with Good Clinical Practice (ICH GCP) and Good Laboratory Practice (GLP). Their implementation requires strict adherence to procedures for participant qualification, biological sample collection, laboratory analysis, and statistical evaluation of the results. An important aspect of the study is also ensuring participant safety through adverse event monitoring and continuous medical supervision.
Although bioequivalence studies are most commonly associated with generic medicines, they are also used when developing new pharmaceutical formulations, changing manufacturing processes, or modifying the composition of a medicinal product. In such cases, they help confirm that the introduced changes do not affect the release and absorption of the active substance.
Bioequivalence studies play a key role in the development of medicinal products. They enable high-quality generic medicines to be introduced to the market, providing patients with effective and safe treatment while increasing access to therapy and reducing healthcare costs.
