During the last four decades, there is increased use of generic drugs to lower the healthcare cost. The most appropriate method of ensuring therapeutic equivalence between two medicinal drugs is Bioequivalence. It is the property by which, two drugs with similar ingredients or two different dosage forms of the same drug possessing similar bioavailability producing the same effect at the site of physiological activity. In other words, it can be explained as if two drugs having similar properties, its purpose is considered to be the same. The detailed study of bioequivalence is called the bioequivalence study.
Definition of bioequivalence study:
Bioequivalence studies are very important for the development of a pharmaceutical preparation (drugs/medicine) in the pharmaceutical industry. Bioequivalence study includes the drug substances in two or more dosage forms. This is conducted if there is a risk of failure. Let us discuss in brief about how the bioequivalence study is implemented.
Whenever a new product is intended or found to be a substitute for an approved medical product as a pharmaceutical equivalent or alternative by the pharmaceutical team, the equivalence of this product should be known or justified. To ensure this, bioequivalence study is important. When statistically significant changes are seen in bioavailability in two or more drug products, bioequivalence study is used. This requires a longer time to complete the studies.
How should the bioequivalence study be carried out?
A bioequivalence study should be conducted for comparing the medicinal products containing the same active substance. Such studies need to be carefully designed to take into account biopharmaceutical, ethical, medical, pharmacokinetics, analytical and statistical considerations. These studies should be used to assess the possibility of alternate use of bioequivalent products. The study of both bioequivalence and bioavailability is important during drug development of both new drug products and their generic equivalents. Provision of bioavailability and bioequivalence study data is an important feature in support of Investigational New Drug Applications (INDs), New Drug Applications (NDAs), Abbreviated New Drug Applications (ANDAs) and their supplements. The term generic drug product has been defined as an interchangeable multi-source pharmaceutical product. Generic products are copies of brand-name drugs with the same dosage form, strength, route of administration, intended use, and toxicity profile as the original innovator drug.
Types of Bioequivalence studies:
The whole process of Bioequivalence study is given in two ways as there are two types of Bioequivalence studies. They are:
- Vivo Bioequivalence study
- Vitro Bioequivalence study
Bioequivalence is determined based on the bioavailability of the newly invented medicine versus generic medicine. For example, if there are two drugs to be determined as bioequivalent there must be no more than a 20% difference between the AUC and Cmax. If two drugs are said to be bioequivalent, then they are to be expected to be useful for the same purpose. Bioequivalence study usually takes a longer period but bioequivalence study minimizes the carry-over effect.
Thus, the above-mentioned passage gives an overall insight into the bioequivalence study. To be precise, the importance of bioequivalence study lies until the manufacturing of medicines exists.