What is the difference in increased bioequivalence and increased bioavailability?

Many people are confused when encountering either or both terms. They sound very similar but they are very different and can not be used interchangeably.

The term “bioavailability” refers to the extent to which a drug/nutrient reaches its site of action or a biological fluid such as blood that has access to its site of action. “Relative bioavailability” is assessed using a reference product and “absolute bioavailability” is determined using the iv as 100%.

The term “bioequivalence” refers to pharmaceutically equivalent drug products where the rates/extents of bioavailability of the actives are not significantly different under suitable test conditions. In other words, this is a comparison of two or more products with respect to their bioavailability.

Bio-equivalent simply means that one brand or dosage form of a drug or supplement is equivalent to a reference brand or dosage form of the same drug or supplement in terms of various bioavailability parameters measured via invivo testing in human subjects.

Bio-equivalence cannot be claimed based on invitro testing only or on the basis of animal studies only. Bio-equivalence of human drugs must be determined in humans via established measures of bioavailability. By the same token animal drugs must be tested for bio-equivalence in the animal species for which the drug in intended.

Once bio-equivalence has been established via bioavailability testing in a statistically significant manner subsequent batches of the same product are deemed bio-equivalent based on invitro measures such as drug dissolution.

There is no such thing as increased bio-equivalence. The statement of increased bio-equivalence makes no sense. A product can be either bio-equivalent or bio-inequivalent! A product can’t be more bio-equivalent or less bio-equivalent.