Drug Distribution

• To define what is meant by bioavailability and bioequivalence.

Bioavailability = the amount of drug going into the body and actually doing its action eg 100% bioavailability is only via IV as anything else has slight breakdown or absorption etc by liver therefore the drug must be a tailored concentration based on how it enters the body

Bioequivalence = is the biochemical similarity of two (or more) drugs that share the same active ingredient(s) and desired outcome(s) for patients.

so you can get different types of the same drug (well the same drug as in it has the same action as the original one but maybe a slightly different structure and makeup)

The bioequivalence drug must have between 80-125% of the bioavailability of the original drug it

eg brand name drug - non brand name drug

there are two different ways of creating a bioequivalence drug

Generic substitution

when a different formula (usually slight) of a drug which is to do the same action as

a branded drug is substituted for. the licensing authority will if acceptable consider it to be equivalent to the original drug

usually its ok to switch up the original brand drug vs the generic substitutioned drug between one another although in some circumstances the very very slight change in structure is enough to change things especially in phyciatric drugs which have a very specific for specific patients role in drugs so in these cases it is better to keep them on the original branded drug they have been using and avoid other drugs as it could change prospects for the patient.