• Drug carrier

A carrier is an endogenous protein which binds to a drug and modifies its pharmacokinetics. A carrier may facilitate transport in the bloodstream or across cell membranes. Examples include albumin and sex hormone-binding globulin. A carrier is differentiated from a transporter as a carrier does not exert any activity beyond binding to the drug molecule.

Each carrier in DrugBank is considered a [bio entity] and is associated with a unique identification code that starts with "BE". For example, the code for serum albumin is BE0000530

Note that targets, enzymes, carriers, and transporters may switch roles depending on the drug to which they bind based on each drug's unique pharmacodynamic and pharmacokinetic profiles.