Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient

Targeting agent Natural or artificial substances that enhance absorption of a biologically active agent in a particular part of the body – i.e. in a particular organ or to a particular cell type. Pre-targeting system An example of this is an immuno-conjugate that has a part that recognizes a target antigen and a part that recognizes a further substance to which a therapeutic agent is attached. When said conjugate is administered it binds to target cells, furnishing said cells with binding sites for the therapeutic agent. Modifying agent Natural or artificial substances that enhance the physio-chemical properties of a biologically active agent – i.e. that improve long term storage stability or enhance bioavailability when delivered orally. Macromolecular A chemical moiety (organic or inorganic) that is linked to identical sub-units in numbers of greater than 5. Thus, polysiloxanes are classified in , polyphosphazines in and inorganic species such as polyphosphate Chemically bound When two distinct chemical entities are linked to one another by co-valent bonds. An alternative situation may arise when both chemical entities are linked using ionic bonds, for example using organic/inorganic ions that complex with one another, e.g. see Codrug A dimer, oligomer or polymer of one or more pharmacologically or therapeutically active compounds. e.g. polyaspirin