[The transnasal route of drug administration. Aspects of nasal anatomy and physiology].

The use of transnasal administration of drugs has gained interest with the synthesis of new polypeptidic biologically active substances. Since few years an increasing number of therapeutical hormones delivered through the nose are now available to treat disorders that only used to require parenteral injections to be effective. In its first part the present review describes the anatomy and physiology of the nose in order to gain insight in this site of delivery. The second part deals more specifically with models used to study transnasal absorption and describes parameters that modify drug absorption in relation with the model chosen.