[Absorption of calcitonin in oral and pulmonary administration with polymer-coated liposomes].

We have developed polymer-coated liposomes for effective and non-invasive delivery of peptide drugs. Polymer-coated liposomes, which are liposomal particles coated with functional polymers, were designed in order to have suitable functions required for drug delivery. So far, we have reported prolonged retention in the gastro-intestinal tract owing to the mucoadhesive properties of the polymer-coated liposomes. This review shows outline of effectiveness of polymer-coated liposomes in absorption of calcitonin after oral administration. The main factors for absorption enhancing of calcitonin are mucoadhesion and penetration of polymer-coated liposomes into the mucus layer. Application of polymer-coated liposomes in pulmonal drug delivery and novel strategies for designing mucoadhesive particulate systems are also described.