Influence of dextran on the bioadhesive properties of poly(anhydride) nanoparticles.

This work describes the bioadhesive properties of poly(methyl vinyl ether-co-maleic anhydride) (Gantrez AN) nanoparticles (NP) associated with various types of dextran (two hydroxyl-functionalized dextrans and one amino-derivative of dextran). The association of dextran to the polymer was performed either prior NP formation or by the attachment of dextran to the surface of the just formed NP. The amount of dextran associated to the nanoparticles was quantified by a HPLC/ELSD method and dextran presence in the nanoparticles was confirmed by IR spectroscopy, (1)H NMR and in vitro agglutination assay. The in vivo bioadhesion study has demonstrated significantly higher adhesive interactions with the gastrointestinal tract of rats for all types of dextran associated nanoparticles compared with control nanoparticles. For nanoparticles associated with the aminated-dextran, the curves of bioadhesion were characterized by a maximum of adhesion just after administration followed by a rapid and constant decline with time. On the contrary, nanoparticles associated to conventional dextrans displayed a maximum bioadhesion between 1 and 3h post-administration. These results encourage us for further use of these systems for oral delivery of drugs.