Acrylated chitosan for mucoadhesive drug delivery systems.

A new mucoadhesive polymer was synthesized by conjugating chitosan to poly(ethylene glycol)diacrylate (PEGDA) via the Michael type reaction. The product was characterized using NMR. Higher PEGDA grafting efficacy was observed with low molecular weight PEGDA (0.7kDa), compared to long 10kDa PEGDA. The acrylation percentage was calculated based on the reaction of ninhydrin with chitosan, and supported the qualitative NMR findings. The adhesive properties were studied by tensile test and rotating system involving detachment of polymer tablets from a fresh intestine sample. Chitosan modified with high molecular weight PEGDA presented improvement in mucoadhesive properties compared to both non-modified and thiolated chitosan. On the molecular level, rheology measurements of polymer/mucin mixtures provided additional evidence of strong interaction between modified chitosan and mucin glycoproteins. This new polymer shows promise as a useful polymeric carrier matrix for delivery systems, which could provide prolonged residence time of the vehicle on the mucosa surface.