(136i) Rheological Behavior and Drug-Controlled Release Property of Chitosan/rectorite Nanocomposites

The rheological behaviour of chitosan/rectorite (CS/REC) nanocomposites was evaluated; the nanocomposites showed the low shear-rate non-Newtonian viscosity and rapid shear-thinning behaviour, zero shear rate viscosity and the storage and loss moduli for the nanocomposites displayed a monotonic increase with increasing REC content in comparison with pure CS. The results implied the interaction between CS and REC took place, the fact corroborated by the SEM images and FTIR analysis; the CS/REC nanocomposite beads prepared from the crosslink interaction of sodium tripolyphosphate (TPP) have compacter surface and internal structure than CS beads. The swelling degree of the nanocomposites in 0.9% (w/v) saline was only about 15% compared to CS beads of 30% swelling degree. The nanocomposite beads can release the drug continuously, in the given 6 days the minimum cumulative release only reached 51.9%, much lower than pure CS beads. CS/REC nanocomposites are considerably suitable to apply as mucoadhesive drug carriers.