Drug Release Modeling Through a 3-Stage Model on Hydrophobic Modified Carboxymethyl Chitosan Nanoparticles

In this paper, the mechanism of releasing a small molecule (curcumin) from chitosan nanoparticles was investigated by a three-stage model with constant D. This model takes into account simultaneously initial burst, nanoparticle degradation–relaxation and diffusion with constant diffusion coefficient. Modified chitosan with hydrophobic functional groups is able to make self-assembled nanoparticles in aqueous media which in this study FA modified degraded carboxymethyl chitosan has been synthesized using folic acid, N hydroxy succinimide (NHS), N, N, dicyclohexylcarbodiimide (DCC) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide EDC). The morphology of nanoparticles was observed by scanning electron microscopy which had spherical shape with an average size less than 200 nm. In vitro drug release studies were performed at 37 °C using dissolution medium phosphate buffered saline (pH 7/4). The release profiles exhibited three well defined phases, which were modeled as well by three-phase model with best coefficient of determination (R² = 0.9649).