Study of the Release Kinetic and the Diffusion Coefficient of Doxorubicin-Chrysin Coated with Fe₃O₄ and Polycaprolactone-Polyethylene glycol Copolymers

Recent advances in the development of magnetic nanoparticles modified with biodegradable polymers have shown promise in the improvement of therapeutic approaches for the clinical management of cancer patients. In this study, polycaprolactone-polyethylene glycol polycaprolactone (PCL-PEG-PCL) copolymers modified with magnetic nanoparticles were used for encapsulation of doxorubicin (DOX) and chrysin (Chr) anticancer drugs by dual emulsion (W / O / W). The effect of temperature and pH on drug release was investigated. The release of the doxorubicin drug in pH 7.4 and 5.8 were 26.5% and 30.6%, respectively after 144 h. In chrysin drug, the release of drug in pH 7.4 and 5.8 was equal to 45% and 49%, respectively after 144 h. The kinetics of the drug's release was also studied based on zero-order, first-order, Higuchi, and Korsmeyer-Peppas models. From the kinetic models, based on the correlation coefficient, Higuchi (R-2=0.9017) and Korsmeyer-Peppas (R-2=0.9639) models were found to be the best models for doxorubicin and chrysin, respectively. After performing kinetic studies, the diffusion coefficient of drug release was also studied. The drug distribution was considered uniform, and the system was investigated in Cartesian and spherical coordinates. The results showed that the diffusion coefficient of drug release followed Fick's law. The diffusion coefficient decreased with increasing time due to decreasing the concentration difference.