Abstract: The technology of controlled release is widely used in the field of medicine. In this work, a Fickian diffusion model of controlled release for the polymer-drug microspheres was established firstly. The simulation results show that the diffusion rate of drug in polymer carrier was determined by the diffusion coefficient greatly. Moreover, the particle size distribution of microspheres had a significant influence on the release performance. Therefore, the average particle size can be adopted as the model parameters only if the narrow particle size distribution exists. In addition, plasma concentration-time curves have been obtained on the basis of the integration model of Fickian diffusion and in vivo pharmaco-kinetic. Compared to the solution dosage, the polymer-drug microspheres dosage provided a reduced plasma concentration peak, a slower release of drug. The polymer-drug microspheres dosage can significantly reduce the blood concentration fluctuations between dosage intervals as well.
Keywords: Controlled release; Polymer microsphere; Fickian diffusion; Pharmoco-kinetics; Modeling