Dielectric monitoring method for the drug release mechanism of drug-loading chitosan microspheres

The chitosan microspheres loaded with model drug, salicylate molecular, are prepared, and the dielectric spectroscopy of this kind of suspension is measured, meanwhile a significant relaxation is observed for the microspheres suspension. By the modeling analytic of the relaxation, the parameters, which can reflect the properties of microspheres and continuous medium, are obtained. Furthermore, the releasing process of microspheres in aqueous phase is monitored real-timely, namely, by analyzing the time-dependent variation of the parameters reflecting the relaxation characteristics and electrical parameters in each phase the releasing process is detected. The research shows that the controlled release process of chitosan microspheres loaded with salicylate in aqueous phase is divided into three phases according to different releasing mechanisms. At the release stage, the quantitative relation between the phase parameters obtained by dielectric analysis and the amount of the salicylate carried in microspheres was derived, and a real-time monitoring method was established through releasing material in the microspheres at different times obtained by measuring and analyzing the dielectric spectroscopy.