Preparation And Study Of Etoposide-loaded Chitosan Microspheres For The Nasal Administration

Objects: Etoposide was selected as the model drug for the study of microspheres for nasal adminisration. Drug delivery by the nasal route has recently received lots of attention. It has lots of advantages, such as rapid absorption, avoidance of first-pass elimination and so on. At present, the most important thing to deal with it is how to prolong the nasal residence time of drug. In our study, Etoposide was made into chitosan microspheres to increse the residence time in the nasal cavity and improve its absorption.Methods: On the basis of scientific literatures and pretesting, chitosan microspheres were prepared using emulsion crosslinking technique. We analyzed the formula factors and the process factors that had more influence to the evaluation indexes of microspheres. Then orthogonal design was used to select the optimal formula. In the course of that, the average diameter, the diameter distribution, the drug loading and the entrapment efficiency of microspheres were selected as evaluation indexes. Using the scanning electron photomicrographs the surface and interior of microspheres were observed. In the investigation of release behavior, the instrument and phosphate buffer were selected. We also investigated the release behavior in different...