Disodium norcantharidate-loaded poly(ɛ-caprolactone) microspheres: II. Modification of morphology and release behavior

Disodium norcantharidate (DSNC)-loaded poly(ɛ-caprolactone) (PCL) microspheres were prepared by s/o/w solvent evaporation technique, and their morphology and drug release behavior were modified by adding NaCl (3, 6 and 9%) in the continuous phase during the preparation. The addition of NaCl decreased the water influx into the emulsion droplets and the porosity of the resultant microspheres. Higher NaCl concentration resulted in smaller particle size, lower density and higher drug loading of the microspheres. Despite higher drug loading and smaller particle size, the microspheres prepared with NaCl in the continuous phase exhibited slower drug release. The modification of the release profiles was correlated with the changes in the surface and internal morphology of the microspheres. Therefore, by adding NaCl in the continuous phase during the preparation, both morphology and release behavior of the microspheres can be modified to a certain extent.