Effects of external phase on D-cycloserine loaded W/O nanocapsules prepared by the interfacial polymerization method

Water in oil (W/O) polybutylcyanoacrylate nanocapsules containing D-cycloserine (D-CS) for intranasaldelivery were prepared by the interfacial polymerization method. Different oils, as external phase, for thepreparation of the initial W/O miniemulsions were used and their effect on mean size and other physicochemicalproperties were evaluated by photon correlation spectroscopy (PCS) and scanning electronmicroscopy (SEM) analysis. Two probes at different hydrophilicity were used to verify the internalaqueous nature of the core. Both miniemulsions and nanocapsules mean size and polydispersity index wereinfluenced by the used external phase. Different entrapment efficiency were obtained forD-cycloserine-loaded nanocapsules correlated to the used oil [ranging from 39 to 51% encapsulationefficiency (E.E.)]. In vitro drug release showed an initial burst effect (ranging from 20 to 40%) followed by a slowrelease of D-CS for all preparations. This study demonstrated that many relevant physico-chemical andtechnological properties of polybutylcyanoacrylate nanocapsules prepared by interfacial polymerizationof miniemulsions are significantly influenced by the external oil phase used.