Dimethyl Fumarate Sterically Stabilized Solid Lipid Nanoparticles. Physicochemical properties and in vitro drug release

In this work Dimethyl Fumarate (DMF)-loaded and DMF-unloaded Solid Lipid Nanoparticles (SLNs) were developed and characterized by Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), and X-ray Diffraction (XRD). In vitro release assay was also performed, and DMF was quantified by GC-MS. SLNs were prepared by a two-step methodology using hot nanoemulsification followed by ultrasound irradiation. The results of the mean diameter, the polydispersity, and the zeta potential were in the range of 157 to 525 nm, 0.20 to 0.6, and -30 to -7mV, respectively. SLNs with spherical and elliptical shapes were evidenced by AFM and SEM techniques. XRD and DSC analyses revealed a strong interaction among the SLN components and a significant loss of crystallinity of the set of these components in the structured SLNs. Encapsulation efficiency up to 99% and loading capacity dependent on the O/S ratio has been achieved. The in vitro release of DMF was also dependent on the O/S ratio and could be analyzed by first-order kinetics.