Preparation and Cytotoxicity of Imiquimod-Loaded Solid Lipid Nanoparticles

Based on the experience with pure hard fats SLN, a new type of solid lipid nanoparticles (SLN) has been developed by mixturing monoglyceride with semisolid lipid. Imiquimod, as a water-insoluble drug model, was incorporated into SLN (IMQD-SLN). Particle size measured by photo correlation spectroscope (PCS) was found to be 133±6 nm with a polydispersity index 0.348±0.05. Differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) studies were performed to explore the state of lipid modification and drug. The cytotoxicity of SLN was researched by MTT method. DSC and PXRD analysis showed that imiquimod was dispersed in SLN in an amorphous state. No cytotoxicity which could suggest that IMQD-SLNs have no irritation to skin was found in MTT experiment. It could be concluded that the IMQD-SLN might be a promiseful transdermal delivery system for imiquimod.