Introduction: Solid Lipid nanoparticles (SLN) are comprising of a solid lipid core with a mean diameter between 50 and 1000 nm. SLN is an advanced carrier system to traditional colloidal carriers such as emulsion, liposomes, and polymeric microparticles. Objective: The objective of this study was to formulate SLN of Itraconazole (ITZ) for intranasal administration. Methods: ITZ-loaded SLN were prepared by high pressure homogenization technique using the Central Composite Design (CCD). The concentration of surfactant (X1) and drug to lipid ratio (X2) was considered as independent variables, whereas particle size (Y1) and percentage entrapment efficiency (Y2) were considered as a response. The compatibility of ingredients with the drug was tested using differential scanning calorimetry. SLN were characterized for their particle size, entrapment efficiency, transmission electron microscopy, in vitro drug release, and ex vivo study. Results: The solid lipid nanoparticles were successfully prepared using high pressure homogenization technique and glyceryl monostearate was used as solid lipid. The lipid ratio significantly increases the particle size as well as entrapment efficiency. The particle size and (%) entrapment efficiency of optimized formulation were found to be 29 nm and 78.9%, respectively. The differential scanning calorimetry confirmed that the drug existed in amorphous form. Nasal histopathology study on sheep mucosa revealed that the developed SLN was non-toxic and safe to use for intranasal administration. The results of ex vivo study showed that the Higuchi pattern of drug release was followed. The in vitro release studies showed the significant difference in drug release from ITZ-loaded SLN compared to plain ITZ-solution. Conclusion: ITZ-loaded SLN were successfully prepared and validated. The best batch was selected based on the desired particle size, and EE which is an important characteristic for SLN formulations. The developed formulations were nontoxic as determined by histo-pathological studies.
