Comparative Development and Characterization of ItraconazoleLoaded Solid Lipid Nanoparticles Incorporating Myristic Acid and Pluronic F127 for Oral Delivery

Abstract

This study developed itraconazole-loaded solid lipid nanoparticles (SLNs) to enhance the solubility of this poorly water-soluble antifungal drug and evaluate key physicochemical properties. SLNs were prepared using the microemulsion technique with solid lipids stearic acid, palmitic acid, and myristic acid, and surfactants Tween 80 and Pluronic F127. The synthesized SLNs were characterized using dynamic light scattering (DLS) and electrophoretic light scattering (ELS) for size and zeta potential determination, while transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were employed to examine surface morphology. Furthermore, the structural and thermal properties of the formulation were analyzed via Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC). Among the formulations, SLN3 (containing stearic acid–Pluronic F127) and SLN9 (containing myristic acid–Tween 80) exhibited the smallest particle sizes and lowest polydispersity indices. Encapsulation efficiency was 97.04 ± 0.004 % for SLN3 and 42.69 ± 0.02 % for SLN9, with drug loading capacities of 3 ± 0.1 % and 1.8 ± 0.17 %, and yields of 50.03 ± 3.55 % and 57.9 ± 6.6 %, respectively. Solubility of ITZ increased to 2900 µg/mL (SLN3) and 3369 µg/mL (SLN9). In vitro release studies demonstrated controlled and sustained drug release, with SLNs exhibiting formulation- and pH-dependent behavior; SLN3 provided more prolonged release under acidic conditions, whereas SLN9 showed relatively higher release at intestinal pH, reflecting differences in lipid chain length and surfactant type. These results indicate that the optimized SLNs improve ITZ solubility and exhibit favorable physicochemical characteristics, supporting their potential as oral delivery systems for poorly soluble antifungal agents.