Effect of Oil Content on Physiochemical Characteristics of γ-Oryzanol-Loaded Nanostructured Lipid Carriers.

Nanostructured lipid carriers (NLCs) are used as alternative carriers for many different drug delivery administration routes. They are composed of both solid lipid and liquid lipid (oil content) with both influencing their structural properties. Amounts of liquid lipid in NLCs play a role in drug release. Effect of liquid lipid (oil content) on physiochemical characteristics of NLCs related to drug-release requires detailed investigation. Here, many techniques were performed to analyze the physiochemical characteristics of NLCs, especially inside the particles. γ-Oryzanol (GO)-loaded NLCs were prepared at varying solid lipid to liquid lipid ratios. Their physicochemical properties, drug release profiles, and stability studies of prepared NLCs were investigated. Oil contents in NLCs were found to play a significant role in physiochemical characteristics related to drug release and stability, and also influence the efficiency of analytical techniques such as transmission electron microscopy (TEM) and dynamic force microscopy (DFM). Moreover, x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) gave information regarding crystallinity inside the NLCs. FTIR showed broad peaks in the range from 1184 cm-1 to 1475 cm-1 while XRD presented a broad curve indicated amorphous forms in NLCs. Orthorhombic lattices (β' polymorph) were also elucidated by XRD and differential scanning calorimetry (DSC).