Development and characterisation of nanostructured lipid carriers (NLCs) loaded with donepezil (DZP) and curcumin (CUR) for brain

Alzheimer's disease (AD) presents significant challenges due to limited treatment options targeting disease-modifying mechanisms. We developed and characterized nanostructured lipid carriers (NLCs) loaded with donepezil (DZP) and curcumin (CUR) for enhanced AD therapy. These carriers aim to improve drug delivery to the brain by surpassing the blood-brain barrier (BBB) and enhancing drug bioavailability. Differential scanning calorimetry (DSC) analysis confirmed the amorphous state of DZP and CUR loaded NLCs, enhancing drug solubility within the lipid matrix. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) affirmed the spherical and uniform morphology of the NLCs. In vitro release studies demonstrated sustained drug release profiles with biphasic patterns, indicating surface adsorption and matrix diffusion mechanisms. Higuchi's model best described the release kinetics, suggesting diffusion-controlled drug release from the lipid matrix. Ex vivo permeation studies on sheep nasal mucosa showed efficient drug permeation, indicating the potential of NLCs for nasal drug delivery. These findings suggest promising applications for NLC formulations in AD therapy, warranting further evaluation of their efficacy and safety in in vivo AD models.