*2.3. NLC Characterization*

The mean particle size (Z-average diameter) and the polydispersity index (PDI) were measured by dynamic light scattering (DLS), and the zeta potential was determined through laser Doppler micro-electrophoresis (Malvern® Zetasizer Nano ZS, Model Zen 3600; Malvern Instruments Ltd., Malvern, UK). Three independent measurements were performed for each formulation. The data are represented as the mean ± SD. Nanoparticle surface characteristics and morphology were examined by transmission electron microscopy (JEOL JEM 1400 Plus, Izasa Scientific, Madrid, Spain). The thermal behavior of the nanoparticles and the excipients and components themselves were studied using differential scanning calorimetry (DSC) (DSC-50, Shimadzu, Kioto, Japan). Each sample was sealed in an aluminum pan and heated from 25 ◦C to 350 ◦C at a heating rate of 10 ◦C per minute. The sample size was 1–2 mg for each measurement. Finally, Fourier transform infrared (FTIR) spectra of Mygliol-NLC and DHAH-NLC with and without CS and TAT coating were carried out on a Nicolet Nexus FTIR spectrometer using ATR Golden Gate (Thermo Scientific, Madrid, Spain) with a crystal ZnSe. The sample was placed directly onto the ATR crystal and the spectrum was obtained in transmittance mode. Each spectrum was the result of an average of 32 scans at 4 cm−<sup>1</sup> resolution. Measurements were recorded in the wavelength range of 4000–750 cm−<sup>1</sup> .
