# Assessment of the Technological Properties of Idebenone and
## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **Size \(\pm\) S.D.** & **PDI \(\pm\) S.D.** & **Zeta \(\pm\) S.D.** & **PIT (\(\mathbf{\lx@overaccentset{{\text{\text{\text{\text{\text{\text{\text{\text{ \text{\text{\text{\text{\text{\text{\text{\text{\text{ \text{    }}}}}}}}}}}}}\)C)** \\ **(nm)** & **PDI \(\pm\) S.D.** & **(mV)** & **(\(\mathbf{\lx@overaccentset{{\text{\text{\text{\text{\text{\text{ \text{\text{{\text{\text{\text{\text{\text{\text{\text{ \text{   { }}}}}}}}}}}}}}}\)C)** \\ \hline SLN & 35.5 \(\pm\) 0.9 & 0.22 \(\pm\) 0.01 & \(-\)7.52 & 78 \\ VIT 1 & 28.8 \(\pm\) 0.9 & 0.23 \(\pm\) 0.03 & \(-\)6.89 & 85 \\ VIT 2 & 28.0 \(\pm\) 0.6 & 0.23 \(\pm\) 0.05 & \(-\)7.34 & 78 \\ VIT 3 & 26.0 \(\pm\) 0.5 & 0.18 \(\pm\) 0.01 & \(-\)8.14 & 82 \\ VIT 3.5 & 26.8 \(\pm\) 0.8 & 0.22 \(\pm\) 0.01 & \(-\)7.66 & 85 \\ VIT 4 & 38.6 \(\pm\) 0.4 & 0.55 \(\pm\) 0.02 & \(-\)8.39 & 72 \\ SLN IDE1 & 36.4 \(\pm\) 0.3 & 0.26 \(\pm\) 0.01 & \(-\)8.43 & 78 \\ VIT 1 IDE1 & 26.8 \(\pm\) 1.3 & 0.18 \(\pm\) 0.04 & \(-\)7.91 & 78 \\ VIT 1 IDE1,5 & 24.1 \(\pm\) 0.3 & 0.16 \(\pm\) 0.04 & \(-\)6.54 & 65 \\ VIT 1 IDE2 & N.D. a & N.D. a & N.D. a & 62 \\ VIT 2 IDE1 & 25.3 \(\pm\) 0.6 & 0.17 \(\pm\) 0.03 & \(-\)7.01 & 75 \\ VIT 2 IDE 1,5 & 23.2 \(\pm\) 0.1 & 0.11 \(\pm\) 0.01 & \(-\)7.55 & 68 \\ VIT 2 IDE2 & N.D. a & N.D. a & N.D. a & 63 \\ VIT 3 IDE1 & 25.3 \(\pm\) 0.8 & 0.16 \(\pm\) 0.02 & \(-\)8.69 & 75 \\ VIT 3 IDE1,5 & 23.3 \(\pm\) 0.2 & 0.15 \(\pm\) 0.01 & \(-\)7.31 & 69 \\ VIT 3 IDE2 & 23.6 \(\pm\) 0.5 & 0.19 \(\pm\) 0.08 & \(-\)8.33 & 67 \\ VIT 3 IDE2,5 & 24.5 \(\pm\) 0.3 & 0.24 \(\pm\) 0.01 & \(-\)7.49 & 62 \\ VIT 3 IDE3 & 27.8 \(\pm\) 0.5 & 0.20 \(\pm\) 0.01 & \(-\)7.78 & 60 \\ VIT 3 IDE3,5 & N.D. a & N.D. a & N.D. a & 57 \\ VIT 3,5 IDE1 & 25.3 \(\pm\) 0.2 & 0.17 \(\pm\) 0.01 & \(-\)6.98 & 70 \\ VIT 3,5 IDE1,5 & 22.1 \(\pm\) 0.1 & 0.16 \(\pm\) 0.04 & \(-\)6.71 & 66 \\ VIT 3,5 IDE2 & 25.5 \(\pm\) 0.4 & 0.18 \(\pm\) 0.06 & \(-\)7.86 & 64 \\ VIT 3,5 IDE2,5 & 25.4 \(\pm\) 0.3 & 0.19 \(\pm\) 0.03 & \(-\)8.76 & 63 \\ VIT 3,5 IDE3 & 28.8 \(\pm\) 0.2 & 0.18 \(\pm\) 0.01 & \(-\)8.43 & 62 \\ VIT 3,5 IDE3,5 & 32.4 \(\pm\) 0.4 & 0.16 \(\pm\) 0.01 & \(-\)7.53 & 60 \\ VIT 3,5 IDE4 & 36.7 \(\pm\) 0.5 & 0.15 \(\pm\) 0.01 & \(-\)6.99 & 59 \\ VIT 4 IDE1 & 25.7 \(\pm\) 1.5 & 0.13 \(\pm\) 0.03 & \(-\)8.43 & 70 \\ VIT 4 IDE1,5 & 22.2 \(\pm\) 0.2 & 0.12 \(\pm\) 0.01 & \(-\)7.42 & 64 \\ VIT 4 IDE2 & N.D. a & N.D. a & N.D. a & 58 \\ \hline \hline \end{tabular} \({}^{\text{a}}\)N.D. = not determined, as a slight precipitate was observed after 24 h.  
\end{table} 
Table 2: Mean size, polydispersity index (PDI), \(\zeta\)-potential (Zeta) and phase inversion temperature (PIT) of unloaded and IDE-loaded lipid nanoparticles. Figure 1: Mean sizes of unloaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) during storage at room temperature for 12 months. phase of the colloidal dispersion. Therefore, in clear colloidal dispersion, the incorporation rate of a lipophilic drug is for all practical purposes 100%. In a previous work [20], we determined that IDE water solubility was 5 ug/mL. Therefore, when we obtained clear lipid nanoparticles dispersions, we considered that all added drug was entrapped into the nanoparticle lipid core. IDE loading capacity was 1% \(w/w\) for SLN, and it increased by introducing TA up to 3.5% \(w/w\) into the nanoparticle lipid core (IDE loading capacity: 1.5% \(w/w\) for VIT 1 and VIT 2; 3% \(w/w\) for VIT 3; 4% \(w/w\) for VIT 3,5). Unexpectedly, although formulation VIT 4 contained the highest percentage of TA, its loading capacity was similar to that of VIT 1 and VIT 2, thus suggesting the existence of an optimal percentage of liquid lipid to obtain the maximum drug loading. IDE-loaded lipid nanoparticles showed mean sizes in the range 22-37 nm, narrow dimensional distributions (PDI < 0.300), and slightly negative zeta potentials.