# Assessment of the Technological Properties of Idebenone and
## 2 Materials and Methods
### Differential Scanning Calorimetry Analyses  
Calorimetric analyses were performed by a Mettler Toledo STARe system (Switzerland) equipped with a DSC-822\({}^{\mathrm{e}}\) calorimetric cell; a Mettler TA-STAR\({}^{\mathrm{e}}\) software was used. The  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Code** & **Oleth-20** & **GO** & **CP** & **TA** & **IDE** \\ \hline SLN & 8.7 & 4.4 & 7.0 & - & - \\ VIT 1 & 8.7 & 4.4 & 6.0 & 1.0 & - \\ VIT 2 & 8.7 & 4.4 & 5.0 & 2.0 & - \\ VIT 3 & 8.7 & 4.4 & 4.0 & 3.0 & - \\ VIT 3,5 & 8.7 & 4.4 & 3.5 & 3.5 & - \\ VIT 4 & 8.7 & 4.4 & 3.0 & 4.0 & - \\ SLN IDE1 & 8.7 & 4.4 & 7.0 & - & 1.0 \\ VIT 1 IDE1 & 8.7 & 4.4 & 6.0 & 1.0 & 1.0 \\ VIT 1 IDE1,5 & 8.7 & 4.4 & 6.0 & 1.0 & 1.5 \\ VIT 1 IDE2 & 8.7 & 4.4 & 6.0 & 1.0 & 2.0 \\ VIT 2 IDE1 & 8.7 & 4.4 & 5.0 & 2.0 & 1.0 \\ VIT 2 IDE 1,5 & 8.7 & 4.4 & 5.0 & 2.0 & 1.5 \\ VIT 2 IDE2 & 8.7 & 4.4 & 5.0 & 2.0 & 2.0 \\ VIT 3 IDE1 & 8.7 & 4.4 & 4.0 & 3.0 & 1.0 \\ VIT 3 IDE1,5 & 8.7 & 4.4 & 4.0 & 3.0 & 1.5 \\ VIT 3 IDE2 & 8.7 & 4.4 & 4.0 & 3.0 & 2.0 \\ VIT 3 IDE2,5 & 8.7 & 4.4 & 4.0 & 3.0 & 2.5 \\ VIT 3 IDE3 & 8.7 & 4.4 & 4.0 & 3.0 & 3.0 \\ VIT 3 IDE3,5 & 8.7 & 4.4 & 4.0 & 3.0 & 3.5 \\ VIT 3,5 IDE1 & 8.7 & 4.4 & 3.5 & 3.5 & 1.0 \\ VIT 3,5 IDE1,5 & 8.7 & 4.4 & 3.5 & 3.5 & 1.5 \\ VIT 3,5 IDE2,5 & 8.7 & 4.4 & 3.5 & 3.5 & 2.0 \\ VIT 3,5 IDE3,5 & 8.7 & 4.4 & 3.5 & 3.5 & 2.5 \\ VIT 3,5 IDE4 & 8.7 & 4.4 & 3.5 & 3.5 & 3.0 \\ VIT 4 IDE1 & 8.7 & 4.4 & 3.0 & 4.0 & 1.0 \\ VIT 4 IDE1,5 & 8.7 & 4.4 & 3.0 & 4.0 & 1.5 \\ VIT 4 IDE2 & 8.7 & 4.4 & 3.0 & 4.0 & 2.0 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Composition (% \(w/w\)) of lipid nanoparticles containing different percentages of tocophenyl acetate and idebenone. GO = glyceryl oleate; CP = cetyl palmitate; TA = tocophenyl acetate, IDE = idebenone.  
sensitivity was automatically chosen as the maximum possible by the calorimetric system. The reference pan was filled with the same vehicle of the samples under study. The calorimetric system was calibrated, in temperature and enthalpy changes, following the procedure of the DSC 822 Mettler TA STARe instrument, by using indium, stearic acid, and cyclohexane as standards. In total, 100 uL of sample was put into the calorimetric pan, hermetically sealed and submitted to analysis as follows: (i) a heating scan from 5 to 65 \({}^{\circ}\)C (2 \({}^{\circ}\)C/min); (ii) a cooling scan from 65 to 5 \({}^{\circ}\)C (4 \({}^{\circ}\)C/min) at least three times. Each analysis was carried out in triplicate. The melting enthalpy (\(\Delta\)H) was obtained by integration of the area under the transition peak. The recrystallization index (RI), expressed as a percentage, was calculated from the following equation [21]:  
\[\text{RI}(\%)=[\Delta\text{H}_{\text{aq. lipid np disp.}}/(\Delta\text{H}_{ \text{bulk material}}\times\text{conc sol. lip. phase})]\times 100\]  
where \(\Delta\text{H}_{\text{aq. lipid np disp.}}\) is \(\Delta\)H of the aqueous lipid nanoparticle dispersion, \(\Delta\text{H}_{\text{bulk material}}\) is calculated as cetyl palmitate enthalpy variation and \(\text{conc sol. lip. phase}\) is the concentration of the solid lipid phase.