*3.6. Stability Studies*

Thermodynamic stability in an aqueous solution was evaluated by placing an excess of the sample in a vial and stirring in deionized water at 25 ◦C. After 24 h, the product was filtered, dried at room temperature, and characterized by PXRD. Powder patterns showed high stability for the pure DIC and DIC–ADE cocrystal. However, DIC–CYT and DIC–ICT phases could not remain stable for more than 3 h and 30 min, respectively (Figures 7 and S7). Multicomponent DIC phases were also stored at accelerating ageing conditions (40 ◦C, 75% RH). At the determined time, samples were characterized by PXRD to assess their stability. DIC was included in the experiment for better comparison with the new materials. Under these conditions, it was observed that all samples remained stable for two months (Figure 8).

**Figure 7.** PXRD diagrams corresponding to the stability of DIC–ADE, DIC–CYT, and DIC–ICT in aqueous slurry experiments at 24 h.

**Figure 8.** PXRD diagrams corresponding to the stability of DIC–ADE, DIC–CYT, and DIC–ICT in accelerated ageing conditions (40 ◦C, 75% RH) at two months.
