**Aqueous Solubility of the Eutectics**

To measure the solubility, each experiment was performed in a jacketed, circulating flask maintained at 25 ◦C and in two sets to ensure consistency. Interestingly, the eutectics show significantly improved solubility over the parent drug AMG with a solubility of 1.9 ± 0.01 mg/mL at 25 ◦C (See Figure 9). The AMG-CAF, AMG-NIC and AMG-ZMD eutectics exhibit nearly 2.5-fold, 1.5 fold and 1.3 times higher solubility than AMG.

**Figure 9.** Comparison of solubilities of AMG and its eutectic mixtures in water at 25 ◦C.

Different thermodynamic parameters like melting temperature depression and the heat of fusion (ΔHf) can affect the overall solubility [27,28]. Considerable decrease in the ΔHf (see Table 1) is observed for the AMG-CAF system and expectedly it is showing higher solubility than the AMG. However, higher ΔHf has been observed for the eutectics AMG-ZMD and AMG-NIC, and as a result, the solubility difference is not significant. Particularly, despite having higher soluble coformer NIC, the eutectic AMG-NIC exhibited less solubility compared to AMG-CAF. The experimental solubility results are supported by the ideal solubility data for the eutectic mixtures calculated by using the van't Hoff equation (Figure S2, Supporting Information), showing similar trends for the solubilities. Moreover, the precipitates obtained from the solubility experiment were further evaluated by PXRD measurements, which are presented in Figure S3 (Supporting Information). The PXRD patterns observed from the eutectics before and after solubility evaluations contain

the characteristic peaks for the starting materials and, in addition are similar. Thus, they confirmed no new phase or cocrystal formation during solubility experiments.
