2.5. Gravimetric Solubility Analysis Procedure

The solubility of PCM in the binary solvent mixtures (crystallization and wash solvents) was determined experimentally by equilibration and gravimetric analysis. A Hailea HC-100A chiller was used to maintain the temperature at 22 °C (the average temperature of the lab where the anti-solvent screening experiments were conducted). Excess PCM was added to 20 mL, clear glass vials together with the binary solvent mixture and a magnetic stirrer bar. The vials were sealed and left on a multi-position stirrer plate inside the water bath for around 48 h to equilibrate. Samples of the solutions were then taken from the slurry in the vials using a syringe, filtered using a PES syringe filter (Fisherbrand, cat no. 15206869, 0.2 μm, sterile), and added to a separate glass vial which was weighed and then left to dry. Table 1 shows all the ratios of binary solvent mixtures for which solubility was determined.