“…Moreover, the DSC evaluation of phase changes in the recovered solids after their dissolution study also seems questionable. In any case, for other purposes,29 we also measured the RA polymorphs' solubility in aqueous solution (phosphate buffered saline) assaying RA in the lyophilized product obtained from the filtered saturated solutions. Under these conditions, the solubility of form II (±95% CI) was 0.1 ± 0.02 µM and that of the form I was 0.07 ± 0.02 µM, thus indicating the same energetic relationship found using the dissolving mediums reported in Table 3, with form I more stable than form II.…”