Crystallographic Analysis of Phase Dissociation Related to Anomalous Solubility of Irsogladine Maleate

Abstract

We report the anomalous solubility of the pharmaceutical salt irsogladine maleate, which is associated with phase dissociation. The anomalous solubility was demonstrated by the similarity of solubility and miscibility between the salt and its base in ethanol solvent. The phase dissociation was revealed and confirmed by distinguishing irsogladine maleate and its free base using single-crystal X-ray analysis. Herein, the crystal structures of irsogladine maleate and its base were reported for the first time, and the plausible mechanism for phase dissociation was established based on the structural correlations between those phases.

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