A new polymorph of ammonium succinate – serendipity in action

Abstract

Succinic acid has been known since 1546 and was first chemically identified in the mid‐19th century. In an attempt to prepare a molecular salt of succinic acid with (S)‐(−)‐α‐methylbenzylamine, we have obtained the second polymorph of the monoammonium salt of succinic acid, NH4+·C4H5O4−. The crystal structure determination proves the structure of the ionic compound and the intimate role of the ammonium ion in the structure, which is compared to the earlier described polymorph.

Pushing Technique Boundaries to Probe Conformational Polymorphism

“…This is, in part, due to a strong emphasis placed on thorough screening of the solid-state landscape during the drug development process in the pharmaceutical industry . The often-quoted view of McCrone is logical, valid, and widely accepted in the community; however, a broad range of crystallization strategies are often also required, especially regarding the observation of metastable polymorphs. ,− Another key reason for an API to display polymorphism is the high degree of flexibility often demonstrated by the constituent molecule(s). , As APIs become more complex, they exhibit greater conformational flexibility, which gives rise to the possibility of conformational polymorphism (different conformations of the molecules between forms). Computational crystal structure prediction (CSP) studies have proven to be a powerful complementary tool to help guide and validate experimental solid-form screening.…”