Figure 16.

Cocrystal screening using the Kofler technique under a hot-stage microscope. Images (a–c) depict the growth of the cocrystal (brown curved zone in center) at the boundary of the glutaric acid. The dark area corresponds to the melting of the eutectic formed by the cocrystal and the API. In (d) a narrow dark area corresponds to the melting of the eutectic formed between the cocrystal and the glutaric acid. Image (e) depicts complete melting of the glutaric acid, making the boundary with the cocrystal clearly visible. Image (f), shows growth of the glutaric acid with formation of eutectic with the cocrystal, following cooling of the melt. (Reprinted from [58] with permission. Copyright 2006 Springer).