Rapid conversion of API hydrates to anhydrous forms in aqueous media

Precipitation in and Supersaturation of Contents of the Upper Small Intestine After Administration of Two Weak Bases to Fasted Adults

“…Hydrates are known to have lower solubities than anhydrous forms (e.g. 22), and the crystalline state of most KCZ precipitates after their incubation at 37°C for 48 h was that shown in Fig. 3c and not that of the reference material ( Fig.…”

Solid-State Forms of Zoledronic Acid: Polymorphism in Hydrates

“…Consequently, if several hydration degrees could be obtained, the possibility to obtain several anhydrous forms is also open. Several studies have shown that phase transformations and mixture of solid‐state forms can occur during wet granulation15–18 or wet manipulation (hydrates formation) but this process can revert when the compounds are dried, resulting in either a different form from the original API material19, 20 or the formation of amorphous material after dehydration 21, 22…”

A crystallographic and thermal study of pridinol mesylate and its monohydrated solvate

“…Subsequently, when the compound is formulated, in particular during wet granulation, knowledge about potential hydrates (or solvates in general) is especially useful. In the case of hydrates, several studies have shown that phase transformations and mixtures of solid-state forms can occur during wet processes (Wikströ m et al, 2005;Williams et al, 2004;Gift et al, 2009;Petrova et al, 2009). Moreover, in some attempts to reverse hydrate formation, the drying process can lead either to a form different to the original API (Phadnis & Suryanarayanan, 1997;Dugué et al, 1991) or even to the formation of a different material, after dehydration (Saleki-Herhardt et al, 1995;Li et al, 2000).…”