C. Guguta, E. V. Eck, R. Gelder
Jul 15, 2009
Citations
1
Influential Citations
7
Citations
Journal
Crystal Growth & Design
Abstract
For the chemically and structurally related antagonists naltrexone and naloxone, hydrate and anhydrate forms exist for the hydrochloride salts, the generic forms that are on the market. The hydration/dehydration behavior of these salts was studied by applying hot-humidity stage X-ray powder diffraction, microscopy, differential scanning calorimetry, thermogravimetric analysis, and solid-state NMR. The combination of these techniques shows consistent results and yields a detailed conversion scheme. A new crystal structure, determined from X-ray powder diffraction data, for naltrexone hydrochloride anhydrate is presented. The structure was solved by the DASH program and was refined with TOPAS. This new structure, together with the already known structures of naltrexone and naloxone hydrochloride, enabled us to investigate the influence of the subtle molecular differences between the two antagonists and the role of water on structural properties in the solid state. All known hydrate and anhydrate forms of na...