PURPOSE: To understand the transformation pathways amongst anhydrate/hydrate solid forms of sodium naproxen and to highlight the importance of a polymorphic dihydrate within this context. METHODS: Multi-temperature dynamic vapour sorption (DVS) analysis combined with variable-humidity X-ray powder diffraction (XRPD) to establish the transformation pathways as a function of temperature and humidity. XRPD and thermogravimetric analysis (TGA) to characterise bulk samples. Monitoring of in-situ dehydration using solid-state (13)C CP/MAS spectroscopy. RESULTS: At 25 °C, anhydrous sodium naproxen (AH) transforms directly to one dihydrate polymorph (DH-II). At 50 °C, AH transforms stepwise to a monohydrate (MH) then to the other dihydrate polymorph (DH-I). DH-II transforms to a tetrahydrate (TH) more readily than DH-I transforms to TH. Both dihydrate polymorphs transform to the same MH. CONCLUSIONS: The properties of the polymorphic dihydrate control the transformation pathways of sodium naproxen.
PURPOSE: To understand the transformation pathways amongst anhydrate/hydrate solid forms of sodium naproxen and to highlight the importance of a polymorphic dihydrate within this context. METHODS: Multi-temperature dynamic vapour sorption (DVS) analysis combined with variable-humidity X-ray powder diffraction (XRPD) to establish the transformation pathways as a function of temperature and humidity. XRPD and thermogravimetric analysis (TGA) to characterise bulk samples. Monitoring of in-situ dehydration using solid-state (13)C CP/MAS spectroscopy. RESULTS: At 25 °C, anhydrous sodium naproxen (AH) transforms directly to one dihydrate polymorph (DH-II). At 50 °C, AH transforms stepwise to a monohydrate (MH) then to the other dihydrate polymorph (DH-I). DH-II transforms to a tetrahydrate (TH) more readily than DH-I transforms to TH. Both dihydrate polymorphs transform to the same MH. CONCLUSIONS: The properties of the polymorphic dihydrate control the transformation pathways of sodium naproxen.
Authors: Martin P Feth; Norbert Nagel; Bruno Baumgartner; Martin Bröckelmann; David Rigal; Bernhard Otto; Michael Spitzenberg; Markus Schulz; Bernd Becker; Franceska Fischer; Christine Petzoldt Journal: Eur J Pharm Sci Date: 2010-11-10 Impact factor: 4.384
Authors: Martin Philipp Feth; Jörg Jurascheck; Michael Spitzenberg; Jürgen Dillenz; Günter Bertele; Herbert Stark Journal: J Pharm Sci Date: 2010-08-25 Impact factor: 3.534
Authors: Doris E Braun; Lien H Koztecki; Jennifer A McMahon; Sarah L Price; Susan M Reutzel-Edens Journal: Mol Pharm Date: 2015-06-30 Impact factor: 4.939
Authors: Doris E Braun; Karol P Nartowski; Yaroslav Z Khimyak; Kenneth R Morris; Stephen R Byrn; Ulrich J Griesser Journal: Mol Pharm Date: 2016-01-25 Impact factor: 4.939