Exploring the Solid-Form Landscape of Pharmaceutical Hydrates: Transformation Pathways of the Sodium Naproxen Anhydrate-Hydrate System

Abstract

The properties of the polymorphic dihydrate control the transformation pathways of sodium naproxen.

Simultaneous UV Imaging and Raman Spectroscopy for the Measurement of Solvent-Mediated Phase Transformations During Dissolution Testing

“…). Various hydrate forms of sodium naproxen with complex structure (at least monohydrate, dihydrate, and tetrahydrate, as well polymorphic hydrate forms) have been reported in the literature . However, detailed assignment of the molar ratio of water of crystallization for these intermediate species detected was not possible from the Raman spectra.…”

“…Various hydrate forms of sodium naproxen with complex structure (at least monohydrate, dihydrate, and tetrahydrate, as well polymorphic hydrate forms) have been re- ported in the literature. [40][41][42][43] However, detailed assignment of the molar ratio of water of crystallization for these intermediate species detected was not possible from the Raman spectra. The estimated fractional amounts of the various solid forms presented in Figure 6b should be interpreted with caution because of the complexity of the multivariate data and the uncertainty in the MCR data analysis.…”

Structural basis for the transformation pathways of the sodium naproxen anhydrate–hydrate system

“…In this paper we consider the non-steroidal anti-inflammatory drug (NSAID) sodium (S)-naproxen (chemical structure shown in Scheme 1 with applied labelling scheme). The compound is known to exist as an anhydrate (AH), a monohydrate (MH), two dihydrate polymorphs (DH-I and DH-II) and a tetrahydrate (TH) (Di Martino et al, 2001Martino et al, , 2007Malaj et al, 2009;Raijada et al, 2013). A thorough empirical study of the thermodynamic and kinetic aspects of dehydration in the system has been reported by Malaj et al (2009).…”

“…Those authors refer to the various phases as ASN (= AH), MSN (= MH), CSN (= DH-I), DSN (= DH-II) and TSN (= TH). We have also previously studied the transformation pathways for the system using multitemperature dynamic vapour sorption (DVS) and variabletemperature/humidity powder X-ray diffraction (PXRD), and we have identified routes to isolate bulk samples of the various phases (Raijada et al, 2013).…”

Structures of cefradine dihydrate and cefaclor dihydrate from DFT-D calculations

“…Hydrates, and especially their dehydration properties, are important in the pharmaceutical industry (see, for example, Fujii et al, 2012;Kachrimanis & Griesser, 2012;Raijada et al, 2013). For crystalline hydrates, the dehydration properties are dependent to a large extent on the environment of the water molecules in the crystal structure.…”