A new tetrahydrated form of sodium naproxen.
The anhydrous sodium naproxen (ASN) can form several hydrated phases if maintained at different relative humidities (RH). The water uptake can promote crystallographic modifications, according to the amount of water. In a previous work, the authors showed that a dihydrated form could be obtained either by crystallization in water or by exposure of the anhydrous form to a RH of 55%. In the present work, the authors report about the formation and characterization of a new tetrahydrated form, obtained by exposing the ASN to RH >or= 75%. All the hydrated compounds were characterized by the combined use of several spectroscopic, thermal, and crystallographic techniques. The thermal stability of both the dihydrated and tetrahydrated compounds was also tested.
Di Martino
Piera
P
Dipartimento di Scienze Chimiche, Università di Camerino, Via S. Agostino, Camerino, Italy. piera.dimartino@unicam.it
Barthélémy
Christine
C
Joiris
Etienne
E
Capsoni
Doretta
D
Masic
Admir
A
Massarotti
Vincenzo
V
Gobetto
Roberto
R
Bini
Marcella
M
Martelli
Sante
S
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D018360:Crystallography, X-Ray; D003890:Desiccation; D004355:Drug Stability; D006813:Humidity; D009682:Magnetic Resonance Spectroscopy; D009288:Naproxen / Q000737:chemistry*; D011208:Powders; D012964:Sodium / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013816:Thermodynamics; D013818:Thermogravimetry; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D011208:Powders; D014867:Water; D009288:Naproxen; D012964:Sodium