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Thermodynamic stability considerations for isostructural dehydrates.
J Pharm Sci. 2012 Apr; 101(4):1486-95.JP

Abstract

Nonstoichiometric channel hydrates are a class of crystalline hydrates that can incorporate a range of water levels as a function of temperature and relative humidity (RH). When a nonstoichiometric channel hydrate can dehydrate to yield a physically stable isostructural crystalline lattice, it may become challenging to accurately evaluate the thermodynamic stability relationship associated with a polymorphic system using traditional methods. This work demonstrates application of a eutectic-melting method to determine the stability relationship between a nonstoichiometric channel dehydrate and an anhydrous form. A transition temperature (122°C) between the isostructural dehydrate of the nonstoichiometric channel hydrate and the anhydrous polymorph was identified, with the nonstoichiometric channel hydrate being the thermodynamically stable anhydrous form at room temperature (RT). Solid-state storage at a range of RH conditions demonstrated that the nonstoichiometric channel hydrate is also the stable form at RT above an RH of 94%. These results demonstrate that the nonstoichiometric channel hydrate is the stable form at low temperatures, independent of its hydration state. It has been demonstrated that the eutectic-melting method is applicable to the study of thermodynamic stability relationships between anhydrous forms and dehydrated channel hydrates.

Links

Publisher Full Text
linkinghub.elsevier.com
onlinelibrary.wiley.com

Authors+Show Affiliations

Murphy BJ
Materials Science, Pfizer Inc., Eastern Point Road, Groton, Connecticut 06340, USA. brendan.j.murphy@pfizer.com
Casteel MJ
No affiliation info available
Samas B
No affiliation info available
Krzyzaniak JF
No affiliation info available

MeSH

Calorimetry, Differential ScanningCrystallizationDrug StabilityHumidityMagnetic Resonance SpectroscopyThermodynamicsWaterX-Ray Diffraction

Pub Type(s)

Journal Article

Language

eng

PubMed ID

22262468

Citation

Murphy, Brendan J., et al. "Thermodynamic Stability Considerations for Isostructural Dehydrates." Journal of Pharmaceutical Sciences, vol. 101, no. 4, 2012, pp. 1486-95.
Murphy BJ, Casteel MJ, Samas B, et al. Thermodynamic stability considerations for isostructural dehydrates. J Pharm Sci. 2012;101(4):1486-95.
Murphy, B. J., Casteel, M. J., Samas, B., & Krzyzaniak, J. F. (2012). Thermodynamic stability considerations for isostructural dehydrates. Journal of Pharmaceutical Sciences, 101(4), 1486-95. https://doi.org/10.1002/jps.23037
Murphy BJ, et al. Thermodynamic Stability Considerations for Isostructural Dehydrates. J Pharm Sci. 2012;101(4):1486-95. PubMed PMID: 22262468.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Thermodynamic stability considerations for isostructural dehydrates. AU - Murphy,Brendan J, AU - Casteel,Melissa J, AU - Samas,Brian, AU - Krzyzaniak,Joseph F, Y1 - 2012/01/19/ PY - 2011/08/10/received PY - 2011/12/13/accepted PY - 2011/12/06/revised PY - 2012/1/21/entrez PY - 2012/1/21/pubmed PY - 2012/6/30/medline SP - 1486 EP - 95 JF - Journal of pharmaceutical sciences JO - J Pharm Sci VL - 101 IS - 4 N2 - Nonstoichiometric channel hydrates are a class of crystalline hydrates that can incorporate a range of water levels as a function of temperature and relative humidity (RH). When a nonstoichiometric channel hydrate can dehydrate to yield a physically stable isostructural crystalline lattice, it may become challenging to accurately evaluate the thermodynamic stability relationship associated with a polymorphic system using traditional methods. This work demonstrates application of a eutectic-melting method to determine the stability relationship between a nonstoichiometric channel dehydrate and an anhydrous form. A transition temperature (122°C) between the isostructural dehydrate of the nonstoichiometric channel hydrate and the anhydrous polymorph was identified, with the nonstoichiometric channel hydrate being the thermodynamically stable anhydrous form at room temperature (RT). Solid-state storage at a range of RH conditions demonstrated that the nonstoichiometric channel hydrate is also the stable form at RT above an RH of 94%. These results demonstrate that the nonstoichiometric channel hydrate is the stable form at low temperatures, independent of its hydration state. It has been demonstrated that the eutectic-melting method is applicable to the study of thermodynamic stability relationships between anhydrous forms and dehydrated channel hydrates. SN - 1520-6017 UR - https://www.unboundmedicine.com/medline/citation/22262468/Thermodynamic_stability_considerations_for_isostructural_dehydrates_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0022-3549(15)31643-9 DB - PRIME DP - Unbound Medicine ER -