The topological phase diagram of cimetidine: A case of overall monotropy.
Cimetidine is a histamine H2-receptor antagonist used against peptic ulcers. It is known to exhibit crystalline polymorphism. Forms A and D melt within 0.35 degrees from each other and the enthalpies of fusion are similar as well. The present paper demonstrates how to construct a pressure-temperature phase diagram with only calorimetric and volumetric data available. The phase diagram provides the stability domains and the phase equilibria for the phases A, D, the liquid and the vapor. Cimetidine is overall monotropic with form D the only stable solid phase.
Letiam, EA7357, IUT Orsay, université Paris-Sud, rue Noetzlin, 91405 Orsay cedex, France.
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Caracterisation des matériaux moléculaires à activité thérapeutique (CAMMAT), faculté de pharmacie, université Paris-Descartes, 4, avenue de l'observatoire, 75006 Paris, France. Electronic address: ivo.rietveld@parisdescartes.fr.
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D002151:Calorimetry; D002927:Cimetidine / Q000737:chemistry*; D003460:Crystallization; D004355:Drug Stability; D011312:Pressure; D013696:Temperature; D013816:Thermodynamics
D002927:Cimetidine
Cimetidine; Cimétidine; Crystalline polymorphism; Diagramme P-T topologique; Polymorphisme cristallin; Stabilité thermodynamique; Thermodynamic stability; Topological P-T diagram