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  • Polymorphism of 2-Adamantanone

     Negrier, Philippe; Del Barrio Casado, Maria; Romanini, Michela; Tamarit Mur, Jose Luis; Mondieig, Denise; Krivchikov, Alexander I; Kepinski, L.; Jezowski, Andrzej; Szewczyk, Daria
    Crystal growth and design
    Vol. 14, num. 5, p. 2626-2632
    DOI: 10.1021/cg500313m
    Date of publication: 2014-05-07
    Journal article

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    The polymorphism of 2-adamantanone (C10H14O) has been investigated by means of X-ray diffraction and high-pressure thermal analysis. The intricate behavior of the low-temperature crystalline phases has been disentangled. The stable phase has been found to be orthorhombic (Cmc2 1, Z = 4), fully ordered, with lattice parameters a = 6.8884(18) Å, b = 10.830(3) Å, c = 10.658(3) Å, and V/Z = 198.8(1) Å3. The metastable phase was determined to be monoclinic (P21/c, Z = 4) with lattice parameters a = 6.5920(17) Å, b = 11.118(3) Å, c = 12.589(3) Å, ß= 118.869(11) o, and V/Z = 202.0(1) Å3. The pressure-temperature phase diagram irrefutably shows the stability relation between both phases and, accordingly, the long-time unknown polymorphic behavior is now revealed and gives coherent physical explanation of the literature published so far.

    The polymorphism of 2-adamantanone (C10H14O) has been investigated by means of X-ray diffraction and high-pressure thermal analysis. The intricate behavior of the low-temperature crystalline phases has been disentangled. The stable phase has been found to be orthorhombic (Cmc2 1, Z = 4), fully ordered, with lattice parameters a = 6.8884(18) Å, b = 10.830(3) Å, c = 10.658(3) Å, and V/Z = 198.8(1) Å3. The metastable phase was determined to be monoclinic (P21/c, Z = 4) with lattice parameters a = 6.5920(17) Å, b = 11.118(3) Å, c = 12.589(3) Å, ß= 118.869(11) o, and V/Z = 202.0(1) Å3. The pressure-temperature phase diagram irrefutably shows the stability relation between both phases and, accordingly, the long-time unknown polymorphic behavior is now revealed and gives coherent physical explanation of the literature published so far.

  • Barocaloric effect in metamagnetic shape memory alloys

     Mañosa Carrera, Lluis; Stern Taulats, Enric; Planes Vila, Antoni; Lloveras Muntane, Pol Marcel; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Emre, Baris; Yuce, Suheyla; Fabbrici, Simone; Albertini, Franca
    physical status solidi B
    p. 1-6
    DOI: 10.1002/pssb.201350371
    Date of publication: 2014-03-10
    Journal article

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  • On the polymorphism of l -citrulline: Crystal structure and characterization of the orthorhombic d form

     Allouchi, Hassan; Nicolai, Beatrice; Del Barrio Casado, Maria; Céolin, René; Mahé, Nathalie; Tamarit Mur, Jose Luis; Do, Bernard; Rietveld, Ivo B.
    Crystal growth and design
    Vol. 14, num. 3, p. 1279-1286
    DOI: 10.1021/cg401801u
    Date of publication: 2014-03-01
    Journal article

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    Solid-state properties of active pharmaceutical compounds are closely related to their dissolution behavior and bioavailability, and understanding their phase behavior leads to better control in the drug formulation process. L-Citrulline is an amino acid, which is known to exhibit polymorphism; however, only the structure of the alpha form is reported in the literature. The structure of the form has been elusive due to lack of good quality single crystals. It has been found to be orthorhombic P2(1)2(1)2(1) with the cell parameters a, b, and c respectively 14.895(5) angstrom, 9.852(2) angstrom, and 5.353(2) angstrom. The unit cell contains four molecules, and its volume is 785.5(4) angstrom(3). Both the alpha form and the delta form possess uniaxial negative thermal expansion along the direction of the charge exchange of the L-citrulline zwitterions. In mixtures containing solid and saturated aqueous, solution, the alpha form quickly transforms in a dihydrate, whereas the delta phase persists for over three weeks. Although the evidence is not conclusive, the delta phase is most likely the more stable form and most suitable for storage.

    Solid-state properties of active pharmaceutical compounds are closely related to their dissolution behavior and bioavailability, and understanding their phase behavior leads to better control in the drug formulation process. L-Citrulline is an amino acid, which is known to exhibit polymorphism; however, only the structure of the alpha form is reported in the literature. The structure of the form has been elusive due to lack of good quality single crystals. It has been found to be orthorhombic P2(1)2(1)2(1) with the cell parameters a, b, and c respectively 14.895(5) angstrom, 9.852(2) angstrom, and 5.353(2) angstrom. The unit cell contains four molecules, and its volume is 785.5(4) angstrom(3). Both the alpha form and the delta form possess uniaxial negative thermal expansion along the direction of the charge exchange of the L-citrulline zwitterions. In mixtures containing solid and saturated aqueous, solution, the alpha form quickly transforms in a dihydrate, whereas the delta phase persists for over three weeks. Although the evidence is not conclusive, the delta phase is most likely the more stable form and most suitable for storage.

  • Barocaloric and magnetocaloric effects in Fe49Rh51

     Stern Taulats, Enric; Planes Vila, Antoni; Lloveras Muntane, Pol Marcel; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Pramanick, Sabyasachi; Majumdar, Subham; Frontera Beccaria, Carlos; Mañosa Carrera, Lluis
    Physical review. B, solid state
    Vol. 89, num. 21, p. 214105-1-214105-8
    DOI: 10.1103/PhysRevB.89.214105
    Date of publication: 2014-06-06
    Journal article

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    We report on calorimetry under applied hydrostatic pressure and magnetic field at the antiferromagnetic-ferromagnetic (AFM/FM) transition of Fe49Rh51. Results demonstrate the existence of a giant barocaloric effect in this alloy, a functional property that adds to the magnetocaloric and elastocaloric effects previously reported for this alloy. All caloric effects originate from the AFM/FM transition which encompasses changes in volume, magnetization, and entropy. The strong sensitivity of the transition temperatures to both hydrostatic pressure and magnetic field confers to this alloy outstanding values for the barocaloric and magnetocaloric strengths (vertical bar Delta S vertical bar/Delta p similar to 12 J kg(-1) K(-1)kbar(-1) and vertical bar Delta S vertical bar/mu(0)Delta H similar to 12 J kg(-1) K-1T-1). Both barocaloric and magnetocaloric effects have been found to be reproducible upon pressure and magnetic field cycling. Such a good reproducibility and the large caloric strengths make Fe-Rh alloys particularly appealing for solid-state cooling technologies at weak external stimuli.

    We report on calorimetry under applied hydrostatic pressure and magnetic field at the antiferromagnetic-ferromagnetic (AFM/FM) transition of Fe49Rh51. Results demonstrate the existence of a giant barocaloric effect in this alloy, a functional property that adds to the magnetocaloric and elastocaloric effects previously reported for this alloy. All caloric effects originate from the AFM/FM transition which encompasses changes in volume, magnetization, and entropy. The strong sensitivity of the transition temperatures to both hydrostatic pressure and magnetic field confers to this alloy outstanding values for the barocaloric and magnetocaloric strengths (|¿S|/¿p ~ 12 J kg-1K-1kbar-1 and |¿S|/µ0¿H~ 12 J kg-1K-1T-1). Both barocaloric and magnetocaloric effects have been found to be reproducible upon pressure and magnetic field cycling. Such a good reproducibility and the large caloric strengths make Fe-Rh alloys particularly appealing for solid-state cooling technologies at weak external stimuli.

  • Polymorphism of organic compounds as a function of temperature and pressure

     Tamarit Mur, Jose Luis; Céolin, René; Del Barrio Casado, Maria; Rietveld, Ivo B.
    Journées de Calorimétrie et d'Analyse Thermique
    p. INV2
    Presentation's date: 2014-05-21
    Presentation of work at congresses

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  • 2-Adamantanone (C10H14O): ordered and disordered phases, a complex case of polymorphism

     Negrier, Philippe; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Romanini, Michela; Mondieig, D.
    Journées d¿Etude des Equilibres entre Phases
    p. 26
    Presentation's date: 2014-03-27
    Presentation of work at congresses

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  • Plastic phases under pressure, the case succinonitrile

     Rietveld, Ivo B.; Del Barrio Casado, Maria; Céolin, René; Tamarit Mur, Jose Luis
    Journées d¿Etude des Equilibres entre Phases
    p. 30
    Presentation's date: 2014-03-28
    Presentation of work at congresses

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  • The pressure-temperature phase relationships between benzocaine forms II, III, and its liquid

     Gana, Inès; Del Barrio Casado, Maria; Do, Bernard; Céolin, René; Tamarit Mur, Jose Luis; Rietveld, Ivo B.
    Journées d¿Etude des Equilibres entre Phases
    p. 122
    Presentation's date: 2014-03-26
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  • Much ado about nothing: Statistical occupational disorder and glassy features

     Tamarit Mur, Jose Luis; Bermejo, F. Javier; Del Barrio Casado, Maria; Pardo Soto, Luis Carlos; Krivchikov, Alexander I
    Reunión de la Sociedad Española de Técnicas Neutrónicas
    p. 17
    Presentation's date: 2014-06-23
    Presentation of work at congresses

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  • Polymorphism of 1,2-dibromo-ethane (C2Br2D4 and C2Br2H4)

     Negrier, Philippe; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Mondieig, D.
    Journées d¿Etude des Equilibres entre Phases
    p. 74
    Presentation's date: 2014-03-26
    Presentation of work at congresses

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  • Solid-state properties and dehydration behavior of the active pharmaceutical ingredient potassium guaiacol-4-sulfonate

     Mahé, Nathalie; Nicolai, Beatrice; Del Barrio Casado, Maria; Perrin, Marc Antoine; Do, Bernard; Tamarit Mur, Jose Luis; Céolin, René; Rietveld, Ivo B.
    Crystal growth and design
    Vol. 13, num. 7, p. 3028-3035
    DOI: 10.1021/cg400427v
    Date of publication: 2013-05-20
    Journal article

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    Potassium guaiacolsulfonate is an active pharmaceutical ingredient that has been in use for more than a century, and it is still widely used in cough syrups. Nonetheless, no crystal structure has ever been determined to facilitate quality control. This is all the more surprising because two isomers are known to exist. A commercial sample has been studied by X-ray diffraction and thermogravimetric methods. It consists of potassium guaiacol-4-sulfonate, and it crystallizes in the monoclinic space group C2/c as a hemihydrate. The crystals exhibit uniaxial negative thermal expansion, and the electrostatic forces between the ions appear to be the major driving force of the observed displacements. Dehydration of the hemihydrate was observed above 380 K. The anhydrate has a structure similar to the hemihydrate with almost the same unit cell parameters. The dehydration kinetics points to a displacive mechanism; water molecules are located in channels, through which they leave the crystal. The structural readjustments that occur to accommodate the loss of water are driven by electrostatic interactions between the ions similar to the displacements observed for thermal expansion. Under ambient conditions (and humidity), the anhydrate is not stable and transforms into the hemihydrate.

    Potassium guaiacolsulfonate is an active pharmaceutical ingredient that has been in use for more than a century, and it is still widely used in cough syrups. Nonetheless, no crystal structure has ever been determined to facilitate quality control. This is all the more surprising because two isomers are known to exist. A commercial sample has been studied by X-ray diffraction and thermogravimetric methods. It consists of potassium guaiacol-4-sulfonate, and it crystallizes in the monoclinic space group C2/c as a hemihydrate. The crystals exhibit uniaxial negative thermal expansion, and the electrostatic forces between the ions appear to be the major driving force of the observed displacements. Dehydration of the hemihydrate was observed above 380 K. The anhydrate has a structure similar to the hemihydrate with almost the same unit cell parameters. The dehydration kinetics points to a displacive mechanism; water molecules are located in channels, through which they leave the crystal. The structural readjustments that occur to accommodate the loss of water are driven by electrostatic interactions between the ions similar to the displacements observed for thermal expansion. Under ambient conditions (and humidity), the anhydrate is not stable and transforms into the hemihydrate.

  • Benzocaine polymorphism: Pressure-temperature phase diagram involving forms II and III

     Gana, Inès; Del Barrio Casado, Maria; Do, Bernard; Tamarit Mur, Jose Luis; Céolin, René; Rietveld, Ivo B.
    International journal of pharmaceutics
    Vol. 456, num. 2, p. 480-488
    DOI: 10.1016/j.ijpharm.2013.08.031
    Date of publication: 2013-11-18
    Journal article

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    Understanding the phase behavior of an active pharmaceutical ingredient in a drug formulation is required to avoid the occurrence of sudden phase changes resulting in decrease of bioavailability in a marketed product. Benzocaine is known to possess three crystalline polymorphs, but their stability hierarchy has so far not been determined. A topological method and direct calorimetric measurements under pressure have been used to construct the topological pressure-temperature diagram of the phase relationships between the solid phases II and III, the liquid, and the vapor phase. In the process, the transition temperature between solid phases III and II and its enthalpy change have been determined. Solid phase II, which has the highest melting point, is the more stable phase under ambient conditions in this phase diagram. Surprisingly, solid phase I has not been observed during the study, even though the scarce literature data on its thermal behavior appear to indicate that it might be the most stable one of the three solid phases. © 2013 Elsevier B.V. All rights reserved.

    tUnderstanding the phase behavior of an active pharmaceutical ingredient in a drug formulation isrequired to avoid the occurrence of sudden phase changes resulting in decrease of bioavailability in amarketed product. Benzocaine is known to possess three crystalline polymorphs, but their stability hier-archy has so far not been determined. A topological method and direct calorimetric measurements underpressure have been used to construct the topological pressure–temperature diagram of the phase rela-tionships between the solid phases II and III, the liquid, and the vapor phase. In the process, the transitiontemperature between solid phases III and II and its enthalpy change have been determined. Solid phaseII, which has the highest melting point, is the more stable phase under ambient conditions in this phasediagram. Surprisingly, solid phase I has not been observed during the study, even though the scarce lit-erature data on its thermal behavior appear to indicate that it might be the most stable one of the threesolid phases.

  • Rimonabant dimorphism and its pressure¿temperature phasegiagram: A delicate case of overall monotropic behavior

     Perrin, Marc-Antoine; Bauer, Michel; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Céolin, René; Rietveld, Ivo B.
    Journal of pharmaceutical sciences
    Vol. 102, num. 7, p. 2311-2321
    DOI: 10.1002/jps.23612
    Date of publication: 2013-05-20
    Journal article

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    Crystalline polymorphism occurs frequently in the solid state of active pharmaceutical ingredients, and this is problematic for the development of a suitable dose form. Rimonabant, an active pharmaceutical ingredient developed by Sanofi and discontinued because of side effects, exhibits dimorphism; both solid forms have nearly the same melting temperatures, melting enthalpies, and specific volumes. Although the problem may well be academic from an industrial point of view, the present case demonstrates the usefulness of constructing pressure¿temperature phase diagrams by direct measurement as well as by topological approach. The system is overall monotropic and form II is the more stable solid form. Interestingly, the more stable form does not possess any hydrogen bonds, whereas the less stable one does.

    Crystalline polymorphism occurs frequently in the solid state of active pharmaceutical ingredients, and this is problematic for the development of a suitable dose form. Rimonabant, an active pharmaceutical ingredient developed by Sanofi and discontinued because of side effects, exhibits dimorphism; both solid forms have nearly the same melting temperatures, melting enthalpies, and specific volumes. Although the problem may well be academic from an industrial point of view, the present case demonstrates the usefulness of constructing pressure–temperature phase diagrams by direct measurement as well as by topological approach. The system is overall monotropic and form II is the more stable solid form. Interestingly, the more stable form does not possess any hydrogen bonds, whereas the less stable one does.

  • Conformational polymorphism: The missing phase of 1,1,2,2-tetrachloroethane (Cl2HC-CHCl2)

     Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Mondieig, Denise; Zuriaga, Jose Mariano; Perez, Silvina C.; Negrier, Philippe
    Crystal growth and design
    Vol. 13, num. 5, p. 2143-2148
    DOI: 10.1021/cg400235b
    Date of publication: 2013-05
    Journal article

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    Halogenoethane derivatives are known to exhibit different polymorphs involving a different translational, orientational, and conformational order. The 1,1,2,2-tetrachloroethane (Cl2HC-CHCl2) exhibits a normal pressure orthorhombic phase beta (space group P2(1)2(1)2(1) with Z = 8 and Z' = 2), formed by molecules with one of the two gauche conformations. At high pressure, the stable polymorph is known to be monoclinic (space group P2(1)/c, with Z = 2 and Z' = 0.5), phase alpha, in which only the trans conformer appears. In this work, we demonstrate the existence of a normal pressure metastable polymorph, phase gamma, for which the two gauche conformers show up in the asymmetric unit of a monoclinic (space group P2(1)/c with Z = 8 and Z' = 2) structure. The new phase gamma is obtained by recrystallization upon heating the glass obtained after quench of the melt. It displays shorter type II Cl center dot center dot center dot Cl contacts than the high-pressure phase alpha due to attractive and directional interactions.

    Halogenoethane derivatives are known to exhibit different polymorphs involving a different translational, orientational, and conformational order. The 1,1,2,2- tetrachloroethane (Cl2HC−CHCl2) exhibits a normal pressure orthorhombic phase β (space group P212121 with Z = 8 and Z′ = 2), formed by molecules with one of the two gauche conformations. At high pressure, the stable polymorph is known to be monoclinic (space group P21/c, with Z = 2 and Z′ = 0.5), phase α, in which only the trans conformer appears. In this work, we demonstrate the existence of a normal pressure metastable polymorph, phase γ, for which the two gauche conformers show up in the asymmetric unit of a monoclinic (space group P21/c with Z = 8 and Z′ = 2) structure. The new phase γ is obtained by recrystallization upon heating the glass obtained after quench of the melt. It displays shorter type II Cl···Cl contacts than the high-pressure phase α due to attractive and directional interactions.

  • Crystal structure and solid-state properties of 3,4-diaminopyridine dihydrogen phosphate and their comparison with other diaminopyridine salts

     Mahe, Nathalie; Nicolaï, Béatrice; Allouchi, Hassan; Del Barrio Casado, Maria; Do, Bernard; Céolin, René; Tamarit Mur, Jose Luis; Rietveld, Ivo B.
    Crystal growth and design
    Vol. 13, num. 2, p. 708-715
    DOI: 10.1021/cg3014249
    Date of publication: 2013-02
    Journal article

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    3,4-Diaminopyridine is an active pharmaceutical ingredient for the treatment of Lambert-Eaton myasthenic syndrome (LEMS). It is 3,4-diaminopyridine dihydrogen phosphate that has become the active ingredient of choice. As part of a larger study for the development of this drug, solid-state studies have been carried out. At room temperature, the crystals are monoclinic (C2/c). Dihydrogen phosphate anions H2PO4 - form infinite chains parallel to the b axis, and these chains can be considered as macroanions (H2PO4)8. The organic cations form hydrogen bonds with the macroanions bridging them together. A negative thermal expansion is observed along the [103] direction in the crystal, which coincides with the direction of chains of interchanging anions and cations. The crystal packing shows similarities with the hydrogen tartrate salt as illustrated by a Hirshfeld surface analysis. This phosphate and this tartrate salt are also the two diaminopyridine salts that have been selected for therapeutic use because of their appropriate physical properties. © 2012 American Chemical Society.

    3,4-Diaminopyridine is an active pharmaceutical ingredient for the treatment of Lambert−Eaton myasthenic syndrome (LEMS). It is 3,4-diaminopyridine dihydrogen phosphate that has become the active ingredient of choice. As part of a larger study for the development of this drug, solid-state studies have been carried out. At room temperature, the crystals are monoclinic (C2/c). Dihydrogen phosphate anions H2PO4 − form infinite chains parallel to the b axis, and these chains can be considered as macroanions (H2PO4)∞. The organic cations form hydrogen bonds with the macroanions bridging them together. A negative thermal expansion is observed along the [103] direction in the crystal, which coincides with the direction of chains of interchanging anions and cations. The crystal packing shows similarities with the hydrogen tartrate salt as illustrated by a Hirshfeld surface analysis. This phosphate and this tartrate salt are also the two diaminopyridine salts that have been selected for therapeutic use because of their appropriate physical properties.

  • Liquid-liquid miscibility gaps in drug-water binary systems: crystal Structure and thermodynamic properties of prilocaine and the temperature-composition phase diagram of the prilocaine-water system

     Rietveld, Ivo B.; Perrin, Jean-Claude; Toscani, Siro; Del Barrio Casado, Maria; Nicolai, Beatrice; Tamarit Mur, Jose Luis; Céolin, René
    Molecular pharmaceutics
    Vol. 10, num. 4, p. 1332-1339
    DOI: 10.1021/mp300542k
    Date of publication: 2013-04
    Journal article

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    EMLA cream, a ¿eutectic mixture of local anesthetics¿, was developed in the early 1980s by Astra Pharmaceutical Production. The mixture of anesthetics containing lidocaine, prilocaine, and water is liquid at room temperature, which is partly due to the eutectic equilibrium between prilocaine and lidocaine at 293 K, as was clear from the start. However, the full thermodynamic background for the stability of the liquid and its emulsion-like appearance has never been elucidated. In the present study of the binary system prilocaine-water, a region of liquid-liquid demixing has been observed, linked to a monotectic equilibrium at 302.4 K. It results in a prilocaine-rich liquid containing approximately 0.7 mol fraction of anesthetic. Similar behavior has been reported for the binary system lidocaine-water (Ce´olin, R.; et al. J. Pharm. Sci. 2010, 99 (6), 2756-2765). In the ternary mixture, the combination of the monotectic equilibrium and the above-mentioned eutectic equilibrium between prilocaine and lidocaine results in an anesthetic-rich liquid that remains stable below room temperature. This liquid forms an emulsion-like mixture in the presence of an aqueous solution saturated with anesthetics. Physical properties and the crystal structure of prilocaine are also reported.

    EMLA cream, a “eutectic mixture of local anesthetics”, was developed in the early 1980s by Astra Pharmaceutical Production. The mixture of anesthetics containing lidocaine, prilocaine, and water is liquid at room temperature, which is partly due to the eutectic equilibrium between prilocaine and lidocaine at 293 K, as was clear from the start. However, the full thermodynamic background for the stability of the liquid and its emulsion-like appearance has never been elucidated. In the present study of the binary system prilocaine−water, a region of liquid−liquid demixing has been observed, linked to a monotectic equilibrium at 302.4 K. It results in a prilocaine-rich liquid containing approximately 0.7 mol fraction of anesthetic. Similar behavior has been reported for the binary system lidocaine−water (Céolin, R.; et al. J. Pharm. Sci. 2010, 99 (6), 2756−2765). In the ternary mixture, the combination of the monotectic equilibrium and the above-mentioned eutectic equilibrium between prilocaine and lidocaine results in an anesthetic-rich liquid that remains stable below room temperature. This liquid forms an emulsion-like mixture in the presence of an aqueous solution saturated with anesthetics. Physical properties and the crystal structure of prilocaine are also reported.

  • Polymorphism in halogen-ethane derivatives: CCl3-CCl3 and ClF2C-CF2Cl

     Negrier, Philippe; Tamarit Mur, Jose Luis; Del Barrio Casado, Maria; Mondieig, Denise
    Crystal growth and design
    Vol. 13, num. 2, p. 782-791
    DOI: 10.1021/cg301498f
    Date of publication: 2013-02-06
    Journal article

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    The polymorphism of hexachloroethane, Cl3C−CCl3, has been reinvestigated by means of X-ray and neutron scattering. The long time unknown structure of the intermediate phase II of Cl3C−CCl3 has been determined as monoclinic C2/m, with lattice parameters a = 17.9835(21) Å, b = 10.3642(11) Å, c = 6.3014(8) Å, and β = 94.410(5)° at 323 K, Z = 6. The polymorphism of 1,2-dichloro-1,1,2,2-tetrafluoro-ethane, ClF2C−CF2Cl, has also been investigated, and the structure of the intermediate phase II has been found to be orthorhombic (Cmca, Z = 4) with lattice parameters a = 6.305(4) Å, b = 10.177(12) Å, c = 8.714 (7) Å. The high-temperature phase I of ClF2C− CF2Cl has been found to be isomorphous with the orientationally disordered phase I of Cl3C−CCl3 (body centered cubic, Im3̅m), a consequence of the pseudospherical molecular shape of halogeno-ethane C2X6−nYn (X = Cl, Y = F) molecular crystals. The similarities of the intricate disorder of the intermediate phases II of both Cl3C−CCl3 and ClF2C−CF2Cl compounds are analyzed, together with the influence of the conformational disorder appearing in the last compound.

  • Dynamics as a function of temperature and pressure for an antiprotozoal drug

     Romanini, Michela; Capaccioli, Simone; Del Barrio Casado, Maria; Prevosto, Daniele; Tamarit Mur, Jose Luis
    International Discussion Meeting on Relaxation in Complex Systems
    p. 42
    Presentation's date: 2013-07-23
    Presentation of work at congresses

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  • Well-ordered glasses: glassy features in long-range ordered systems

     Del Barrio Casado, Maria; Negrier, Philippe; Romanini, Michela; Capaccioli, Simone; Pardo Soto, Luis Carlos; Mondieig, Denise; Tamarit Mur, Jose Luis
    International Discussion Meeting on Relaxation in Complex Systems
    p. 358
    Presentation's date: 2013-07-25
    Presentation of work at congresses

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  • Secondary relaxations on a strong orientational glass

     Romanini, Michela; Del Barrio Casado, Maria; Capaccioli, Simone; Prevosto, Daniele; Tamarit Mur, Jose Luis
    International Discussion Meeting on Relaxation in Complex Systems
    p. 311
    Presentation's date: 2013-07-25
    Presentation of work at congresses

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  • A glacial state from a plastic molecular crystal

     Szewczyk, Daria; Jezowski, Andrzej; Krivchikov, Alexander I; Vdovichenko, Georgii A.; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis
    International Discussion Meeting on Relaxation in Complex Systems
    p. 360
    Presentation's date: 2013-07-25
    Presentation of work at congresses

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  • Pressure-temperature phase diagrams of drugs

     Del Barrio Casado, Maria; Rietveld, Ivo B.; Céolin, René; Tamarit Mur, Jose Luis
    Workshop on Stability of Amorphous Pharmaceuticals
    p. 20
    Presentation's date: 2013-10-18
    Presentation of work at congresses

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  • Rimonabant dimorphism, much ado about almost nothing

     Perrin, Marc-Antoine; Bauer, M; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Céolin, René; Rietveld, I.B.
    Joint European days on Equilibrium between Phases
    p. 65
    Presentation's date: 2013-03-21
    Presentation of work at congresses

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  • The conformational polymorphism of 1,1,2,2-tetrachloroehtane (C2 H2CI4)

     Negrier, Philippe; Del Barrio Casado, Maria; Zuriaga, Jose Mariano; Perez, Silvina C.; Tamarit Mur, Jose Luis; Mondieig, Denise
    Joint European days on Equilibrium between Phases
    p. 141
    Presentation's date: 2013-03-20
    Presentation of work at congresses

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    Halogenoethane derivatives are known to exhibit different polymorphs involving a different translational, orientational, and conformational order. The 1,1,2,2-tetrachloroethane (Cl2HC-CHCl2) exhibits a normal pressure orthorhombic phase (space group P212 121 with Z = 8 and Z = 2), formed by molecules with one of the two gauche conformations. At high pressure, the stable polymorph is known to be monoclinic (space group P21/c, with Z = 2 and Z = 0.5), phase , in which only the trans conformer appears. In this work, we demonstrate the existence of a normal pressure metastable polymorph, phase , for which the two gauche conformers show up in the asymmetric unit of a monoclinic (space group P21/c with Z = 8 and Z = 2) structure. The new phase is obtained by recrystallization upon heating the glass obtained after quench of the melt. It displays shorter type II ClCl contacts than the high-pressure phase due to attractive and directional interactions

  • Dinámica en sólidos desordenados

     Romanini, Michela; Macovez, Roberto; Ruiz Martin, Maria Dolores; Levit Valenzuela, Rafael; Pardo Soto, Luis Carlos; Del Barrio Casado, Maria; Vispa, Alessandro; Tamarit Mur, Jose Luis
    Competitive project

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  • Polymorphism in halogen-ethane derivatives: CCl3-CF2Cl and CF3-CF2Cl

     Negrier, Philippe; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Pardo Soto, Luis Carlos; Mondieig, Denise
    Crystal growth and design
    Vol. 12, num. 3, p. 1513-1519
    DOI: 10.1021/cg201575v
    Date of publication: 2012-01-03
    Journal article

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    Molecular crystals of halogen–ethane derivatives C2X6–nYn (X = Cl, Y = F) are known to display order–disorder phase transitions involving changes of the translational, orientational, and conformational order. The appearance of a high-temperature orientationally disordered phase with a high symmetry lattice is expected for this set of compounds in view of their “pseudospherical” molecular geometry. In this work, we present a study of polymorphism of the compounds 1,1,1,2-tetrachloro-2,2-difluoroethane (CCl3–CF2Cl) and 1-chloro-1,1,2,2,2-pentafluoroethane (CF3–CF2Cl), in which conformational disorder is not present, by combining neutron (D2B and D1B instruments at the Laue-Langevin Institute) and X-ray scattering experiments. We show that despite the close molecular shapes and molecular structures of both compounds, strong differences concerning the disorder appear in the low-temperature phase. The low-temperature phase for CF3–CF2Cl is found to be fully ordered, with a monoclinic P21/n structure (Z = 4), while that of CCl3–CF2Cl is found to be orthorhombic Pmna (Z = 4) with a disorder concerning one Cl and one F sites, each one with a fractional occupancy of 50%. Details related to the high-temperature orientationally disordered phases (both body-centered-cubic) are also given.

  • Uniaxial negative thermal expansion in crystals of tienoxolol

     Nicolaï, Beatrice; Rietveld, Ivo B.; Del Barrio Casado, Maria; Mahé, Nathalie; Tamarit Mur, Jose Luis; Céolin, René; Guéchot, Christophe; Teulon, Jean-Marie
    Structural chemistry
    Vol. 24, num. 1, p. 279-283
    DOI: 10.1007/s11224-012-0078-z
    Date of publication: 2012-06-17
    Journal article

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    The thermal expansion of tienoxolol has been investigated by X-ray powder diffraction up to its melting temperature. The data indicate that the expansion is anisotropic and even negative in one direction of the unit cell. The supramolecular structure formed by hydrogenbonds reflects that of a trellis, which explains the observed behavior of tienoxolol crystals.

  • Barocaloric effect in the magnetocaloric prototype Gd 5Si 2Ge 2

     Yuce, Suheyla; Del Barrio Casado, Maria; Emre, Baris; Stern Taulats, Enric; Planes Vila, Antoni; Tamarit Mur, Jose Luis; Mudryk, Yaroslav; Gschneidner, Karl A.; Pecharsky, Vitalij K.; Mañosa Carrera, Lluis
    Applied physics letters
    Vol. 101, num. 7, p. 1-4
    DOI: 10.1063/1.4745920
    Date of publication: 2012-08-13
    Journal article

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  • Pressure¿temperature state diagram for the phase relationships between benfluorex hydrochloride forms I and II: A case of enantiotropic behavior

     Del Barrio Casado, Maria; Maccaroni, Elisabetta; Rietveld, Ivo B.; Macpezzi, Luciana; Masciocchi, Norberto; Céolin, René; Tamarit Mur, Jose Luis
    Journal of pharmaceutical sciences
    Vol. 101, num. 3, p. 1072-1078
    DOI: 10.1002/jps.22821
    Date of publication: 2012-03
    Journal article

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    The active pharmaceutical ingredient racemic benfluorex hydrochloride (benfluorex–HCl) has an interesting phase behavior due to an elusive solid–solid phase transition. The stability hierarchy between different phases is often determined based on heat-related experiments only or slurry interconversion. It is shown that if pressure and volume are taken into account, not only the phase equilibria are correctly positioned in the pressure–temperature phase diagram, but the experimental data also improves. Thus, it has been found that the racemic benfluorex–HCl is enantiotropic under “ordinary conditions” with polymorph II and polymorph I, respectively, being the low- and the high-temperature phases. Above ∼151 MPa, the system becomes monotropic and polymorph II is the single stable phase.

  • Overall stability for the ibuprofen racemate: experimental and topological results leading to the pressure-temperature phase relationships between its racemate and conglomerate

     Rietveld, Ivo B.; Del Barrio Casado, Maria; Do, Bernard; Tamarit Mur, Jose Luis; Céolin, René
    Journal of physical chemistry B
    Vol. 116, num. 18, p. 5568-5574
    DOI: 10.1021/jp302508g
    Date of publication: 2012-05-10
    Journal article

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    Enantiomer resolution is much sought after for pharmaceutical applications, because many optically active drug molecules have only one pharmaceutically active enantiomer. Although it is always possible to force separation, it will come at a cost. The present method, based on thermodynamics, provides a relatively easy approach to investigate whether separation can be thermodynamically spontaneous. A topological phase diagram of the binary enantiomer system at 0.5 mol-fraction is constructed as a function of temperature and pressure after analysis of pressure and heat related quantities. It is demonstrated that for ibuprofen, an optically active analgesic, the racemate is the only stable solid form; the phase relationship between the racemate and the conglomerate is analogous to dimorphism with overall monotropy in pure chemical compounds.

  • Access to the full text
    Emergence of glassy-like dynamics in an orientationally ordered phase  Open access

     Romanini, Michela; Negrier, Philippe; Tamarit Mur, Jose Luis; Capaccioli, Simone; Del Barrio Casado, Maria; Pardo Soto, Luis Carlos; Mondieig, Denise
    Physical review B: condensed matter and materials physics
    Vol. 85, num. 13, p. 134201-1-134201-7
    DOI: 10.1103/PhysRevB.85.134201
    Date of publication: 2012-04-04
    Journal article

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    The dynamics of a simple rigid pseudoglobular molecule (2-adamantanone) has been studied by means of dielectric spectroscopy and examined under the constraints imposed by the space group of the crystal structure determined by x-ray powder diffraction. The low-temperature monoclinic structure of 2-adamantanone, with one molecule per asymmetric unit (Z'= 1), displays a statistical intrinsic disorder, concerning the site occupancy of the oxygen atom along three different sites. Such a physically identifiable disorder gives rise to large-angle molecular rotations which inherently lead to time-average fluctuations of the molecular dipole, thus contributing to the dielectric susceptibility. The dielectric spectra for the low-temperature “ordered” phase displays a universal feature of glassy-like materials, i.e., coexistence of α- and β-relaxation processes. The former is clearly identified with the strongly restricted reorientational motions within the long-range “ordered” crystalline lattice. The latter, never observed before in fully translationally and highly orientationally ordered phases, displays all the properties of an original Johari-Goldstein β-relaxation, in spite of the strong character of this glass-like phase. These findings can be explained according to the coupling model, applied to such “ordered” phases.

  • Crystal structure and solid-state studies of aged samples of tienoxolol, an API designed against hypertension

     Mahé, Nathalie; Do, Bernard; Nicolaï, Béatrice; Rietveld, Ivo B.; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Céolin, René; Ghéchot, Christophe; Teulon, Jean-Marie
    International journal of pharmaceutics
    Vol. 422, num. 1-2, p. 47-51
    DOI: 10.1016/j-ijpharm.2011.10.025
    Date of publication: 2012
    Journal article

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    Aging of drug molecules is generally studied following regulatory procedures, i.e. under forced conditions and for relatively limited storage time; therefore naturally aged samples are rare and provide scientific reference data beyond regulatory considerations. Tienoxolol was studied after 25 years of storage in the dark under ambient conditions. About 86% of the samples still consisted of tienoxolol and the main impurity (13%) was caused by the hydrolysis of the ester moiety. Protection from humidity is therefore important. Other sensitive groups containing nitrogen and sulfur appear to be quite stable with less than 0.8% conversion over 25 years. In addition, the crystal structure has been solved. Tienoxolol orange needles were found to crystallize in the orthorhombic non-centrosymmetric space group Iba2, indicating that the crystal is a racemic compound. The unit cell parameters at room temperature are a = 10.069(5)A˚ , b = 45.831(10)A˚ , and c = 9.822(5) ˚A and the unit cell volume is 4533(3) ˚A3 with Z = 8. © 2011 Elsevier B.V.

  • Influence of the pressure on the stability of co-crystals and other binary molecular compounds

     Céolin, René; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Rietveld, I.B.
    International Workshops on Physical Characterization of Pharmaceutical Solids
    p. 24-25
    Presentation's date: 2012-06-27
    Presentation of work at congresses

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  • The phase behavior of benfluorex hydrochloride: unexpected enantiotropy at ordinary pressure and an elusive solid-solid transition

     Del Barrio Casado, Maria; Maccaroni, Elisabetta; Rietveld, I.B.; Malpezzi, Luciana; Masciocchi, Norberto; Céolin, René; Tamarit Mur, Jose Luis
    International Workshops on Physical Characterization of Pharmaceutical Solids
    p. 37-38
    Presentation's date: 2012-06-28
    Presentation of work at congresses

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  • A new way of enantiomer resolution: pressure, the thermodynaic pathway

     Rietveld, I.B.; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Do, Bernard; Céolin, René
    Journées d'Études des Équilibres entre Phases
    p. 73-74
    DOI: /jeep2012.colloques.univ-rouen.fr/images/Documents/final%20scientific%20program.pdf
    Presentation's date: 2012-03-30
    Presentation of work at congresses

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  • Binary system Br-Adamantane + I-Adamantane

     Negrier, Philippe; Gueye, M.; Mondieig, Denise; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis
    Journées d'Études des Équilibres entre Phases
    p. 113-114
    DOI: /jeep2012.colloques.univ-rouen.fr/index.php?option=com_content&view=article&id=46&Itemid=1&lang=fr
    Presentation's date: 2012-03-28
    Presentation of work at congresses

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  • Glassy dynamics in ordered phases

     Tamarit Mur, Jose Luis; Pardo Soto, Luis Carlos; Romanini, Michela; Zuriaga, Jose Mariano; Capaccioli, Simone; Del Barrio Casado, Maria; Lunkenheimer, P.; Loidl, A.
    International Discussion Meeting on Glass Transition
    p. 24
    Presentation's date: 2012-02-27
    Presentation of work at congresses

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  • Influence of the pressure on the stability of co-crystals and other molecular binary compounds

     Céolin, René; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Rietveld, I.
    International Workshop on Physical Characterization of Pharmaceutical Solids
    Presentation's date: 2012-06-25
    Presentation of work at congresses

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  • Enantiomer resolution by pressure increase

     Rietveld, I.B.; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Do, Bernard; Céolin, René
    International Workshops on Physical Characterization of Pharmaceutical Solids
    p. 39-40
    Presentation's date: 2012-06-28
    Presentation of work at congresses

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  • The road map of polymorphism: pressure-temperature phase diagram

     Tamarit Mur, Jose Luis; Céolin, René; Del Barrio Casado, Maria; Rietveld, I.
    International Workshops on Physical Characterization of Pharmaceutical Solids
    p. 23-24
    Presentation's date: 2012-06-27
    Presentation of work at congresses

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  • Polymorphism in halogen hexasubstitued ethane derivatives

     Negrier, Philippe; Mondieig, Denise; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis
    Journées d'Études des Équilibres entre Phases
    p. 111-112
    DOI: /jeep2012.colloques.univ-rouen.fr/index.php?option=com_content&view=article&id=46&Itemid=1&lang=fr
    Presentation's date: 2012-03-28
    Presentation of work at congresses

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  • The phase behavior of Benfluorex hydroxide: unexpected enantiotropy at ordinary pressure and an elusive solid-solid transition

     Del Barrio Casado, Maria; MACCARONI, E.; RIETVELD, I.B.; MALPEZZI, L.; MASCIOCCHI, N.; CEOLIN, R.; Tamarit Mur, Jose Luis
    Journées d'Études des Équilibres entre Phases
    p. 145-146
    Presentation's date: 2012-03-28
    Presentation of work at congresses

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  • Polymorphism of some halogen-ethane derivatives

     Negrier, Philippe; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Pardo Soto, Luis Carlos; Mondieig, Denise
    Journées d'Études des Équilibres entre Phases
    p. 123-124
    Presentation's date: 2011-03-30
    Presentation of work at congresses

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  • Topological and experimental approach to the pressure-temperature-composition phase diagram of the binary enantiomer system d- and I-camphor

     Rietveld, Ivo B.; Del Barrio Casado, Maria; Espeau, Philippe; Tamarit Mur, Jose Luis; Céolin, René
    Journal of physical chemistry B
    Vol. 115, num. 7, p. 1672-1678
    DOI: 10.1021/jp108900v
    Date of publication: 2011-01-31
    Journal article

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    In 1981, Jacques, Collet, and Wilen already put forward the idea to use pressure to influence equilibria in binary enantiomer systems in analogy with temperature (Jacques et al. Enantiomers, Racemates and Resolutions; John Wiley & Sons: New York, 1981). Whereas temperature is used routinely to study phase equilibria, pressure is an all but forgotten parameter. This is therefore possibly the first paper on the influence of pressure on a binary enantiomer system: d- and l-camphor. The study consists of two parts, a topological approach, which uses data obtained from routine measurements (differential scanning calorimetry, X-ray diffraction), and the experimental determination of phase transitions as a function of pressure and temperature. This has resulted in two topological pressure-temperature phase diagrams of the pure enantiomer d-camphor and of the racemic mixture dl-camphor; both have been verified by the experiments as a function of pressure. In turn, these results have been used to construct part of the pressure-temperature-composition phase diagram of d- and l-camphor. A method to obtain the excess Gibbs energy from these binary phase diagrams as a function of pressure is proposed

  • From figh-temperature orientationally disordered mixed crystals to low-temperature complex formation in the two-component system (CH3)3CBr + Cl3CBr

     Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Mondieig, Denise; Negrier, Philippe
    Journal of physical chemistry B
    Vol. 115, num. 7, p. 1679-1688
    DOI: 10.1021/jp109702t
    Date of publication: 2011-02-02
    Journal article

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    The phase diagram of the two-component systems (CH(3))(3)CBr + Cl(3)CBr has been experimentally determined by means of differential scanning calorimetry and X-ray powder diffraction techniques from the low-temperature ordered phases to the liquid state. Before melting, both components have the same orientationally disordered (OD) face-centered cubic (FCC) and rhombohedral (R) phases, and the two-phase equilibria [FCC + L] and [R + FCC] are accounted for by means of the existence of an isomorphic relationship between the OD phases of pure compounds. The thermodynamic assessment of such equilibria enables us to get the excess properties of the involved OD phases and to rationalize the existence of a maximum and a minimum in the [R + FCC] equilibrium on the basis of the contribution of the entropic term in the excess Gibbs energy function. At low temperature, two complexes, (CH(3))(3)CBr:Cl(3)CBr (1:1) and (CH(3))(3)CBr:2Cl(3)CBr (1:2), appear. The structures of 1:1 and 1:2 complexes have been determined to be monoclinic (P2(1)/n, c, Z = 4) and hexagonal (P6(3), Z = 6). Within both "ordered" structures, the Cl(3)CBr entities of the asymmetric unit were found to be disordered so that sites have fractional occupancies of 0.75 and 0.25 for Cl and Br atoms, in the same way that it occurs for the low-temperature monoclinic (C2/c, Z = 32) phase of Cl(3)CBr. Finally, the existence of complexes is connected with the special intermolecular interactions appearing between a methyl group and a halogen, as previously inferred by Calvet et al. [T. Calvet et al. J. Chem. Phys.1999, 110, 4841].

  • Tyrosine alkyl esters as produg: the estructure and intermolecular interactions of L-tyrosine methyl ester compared to L-tyrosine and its ethyl and n-butyl esters

     Nicolaï, Beatrice; Mahé, Nathalie; Céolin, René; Rietveld, Ivo B.; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis
    Structural chemistry
    Vol. 22, num. 3, p. 649-659
    DOI: 10.1007/s11224-010-9723-6
    Date of publication: 2011-01-25
    Journal article

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  • Solid-State Studies of the Triclinic (Z¿ = 2) Antiprotozoal Drug Ternidazole

     Mahé, N.; Perrin, Marc Antoine; Del Barrio Casado, Maria; Nicolai, B.; Rietveld, I.B.; Tamarit Mur, Jose Luis; Céolin, R.
    Journal of pharmaceutical sciences
    Vol. 100, num. 6, p. 2258-2266
    DOI: 10.1002/jps
    Date of publication: 2011-05-01
    Journal article

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  • Dimorphism of the Produg L-Tyrosine Ethyl Ester: Pressure-Temperature State Diagram and Crystal Structure of Phase II

     Rietveld, Ivo B.; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Nicolaï, Beatrice; Van de Streek, J.; Mahé, Nathalie; Céolin, René; Do, Bernard
    Journal of pharmaceutical sciences
    Vol. 100, num. 11, p. 4774-4782
    DOI: 10.1002/jps.22672
    Date of publication: 2011-06-22
    Journal article

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  • Enantiomer resolution by pressure increase: inferences from experimental and topological results for the binary enantiomer system (R)- and (S)-mandelic acid

     Rietveld, Ivo B.; Del Barrio Casado, Maria; Tamarit Mur, Jose Luis; Do, Bernard; Céolin, René
    Journal of physical chemistry B
    Vol. 115, num. 49, p. 14698-14703
    DOI: 10.1021/jp209328d
    Date of publication: 2011-11-02
    Journal article

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    In pharmacy, racemic compounds are often problematic, because generally only one of the enantiomers possesses therapeutic activity and it is often difficult to separate them. Even though this problem is likely as old as the pharmaceutical industry, one thermodynamically obvious way of separating racemic crystals has never been studied experimentally, which is by using pressure. Data have been obtained on the equilibria of the (R)- and (S)-mandelic acid system as a function of pressure and temperature. With the use of thermodynamic arguments including the Clapeyron, Schr€oder, and Prigogine Defay equations, it has been demonstrated that the conglomerate (crystals of separated enantiomers) becomes more stable than the racemic compound at approximately 0.64 GPa and 460 K. Even though this pressure is still higher than at the bottom of the Mariana Trench, there are no technical obstacles to produce such conditions, making pressure a viable option for separating enantiomers.

  • Secondary relaxations of orientationally disordered mixed crystals at temperatures lower than the glass transition temperature

     Martinez-Garcia, Julio C.; Tamarit Mur, Jose Luis; Pardo Soto, Luis Carlos; Del Barrio Casado, Maria; Rzoska, S. J.; Drozd-Rzoska, A.
    Physica status solidi A. Applications and materials science (Print edition)
    Vol. 208, num. 10, p. 2254-2257
    DOI: 10.1002/pssa.201000726
    Date of publication: 2011-06-16
    Journal article

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