1
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Beran GJO. Frontiers of molecular crystal structure prediction for pharmaceuticals and functional organic materials. Chem Sci 2023; 14:13290-13312. [PMID: 38033897 PMCID: PMC10685338 DOI: 10.1039/d3sc03903j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023] Open
Abstract
The reliability of organic molecular crystal structure prediction has improved tremendously in recent years. Crystal structure predictions for small, mostly rigid molecules are quickly becoming routine. Structure predictions for larger, highly flexible molecules are more challenging, but their crystal structures can also now be predicted with increasing rates of success. These advances are ushering in a new era where crystal structure prediction drives the experimental discovery of new solid forms. After briefly discussing the computational methods that enable successful crystal structure prediction, this perspective presents case studies from the literature that demonstrate how state-of-the-art crystal structure prediction can transform how scientists approach problems involving the organic solid state. Applications to pharmaceuticals, porous organic materials, photomechanical crystals, organic semi-conductors, and nuclear magnetic resonance crystallography are included. Finally, efforts to improve our understanding of which predicted crystal structures can actually be produced experimentally and other outstanding challenges are discussed.
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Affiliation(s)
- Gregory J O Beran
- Department of Chemistry, University of California Riverside Riverside CA 92521 USA
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2
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Global analysis of the energy landscapes of molecular crystal structures by applying the threshold algorithm. Commun Chem 2022; 5:86. [PMID: 36697680 PMCID: PMC9814927 DOI: 10.1038/s42004-022-00705-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 07/15/2022] [Indexed: 01/28/2023] Open
Abstract
Polymorphism in molecular crystals has important consequences for the control of materials properties and our understanding of crystallization. Computational methods, including crystal structure prediction, have provided important insight into polymorphism, but have usually been limited to assessing the relative energies of structures. We describe the implementation of the Monte Carlo threshold algorithm as a method to provide an estimate of the energy barriers separating crystal structures. By sampling the local energy minima accessible from multiple starting structures, the simulations yield a global picture of the crystal energy landscapes and provide valuable information on the depth of the energy minima associated with crystal structures. We present results from applying the threshold algorithm to four polymorphic organic molecular crystals, examine the influence of applying space group symmetry constraints during the simulations, and discuss the relationship between the structure of the energy landscape and the intermolecular interactions present in the crystals.
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3
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Price SL. Progress in understanding crystallisation: a personal perspective. Faraday Discuss 2022; 235:569-581. [DOI: 10.1039/d2fd00077f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
After this discussion meeting, most participants felt that we do not understand crystallisation. However, in the 1980s I believe that most scientists would have considered that crystallisation was adequately understood....
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4
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Braun DE. The trimorphism of 3-hydroxybenzoic acid: an experimental and computational study. CrystEngComm 2021. [DOI: 10.1039/d1ce00159k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A computationally driven experimental search for polymorphs of 3-hydroxybenzoic acid confirmed the third form and the small energy differences between the polymorphs.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy
- University of Innsbruck
- 6020 Innsbruck
- Austria
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5
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Reutzel-Edens SM, Bhardwaj RM. Crystal forms in pharmaceutical applications: olanzapine, a gift to crystal chemistry that keeps on giving. IUCRJ 2020; 7:955-964. [PMID: 33209310 PMCID: PMC7642794 DOI: 10.1107/s2052252520012683] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
This contribution reviews the efforts of many scientists around the world to discover and structurally characterize olanzapine crystal forms, clearing up inconsistencies in the scientific and patent literature and highlighting the challenges in identifying new forms amidst 60+ known polymorphs and solvates. Owing to its remarkable solid-state chemistry, olanzapine has emerged over the last three decades as a popular tool compound for developing new experimental and computational methods for enhanced molecular level understanding of solid-state structure, form diversity and crystallization outcomes. This article highlights the role of olanzapine in advancing the fundamental understanding of crystal forms, interactions within crystal structures, and growth units in molecular crystallization, as well as influencing the way in which drugs are developed today.
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Affiliation(s)
- Susan M. Reutzel-Edens
- Synthetic Molecule Design and Development, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Rajni M. Bhardwaj
- Synthetic Molecule Design and Development, Eli Lilly and Company, Indianapolis, IN 46285, USA
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6
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Jurczak E, Mazurek AH, Szeleszczuk Ł, Pisklak DM, Zielińska-Pisklak M. Pharmaceutical Hydrates Analysis-Overview of Methods and Recent Advances. Pharmaceutics 2020; 12:pharmaceutics12100959. [PMID: 33050621 PMCID: PMC7601571 DOI: 10.3390/pharmaceutics12100959] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/26/2020] [Accepted: 10/07/2020] [Indexed: 11/16/2022] Open
Abstract
This review discusses a set of instrumental and computational methods that are used to characterize hydrated forms of APIs (active pharmaceutical ingredients). The focus has been put on highlighting advantages as well as on presenting some limitations of the selected analytical approaches. This has been performed in order to facilitate the choice of an appropriate method depending on the type of the structural feature that is to be analyzed, that is, degree of hydration, crystal structure and dynamics, and (de)hydration kinetics. The presented techniques include X-ray diffraction (single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD)), spectroscopic (solid state nuclear magnetic resonance spectroscopy (ssNMR), Fourier-transformed infrared spectroscopy (FT-IR), Raman spectroscopy), thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)), gravimetric (dynamic vapour sorption (DVS)), and computational (molecular mechanics (MM), Quantum Mechanics (QM), molecular dynamics (MD)) methods. Further, the successful applications of the presented methods in the studies of hydrated APIs as well as studies on the excipients' influence on these processes have been described in many examples.
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Affiliation(s)
- Ewa Jurczak
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 str., 02-093 Warsaw, Poland; (E.J.); (A.H.M.); (D.M.P.)
| | - Anna Helena Mazurek
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 str., 02-093 Warsaw, Poland; (E.J.); (A.H.M.); (D.M.P.)
| | - Łukasz Szeleszczuk
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 str., 02-093 Warsaw, Poland; (E.J.); (A.H.M.); (D.M.P.)
- Correspondence: ; Tel.: +48-501-255-121
| | - Dariusz Maciej Pisklak
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 str., 02-093 Warsaw, Poland; (E.J.); (A.H.M.); (D.M.P.)
| | - Monika Zielińska-Pisklak
- Department of Biomaterials Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 str., 02-093 Warsaw, Poland;
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7
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Mazurek AH, Szeleszczuk Ł, Pisklak DM. Periodic DFT Calculations-Review of Applications in the Pharmaceutical Sciences. Pharmaceutics 2020; 12:E415. [PMID: 32369915 PMCID: PMC7284980 DOI: 10.3390/pharmaceutics12050415] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 12/31/2022] Open
Abstract
In the introduction to this review the complex chemistry of solid-state pharmaceutical compounds is summarized. It is also explained why the density functional theory (DFT) periodic calculations became recently so popular in studying the solid APIs (active pharmaceutical ingredients). Further, the most popular programs enabling DFT periodic calculations are presented and compared. Subsequently, on the large number of examples, the applications of such calculations in pharmaceutical sciences are discussed. The mentioned topics include, among others, validation of the experimentally obtained crystal structures and crystal structure prediction, insight into crystallization and solvation processes, development of new polymorph synthesis ways, and formulation techniques as well as application of the periodic DFT calculations in the drug analysis.
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Affiliation(s)
| | - Łukasz Szeleszczuk
- Chair and Department of Physical Pharmacy and Bioanalysis, Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 str., 02-093 Warsaw, Poland; (A.H.M.); (D.M.P.)
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8
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Hu Y, Jiang C, Li B, Zhou L, Xu R, Guo Y, Cao Y, Cao G, Lu S. A novel lurasidone hydrochloride–shikimic acid co-amorphous system formed by hydrogen-bonding interaction with the retained pH-dependent solubility behavior. CrystEngComm 2020. [DOI: 10.1039/d0ce00952k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The current study was aimed at investigating the lurasidone hydrochloride–shikimic acid co-amorphous system using a new type of organic acid.
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Affiliation(s)
- Yi Hu
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
| | - Cuiping Jiang
- School of Traditional Chinese Medicine
- Southern Medical University
- Guangzhou 510515
- PR China
| | - Bin Li
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
| | - Lijing Zhou
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
| | - Renjie Xu
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
| | - Yujie Guo
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
| | - Yan Cao
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
| | - Guosheng Cao
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
| | - Shan Lu
- School of Pharmacy
- Hubei University of Chinese Medicine
- Wuhan 430065
- PR China
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9
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Braun D, Rivalta A, Giunchi A, Bedoya-Martinez N, Schrode B, Venuti E, Della Valle RG, Werzer O. Surface Induced Phenytoin Polymorph. 1. Full Structure Solution by Combining Grazing Incidence X-ray Diffraction and Crystal Structure Prediction. CRYSTAL GROWTH & DESIGN 2019; 19:6058-6066. [PMID: 31728132 PMCID: PMC6839513 DOI: 10.1021/acs.cgd.9b00857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/15/2019] [Indexed: 05/31/2023]
Abstract
Understanding the behavior and properties of molecules assembled in thin layers requires knowledge of their crystalline packing. The drug phenytoin (5,5-diphenylhydantoin) is one of the compounds that can be grown as a surface induced polymorph. By using grazing incidence X-ray diffraction, the monoclinic unit cell of the new form II can be determined, but, due to crystal size and the low amount of data, a full solution using conventional structure solving strategies fails. In this work, the full solution has been obtained by combining computational structure generation and experimental results. The comparison between the bulk and the new surface induced phase reveals significant packing differences of the hydrogen-bonding network, which might be the reason for the faster dissolution of form II with respect to form I. The results are very satisfactory, and the method might be adapted for other systems, where, due to the limited amount of experimental data, one must rely on additional approaches to gain access to more detailed information to understand the solid-state behavior.
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Affiliation(s)
- Doris
E. Braun
- Institute
of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Arianna Rivalta
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Andrea Giunchi
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | | | - Benedikt Schrode
- Institute
of Solid State Physics, NAWI Graz, Graz
University of Technology, Petersgasse 16, 8010 Graz, Austria
- Institute
of Pharmaceutical Science, Department of Pharmaceutical Technology, University of Graz, Univertitaetsplatz 1, 8010 Graz, Austria
| | - Elisabetta Venuti
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Raffaele Guido Della Valle
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Oliver Werzer
- Institute
of Pharmaceutical Science, Department of Pharmaceutical Technology, University of Graz, Univertitaetsplatz 1, 8010 Graz, Austria
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10
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Bhardwaj RM, McMahon JA, Nyman J, Price LS, Konar S, Oswald IDH, Pulham CR, Price SL, Reutzel-Edens SM. A Prolific Solvate Former, Galunisertib, under the Pressure of Crystal Structure Prediction, Produces Ten Diverse Polymorphs. J Am Chem Soc 2019; 141:13887-13897. [DOI: 10.1021/jacs.9b06634] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rajni M. Bhardwaj
- Small Molecule Design & Development, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
| | - Jennifer A. McMahon
- Small Molecule Design & Development, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
| | - Jonas Nyman
- Small Molecule Design & Development, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
- School of Pharmacy, University of Wisconsin—Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Louise S. Price
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Sumit Konar
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Iain D. H. Oswald
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral St, Glasgow G4 0RE, U.K
| | - Colin R. Pulham
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Sarah L. Price
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Susan M. Reutzel-Edens
- Small Molecule Design & Development, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
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11
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Braun DE, Vickers M, Griesser UJ. Dapsone Form V: A Late Appearing Thermodynamic Polymorph of a Pharmaceutical. Mol Pharm 2019; 16:3221-3236. [PMID: 31075201 DOI: 10.1021/acs.molpharmaceut.9b00419] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Five anhydrate polymorphs (forms I-V) and the isomorphic dehydrate (Hydehy) of dapsone (4,4'-diaminodiphenyl sulfone or DDS) were prepared and characterized in an interdisciplinary experimental and computational study, elucidating the kinetic and thermodynamic stabilities, solid form interrelationships, and structural features of the known forms I-IV, the novel polymorph form V, and Hydehy. Calorimetric measurements, solubility experiments, and lattice energy calculations revealed that form V is the thermodynamically stable polymorph from absolute zero to at least 90 °C. At higher temperatures, form II, and then form I, becomes the most stable DDS solid form. The computed 0 K stability order (lattice energy calculations) was confirmed with calorimetric measurements as follows, V (most stable) > III > Hydehy > II > I > IV (least stable). The discovery of form V was complicated by the fact that the metastable but kinetically stabilized form III shows a higher nucleation and growth rate. By combining laboratory powder X-ray diffraction data and ab initio calculations, the crystal structure of form V ( P21/ c, Z' = 4) was solved, with a high energy DDS conformation allowing a denser packing and more stable intermolecular interactions, rationalizing the formation of a high Z' structure. The structures of the forms I and IV, only observed from the melt and showing distinct packing features compared to the forms II, III, and V, were derived from the computed crystal energy landscapes. Dehydration modeling of the DDS hydrate led to the Hydehy structure. This study expands our understanding about the complex crystallization behavior of pharmaceuticals and highlights the big challenge in solid form screening, especially that there is no clear end point.
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Affiliation(s)
- Doris E Braun
- Institute of Pharmacy , University of Innsbruck , Innrain 52c , 6020 Innsbruck , Austria
| | - Martin Vickers
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , U.K
| | - Ulrich J Griesser
- Institute of Pharmacy , University of Innsbruck , Innrain 52c , 6020 Innsbruck , Austria
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12
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Quan Y, Yang Y, Xu S, Zhu P, Liu S, Jia L, Gong J. Insight into the role of piperazine in the thermodynamics and nucleation kinetics of the triethylenediamine–methyl tertiary butyl ether system. CrystEngComm 2019. [DOI: 10.1039/c8ce01179f] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Considering the role of piperazine in the TEDA–MTBE system, we investigate how to control the crystal size distribution.
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Affiliation(s)
- Yufeng Quan
- State Key Laboratory of Chemical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Yang Yang
- State Key Laboratory of Chemical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Shijie Xu
- State Key Laboratory of Chemical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Peipei Zhu
- State Key Laboratory of Chemical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Shiyuan Liu
- State Key Laboratory of Chemical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Lina Jia
- State Key Laboratory of Chemical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Junbo Gong
- State Key Laboratory of Chemical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- P. R. China
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13
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Price SL. Control and prediction of the organic solid state: a challenge to theory and experiment †. Proc Math Phys Eng Sci 2018; 474:20180351. [PMID: 30333710 PMCID: PMC6189584 DOI: 10.1098/rspa.2018.0351] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/15/2018] [Indexed: 11/12/2022] Open
Abstract
The ability of theoretical chemists to quantitatively model the weak forces between organic molecules is being exploited to predict their crystal structures and estimate their physical properties. Evolving crystal structure prediction methods are increasingly being used to aid the design of organic functional materials and provide information about thermodynamically plausible polymorphs of speciality organic materials to aid, for example, pharmaceutical development. However, the increasingly sophisticated experimental studies for detecting the range of organic solid-state behaviours provide many challenges for improving quantitative theories that form the basis for the computer modelling. It is challenging to calculate the relative thermodynamic stability of different organic crystal structures, let alone understand the kinetic effects that determine which polymorphs can be observed and are practically important. However, collaborations between experiment and theory are reaching the stage of devising experiments to target the first crystallization of new polymorphs or create novel organic molecular materials.
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Affiliation(s)
- Sarah L. Price
- Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, UK
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14
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Braun DE, Griesser UJ. Supramolecular Organization of Nonstoichiometric Drug Hydrates: Dapsone. Front Chem 2018; 6:31. [PMID: 29520359 PMCID: PMC5826966 DOI: 10.3389/fchem.2018.00031] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/09/2018] [Indexed: 12/16/2022] Open
Abstract
The observed moisture- and temperature dependent transformations of the dapsone (4,4'-diaminodiphenyl sulfone, DDS) 0. 33-hydrate were correlated to its structure and the number and strength of the water-DDS intermolecular interactions. A combination of characterization techniques was used, including thermal analysis (hot-stage microscopy, differential scanning calorimetry and thermogravimetric analysis), gravimetric moisture sorption/desorption studies and variable humidity powder X-ray diffraction, along with computational modeling (crystal structure prediction and pair-wise intermolecular energy calculations). Depending on the relative humidity the hydrate contains between 0 and 0.33 molecules of water per molecule DDS. The crystal structure is retained upon dehydration indicating that DDS hydrate shows a non-stoichiometric (de)hydration behavior. Unexpectedly, the water molecules are not located in structural channels but at isolated-sites of the host framework, which is counterintuitively for a hydrate with non-stoichiometric behavior. The water-DDS interactions were estimated to be weaker than water-host interactions that are commonly observed in stoichiometric hydrates and the lattice energies of the isomorphic dehydration product (hydrate structure without water molecules) and (form III) differ only by ~1 kJ mol-1. The computational generation of hypothetical monohydrates confirms that the hydrate with the unusual DDS:water ratio of 3:1 is more stable than a feasible monohydrate structure. Overall, this study highlights that a deeper understanding of the formation of hydrates with non-stoichiometric behavior requires a multidisciplinary approach including suitable experimental and computational methods providing a firm basis for the development and manufacturing of high quality drug products.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
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15
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Price SL. Is zeroth order crystal structure prediction (CSP_0) coming to maturity? What should we aim for in an ideal crystal structure prediction code? Faraday Discuss 2018; 211:9-30. [PMID: 30051901 DOI: 10.1039/c8fd00121a] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crystal structure prediction based on searching for the global minimum in the lattice energy (CSP_0) is growing in use for guiding the discovery of new materials, for example, new functional materials, new phases of interest to planetary scientists and new polymorphs relevant to pharmaceutical development. This Faraday Discussion can assess the progress of CSP_0 over the range of types of materials to which CSP is currently and could be applied, which depends on our ability to model the variety of interatomic forces in crystals. The basic hypothesis, that the outcome of crystallisation is determined by thermodynamics, needs examining by considering methods of modelling relative thermodynamic stability not only as a function of pressure and temperature, but also of size, solvent and the presence of heterogeneous templates or impurities (CSP_thd). Given that many important materials persist, and indeed may be formed, when they are not the most thermodynamically stable structure, we need to define what would be required of an ideal CSP code (CSP_aim).
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Affiliation(s)
- Sarah L Price
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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16
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Braun DE, Raabe K, Schneeberger A, Kahlenberg V, Griesser UJ. New Insights into Solid Form Stability and Hydrate Formation: o-Phenanthroline HCl and Neocuproine HCl. Molecules 2017; 22:molecules22122238. [PMID: 29244765 PMCID: PMC6149885 DOI: 10.3390/molecules22122238] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 12/11/2017] [Accepted: 12/12/2017] [Indexed: 11/27/2022] Open
Abstract
The moisture- and temperature dependent stabilities and interrelation pathways of the practically relevant solid forms of o-phenanthroline HCl (1) and neocuproine HCl (2) were investigated using thermal analytical techniques (HSM, DSC and TGA) and gravimetric moisture sorption/desorption studies. The experimental stability data were correlated with the structural changes observed upon dehydration and the pairwise interaction and lattice energies calculated. For 1 the monohydrate was identified as the only stable form under conditions of RH typically found during production and storage, but at RH values >80% deliquescence occurs. The second compound, 2, forms an anhydrate and two different hydrates, mono- (2-Hy1) and trihydrate (2-Hy3). The 2-Hy1 structure was solved from SCXRD data and the anhydrate structure derived from a combination of PXRD and CSP. Depending on the environmental conditions (moisture) either 2-Hy1 or 2-Hy3 is the most sable solid form of 2 at RT. The monohydrates 1-Hy1 and 2-Hy1 show a high enthalpic stabilization (≥20 kJ mol−1) relative to the anhydrates. The anhydrates are unstable at ambient conditions and readily transform to the monohydrates even in the presence of traces of moisture. This study demonstrates how the right combination of experiment and theory can unravel the properties and interconversion pathways of solid forms.
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Affiliation(s)
- Doris E Braun
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria.
| | - Katharina Raabe
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria.
| | - Anna Schneeberger
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria.
| | - Volker Kahlenberg
- Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria.
| | - Ulrich J Griesser
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria.
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17
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Braun DE, Schneeberger A, Griesser UJ. Understanding the Role of Water in 1,10-Phenanthroline Monohydrate. CrystEngComm 2017; 19:6133-6145. [PMID: 30344448 PMCID: PMC6195195 DOI: 10.1039/c7ce01371j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The solid forms emerging from an experimental screening programme of 1,10-phenanthroline (o-phen), a heavily used bidentate ligand, and interconversion pathways of its two neat forms, the monohdyrate (Hy1) and four solvates with acetone, chloroform, dichloromethane and 1,2-dichloroethane are described. The solvates, identified and characterised with thermoanalyical methods, are unstable when removed from the mother liquor and desolvate at room temperature depending on the relative humidity (RH) to anhydrate I° (AH I°) or transform to Hy1. At ambient conditions Hy1, a stoichiometric channel hydrate, is the thermodynaically most stable o-phen solid form. The enthalpically stabilised Hy1 melts at 102 °C or dehydrates to AH I° at RH < 10% at 25 °C. The potential energy difference between Hy1 and AH I° was calculated to be approx. 15 kJ mol-1. The second anhydrate polymorph (AH II) can be obatined from the quench cooled melt of o-phen, but is unstable at ambient conditions and transforms wihtin minutes to either AH I° or Hy1. The two neat polymorphs are enantiotropically related and water-free o-phen transforms to Hy1 at RH > 16%. The structural and stablity features of the solid forms, in paricular Hy1, are unravelled by a combination of experimental (thermal analysis, moisture sorption/desorption and storage experiments, infrared spectroscopy and powder X-ray diffraction) and computational modelling (crystal structure prediction and lattice energy calculations), providing a consistent picture why o-phen forms a very stable Z' = 3 channel hydrate.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020
Innsbruck, Austria
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18
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Braun D, Lingireddy SR, Beidelschies MD, Guo R, Müller P, Price SL, Reutzel-Edens SM. Unraveling Complexity in the Solid Form Screening of a Pharmaceutical Salt: Why so Many Forms? Why so Few? CRYSTAL GROWTH & DESIGN 2017; 17:5349-5365. [PMID: 29018305 PMCID: PMC5629560 DOI: 10.1021/acs.cgd.7b00842] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/28/2017] [Indexed: 06/07/2023]
Abstract
The solid form landscape of 5-HT2a antagonist 3-(4-(benzo[d]isoxazole-3-yl)piperazin-1-yl)-2,2-dimethylpropanoic acid hydrochloride (B5HCl) proved difficult to establish. Many crystalline materials were produced by solid form screening, but few forms readily grew high quality crystals to afford a clear picture or understanding of the solid form landscape. Careful control of crystallization conditions, a range of experimental methods, computational modeling of solvate structures, and crystal structure prediction were required to see potential arrangements of the salt in its crystal forms. Structural diversity in the solid form landscape of B5HCl was apparent in the layer structures for the anhydrate polymorphs (Forms I and II), dihydrate and a family of solvates with alcohols. The alcohol solvates, which provided a distinct packing from the neat forms and the dihydrate, form layers with conserved hydrogen bonding between B5HCl and the solvent, as well as stacking of the aromatic rings. The ability of the alcohol hydrocarbon moieties to efficiently pack between the layers accounted for the difficulty in growing some solvate crystals and the inability of other solvates to crystallize altogether. Through a combination of experiment and computation, the crystallization problems, form stability, and desolvation pathways of B5HCl have been rationalized at a molecular level.
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Affiliation(s)
- Doris
E. Braun
- Institute
of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | | | - Mark D. Beidelschies
- Eurofins
Lancaster Laboratories, PSS, Indianapolis, Indiana 46285, United States
| | - Rui Guo
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Peter Müller
- X-Ray Diffraction
Facility, MIT Department of Chemistry, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Sarah L. Price
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
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Iuzzolino L, Reilly AM, McCabe P, Price SL. Use of Crystal Structure Informatics for Defining the Conformational Space Needed for Predicting Crystal Structures of Pharmaceutical Molecules. J Chem Theory Comput 2017; 13:5163-5171. [PMID: 28892623 DOI: 10.1021/acs.jctc.7b00623] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Determining the range of conformations that a flexible pharmaceutical-like molecule could plausibly adopt in a crystal structure is a key to successful crystal structure prediction (CSP) studies. We aim to use conformational information from the crystal structures in the Cambridge Structural Database (CSD) to facilitate this task. The conformations produced by the CSD Conformer Generator are reduced in number by considering the underlying rotamer distributions, an analysis of changes in molecular shape, and a minimal number of molecular ab initio calculations. This method is tested for five pharmaceutical-like molecules where an extensive CSP study has already been performed. The CSD informatics-derived set of crystal structure searches generates almost all the low-energy crystal structures previously found, including all experimental structures. The workflow effectively combines information on individual torsion angles and then eliminates the combinations that are too high in energy to be found in the solid state, reducing the resources needed to cover the solid-state conformational space of a molecule. This provides insights into how the low-energy solid-state and isolated-molecule conformations are related to the properties of the individual flexible torsion angles.
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Affiliation(s)
- Luca Iuzzolino
- Department of Chemistry, University College London , 20 Gordon Street, London WC1H 0AJ, England
| | - Anthony M Reilly
- The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, England
| | - Patrick McCabe
- The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, England
| | - Sarah L Price
- Department of Chemistry, University College London , 20 Gordon Street, London WC1H 0AJ, England
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Braun DE, Kahlenberg V, Griesser UJ. Experimental and Computational Hydrate Screening: Cytosine, 5-Flucytosine and Their Solid Solution. CRYSTAL GROWTH & DESIGN 2017; 17:4347-4364. [PMID: 30344452 PMCID: PMC6193535 DOI: 10.1021/acs.cgd.7b00664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The structural, temperature- and moisture dependent stability features of cytosine and 5-flucytosine monohydrates, two pharmaceutically important compounds, were rationalized using complementary experimental and computational approaches. Moisture sorption/desorption, water activity, thermal analysis and calorimetry were applied to determine the stability ranges of hydrate ↔ anhydrate systems, while X-ray diffraction, IR spectroscopy and crystal structure prediction provided the molecular level understanding. At 25 °C, the critical water activity for the cytosine hydrate ↔ anhydrate system is ~0.43 and for 5-flucytosine ~0.41. In 5-flucytosine the water molecules are arranged in open channels, therefore the kinetic desorption data, dehydration < 40% relative humidity (RH), conform with the thermodynamic data, whereas for the cytosine isolated site hydrate dehydration was observed at RH < 15%. Peritectic dissociation temperatures of the hydrates were measured to be 97 °C and 84.2 °C for cytosine and 5-flucytosine, respectively, and the monohydrate to anhydrate transition enthalpies to be around 10 kJ mol-1. Computed crystal energy landscapes not only revealed that the substitution of C5 (H or F) controls the packing and properties of cytosine/5-flucytosine solid forms, but also have enabled the finding of a monohydrate solid solution of the two substances which shows increased thermal- and moisture-dependent stability compared to 5-flucytosine monohydrate.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Volker Kahlenberg
- Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria
| | - Ulrich J. Griesser
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
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Braun DE, Griesser UJ. Prediction and experimental validation of solid solutions and isopolymorphs of cytosine/5-flucytosine. CrystEngComm 2017; 19:3566-3572. [PMID: 30405321 PMCID: PMC6218006 DOI: 10.1039/c7ce00939a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
A computational search for polymorphs of cytosine, 5-flucytosine and a 1 : 1 mixture of the two substances not only rationalised the preferred packing arrangements but also enabled the finding and characterisation of cytosine/5-flucytosine solid solutions. The structures of the new solid forms were determined by combining laboratory powder X-ray diffraction data and computational modelling.
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Affiliation(s)
| | - U. J. Griesser
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
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Putra OD, Umeda D, Nugraha YP, Furuishi T, Nagase H, Fukuzawa K, Uekusa H, Yonemochi E. Solubility improvement of epalrestat by layered structure formation via cocrystallization. CrystEngComm 2017. [DOI: 10.1039/c7ce00284j] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Braun DE, Griesser UJ. Why do Hydrates (Solvates) Form in Small Neutral Organic Molecules? Exploring the Crystal Form Landscapes of the Alkaloids Brucine and Strychnine. CRYSTAL GROWTH & DESIGN 2016; 16:6405-6418. [PMID: 28670205 PMCID: PMC5486441 DOI: 10.1021/acs.cgd.6b01078] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Computational methods were used to generate and explore the crystal structure landscapes of the two alkaloids strychnine and brucine. The computed structures were analyzed and rationalized by correlating the modelling results to a rich pool of available experimental data. Despite their structural similarity, the two compounds show marked differences in the formation of solid forms. For strychnine only one anhydrous form is reported in the literature and two new solvates from 1,4-dioxane were detected in the course of this work. In contrast, 22 solid forms are so far known to exist for brucine, comprising two anhydrates, four hydrates (HyA - HyC and a 5.25-hydrate), twelve solvates (alcohols and acetone) and four heterosolvates (mixed solvates with water and alcohols). For strychnine it is hard to produce any solid form other than the stable anhydrate while the formation of specific solid state forms of brucine is governed by a complex interplay between temperature and relative humidity/water activity and it is rather a challenging to avoid hydrate formation. Differences in crystal packing and the high tendency for brucine to form hydrates are not intuitive from the molecular structure alone, as both molecules have hydrogen bond acceptor groups but lack hydrogen bond donor groups. Only the evaluation of the crystal energy landscapes, in particular the close-packed crystal structures and high-energy open frameworks containing voids of molecular (water) dimensions, allowed us to unravel the diverse solid state behavior of the two alkaloids at a molecular level. In this study we demonstrate that expanding the analysis of anhydrate crystal energy landscapes to higher energy structures and calculating the solvent-accessible volume can be used to estimate non-stoichiometric or channel hydrate (solvate) formation, without explicitly computing the hydrate/solvate crystal energy landscapes.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Ulrich J. Griesser
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
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Braun DE, Griesser UJ. Stoichiometric and Non-Stoichiometric Hydrates of Brucine. CRYSTAL GROWTH & DESIGN 2016; 16:6111-6121. [PMID: 28670204 PMCID: PMC5486439 DOI: 10.1021/acs.cgd.6b01231] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The complex interplay of temperature and water activity (aw) / relative humidity (RH) on the solid form stability and transformation pathways of three hydrates (HyA, HyB and HyC), an isostructural dehydrate (HyAdehy ), an anhydrate (AH) and amorphous brucine has been elucidated and the transformation enthalpies quantified. The dihydrate (HyA) shows a non-stoichimetric (de)hydration behavior at RH < 40% at 25 °C and the removal of the water molecules results in an isomorphic dehydrate structure. The metastable dehydration product converts to AH upon storage at driest conditions or to HyA if exposed to moisture. HyB is a stoichiometric tetrahydrate. The loss of the water molecules causes HyB to collapse to an amorphous phase. Amorphous brucine transforms to AH at RH < 40% RH and a mixture of hydrated phases at higher RH values. The third hyrdate (HyC) is only stable at RH ≥ 55% at 25 °C and contains 3.65 to 3.85 mole equivalent of water. Dehydration of HyC occurs in one step at RH < 55% at 25 °C or upon heating and AH is obtained. The AH is the thermodynamically most stable phase of brucine at RH < 40% at 25 °C. Depending on the conditions, temperature and aw, each of the three hydrates becomes the thermodynamically most stable form. This study demonstrates the importance of applying complimentary analytical techniques and appropriate approaches for understanding the stability ranges and transition behavior between the solid forms of compounds with multiple hydrates.
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Price SL, Braun DE, Reutzel-Edens SM. Can computed crystal energy landscapes help understand pharmaceutical solids? Chem Commun (Camb) 2016; 52:7065-77. [PMID: 27067116 PMCID: PMC5486446 DOI: 10.1039/c6cc00721j] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Computational crystal structure prediction (CSP) methods can now be applied to the smaller pharmaceutical molecules currently in drug development. We review the recent uses of computed crystal energy landscapes for pharmaceuticals, concentrating on examples where they have been used in collaboration with industrial-style experimental solid form screening. There is a strong complementarity in aiding experiment to find and characterise practically important solid forms and understanding the nature of the solid form landscape.
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Affiliation(s)
- Sarah L Price
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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Price SL, Reutzel-Edens SM. The potential of computed crystal energy landscapes to aid solid-form development. Drug Discov Today 2016; 21:912-23. [DOI: 10.1016/j.drudis.2016.01.014] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/04/2015] [Accepted: 01/26/2016] [Indexed: 11/29/2022]
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Braun DE, Gelbrich T, Wurst K, Griesser UJ. Computational and Experimental Characterization of Five Crystal Forms of Thymine: Packing Polymorphism, Polytypism/Disorder and Stoichiometric 0.8-Hydrate. CRYSTAL GROWTH & DESIGN 2016; 16:3480-3496. [PMID: 28663717 PMCID: PMC5486440 DOI: 10.1021/acs.cgd.6b00459] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
New polymorphs of thymine emerged in an experimental search for solid forms, which was guided by the computationally generated crystal energy landscape. Three of the four anhydrates (AH) are homeoenergetic (A° - C) and their packing modes differ only in the location of oxygen and hydrogen atoms. AHs A° and B are ordered phases, whereas AH C shows disorder (X-ray diffuse scattering). Anhydrates AHs A° and B are ordered phases, whereas AH C shows disorder (X-ray diffuse scattering). Analysis of the crystal energy landscape for alternative AH C hydrogen bonded ribbon motifs identified a number of different packing modes, whose 3D structures were calculated to deviate by less than 0.24 kJ mol-1 in lattice energy. These structures provide models for stacking faults. The three anhydrates A° - C show strong similarity in their powder X-ray diffraction, thermoanalytical and spectroscopic (IR and Raman) characteristics. The already known anhydrate AH A° was identified as the thermodynamically most stable form at ambient conditions; AH B and AH C are metastable but show high kinetic stability. The hydrate of thymine is stable only at water activities (aw) > 0.95 at temperatures ≤ 25 °C. It was found to be a stoichiometric hydrate despite being a channel hydrate with an unusual water:thymine ratio of 0.8:1. Depending on the dehydration conditions, either AH C or AH D is obtained. The hydrate is the only known precursor to AH D. This study highlights the value and complementarity of simultaneous explorations of computationally and experimentally generated solid form landscapes of a small molecule anhydrate ↔ hydrate system.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Thomas Gelbrich
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Klaus Wurst
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Ulrich J. Griesser
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
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Saïd S, Naïli H, Bataille T, Herrera RP. Crystallisation, thermal analysis and acetal protection activity of new layered Zn( ii) hybrid polymorphs. CrystEngComm 2016. [DOI: 10.1039/c6ce00486e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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