1
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Andrews J, Kennedy SR, Yufit DS, McCabe JF, Steed JW. Designer Gelators for the Crystallization of a Salt Active Pharmaceutical Ingredient-Mexiletine Hydrochloride. CRYSTAL GROWTH & DESIGN 2022; 22:6775-6785. [PMID: 36345390 PMCID: PMC9635620 DOI: 10.1021/acs.cgd.2c00925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 10/03/2022] [Indexed: 06/16/2023]
Abstract
We report an approach to obtain drug-mimetic supramolecular gelators, which are capable of stabilizing metastable polymorphs of the pharmaceutical salt mexiletine hydrochloride, a highly polymorphic antiarrhythmic drug. Solution-phase screening led to the discovery of two new solvated solid forms of mexiletine, a type C 1,2,4-trichlorobenzene tetarto-solvate and a type D nitrobenzene solvate. Various metastable forms were crystallized within the gels under conditions which would not have been possible in solution. Despite typically crystallizing concomitantly with form 1, a pure sample of form 3 was crystallized within a gel of ethyl methyl ketone. Various type A channel solvates were crystallized from gels of toluene and ethyl acetate, in which the contents of the channels varied from those of solution-phase forms. Most strikingly, the high-temperature-stable form 2 was crystallized from a gel in 1,2-dibromoethane: the only known route to access this form at room temperature. These results exemplify the powerful stabilizing effect of drug-mimetic supramolecular gels, which can be exploited in pharmaceutical polymorph screens to access highly metastable or difficult-to-nucleate solid forms.
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Affiliation(s)
- Jessica
L. Andrews
- Department
of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K.
| | - Stuart R. Kennedy
- Department
of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K.
| | - Dmitry S. Yufit
- Department
of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K.
| | - James F. McCabe
- Pharmaceutical
Sciences, R&D, AstraZeneca, Charter Way, Silk Road Business Park, Macclesfield SK10 2NA, U.K.
| | - Jonathan W. Steed
- Department
of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K.
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2
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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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3
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Sanphui P, Pillai RS. A disappearing metastable hydrate form of L-citrulline: Variable conformations in polymorphs and hydrates. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Pettersen A, Putra OD, Light ME, Namatame Y. A peculiar dehydration and solid–solid phase transition of the active pharmaceutical ingredient AZD9898 based on in situ single crystal-to-single crystal transformations. CrystEngComm 2020. [DOI: 10.1039/d0ce00276c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Isostructural dehydration from form A hydrate to form B, and solid–solid phase transition from form B to C of AZD9898 were revealed by in situ single crystal-to-single crystal transformations.
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Affiliation(s)
- Anna Pettersen
- Early Product Development and Manufacturing
- Pharmaceutical Sciences
- BioPharmaceuticals R&D
- AstraZeneca Gothenburg
- Mölndal SE-431 83
| | - Okky Dwichandra Putra
- New Modality and Parenteral Development
- Pharmaceutical Technology and Development
- AstraZeneca Gothenburg
- Mölndal SE-431 83
- Sweden
| | - Mark E. Light
- UK National Crystallography Service
- School of Chemistry
- Faculty of Engineering and Physical Sciences
- University of Southampton
- SO17 1BJ Southampton
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5
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Baranović G, Šegota S. Infrared spectroscopy of flavones and flavonols. Reexamination of the hydroxyl and carbonyl vibrations in relation to the interactions of flavonoids with membrane lipids. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 192:473-486. [PMID: 29220817 DOI: 10.1016/j.saa.2017.11.057] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/18/2017] [Accepted: 11/25/2017] [Indexed: 05/27/2023]
Abstract
Detailed vibrational assignments for twelve flavonoids (seven flavones (flavone, 3- and 5-hydroxyflavone, chrysin, apigenin, fisetin and luteolin) and five flavonols (galangin, kaempferol, quercetin, morin and myricetin)) have been made based on own and reported experimental data and calculations at the B3LYP/6-31+G(d,p) level of theory. All the molecules are treated in a uniform way by using the same set of redundancy-free set of internal coordinates. A generalized harmonic mode mixing is used to corroborate the vibrational characteristics of this important class of molecules. Each flavonoid molecule can be treated from the vibrational point of view as made of relatively weakly coupled chromone and phenyl part. It has been shown that the strongest band around 1600cm-1 need not be attributable to the CO stretching. The way the vibrations of any of the hydroxyl groups are mixed with ring vibrations and vibrations of other neighboring hydroxyl groups is rather involved. This imposes severe limitations on any attempt to describe normal modes of a flavonol in terms of hydroxyl or carbonyl group vibrations. The role of water molecules in the appearance of flavonoid IR spectra is emphasized. Knowing for the great affinity of phosphate groups in lipids towards water, the immediate consequence is a reasonable assumption that flavonoid lipid interactions is mediated by water.
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Affiliation(s)
- Goran Baranović
- Division of Organic Chemistry and Biochemistry, R. Bošković Institute, Zagreb, Croatia
| | - Suzana Šegota
- Division of Physical Chemistry, R. Bošković Institute, Zagreb, Croatia.
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6
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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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7
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Surov AO, Voronin AP, Drozd KV, Churakov AV, Roussel P, Perlovich GL. Diversity of crystal structures and physicochemical properties of ciprofloxacin and norfloxacin salts with fumaric acid. CrystEngComm 2018. [DOI: 10.1039/c7ce02033c] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The crystallization of norfloxacin and ciprofloxacin – antibacterial fluoroquinolone compounds – with fumaric acid resulted in the isolation of six distinct solid forms of the drugs with different stoichiometries and hydration levels.
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Affiliation(s)
- Artem O. Surov
- Institution of the Russian Academy of Sciences
- G.A. Krestov Institute of Solution Chemistry RAS
- Ivanovo
- Russia
| | - Alexander P. Voronin
- Institution of the Russian Academy of Sciences
- G.A. Krestov Institute of Solution Chemistry RAS
- Ivanovo
- Russia
| | - Ksenia V. Drozd
- Institution of the Russian Academy of Sciences
- G.A. Krestov Institute of Solution Chemistry RAS
- Ivanovo
- Russia
| | | | - Pascal Roussel
- UCCS UMR 8181 University des Sciences et Technologies de Lille-1
- Lille
- France
| | - German L. Perlovich
- Institution of the Russian Academy of Sciences
- G.A. Krestov Institute of Solution Chemistry RAS
- Ivanovo
- Russia
- Department of Chemistry
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8
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Sugden I, Adjiman CS, Pantelides CC. Accurate and efficient representation of intramolecular energy in ab initio generation of crystal structures. I. Adaptive local approximate models. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2016; 72:864-874. [PMID: 27910837 PMCID: PMC5134761 DOI: 10.1107/s2052520616015122] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 09/26/2016] [Indexed: 05/14/2023]
Abstract
The global search stage of crystal structure prediction (CSP) methods requires a fine balance between accuracy and computational cost, particularly for the study of large flexible molecules. A major improvement in the accuracy and cost of the intramolecular energy function used in the CrystalPredictor II [Habgood et al. (2015). J. Chem. Theory Comput. 11, 1957-1969] program is presented, where the most efficient use of computational effort is ensured via the use of adaptive local approximate model (LAM) placement. The entire search space of the relevant molecule's conformations is initially evaluated using a coarse, low accuracy grid. Additional LAM points are then placed at appropriate points determined via an automated process, aiming to minimize the computational effort expended in high-energy regions whilst maximizing the accuracy in low-energy regions. As the size, complexity and flexibility of molecules increase, the reduction in computational cost becomes marked. This improvement is illustrated with energy calculations for benzoic acid and the ROY molecule, and a CSP study of molecule (XXVI) from the sixth blind test [Reilly et al. (2016). Acta Cryst. B72, 439-459], which is challenging due to its size and flexibility. Its known experimental form is successfully predicted as the global minimum. The computational cost of the study is tractable without the need to make unphysical simplifying assumptions.
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Affiliation(s)
- Isaac Sugden
- Molecular Systems Engineering Group Centre for Process Systems Engineering Department of Chemical Engineering, Imperial College London, London SW7 2AZ, England
| | - Claire S. Adjiman
- Molecular Systems Engineering Group Centre for Process Systems Engineering Department of Chemical Engineering, Imperial College London, London SW7 2AZ, England
| | - Constantinos C. Pantelides
- Molecular Systems Engineering Group Centre for Process Systems Engineering Department of Chemical Engineering, Imperial College London, London SW7 2AZ, England
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9
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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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10
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Mohamed S. Solvent inclusion in the crystal structure of bis-[(adamantan-1-yl)methanaminium chloride] 1,4-dioxane hemisolvate monohydrate explained using the computed crystal energy landscape. Acta Crystallogr E Crystallogr Commun 2016; 72:1348-1352. [PMID: 27920932 PMCID: PMC5120722 DOI: 10.1107/s2056989016013256] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 08/18/2016] [Indexed: 11/13/2022]
Abstract
Repeated attempts to crystallize 1-adamantane-methyl-amine hydro-chloride as an anhydrate failed but the salt was successfully crystallized as a solvate (2C11H20N+·2Cl-·0.5C4H8O2·H2O), with water and 1,4-dioxane playing a structural role in the crystal and engaging in hydrogen-bonding inter-actions with the cation and anion. Computational crystal-structure prediction was used to rationalize the solvent-inclusion behaviour of this salt by computing the solvent-accessible voids in the predicted low-energy structures for the anhydrate: the global lattice-energy minimum structure, which has the same packing of the ions as the solvate, has solvent-accessible voids that account for 3.71% of the total unit-cell volume and is 6 kJ mol-1 more stable than the next most stable predicted structure.
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11
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Mohamed S, Karothu DP, Naumov P. Using crystal structure prediction to rationalize the hydration propensities of substituted adamantane hydrochloride salts. ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE CRYSTAL ENGINEERING AND MATERIALS 2016; 72:551-61. [DOI: 10.1107/s2052520616006326] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/14/2016] [Indexed: 12/31/2022]
Abstract
The crystal energy landscapes of the salts of two rigid pharmaceutically active molecules reveal that the experimental structure of amantadine hydrochloride is the most stable structure with the majority of low-energy structures adopting a chain hydrogen-bond motif and packings that do not have solvent accessible voids. By contrast, memantine hydrochloride which differs in the substitution of two methyl groups on the adamantane ring has a crystal energy landscape where all structures within 10 kJ mol−1of the global minimum have solvent-accessible voids ranging from 3 to 14% of the unit-cell volume including the lattice energy minimum that was calculated after removing water from the hydrated memantine hydrochloride salt structure. The success in using crystal structure prediction (CSP) to rationalize the different hydration propensities of these substituted adamantane hydrochloride salts allowed us to extend the model to predict under blind test conditions the experimental crystal structures of the previously uncharacterized 1-(methylamino)adamantane base and its corresponding hydrochloride salt. Although the crystal structure of 1-(methylamino)adamantane was correctly predicted as the second ranked structure on the static lattice energy landscape, the crystallization of aZ′ = 3 structure of 1-(methylamino)adamantane hydrochloride reveals the limits of applying CSP when the contents of the crystallographic asymmetric unit are unknown.
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12
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Braun DE, Oberacher H, Arnhard K, Orlova M, Griesser UJ. 4-Aminoquinaldine monohydrate polymorphism: Prediction and impurity aided discovery of a difficult to access stable form. CrystEngComm 2016; 18:4053-4067. [PMID: 28649176 PMCID: PMC5482396 DOI: 10.1039/c5ce01758k] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Crystal structure prediction studies indicated the existence of an unknown high density monohydrate structure (Hy1B°) as global energy minimum for 4-aminoquinaldine (4-AQ). We thus performed an interdisciplinary experimental and computational study elucidating the crystal structures, solid form inter-relationships, kinetic and thermodynamic stabilities of the stable anhydrate (AH I°), the kinetic monohydrate (Hy1A ) and this novel monohydrate polymorph (Hy1B°) of 4-AQ. The crystal structure of Hy1B° was determined by combining laboratory powder X-ray diffraction data and ab initio calculations. Dehydration studies with differential scanning calorimetry and solubility measurements confirmed the result of the lattice energy calculations, which identified Hy1B° as the thermodynamically most stable hydrate form. At 25 °C the equilibrium of the 4-AQ hydrate/anhydrate system was observed at an aw (water activity) of 0.14. The finding of Hy1B° was complicated by the fact that the metastable but kinetically stable Hy1A shows a higher nucleation and growth rate. The presence of an impurity in an available 4-AQ sample facilitated the nucleation of Hy1B°, whose crystallisation is favored under hydrothermal conditions. The value of combining experimental with theoretical studies in hydrate screening and characterisation, as well as the reasons for hydrate formation in 4-AQ, are discussed.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy, University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria
| | - Herbert Oberacher
- Institute of Legal Medicine, Innsbruck Medical University, Muellerstr. 44, 6020 Innsbruck, Austria
| | - Kathrin Arnhard
- Institute of Legal Medicine, Innsbruck Medical University, Muellerstr. 44, 6020 Innsbruck, Austria
| | - Maria Orlova
- 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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13
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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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14
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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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15
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Braun DE, Nartowski KP, Khimyak YZ, Morris KR, Byrn SR, Griesser UJ. Structural Properties, Order-Disorder Phenomena, and Phase Stability of Orotic Acid Crystal Forms. Mol Pharm 2016; 13:1012-29. [PMID: 26741914 PMCID: PMC4783786 DOI: 10.1021/acs.molpharmaceut.5b00856] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Orotic acid (OTA) is reported to
exist in the anhydrous (AH), monohydrate
(Hy1), and dimethyl sulfoxide monosolvate (SDMSO) forms.
In this study we investigate the (de)hydration/desolvation behavior,
aiming at an understanding of the elusive structural features of anhydrous
OTA by a combination of experimental and computational techniques,
namely, thermal analytical methods, gravimetric moisture (de)sorption
studies, water activity measurements, X-ray powder diffraction, spectroscopy
(vibrational, solid-state NMR), crystal energy landscape, and chemical
shift calculations. The Hy1 is a highly stable hydrate, which dissociates
above 135 °C and loses only a small part of the water when stored
over desiccants (25 °C) for more than one year. In Hy1, orotic
acid and water molecules are linked by strong hydrogen bonds in nearly
perfectly planar arranged stacked layers. The layers are spaced by
3.1 Å and not linked via hydrogen bonds. Upon dehydration the
X-ray powder diffraction and solid-state NMR peaks become broader,
indicating some disorder in the anhydrous form. The Hy1 stacking reflection
(122) is maintained, suggesting that the OTA molecules are still arranged
in stacked layers in the dehydration product. Desolvation of SDMSO, a nonlayer structure, results in the same AH phase as
observed upon dehydrating Hy1. Depending on the desolvation conditions,
different levels of order–disorder of layers present in anhydrous
OTA are observed, which is also suggested by the computed low energy
crystal structures. These structures provide models for stacking faults
as intergrowth of different layers is possible. The variability in
anhydrate crystals is of practical concern as it affects the moisture
dependent stability of AH with respect to hydration.
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Affiliation(s)
- Doris E Braun
- Institute of Pharmacy, University of Innsbruck , Innrain 52c, 6020 Innsbruck, Austria
| | - Karol P Nartowski
- School of Pharmacy, University of East Anglia , Norwich, Norfolk NR4 7TJ, United Kingdom
| | - Yaroslav Z Khimyak
- School of Pharmacy, University of East Anglia , Norwich, Norfolk NR4 7TJ, United Kingdom
| | - Kenneth R Morris
- Lachman Institute for Pharmaceutical Analysis, Arnold & Marie Schwartz College of Pharmacy and Health Sciences, Long Island University-Brooklyn Campus , 75 DeKalb Avenue, Brooklyn, New York 11201, United States
| | - Stephen R Byrn
- Department of Industrial and Physical Pharmacy, Purdue University , 575 Stadium Mall Drive, West Lafayette, Indiana 47906, United States
| | - Ulrich J Griesser
- Institute of Pharmacy, University of Innsbruck , Innrain 52c, 6020 Innsbruck, Austria
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16
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Tian D, Li L, Yuan LJ, Chen SP. Hydrous salts of 1-aminoethylidenediphosphonic acid and piperazidine: temperature induced reversible structural transformation in a humid environment. RSC Adv 2016. [DOI: 10.1039/c5ra22428d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A series of hydrous salts constructed using AEDPH4 and piperazidine (pip) were synthesized and structurally characterized. A reversible structural transformation circle is observed in single crystals of compounds 1–3.
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Affiliation(s)
- Di Tian
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Lang Li
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Liang-jie Yuan
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Shuo-ping Chen
- College of Materials Science and Engineering
- Guilin University of Technology
- Guilin 541004
- P. R. China
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17
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Hathwar VR, Sist M, Jørgensen MRV, Mamakhel AH, Wang X, Hoffmann CM, Sugimoto K, Overgaard J, Iversen BB. Quantitative analysis of intermolecular interactions in orthorhombic rubrene. IUCRJ 2015; 2:563-74. [PMID: 26306198 PMCID: PMC4547824 DOI: 10.1107/s2052252515012130] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/24/2015] [Indexed: 05/24/2023]
Abstract
Rubrene is one of the most studied organic semiconductors to date due to its high charge carrier mobility which makes it a potentially applicable compound in modern electronic devices. Previous electronic device characterizations and first principles theoretical calculations assigned the semiconducting properties of rubrene to the presence of a large overlap of the extended π-conjugated core between molecules. We present here the electron density distribution in rubrene at 20 K and at 100 K obtained using a combination of high-resolution X-ray and neutron diffraction data. The topology of the electron density and energies of intermolecular interactions are studied quantitatively. Specifically, the presence of Cπ⋯Cπ interactions between neighbouring tetracene backbones of the rubrene molecules is experimentally confirmed from a topological analysis of the electron density, Non-Covalent Interaction (NCI) analysis and the calculated interaction energy of molecular dimers. A significant contribution to the lattice energy of the crystal is provided by H-H interactions. The electron density features of H-H bonding, and the interaction energy of molecular dimers connected by H-H interaction clearly demonstrate an importance of these weak interactions in the stabilization of the crystal structure. The quantitative nature of the intermolecular interactions is virtually unchanged between 20 K and 100 K suggesting that any changes in carrier transport at these low temperatures would have a different origin. The obtained experimental results are further supported by theoretical calculations.
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Affiliation(s)
- Venkatesha R. Hathwar
- Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus C DK-8000, Denmark
| | - Mattia Sist
- Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus C DK-8000, Denmark
| | - Mads R. V. Jørgensen
- Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus C DK-8000, Denmark
| | - Aref H. Mamakhel
- Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus C DK-8000, Denmark
| | - Xiaoping Wang
- Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, PO Box 2008 - MS 6475, Oak Ridge, TN 37831, USA
| | - Christina M. Hoffmann
- Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, PO Box 2008 - MS 6475, Oak Ridge, TN 37831, USA
| | - Kunihisa Sugimoto
- Japan Synchrotron Radiation Research Institute, I-I-I, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Jacob Overgaard
- Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus C DK-8000, Denmark
| | - Bo Brummerstedt Iversen
- Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus C DK-8000, Denmark
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18
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Braun DE, Gelbrich T, Kahlenberg V, Griesser UJ. Solid state forms of 4-aminoquinaldine - From void structures with and without solvent inclusion to close packing. CrystEngComm 2015; 17:2504-2516. [PMID: 26726294 PMCID: PMC4693969 DOI: 10.1039/c5ce00118h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Polymorphs of 4-aminoquinaldine (4-AQ) have been predicted in silico and experimentally identified and characterised. The two metastable forms, AH (anhydrate) II and AH III, crystallise in the trigonal space group [Formula: see text] and are less densely packed than the thermodynamically most stable phase AH I° (P21/c ). AH II can crystallise and exist both, as a solvent inclusion compound and as an unsolvated phase. The third polymorph, AH III, is exclusively obtained by desolvation of a carbon tetrachloride solvate. Theoretical calculations correctly estimated the experimental 0K stability order, confirmed that AH II can exist without solvents, gave access to the AH III structure, and identified that there exists a subtle balance between close packing and number of hydrogen bonding interactions in the solid state of anhydrous 4-AQ. Furthermore, the prevalence of void space and solvent inclusion in [Formula: see text] structures is discussed.
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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
| | - 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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19
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Habgood M, Sugden IJ, Kazantsev AV, Adjiman CS, Pantelides CC. Efficient Handling of Molecular Flexibility in Ab Initio Generation of Crystal Structures. J Chem Theory Comput 2015; 11:1957-69. [DOI: 10.1021/ct500621v] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Matthew Habgood
- Molecular Systems Engineering
Group, Centre for Process Systems Engineering, Department of Chemical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Isaac J. Sugden
- Molecular Systems Engineering
Group, Centre for Process Systems Engineering, Department of Chemical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Andrei V. Kazantsev
- Molecular Systems Engineering
Group, Centre for Process Systems Engineering, Department of Chemical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Claire S. Adjiman
- Molecular Systems Engineering
Group, Centre for Process Systems Engineering, Department of Chemical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Constantinos C. Pantelides
- Molecular Systems Engineering
Group, Centre for Process Systems Engineering, Department of Chemical
Engineering, Imperial College London, London SW7 2AZ, United Kingdom
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20
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Reddy GNM, Cook DS, Iuga D, Walton RI, Marsh A, Brown SP. An NMR crystallography study of the hemihydrate of 2', 3'-O-isopropylidineguanosine. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 65:41-48. [PMID: 25686689 DOI: 10.1016/j.ssnmr.2015.01.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 01/05/2015] [Accepted: 01/08/2015] [Indexed: 06/04/2023]
Abstract
An NMR crystallography study of the hemihydrate of 2', 3'-O-isopropylidineguanosine (Gace) is presented, together with powder X-ray diffraction and thermogravimetric analysis. (1)H double-quantum and (14)N-(1)H HMQC spectra recorded at 850MHz and 75kHz MAS (using a JEOL 1mm probe) are presented together with a (1)H-(13)C refocused INEPT spectrum recorded at 500MHz and 12.5kHz MAS using eDUMBO-122(1)H homonuclear decoupling. NMR chemical shieldings are calculated using the GIPAW (gauge-including projector augmented wave) method; good two-dimensional agreement between calculation and experiment is observed for (13)C and (1)H chemical shifts for directly bonded CH and CH3 peaks. There are two Gace molecules in the asymmetric unit cell: differences in specific (1)H chemical shifts are rationalised in terms of the strength of CH-π and intermolecular hydrogen bonding interactions.
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Affiliation(s)
| | - Daniel S Cook
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Dinu Iuga
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK
| | - Richard I Walton
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Andrew Marsh
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Steven P Brown
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
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21
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Braun DE, Orlova M, Griesser U. Creatine: Polymorphs Predicted and Found. CRYSTAL GROWTH & DESIGN 2014; 14:4895-4900. [PMID: 26722225 PMCID: PMC4693963 DOI: 10.1021/cg501159c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Hydrate and anhydrate crystal structure prediction (CSP) of creatine (CTN), a heavily used, badly water soluble, zwitterionic compound, has enabled the finding and characterization of its anhydrate polymorphs, including the thermodynamic room temperature form. Crystal structures of the novel forms were determined by combining laboratory powder X-ray diffraction data and ab initio generated structures. The computational method not only revealed all experimental forms but predicted the correct stability order, which was experimentally confirmed by measurements of the heat of hydration.
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Affiliation(s)
- Doris E. Braun
- Institute of Pharmacy and Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria
- Tel: +43(0)512 507 58653; E-mail:
| | - Maria Orlova
- Institute of Pharmacy and Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria
| | - Ulrich
J. Griesser
- Institute of Pharmacy and Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria
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22
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Braun DE, Gelbrich T, Kahlenberg V, Griesser UJ. Insights into hydrate formation and stability of morphinanes from a combination of experimental and computational approaches. Mol Pharm 2014; 11:3145-63. [PMID: 25036525 PMCID: PMC4685752 DOI: 10.1021/mp500334z] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
![]()
Morphine, codeine, and ethylmorphine
are important drug compounds
whose free bases and hydrochloride salts form stable hydrates. These
compounds were used to systematically investigate the influence of
the type of functional groups, the role of water molecules, and the
Cl– counterion on molecular aggregation and solid
state properties. Five new crystal structures have been determined.
Additionally, structure models for anhydrous ethylmorphine and morphine
hydrochloride dihydrate, two phases existing only in a very limited
humidity range, are proposed on the basis of computational dehydration
modeling. These match the experimental powder X-ray diffraction patterns
and the structural information derived from infrared spectroscopy.
All 12 structurally characterized morphinane forms (including structures
from the Cambridge Structural Database) crystallize in the orthorhombic
space group P212121. Hydrate formation results in higher dimensional hydrogen bond networks.
The salt structures of the different compounds exhibit only little
structural variation. Anhydrous polymorphs were detected for all compounds
except ethylmorphine (one anhydrate) and its hydrochloride salt (no
anhydrate). Morphine HCl forms a trihydrate and dihydrate. Differential
scanning and isothermal calorimetry were employed to estimate the
heat of the hydrate ↔ anhydrate phase transformations, indicating
an enthalpic stabilization of the respective hydrate of 5.7 to 25.6
kJ mol–1 relative to the most stable anhydrate.
These results are in qualitative agreement with static 0 K lattice
energy calculations for all systems except morphine hydrochloride,
showing the need for further improvements in quantitative thermodynamic
prediction of hydrates having water···water interactions.
Thus, the combination of a variety of experimental techniques, covering
temperature- and moisture-dependent stability, and computational modeling
allowed us to generate sufficient kinetic, thermodynamic and structural
information to understand the principles of hydrate formation of the
model compounds. This approach also led to the detection of several
new crystal forms of the investigated morphinanes.
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Affiliation(s)
- Doris E Braun
- Institute of Pharmacy, University of Innsbruck , Innrain 52c, 6020 Innsbruck, Austria
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