Two-dimensional similarity between forms I and II of cytenamide, a carbamazepine analogue

Florence, Alastair J.; Bedford, Colin T.; Fabbiani, Francesca P. A.; Shankland, Kenneth; Gelbrich, Thomas; Hursthouse, M. B.; Shankland, Norman; Johnston, Andrea

doi:10.1039/b719717a

Cited by 21 publications

(28 citation statements)

References 25 publications

(10 reference statements)

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“…26 For CTN I, the final refinement Paper Solution crystallisation of CTN a in formic acid c Solution crystallisation of CTN a in water dent molecules was well preserved, confirming the correctness of the restrained refined crystal structure. 27 Single crystal X-ray diffraction X-ray data were collected at 123 K with graphite monochromatic Mo K 1 radiation (wavelength Mo K 1 ,  = 0.71073 Å) on a BRUKER APEX II diffractometer equipped with a CCD detector and an Oxford Cryostream variable temperature device. Data reduction and cell refinement were performed using BRUKER SMART and SAINT programs.…”

Section: X-ray Powder Diffractionmentioning

confidence: 99%

Structure and stability of two polymorphs of creatine and its monohydrate

et al. 2014

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An experimental search for crystalline forms of creatine including a variable temperature X-ray powder diffraction study has produced three polymorphs and a formic acid solvate. The crystal structures of creatine forms I and II were determined from X-ray powder diffraction data plus the creatine formic acid (1 : 1) solvate structure was obtained by single crystal X-ray diffraction methods. Evidence of a third poly-morphic form of creatine obtained by rapid desolvation of creatine monohydrate is also presented. The results highlight the role of automated parallel crystallisation, slurry experiments and VT-XRPD as powerful techniques for effective physical form screening. They also highlight the importance of various complementary analytical techniques in structural characterisation and in achieving better understanding of the relationship between various solid-state forms. The structural relationships between various solid-state forms of creatine using the XPac method provided a rationale for the different relative stabilities of forms I and II of creatine with respect to the monohydrate form.

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Section: X-ray Powder Diffractionmentioning

confidence: 99%

Structure and stability of two polymorphs of creatine and its monohydrate

et al. 2014

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“…[26][27] In contrast CBZ, an anticonvulsant, serves as a model compound for many groups engaged in the study of crystal polymorphism. [28][29][30][31][32] There are four known polymorphs of CBZ as well as a number of cocrystals. Recently the fourth form was grown using a polymer heteronucleus.…”

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confidence: 99%

Anion-switchable supramolecular gels for controlling pharmaceutical crystal growth

et al. 2010

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Gel media have been utilized for over a century for the growth of inorganic, organic and protein crystals. [1][2][3][4][5] The improved physical characteristics of the resulting crystals (better optical quality, larger size and fewer defects) are usually ascribed to the suppression of convection currents, sedimentation and nucleation afforded by the viscous gel environment. [6][7] In many instances the gel is thought to act as an inert matrix within which crystal growth occurs, however in some cases, the gel structure has been shown to influence the polymorphism, enantiomorphism and habit of crystals. 2 Occasionally gel fibres may become incorporated into the crystal, giving rise to composite materials. 8Conventional gels are formed using polymeric or clay-like materials such as gelatine, solubility were investigated to demonstrate their potential to act as crystallisation media for molecular organic compounds. Compounds 2, and 4 have been reported previously. [23][24] Novel compounds 1 and 3 were prepared by standard methods as detailed in the supplementary information. Gelators 1 -3 were chosen because they reliably form gels in a number of solvents ranging from aqueous systems to toluene. The fibrous nature of the gels is evidenced by SEM images of the dried xerogels ( Figure 1a,b). Compound 4 is a metallogelator which forms blue coloured gels with substoichiometric amounts of CuCl 2 in methanol:water. 23 Between them, these gelators can gel a range of solvents, at different temperatures (T gel ), and with a different critical gelator concentration (CGC). This class of compound has the potential to form the basis of a library of gelators which will allow the selection of gel properties and specific functionalities to match the compound and crystallisation conditions of interest. The synthetic versatility of these gelators could also in principle allow the incorporation of tailored heteronucleating functionality. While we focus upon bis(urea) compounds, the concepts outlined herein equally apply to any LMWG.Crystallisation experiments were undertaken using a range of organic compounds of both drug and non-drug species in parallel in both gel and solution media. We undertook an initial screen using candidate compounds 2-hydroxy benzyl alcohol (HBA, 5), Aspirin (ASP, 6), carbamazepine (CBZ, 7), 1-(3-methylsulfanyl-phenyl)-3-pyridin-2-yl-urea (SPU, 8) and 1,3-bis(m-nitrophenyl)urea (NPU, 9). We then carried out a detailed study on CBZwith all gelators, and a follow up study on gelator ...

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“…Two polymorphs of the carbamazepine–nicotinamide co‐crystal system and two polymorphs of the carbamazepine–saccharin co‐crystal system have reported, where formation of a hetero‐synthon between carbamazepine and saccharin was detected in the crystal structures 48. The structures of two polymorphs of cytenamide (a carbamazepine analog) have been reported, with the structures exhibiting the same two‐dimensional similarity that has been observed for carbamazepine polymorphs 49…”

Section: Structural Characterization and Properties Of Polymorphs Andmentioning

confidence: 62%

Polymorphism Solvatomorphism 2008

Brittain¹

2010

Journal of Pharmaceutical Sciences

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Two-dimensional similarity between forms I and II of cytenamide, a carbamazepine analogue

Abstract: Cytenamide form I (R) undergoes a solid-state transformation upon heating to form II (P), with the structures exhibiting the same two-dimensional similarity that exists between the R and P forms of carbamazepine

Cited by 21 publications

References 25 publications

Structure and stability of two polymorphs of creatine and its monohydrate

Structure and stability of two polymorphs of creatine and its monohydrate

Anion-switchable supramolecular gels for controlling pharmaceutical crystal growth

Polymorphism Solvatomorphism 2008

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