Crystal structures and properties of two hydrated conglomerate forms of the heart-rate-lowering agent ivabradine hydrochloride.

Ivabradine hydrochloride (IVA-HCl) (systematic name: {[3,4-dimethoxybicyclo[4.2.0]octa-1(6),2,4-trien-7-yl]methyl}[3-(7,8-dimethoxy-2-oxo-2,3,4,5-tetrahydro-1H-3-benzazepin-3-yl)propyl]methylazanium), is a novel medication used for the symptomatic management of stable angina pectoris. In many recent patents, it has been claimed to exist in a very large number of polymorphic, hydrated and solvated phases, although no detailed analysis of the structural features of these forms has been published to date. Here, we have successfully crystallized the tetrahydrate form of IVA-HCl (form ß), C27H37N2O5+·Cl-·4H2O, and elucidated its structure for the first time. Simultaneously, a new crystal form of IVA-HCl, i.e. the hemihydrate (form II), C27H37N2O5+·Cl-·0.5H2O, was discovered. Its crystal structure was also accurately determined and compared to that of the tetrahydrate form. While the tetrahydrate form of IVA-HCl crystallized in the orthorhombic space group P212121, the new form (hemihydrate) was solved in the monoclinic space group P21. Detailed conformational and packing comparisons between the two forms have allowed us to understand the role of water in the crystal assembly of this hydrochloride salt. The stabilities of the two forms were compared theoretically by calculating the binding energy of the water in the crystal lattice using differential scanning calorimetry (DSC). The stability experiments show that the tetrahydrate is stable under high-humidity conditions, while the hemihydrate is stable under high-temperature conditions.

A new polymorph of the gastrokinetic drug cisapride monohydrate.

Cisapride monohydrate (systematic name: 4-amino-5-chloro-N-{(3RS,4SR)-1-[3-(4-fluorophenoxy)propyl]-3-methoxypiperidin-4-yl}-2-methoxybenzamide monohydrate), C23H29ClFN3O4·H2O, is a nondopamine-blocking gastrokinetic drug. A new polymorph of cisapride monohydrate has been reported nearly three decades after the report of its first known crystal structure [Collin et al. (1989). J. Mol. Struct. 214, 159-175]. The second polymorph is also monoclinic, but with different unit-cell parameters. A comparison of both polymorphic forms shows that the difference is thus not in the molecular conformation but in the arrangements of molecules in the crystal packing. The crystal morphology of two forms was predicted with the BFDH model in Materials Studio and inferred that the powder of the new polymorph has better flowability than the original polymorph. The results of DSC (differential scanning calorimetry) analysis and slurry experiments show that both polymorphs are stable at room temperature.

Crystal structure of (S)-5-chloro-N-({2-oxo-3-[4-(3-oxomorpholin-4-yl)phen-yl]oxazolidin-5-yl}meth-yl)thio-phene-2-carboxamide.

The asymmetric unit of the crystal of the title compound (common name rivaroxaban), C19H18ClN3O5, contains two rivaroxaban mol-ecules with different conformations; the C-C-N-C torsion angles between the oxazolidine and thio-phene rings are -171.1 (7) and -106.8 (9)° in the two independent mol-ecules. In the crystal, classical N-H⋯O hydrogen bonds and weak C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional supra-molecular architecture.

Crystal structure of vilazodone hydro-chloride methanol monosolvate.

In the title compound, C26H28N5O2+·Cl-·CH3OH {systematic name: 4-(2-carbamoyl-1-benzo-furan-5-yl)-1-[4-(5-cyano-1H-indol-3-yl)but-yl]piperazin-1-ium chloride methanol monosolvate}, the protonated piperazine ring adopts a chair conformation. The indole ring plane is nearly perpendicular to the benzo-furan ring system, with a dihedral angle of 85.77 (2)°. In the crystal, the organic cations, Cl- anions and methanol solvent mol-ecules are linked by classical N-H⋯O and N-H⋯Cl hydrogen bonds, and weak C-H⋯O and C-H⋯π inter-actions into a three-dimensional supra-molecular architecture.

Crystal structure of canagliflozin hemihydrate.

There are two canagliflozin mol-ecules (A and B) and one water mol-ecule in the asymmetric unit of the title compound, C24H25FO5S·0.5H2O [systematic name: (2S,3R,4R,5S,6R)-2-(3-{[5-(4-fluoro-phen-yl)thio-phen-2-yl]meth-yl}-4-methylphen-yl)-6-(hy-droxy-meth-yl)-3,4,5,6-tetra-hydro-2H-pyran-3,4,5-triol hemihydrate]. The dihedral angles between the methyl-benzene and thio-phene rings are 115.7 (4) and 111.7 (4)°, while the dihedral angles between the fluoro-benzene and thio-phene rings are 24.2 (6) and 20.5 (9)° in mol-ecules A and B, respectively. The hydro-pyran ring exhibits a chair conformation in both canagliflozin mol-ecules. In the crystal, the canagliflozin mol-ecules and lattice water mol-ecules are connected via O-H⋯O hydrogen bonds into a three-dimensional supra-molecular architecture.

Comparison of the crystal structures of the potent anticancer and anti-angiogenic agent regorafenib and its monohydrate.

Regorafenib {systematic name: 4-[4-({[4-chloro-3-(trifluoromethy)phenyl]carbamoyl}amino)-3-fluorophenoxy]-1-methylpyridine-2-carboxamide}, C21H15ClF4N4O3, is a potent anticancer and anti-angiogenic agent that possesses various activities on the VEGFR, PDGFR, raf and/or flt-3 kinase signaling molecules. The compound has been crystallized as polymorphic form I and as the monohydrate, C21H15ClF4N4O3·H2O. The regorafenib molecule consists of biarylurea and pyridine-2-carboxamide units linked by an ether group. A comparison of both forms shows that they differ in the relative orientation of the biarylurea and pyridine-2-carboxamide units, due to different rotations around the ether group, as measured by the C-O-C bond angles [119.5 (3)° in regorafenib and 116.10 (15)° in the monohydrate]. Meanwhile, the conformational differences are reflected in different hydrogen-bond networks. Polymorphic form I contains two intermolecular N-H...O hydrogen bonds, which link the regorafenib molecules into an infinite molecular chain along the b axis. In the monohydrate, the presence of the solvent water molecule results in more abundant hydrogen bonds. The water molecules act as donors and acceptors, forming N-H...O and O-H...O hydrogen-bond interactions. Thus, R4(2)(28) ring motifs are formed, which are fused to form continuous spiral ring motifs along the a axis. The (trifluoromethyl)phenyl rings protrude on the outside of these motifs and interdigitate with those of adjacent ring motifs, thereby forming columns populated by halogen atoms.

[Crystal structure and crystal form stability of trelagliptin succinate].

In order to investigate trelagliptin succinate's stability in solution, recrystallization and suspension methods in polar solvent (mainly in water and 95% alcohol) were used to study the crystal form transformation of trelagliptin succinate. Single crystal X-ray diffraction, powder X-ray diffraction and thermalgravimetric analysis, and differential scanning calorimetry were used to characterize the structure of the solid state form before and after transformation. The results showed that trelagliptin succinate can easily convert to trelagliptin hemi-succinate mediated by solvent, especially by polar solvent, namely trelagliptin hemi-succinate is more stable than trelagliptin succinate in solution.

Crystal structures of vortioxetine and its methanol monosolvate.

Vortioxetine, C18H22N2S, (1), systematic name 1-{2-[(2,4-di-methyl-phen-yl)sulfan-yl]phen-yl}piperazine, a new drug used to treat patients with major depressive disorder, has been crystallized as the free base and its methanol monosolvate, C18H22N2S·CH3OH, (2). In both structures, the vortioxetine mol-ecules have similar conformations: in (1), the dihedral angle between the aromatic rings is 80.04 (16)° and in (2) it is 84.94 (13)°. The C-S-C bond angle in (1) is 102.76 (14)° and the corresponding angle in (2) is 103.41 (11)°. The piperazine ring adopts a chair conformation with the exocyclic N-C bond in a pseudo-equatorial orientation in both structures. No directional inter-actions beyond normal van der Waals contacts could be identified in the crystal of (1), whereas in (2), the vortioxetine and methanol mol-ecules are linked by N-H⋯O and O-H⋯N hydrogen bonds, generating [001] chains.

Crystal structure of febuxostat-acetic acid (1/1).

The asymmetric unit of the title compound [systematic name: 2-(3-cyano-4-iso-butyl-oxyphen-yl)-4-methyl-thia-zole-5-carb-oxy-lic acid-acetic acid (1/1)], C16H16N2O3S·CH3COOH, contains a febuxostat mol-ecule and an acetic acid mol-ecule. In the febuxostat mol-ecule, the thia-zole ring is nearly coplanar with the benzene ring [dihedral angle = 3.24 (2)°]. In the crystal, the febuxostat and acetic acid mol-ecules are linked by O-H⋯O, O-H⋯N hydrogen bonds and weak C-H⋯O hydrogen bonds, forming supra-molecular chains propagating along the b-axis direction. π-π stacking is observed between nearly parallel thia-zole and benzene rings of adjacent mol-ecules; the centroid-to-centroid distances are 3.8064 (17) and 3.9296 (17) Å.

[Synthesis of a supermolecular nanoparticle γ-hy-PC/Ada-Dox and its antitumor activity].

OBJECTIVE: To synthesize a (2-Hydroxypropyl)-γ-cyclodextrin-polyethylenimine/adamantane-conjugated doxorubicin (γ-hy-PC/Ada-Dox) based supramolecular nanoparticle with host-guest interaction and to identify its physicochemical characterizations and antitumor effect. METHODS: A novel non-viral gene delivery vector γ-hy-PC/Ada-Dox was synthesized based on host-guest interaction. 1H-NMR, NOESY, UV-Vis, XRD and TGA were used to confirm the structure of the vector. The DNA condensing ability of complexes was investigated by particle size, zeta potential and gel retardation assay. Cytotoxicity of complexes was determined by MTT assay in BEL-7402 and SMMC-7721 cells. Cell wound healing assay was performed in HEK293 and BEL-7404 cells. The transfection efficiency was investigated in HEK293 cells. H/E staining and cell uptake assay was performed in BEL-7402 cells. RESULTS: The structure of γ-hy-PC/Ada-Dox was characterized by 1H-NMR, NOESY, UV-Vis, XRD, TGA. The drug loading was 0.5% and 5.5%. Gel retardation assay showed that γ-hy-PC was able to completely condense DNA at N/P ratio of 2; 0.5% and 5.5% γ-hy-PC/Ada-Dox was able to completely condense DNA at N/P ratio of 3 and 4,respectively. The cytotoxicity of polymers was lower than that of PEI25KDa. The transfection efficiency of γ-hy-PC was higher than that of γ-hy-PC/Ada-Dox at N/P ratio of 30 in HEK293 cells; and the transfection efficiency was decreasing when Ada-Dox loading was increasing. Cell uptake assay showed that γ-hy-PC/Ada-Dox was able to carry drug and FAM-siRNA into cells. CONCLUSION: The novel vector γ-hy-PC/Ada-Dox has been developed successfully, which has certain transfection efficiency and antitumor activity.

[Modified montmorillonite as multifunction gene and drug delivery system].

OBJECTIVE: To develop polyethylenimine-Doxorubicin-montmorillonite (PEI-Dox-MTT) as a novel multifunction delivery system. METHODS: Dox was intercalated into montmorillonite, PEI covered to the surface of Dox/MMT to make the nano-particle. XRD, FT-IR and TGA were used to confirm chemical property of the nano-particle. SEM was used to observe the morphology. The capability of drug release was investigated by PBS buffer solution (pH 7.4). The DNA binding ability of nano-particle was detected by gel electrophoresis retardation assay. The cell viability in COS-7 and SKOV3 cell lines was tested using MTT assay. The gastric mucosa protection was evaluated in vitro. RESULTS: XRD image showed that Dox was intercalated into montmorillonite, inter space of which increased to 31.3Å; the FT-IR spectra showed the vibration bands of PEI at 1 560 cm(-1) and 2 850 cm(-1), the vibration band of Dox at 1 350 cm(-1). Size analysis and SEM revealed that the size of nano-particle was 600 nm, and the zeta-potential was 30 mV. Drug release experiment explored that the nano-particle stably released drug in range of 6 X10(-4) ≊ 8 X10(-4) mg/ml within 72 h. MTT assay showed that the cell viability was over 80% in experiment condition in COS-7 and SKOV3 cell lines. 0.3 mg PEI-MMT nano-particle was able to protect gastric mucosa from alcohol. CONCLUSION: Multifunction system of PEI/Dox/MMT has been prepared successfully.

[Preparation and characterization of Forms A and B of benazepril hydrochloride].

OBJECTIVE: To prepare Form A and Form B of benazepril hydrochloride and to compare the differences in spectrums, thermodynamics and crystal structure between two polymorphic forms. METHODS: Form A and Form B of benazepril hydrochloride were characterized by Fourier transform infrared spectroscopy (IR), thermal gravimetric analysis (TG), differential scanning calorimetry (DSC), powder x-ray diffraction (PXRD) and single crystal x-ray diffraction (SCXRD). RESULTS: Preparation method, crystal structure and polymorphic stability of Form A and Form B of benazepril hydrochloride were obtained. Based on the analysis of crystal structure of both polymorphs, Form A belonged to monoclone space group P2(1) with a=7.8655(4)Å, b= 11.7700(6)Å, c= 13.5560(7)Å, ß= 102.9470(10)°, V=1223.07 (11)Å(3) and Z=2, while Form B belonged to orthorhombic space group P212121, with a=7.9353(8)Å, b=11.6654(11)Å, c=26.6453(16)Å, V=2466.5(4)Å(3) and Z=4. From the DSC and XRD results, Form B of benazepril hydrochloride could be transformed into Form A after heating treatment. CONCLUSION: Form A and Form B of benazepril hydrochloride are both anhydrous and displayed different polymorphs due to different molecular configuration. Furthermore, Form A exhibits more stable than Form B at high temperatures.

Quetiapine N-oxide-fumaric acid (2/1).

THE TITLE COMPOUND (SYSTEMATIC NAME: 2-{2-[4-(dibenzo[b,f][1,4]thia-zepin-11-yl)piperazin-1-yl 1-oxide]eth-oxy}ethanol-fumaric acid (2/1)), C(21)H(25)N(3)O(3)S·0.5C(4)H(4)O(4), is one of the oxidation products of quetiapine hemifumaric acid. In the tricyclic fragment, the central thia-zepine ring displays a boat conformation and the benzene rings are inclined to each other at a dihedral angle of 72.0 (2)°. The piperazine ring adopts a chair conformation with its eth-oxy-ethanol side chain oriented equatorially. In addition to the main mol-ecule, the asymmetric unit contains one-half mol-ecule of fumaric acid, the complete mol-ecule being generated by inversion symmetry. In the crystal, O-H⋯O hydrogen bonds link the components into corrugated layers parallel to bc plane.

Marbofloxacin.

IN THE TITLE COMPOUND, [SYSTEMATIC NAME: 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-piperazin-1-yl)-7-oxo-7H-pyrido[1,2,3-ij][1,2,4]benzoxadiazine-6-carb-oxy-lic acid], C(17)H(19)FN(4)O(4), the carbonyl and carboxyl groups are coplanar with the quinoline ring, making a dihedral angle of 2.39 (2)°. The piperazine ring adopts a chair conformation and the oxadiazinane ring displays an envelope conformation with the CH(2) group at the flap displaced by 0.650 (2) Šfrom the plane through the other five atoms. The mol-ecular structure exhibits an S(6) ring motif, owing to an intra-molecular O-H⋯O hydrogen bond. In the crystal, weak C-H⋯F hydrogen bonds link mol-ecules into layers parallel to the ab plane.

Moxifloxacinium chloride monohydrate.

The title compound {systematic name: 7-[(1S,6S)-8-aza-2-azonia-bicyclo-[4.3.0]non-8-yl]-1-cyclo-propyl-6-fluoro-8-meth-oxy-4-oxo-1,4-dihydro-quinoline-3-carb-oxy-lic acid chloride monohydrate}, C(21)H(25)FN(3)O(4) (+)·Cl(-)·H(2)O, crystallizes with two moxi-floxa-cinium cations, two chloride ions and two uncoordinated water mol-ecules in the unit cell. The crystal structure has a pseudo-inversion center except for the chloride ions. In both moxi-floxa-cinium cations, the quinoline rings are approximately planar, the maximum atomic deviations being 0.107 (3) and 0.118 (3) Å. The piperidine rings adopt a chair conformation while the pyrrolidine rings display a half-chair conformation. In the crystal, the carboxyl groups, the protonated piperidyl groups, the uncoordinated water mol-ecule and chloride anions participate in O-H⋯O, O-H⋯Cl and N-H⋯Cl hydrogen bonding; weak inter-molecular C-H⋯O and C-H⋯Cl hydrogen bonding is also present in the crystal structure.

Bupropion hydro-bromide propanol hemisolvate.

The title compound {systematic name: N-[1-(3-chloro-phen-yl)-1-oxopropan-2-yl]-tert-butanaminium bromide propanol hemisolvate}, C(13)H(19)ClNO(+)·Br(-)·0.5C(3)H(8)O, crystallizes with two independent bupropion hydro-bromide ion pairs and a solvent 1-propanol mol-ecule in the asymmetric unit. In both mol-ecules, the expected proton transfer from HBr to the amino group of the bupropion mol-ecule is observed, and intra- and inter-molecular N-H⋯Br hydrogen-bond inter-actions are formed. These inter-actions link the mol-ecules into hydrogen-bond dimers. The side chains of the two cations have slightly different orientations. The 1-propanol solvent mol-ecule is linked to a bromide ion by an O-H⋯Br hydrogen bond.

Eprosartan mesylate, an angiotensin II receptor antagonist.

The title compound, eprosartan mesylate {systematic name: 2-butyl-1-(4-carb-oxy-benz-yl)-5-[(E)-2-carb-oxy-3-(thio-phen-2-yl)prop-1-en-yl]-1H-imidazol-3-ium methane-sulfonate}, C(23)H(25)N(2)O(4)S(+)·CH(3)O(3)S(-), one of the angiotensin II-receptor antagonists, is effective in regulating hypertension, induced or exacerbated by angiotensin II, and in the treatment of congestive heart failure, renal failure and glaucoma. In the eprosartan residue, which appears in this crystal in the cationic imidazolium form, the benzene ring plane is almost orthogonal to that of the imidazole ring, making a dihedral angle of 87.89 (2)°. The thio-phene ring forms dihedral angles of 66.54 (2) and 67.12 (2)° with the benzene and imidazole rings, respectively. The imidazolium NH group and the H atom of the aromatic carboxyl group participate in hydrogen bonds with the the O atoms of the anion, thus forming centrosymmetric aggregates made up of two cations and two anions each. The second carboxyl group further links the above-mentioned aggregates through a conventional centrosymmetric hydrogen-bonding motif into infinite chains along [011].

Febuxostat methanol solvate.

In the title compound {systematic name: [2-(3-cyano-4-isobutyl-oxyphen-yl)-4-methyl-1,3-thia-zole-5-carb-oxy-lic acid (febuxostat) methanol monosolvate}, C(16)H(16)N(2)O(3)S·CH(4)O, the benzene and thia-zole rings in the febuxostat mol-ecule are twisted at 5.3 (1)°. In the crystal structure, inter-molecular O-H⋯O and O-H⋯N hydrogen bonds link the febuxostat and methanol mol-ecules into helical chains along the 2(1) screw axis.

Triamcinolone acetonide acetate.

IN THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND [SYSTEMATIC NAME: 2-(4b-fluoro-5-hy-droxy-4a,6a,8,8-tetra-methyl-2-oxo-2,4a,4b,5,6,6a,9a,10,10a,10b,11,12-dodeca-hydro-7,9-dioxa-penta-leno[2,1-a]phenanthren-6b-yl)-2-oxoethyl acetate], C(26)H(33)FO(7), the mol-ecules are connected by inter-molecular O-H⋯O hydrogen bonds into an infinite supra-molecular chain along the b axis. The mol-ecular framework consists of five condensed rings, including three six-membered rings and two five-membered rings. The cyclo-hexa-2,5-dienone ring is nearly planar [maximum deviation = 0.013 (3) Å], while the cyclo-hexane rings adopt chair conformations. The two five-membered rings, viz. cyclo-pentane and 1,3-dioxolane, display envelope conformations.

[Peptide CY11 conjugated polyethylenimine-beta-cyclodextrin for gene delivery].

OBJECTIVE: To develop a novel non-viral gene delivery vector CY11-PEI-beta-CyD and to test its gene transfection efficiency. METHODS: CY11 (CGMQLPLATWY) was conjugated to polyethylenimine-beta-cyclodextrin to form CY11-PEI-beta-CyD with a cross-linker [N-succinimidy-3-(2-pyridyldithio) propionate, SPDP]. (1)H-NMR and TGA were used to confirm the structure of vector. The DNA condensing ability of CY11-PEI-beta-CyD was investigated by gel retardation assay. Cytotoxicity of CY11-PEI-beta-CyD was determined by MTT assay and transfection efficiency was investigated in COS-7, Hela and B16 cells. RESULT: CY11 was conjugated onto PEI-beta-CyD successfully, confirmed by(1)H NMR and TGA. The novel vector effectively condensed DNA at N/P ratio of 4îIt showed low cytotoxicity up to the concentration was 160 Mgr;g/ml. The transfection efficiency was 17-fold higher than that of PEI 25 kDa at N/P ratio of 20. CONCLUSION: The novel vector CY11 -PEI-beta-CyD with low cytotoxic and high transfection efficiency may be used as a potential carrier for gene delivery.