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PubMed2006

[Identification of Magnolia biondii Pamp by X-Ray diffraction Fourier pattern method].

OBJECTIVE: To establish a new identification and analysis method of Magnolia biondii Pamp. METHODS: Powder X-Ray diffraction fourier fingerprint pattern method. RESULT: Experiment and analysis were carried out on five samples. The standard X-Ray diffraction Fourier fingerprint pattern method and characteristic diffraction peaks of Magnolia biondii Pamp were obtained. CONCLUSION: The method can be used for the identification of Magnolia biondii Pamp.

Drug Contamination↗
PubMed1991

X-ray powder pattern analysis of cytoplasmic polyhedrosis virus inclusion bodies.

Cytoplasmic polyhedrosis virus is an insect reovirus which is occluded in crystalline inclusion bodies that form in the mid-gut of certain insects. Inclusion bodies of cytoplasmic polyhedrosis virus from Bombyx mori were isolated and purified. These crystalline bodies, about 1-3 microns in linear size, were compacted in a capillary tube while immersed in buffer. X-ray diffraction photographs showed powder rings, extending to 8.2 A resolution, which could be indexed with a cell measuring a = b = 49.9 +/- 0.4 A, c = 41.5 +/- 0.4 A, alpha = beta = gamma = 90 degrees. The polyhedrin protein, which is the major component of the inclusion body, has a molecular weight of about 30,000 daltons and, hence, there are probably two molecules in the unit cell. Thus, the unit cell is monoclinic or possibly triclinic. A Patterson derived from the measured powder pattern intensities, assuming monoclinic symmetry, could be interpreted in terms of a molecule with two larger globes. Such a structure is roughly consistent with the breakdown of the polyhedrin into two larger fragments of molecular weight 17,000 and 14,000 when raising the pH to near 10. Under these conditions the inclusion bodies disintegrate, releasing virus and catalyzing the proteolysis of the polyhedrin.

Electron Probe Microanalysis↗
PubMed2002

[Identification of Ligesticum chuanxiong by X-ray diffraction Fourier pattern method].

OBJECTIVE: To establish a new identification and analysis method of Chinese medicinal materia Ligesticum chuanxiong Hort. METHODS: Powder X-ray diffraction Fourier pattern. RESULTS: Experiments and analysis were carried out on five samples. The standard X-ray diffraction Fourier pattern and characteristic diffraction peaks of Ligesticum chuanxiong Hort. were obtained. CONCLUSION: This method can be used for identification of Ligesticum chuanxiong Hort.

Fourier Analysis↗
PubMed1999

Effect of compressional force on the crystallinity of directly compressible cellulose excipients.

The effect of compressional force on the crystallinity of low crystallinity cellulose (LCPC), microcrystalline celluloses (Avicel PH-101, PH-102 and PH-302 grades) and powdered cellulose (Solka Floc BW-100) has been investigated using an X-ray diffraction method. Microcrystalline and powdered celluloses showed an increase of about 10% in their crystallinities, compared to the values for the corresponding powders, at a compression pressure of 5-10 MPa. The increase in the crystallinity of LCPC was gradual and reached the maximum value of 5% at a compression pressure of 15 MPa. Further increase in compression pressure (to 77 MPa) had no effect on the crystallinity of LCPC, Avicel PH-101, Avicel PH-302 and Solka Floc BW-100. Avicel PH-102, on the other hand, showed a decrease in crystallinity at 15 MPa. Beyond 15 MPa, however, no statistically significant change in the crystallinity of the product was noted.

Cellulose↗
PubMed2004

Structural characterization of chlorobenzylidine.

AIM: To study the structure and crystal forms of chlorobenzylidine. METHODS: Karl Fischer titrimetry, FTIR, thermal analysis, single and powder X-ray diffraction were used for the studies of the structure of chlorobenzylidine and for the identification of two forms of chlorobenzylidine. RESULTS: Chlorobenzylidine and its diastereoisomer have been studied in this article. They can be distinguished by their different melting points. Two crystal forms of chlorobenzylidine (form A and form B) have also been detected and studied. Form A was studied by single-crystal X-ray diffraction, it crystallized in the triclinic system, space group P1(-), with two formula units per cell, is monohydrate. Karl Fischer titrimetry, FTIR, thermal analysis and powder X-ray diffraction were used for identification of the two forms. CONCLUSION: The studies of structure and crystal forms of chlorobenzylidine are very useful for the clinical research and the selection of recrystallization process.

Benzylidene Compounds↗
PubMed2003

[Power X-ray diffraction analysis of Chinese medicinal materials Radix Gentianae macrophyllae].

To identify Radix Gentianae Macrophyllae, eight samples were analyzed by powder X-ray diffraction method. We obtained the characteristic peaks and diffraction fuzzy figures for distinguishing Radix Gentianae Macrophyllae. The results showed that every medicine had its own character which could be well repeated. X-ray diffraction figure plays an important role in distinguishing Chinese materia medica with similar shape and properties, similar tissue texture or similar chemical composition. And X-ray diffraction figure may be used as one fingerprint method for Chinese herbal medicine.

Drug Contamination↗
PubMed2003

[Identification of Chinese medicinal material radix Angelicae sinensis by X-ray diffraction Fourier fingerprint pattern method].

OBJECTIVE: To develop a new identification and analysis method of Chinese medicinal material Radix Angelicae Sinenesis. METHODS: Powder X-ray Diffraction Fourier Fingerpring pattern. RESULTS: Experiments and analysis were carried out on five samples. The standard X-ray diffraction Fourier pattern and characteristic diffraction peaks of Radix Angelicae Sinensis were obtained. CONCLUSION: This method can be used for identification of Chinese medicinal material Radix Angelicae Sinensis.

Angelica↗
PubMed1989

Determination of the relative amounts of anhydrous carbamazepine (C15H12N2O) and carbamazepine dihydrate (C15H12N2O.2H2O) in a mixture by powder x-ray diffractometry.

A powder x-ray diffraction technique has been developed to quantify the relative amounts of anhydrous carbamazepine (C15H12N2O) (I) and carbamazepine dihydrate (C15H12N2O.2H2O) (II) when they occur as a mixture. The theoretical basis of this technique was developed by Alexander and Klug (Anal. Chem. 20:886-889, 1948). The powder x-ray diffraction patterns of I and II revealed that the lines with d-spacings of 6.78 and 9.93 A were unique to I and II, respectively. The ratio of the integrated intensity of the 6.78 A line in a mixture of I and II to the intensity of the 6.78 A line in a sample consisting of only I was calculated as a function of weight fraction of I in the mixture. These ratios were also experimentally determined, and there was a good agreement between the theoretical and the experimental intensity ratios. Similarly good agreements between the theoretical and the experimental intensity ratios for the 9.93 A line of II were obtained. The samples were compressed into tablets and subjected to x-ray analysis. When compressed to a certain pressure, the particles tended to orient the same way in replicate samples resulting in highly reproducible intensity values. Compression into tablets was necessary because the powder samples yielded unsatisfactory results.

Calorimetry, Differential Scanning↗
PubMed2006

Polar symmetry and intercalation of new multilayered hybrid molybdates: [M2(pzc)2(H2O)x][Mo5O16] (M = Co, Ni).

The layered molybdate [M2(pzc)2(H2O)x][Mo5O16] (I: M = Ni, x = 5.0; II: M = Co, x = 4.0; pzc = pyrazinecarboxylate) hybrid solids were synthesized via hydrothermal reactions at 160-165 degrees C. The structures were determined by single-crystal X-ray diffraction data for I (Cc, Z = 4; a = 33.217(4) A, b = 5.6416(8) A, c = 13.982(2) A, beta = 99.407(8) degrees , and V = 2585.0(6) A3) and powder X-ray diffraction data for II (C2/c, Z = 4; a = 35.42(6) A, b = 5.697(9) A, c = 14.28(2) A, beta = 114.95(4) degrees , and V = 2614(12) A3). The polar structure of I contains new [Ni2(pzc)2(H2O)5]2+ double layers that form an asymmetric pattern of hydrogen bonds and covalent bonds to stair-stepped [Mo5O16]2- sheets, inducing a net dipole moment in the latter. In II, however, the [Co2(pzc)2(H2O)4]2+ double layers have one less coordinated water and subsequently exhibit a symmetric pattern of covalent and hydrogen bonding to the [Mo5O16]2- sheets, leading to a centrosymmetric structure. Thermogravimetric analyses and powder X-ray diffraction data reveal that I can be dehydrated and rehydrated with from 0 to 6.5 water molecules per formula unit, which is coupled with a corresponding contraction/expansion of the interlayer distances. Also, the dehydrated form of I can be intercalated by approximately 4.3 H2S molecules per formula unit, but the intercalation by pyridine or methanol is limited to less than one molecule per formula unit.

Journal Article↗
PubMed2003

Polymorphism of a novel sodium ion channel blocker.

2-[[4-(4-Fluorophenoxy)phenyl]-methylene]-hydrazinecarboxamide, a member of the semicarbazone family which has shown potential therapeutic use as anticonvulsants, has been found to exist in two polymorphic forms denoted A and B. In addition to reporting aspects of the physical characterization of both forms, the crystal structure of polymorph A has been determined directly from powder X-ray diffraction data using the Genetic Algorithm technique for structure solution, followed by Rietveld refinement. This structure is compared with that of polymorph B, which was determined previously from single crystal X-ray diffraction data. Knowledge of the crystal structures of the two polymorphs provides the opportunity for establishing structure-property relationships. This work further emphasizes the scope and utility of ab initio structure solution from powder X-ray diffraction data in the pharmaceuticals field.

Calorimetry, Differential Scanning↗
PubMed2001

Dynamic solid-state and tableting properties of four theophylline forms.

Relationships between solid-state, densification and compact properties of theophylline monohydrate (TMO), a mixture of forms (TMIX), and anhydrous polymorphs I (TA-I) and II (TA-II) were evaluated. Solid-state identification of powders and compacts was accomplished by powder X-ray diffraction. A compaction simulator was used to assess deformation behaviour of the powders and to prepare compacts. Porosity and tensile strength of the compacts were determined after 1,24, and 168 h of storage at 22% relative humidity. TA-II was stable, whereas TA-I, TMIX and TMO partially transformed to the TA-II form during storage. All theophylline modifications primarily deformed by plastic flow. Increased water content decreased resistance towards densification and deformation of TMIX and TMO when compared to TA-II or TA-I, demonstrating viscoelasticity. Permanent densification behaviours of TMIX and TMO approached to that of TA-II during storage. Tensile strength of the different theophylline forms were practically equal after 1 h of storage. Tensile strength and porosity of TMIX and TMO compacts increased during the storage. Dynamic solid-state transformations from TMO, TMIX and TA-I to TA-II were associated with parallel changes in their densification and compact properties. The extent of these changes was also dependent on the materials' water content.

Bronchodilator Agents↗
PubMed2002

Flexible sorption and transformation behavior in a microporous metal-organic framework.

Crystals of the metal-organic framework material Ni(2)(4,4'-bipyridine)(3)(NO(3))(4) (A) have been grown by reaction of Ni(NO(3))(2).6H(2)O and 4,4'-bipyridine in methanol solution. Single-crystal X-ray diffraction experiments show that the ladder structure of the framework is maintained after desolvation of the material, resulting in the production of a porous solid stable to 215(4) degrees C. Powder X-ray diffraction has been employed to confirm the bulk purity and temperature stability of this material. The crystal structure indicates that the pore window has an area of 12.3 A(2). However, sorption experiments show these windows will admit toluene, which has a minimum cross-sectional area of 26.6 A(2), with no significant change in the structure. Monte Carlo docking calculations show that toluene can be accommodated within the large pores of the structure. Exposure of the related microporous material Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH (B) to methanol vapor causes a guest-driven solid-state transformation to A which is observed using powder X-ray diffraction. This structural rearrangement proceeds directly from crystalline B to crystalline A and is complete in less than 1 day. Mechanisms for the transformation are proposed which require breaking of at least one in six of the covalent bonds that confer rigidity on the framework.

Journal Article↗
PubMed2004

[Identification on Chinese materia medica liquoric root by X-ray diffraction Fourier fingerprint pattern method].

OBJECTIVE: To develop a new identification and analysis method of Chinese medicinal materia Liquoric Root. METHODS: Powder X-ray diffraction Fourier fingerprint pattern. RESULTS: Experiments and analysis were carried out on ten samples. The standard X-ray diffraction Fourier fingerprint pattern and characteristic diffraction peaks of Liquoric Root were obtained. CONCLUSION: This method can be used for identification of Chinese medicinal materia Liquoric Root.

Drugs, Chinese Herbal↗
PubMedDate not supplied

X-ray studies on phospholipid bilayers. VIII. Interactions with chlorpromazine.HCl.

Chlorpromazine is a widely used phenothiazine tranquilizer known to alter the shape of normal erythrocytes and their osmotic fragility. In order to understand the nature of the interactions chlorpromazine.HCl (CPZ.HCl) was made to interact with phospholipid bilayers formed by dimyristoylphosphatidylethanolamine (DMPE) and dimyristoylphosphatidylcholine (DMPC). This study was carried out by X-ray diffraction on crystalline powders of various molar mixtures of CPZ.HCl with DMPE and DMPC, with and without water. It was found that CPZ.HCl significatively affects the bilayer structure of DMPC in the presence of water, but not that of DMPE.

Chlorpromazine↗
PubMed2005

[Identification of Fritillaria herbal drugs by X-ray diffraction of starch grains].

OBJECTIVE: To provide a simple method to identify different of herbal drugs of Fritillaria. METHOD: The X-ray diffraction spectra of five Fritillaria powders were obtained by X-ray diffractometry (XRD). RESULT: By analyzing the diffraction peaks of starch over the 2theta diffraction angle in the range of 10 degrees-30 degrees, we concluded that the crystal type of starch in F. thunbergii, F. ussurensis, F. pallidifloca and F. hupehensis was B-type. However, the crystal type of starch in F. cirrhosa was CB-type. The degree of crystallinity of starch was 42.1%, 43.6%, 37.7%, 35.9% and 30.8%, corresponding to F. thunbergii, F. ussurensis, F. pallidiflcoca,F. cirrhosa and F. hupehensis. CONCLUSION: Based on the differences of crystallinity of starch and X-ray diffraction spectra of Fritillaria powders, different species of Fritillaria can be identified.

Crystallization↗
PubMed2004

Investigation of intermolecular interaction in molecular complex of tryptamine and benzoic acid by solid-state 2D NMR.

Solid-state NMR spectra and powder X-ray diffraction of the two-component molecular complex composed of tryptamine and benzoic acid were observed to investigate the intermolecular interaction in the molecular complex. 1D (13)C CP/MAS NMR spectrum and powder X-ray diffraction pattern of the complex was clearly different from the convolution of each spectrum of the single component. 2D (1)H-(13)C heteronuclear-correlation (HETCOR) NMR technique indicated that the intermolecular interaction between the primary amine of tryptamine and the carboxyl group of benzoic acid must be related to the complex formation.

Benzoic Acid↗
PubMed2004

Theophylline particle design using chitosan by the spray drying.

Solid dispersions of theophylline with chitosan as a carrier were prepared using a spray-drying method. Chitosan dissolved in an acid solution forms a gel, but it does not dissolve in an alkaline solution. Therefore, drugs which form composite particles with chitosan would gradually be released in an acid solution, and are expected to have considerably sustained release in an alkaline solution. In this study, we aimed to apply this ability to sustained release pharmaceutics. In this study, we used theophylline as a model drug and chitosan as a carrier. Mixtures of chitosan and the drug in prescribed ratios were dissolved in an acid solution. The physicochemical properties of the solid dispersions obtained were investigated by powder X-ray diffraction, differential scanning calorimetry, and dissolution rate analyses, with a view to clarify the effect of crystallinity on the dissolution rate. Furthermore, the interaction between the drug and the carrier was investigated by FT-IR analysis. The powder X-ray diffraction intensity of the drug in the spray-dried samples decreased with an increase in chitosan contents, which also caused changes from crystalline to amorphous forms. These results indicated that the system formed a solid dispersion. The dissolution profiles of the drug from the physical mixtures and solid dispersions were almost the same at pH 1.2. However, at pH 6.8, the release from the solid dispersions was sustained more than that from the physical mixtures. The FT-IR spectroscopy for the theophylline solid dispersions suggested that the carbonyl group of theophylline and the amino group of chitosan formed a hydrogen bond. Mass median aerodynamic diameter (MMAD) was measured by using a cascade impactor to evaluate the possibility of solid dispersions as dry powder inhalations. The MMAD of the spray-dried theophylline-chitosan systems were 4.5-5.0 microm. The results suggested that the spray-drying method is usefull to produce dry powders for inhalation.

Calorimetry, Differential Scanning↗