Authors:Mohammed S. A. Khedr, Mona F. Ali, Abdullah M. A. Kamel, and Manal A. A. El-Ghanam
This research will shed light on studying a terrazzo pavement in Prince Mohamed Ali Museum (the case study). The authors used visual inspection, stereo microscope, USB microscope, XRPD analysis, and SEM.EDX to identify its components, deterioration aspects and execution techniques. The XRPD and SEM.EDX results revealed that Portland cement was used in the three layers of terrazzo because of the detection of Hatrurite, Alite, Anorthite, Albite, Aragonite, etc. Many pigments were used in the topping terrazzo layer as; Goethite, Greenalite, Hematite, Azurite and Magnetite. The divider strips were made of brass alloy and the topping layer chips were prepared from basalt, marble and sea shells.
Authors:G. Bruni, V. Berbenni, C. Milanese, A. Girella, P. Cofrancesco, G. Bellazzi, and A. Marini
In this work the solid-state characterization of anhydrous D-mannitol has been performed: α and β modifications can be distinguished only by XRPD and FTIR as they show melting temperature
and enthalpy that are the same within the standard deviation. The understanding of the thermal behaviour of the δ form (obtained
by re-crystallization in acetone) has required XRPD experiments performed at variable temperature. This form during heating
undergoes a solid phase transition to α modification. By cooling a melted sample, under a wide range of experimental conditions,
a very fast crystallization occurs. Independently of the starting crystal form (β or δ form), the re-crystallization of D-mannitol from melt always leads to α form.
Authors:G. Papageorgiou, A. Docoslis, M. Georgarakis, and D. Bikiaris
In this work, the enhancement of drug dissolution rate through the preparation of new formulations containing Nimodipine in
molecular level dispersion or in nanodispersion into poly(vinyl pyrrolidone) (PVP) matrix, was investigated. Differential
scanning calorimetry (DSC) and modulated-temperature differential scanning calorimetry (MTDSC) in combination with X-ray powder
diffractometry (XRPD) and scanning electron microscopy (SEM) studies showed that Nimodipine was amorphous in solid dispersions
of 10 or 20 mass%, and mainly dispersed on a molecular level. This behaviour is attributed to the strong interactions taking
place between the amine group of Nimodipine and carbonyl group of PVP. At higher drug loadings, crystal reflections in XRPD
patterns and melting peaks of Nimodipine in DSC traces, indicated presence of drug in crystalline form. Micro-Raman studies
in combination with SEM micrographs showed that the mean particle size increases with drug content in the formulations, up
to 10 μm. Moreover, both XRPD patterns and micro-Raman spectra seem to indicate that Nimodipine crystallized in a second,
thermodynamically stable, crystal modification II. The physicochemical characteristics of Nimodipine and the particle size
distribution directly affect the dissolution rate enhancement, which is higher in amorphous dispersions.
Authors:G. Patyi, A. Bódis, I. Antal, B. Vajna, Zs. Nagy, and Gy. Marosi
Solvent and melt techniques were used to obtain molecular dispersion of the poorly soluble spironolactone (SPIR) model drug
enhancing its dissolution rate. DSC study of the interaction between SPIR and hydroxypropyl-β-cyclodextrin confirmed the need
for molecular dispersion if their complexation is required. Solvent-free twin-screw extrusion was suitable for forming inclusion
complex significantly below the melting temperature of the SPIR. According to DSC, Raman and XRPD results fine dispersion
of both components was achieved in a hydrophilic polymer. The molecules of the active ingredient are separated from each other
in the polymer and the lack of the lattice energy causes faster dissolution.
Authors:L. Szirtes, A. Szeleczky, A. Rajeh, and E. Kuzmann
The thermal behaviour of Co(II), Ni(II) and Zn(II)-containing zirconium phosphate of α type was investigated. XRPD analysis
revealed that, for the samples containing Co(II) or Ni(II), the first reflection of the solid phase is split into a doublet.
In contrast, when Zn(II) is present, a single solid phase system is formed. The thermal behaviour of the materials followed
this sequence. For the samples containing Co(II) or Ni(II), phase-transition processes were found and there was also a loss
of crystal water, but for the sample containing Zn(II) there was only one endothermic effect, which corresponded to the decomposition
of phosphate groups.
Authors:V. Drebushchak, Tatiana Drebushchak, N. Chukanov, and Elena Boldyreva
Five polymorphs of chlorpropamide (α, β, δ, γ, and ε) were investigated near the melting point by using DSC. Structure of
samples was tested by X-ray powder diffraction. Four first polymorphs were found to transform into ε-polymorph, which melts
at Tm=128°C, ΔmH=24 kJ mol−1. Enthalpy of the polymorph transitions ranges from +3 kJ mol−1 for α→ε to −0.8 kJ mol−1 for β→ε.
Structure of three first polymorphs was published elsewhere, and the structure of δ-polymorph is published for the first time.
XRPD patterns for all polymorphs are reported, together with the atomic coordinates for the δ-polymorph.
Authors:L. Bernardi, P. Oliveira, F. Murakami, M. Silva, S. Borgmann, and S. Cardoso
The thermal analytical study of venlafaxine hydrochloride, a third generation antidepressant, was investigated using thermogravimetry
(TG) and differential scanning calorimetry (DSC). The DSC curves have shown a sharp endothermic event at 211 °C and TG demonstrated
a single stage of mass loss between 254 and 283 °C. Solid-state characterization was carried out by DRIFT, SEM, and XRPD demonstrating
the drug physicochemical properties including crystallinity. Drug-excipient compatibility studies investigated by DSC have
shown a possible physical interaction of the drug with magnesium stearate, microcrystalline cellulose and starch. Nevertheless,
these results where not confirmed by DRIFT and SEM analyses.
Authors:H. Stulzer, P. Rodrigues, T. Cardoso, J. Matos, and M. Silva
Captopril (CAP) was the first commercially available angiotensine-converting enzyme (ACE) inhibitor. In the anti-hypertensive
therapy is considered the selected drug has to be therapeutically effective together with reduced toxicity. CAP is an antihypertensive
drug currently being administered in tablet form. In order to investigate the possible interactions between CAP and excipients
in tablets formulations, differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis completed by X-ray powder
diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR) were used for compatibility studies. A possible drug-excipient
interaction was observed with magnesium stearate by DSC technique.
Authors:V. Berbenni, A. Marini, G. Bruni, A. Maggioni, and P. Cogliati
A physico-chemical characterization of dipyridamole (C24H40N8O4), a widely used anti-aggregating agent, has been performed by using a combination of thermoanalytical (DSC) and spectroscopic
(XRPD and FT-IR/PAS) techniques. A solid state transition, already reported in literature, has been ascribed to the breaking
of an intramolecular H-bonds network. The rupture of a network of intermolecular H-bonds is thought to accompany the fusion.
The solid state transition has been shown to be reversible provided the sample has not undergone melting.
Mechanical milling and thermal annealing have been shown to decrease melting temperature and enthalpy. The effect brought
about by mechanical and thermal treatment on the solid state transition is different. In the milled samples the transition
peak shifts towards lower temperatures and its enthalpy suggests that all intramolecular H-bonds have been transformed into
Authors:S. Marković, Vera Dondur, R. Dimitrijević, and S. Macura
the present study, we performed an investigation of phase transformation of
zeolite Na-GIS in temperature interval from room temperature up to 1300C.
The collapse of S4R and S8R (secondary building units in zeolite Na-GIS) and
the forming of pure sodium nepheline phase, consists of S6R, was examined.
During the thermal transformation of Na-GIS zeolite symmetry of rings was
changed and their deformation increases. The irregularity of rings causes
the appearance of defect modes in the IR spectra of amorphous precursors.
Investigated phases were characterized by XRPD, IR, NMR and DSC methods. A
semiempirical method AM1 was used for calculation of vibrational spectrum