Crystal Transition and Drug-excipient Compatibility of Clarithromycin in Sustained Release Tablets

2020 ◽  
Vol 16 (7) ◽  
pp. 950-959
Author(s):  
Yu Li ◽  
Xiangwen Kong ◽  
Fan Hu
Keyword(s):  
Sustained Release ◽  
Powder Diffraction ◽  
Magnesium Stearate ◽  
Influential Factor ◽  
High Concentration ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sustained Release Tablets ◽  
Crystal Transition ◽  
Excipient Compatibility

Background: Clarithromycin is widely used for infections of helicobacter pylori. Clarithromycin belongs to polymorphic drug. Crystalline state changes of clarithromycin in sustained release tablets were found. Objective: The aim of this study was to find the influential factor of the crystal transition of clarithromycin in preparation process of sustained-release tablets and to investigate the possible interactions between the clarithromycin and pharmaceutical excipients. Methods and Results: The crystal transition of active pharmaceuticals ingredients from form II to form I in portion in clarithromycin sustained release tablets were confirmed by x-ray powder diffraction. The techniques including differential scanning calorimetry and infrared spectroscopy, x-ray powder diffraction were used for assessing the compatibility between clarithromycin and several excipients as magnesium stearate, lactose, sodium carboxymethyl cellulose, polyvinyl-pyrrolidone K-30 and microcrystalline cellulose. All of these methods showed compatibilities between clarithromycin and the selected excipients. Alcohol prescription simulation was also done, which showed incompatibility between clarithromycin and concentration alcohol. Conclusion: It was confirmed that the reason for the incompatibility of clarithromycin with high concentration of alcohol was crystal transition.

Evidence for room temperature mesomorphism in a mixed-valent diruthenium(II,III) quintapalmitoleate polymer

1998 ◽  
Vol 76 (11) ◽  
pp. 1520-1523
Author(s):  
Jennifer F Caplan ◽  
Christopher A Murphy ◽  
Susan Swansburg ◽  
Robert P Lemieux ◽  
T Stanley Cameron ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Powder Diffraction ◽  
Strong Evidence ◽  
Room Temperature ◽  
Variable Temperature ◽  
Mixed Valence ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystal Transition

The synthesis of Ru2(μ-O2CR)4(μ´-O2CR) (1), R = -CH2(CH2)6CH=CH(CH2)5CH3, has been achieved and characterization using elemental analysis and FTIR and UV-Vis spectroscopies undertaken. Strong evidence for a hexagonal discotic mesophase has been found using differential scanning calorimetry, variable-temperature polarizing optical microscopy, and X-ray powder diffraction. A solid to liquid crystal transition was found upon heating at 128°C and the mesophase is found to persist to room temperature upon cooling from 150°C. This is the first report of room temperature mesomorphism in a mixed-valent metallomesogen. Key words: ruthenium carboxylate, liquid crystal, metallomesogen, mixed valence, polymer.

scholarly journals Investigation of the sustained-release mechanism of hydroxypropyl methyl cellulose skeleton type Acipimox tablets

2018 ◽  
Vol 16 (1) ◽  
pp. 333-339
Author(s):  
Wanying Liu ◽  
Qing Huo ◽  
Yue Wang ◽  
Na Yu ◽  
Rongjian Shi
Keyword(s):  
Sustained Release ◽  
Diffusion Mechanism ◽  
Methyl Cellulose ◽  
Magnesium Stearate ◽  
Test Method ◽  
Release Mechanism ◽  
Hydroxypropyl Methyl Cellulose ◽  
Hypolipidemic Agents ◽  
Sustained Release Tablets ◽  
The Difference

AbstractIn this study, we investigate the production of hypolipidemic agents in the form of Acipimox sustained-release tablets, using a wet pelleting process. The purpose of this research is to reduce the total intake time for patients and to lower the initial dose in such that the adverse reactions could be reduced. This study adopts the single-factor method and orthogonal experiments by using hydroxypropyl methyl cellulose (HPMC K15M) as the main sustained-release prescription composition. The final prescription is Acipimox 20%, HPMC K15M 26.67%, sodium carboxymethyl cellulose 30%, polyethylene glycol (PEG 6000) 1%, ethyl cellulose 16.6%, lactose 4.67% and magnesium stearate 1%. The dissolution of tablets reached 85.88% in 8 h. The difference in the weight, hardness and friability of the tables met the requirements in the Chinese Pharmacopoeia; to test the stability, a temperature and illumination accelerated test method was used, the results indicate that the Acipimox sustained-release tablets should be sealed and stored in a dark, cool area. A preliminary study on the tablets’ releasing mechanism showed that their release curve fitted the Higuchi model (the formula is Mt/M∞ = 31.137 t1/2–3.605 (R2 = 0.9903)). The Acipimox tablets’ release principle is dominated by the diffusion mechanism.

Compatibility between Magnesium Stearate and Pharmaceutical Acidic Active Compounds/Excipients with DSC

2020 ◽  
Vol 856 ◽  
pp. 190-197
Author(s):  
Pornsit Chaiya ◽  
Thawatchai Phaechamud
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnesium Stearate ◽  
X Ray Diffraction ◽  
Salt Form ◽  
Scanning Calorimetry ◽  
Powder Mixtures ◽  
X Ray ◽  
Pharmaceutical Excipients ◽  
Drug Compounds ◽  
Ft Ir

Compatibility investigation was performed between magnesium stearate and acidic drug compounds (ibuprofen, indomethacin and valproic acid) and acidic pharmaceutical excipients (lactic acid and citric acid) using differential scanning calorimetry (DSC). DSC study indicated the possible incompatibility for the mixture between magnesium stearate and any compounds. Alteration in DSC thermogram was found in all mixtures. The eutectic phenomenon was found in the powder mixture of magnesium stearate and ibuprofen. In addition, the presence of melting endothermic peak of stearic acid in other powder mixtures except the mixture of magnesium stearate and indomethacin indicating breakage of salt form of magnesium stearate. This alteration could relate to the influence on physicochemical properties of drug compounds and pharmaceutical excipients which powder x-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FT-IR) should be further analyzed to confirm the interactions between compounds.

scholarly journals Polymorphism of 1,3-X-adamantanes (X = Br, OH, CH3) and the crystal plastic phase formation ability

CrystEngComm ◽  
2020 ◽  
Vol 22 (7) ◽  
pp. 1230-1238 ◽  
Author(s):  
Philippe Negrier ◽  
Bacem Ben Hassine ◽  
Maria Barrio ◽  
Michela Romanini ◽  
Denise Mondieig ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
High Pressure ◽  
Phase Formation ◽  
Powder Diffraction ◽  
Scanning Calorimetry ◽  
Density Measurements ◽  
X Ray ◽  
Plastic Phase

The polymorphism of 1,3-dimethyladamantane (13DMA), 1,3-adamantanediol (13DOHA) and 1,3-dibromoadamantane (13DBrA) has been studied by X-ray powder diffraction, density measurements and differential scanning calorimetry at normal and high-pressure.

Thermal annealing of natural, radiation-damaged pyrochlore

2017 ◽  
Vol 232 (1-3) ◽  
Author(s):  
Peter Zietlow ◽  
Tobias Beirau ◽  
Boriana Mihailova ◽  
Lee A. Groat ◽  
Thomas Chudy ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Scattering ◽  
Radiation Damage ◽  
Thermal Annealing ◽  
Powder Diffraction ◽  
Scanning Calorimetry ◽  
Natural Radiation ◽  
Α Decay ◽  
X Ray ◽  
Decay Products

AbstractRadiation damage in minerals is caused by the α-decay of incorporated radionuclides, such as U and Th and their decay products. The effect of thermal annealing (400–1000 K) on radiation-damaged pyrochlores has been investigated by Raman scattering, X-ray powder diffraction (XRD), and combined differential scanning calorimetry/thermogravimetry (DSC/TG). The analysis of three natural radiation-damaged pyrochlore samples from Miass/Russia [6.4 wt% Th, 23.1·10

Dynamic proton disorder and the II–I structural phase transition in (NH4)3H(SO4)2

2009 ◽  
Vol 65 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Yoo Jung Sohn ◽  
Anja Loose ◽  
Michael Merz ◽  
Karine Sparta ◽  
Helmut Klapper ◽  
...  
Keyword(s):  
Phase Transition ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Structural Phase ◽  
Local Symmetry ◽  
Crystal Structure Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Proton Disorder

X-ray powder diffraction, differential scanning calorimetry (DSC)/thermogravimetry (TG) and single-crystal neutron diffraction methods were used to investigate triammonium hydrogen disulfate (NH4)3H(SO4)2 (TAHS) in the temperature range between 293 and 493 K. The temperature-dependent X-ray powder diffraction measurements show a clear hysteresis of the I \leftrightarrow II phase transition of TAHS with transition temperatures of T up = 412.9 (1) K on heating and of T down = 402.6 (1) K on cooling. From the existence of hysteresis and from the jump-like changes of the lattice parameters, the I \leftrightarrow II phase transition of TAHS is considered to be first order. With DSC/TG measurements we confirmed that there is only one phase transition between 293 and 493 K. Through careful investigation on single crystals of TAHS using neutron diffraction, the correct space group (C2/c) of room-temperature TAHS-II phase was confirmed. Crystal structure analysis by single-crystal neutron diffraction showed a strongly elongated displacement ellipsoid of the proton which lies in the middle of the (SO4)H(SO4) dimer with \bar 1 local symmetry. The protons of the NH4 groups also show strongly enlarged anisotropic mean-square displacements. These findings are interpreted in terms of a characteristic proton disorder in the TAHS-II phase.

scholarly journals First evidence of a phase transition in a high-pressure metal iodate.

2014 ◽  
Vol 70 (a1) ◽  
pp. C53-C53
Author(s):  
Yan Suffren ◽  
Isabelle Gautier-Luneau ◽  
Céline Darie ◽  
Céline Goujon ◽  
Murielle Legendre ◽  
...  
Keyword(s):  
High Pressure ◽  
Powder Diffraction ◽  
Ambient Pressure ◽  
Visible Region ◽  
Structural Evolution ◽  
Solution Chemistry ◽  
Hydrothermal Conditions ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Two Phases

In the 1970s, a large number of metal iodates compounds were extensively investigated for their nonlinear optics (NLO) properties as well as for their ferroelectric, piezoelectric, and pyroelectric properties. Interest in these compounds resumed in the early 2000s. We have shown that metal iodates are particularly interesting for for quadratic NLO in mid IR, as they possess a large domain of transparency from the visible region to the beginning of the far IR region (12.5 μm), thus covering the three atmospheric transparency windows. The synthesis of metal iodates has so far been mainly investigated by solution chemistry, under hydrothermal conditions or by the flux method. The solid state synthesis of these compounds at high pressure has never been explored. To date, only the structural evolution of α-LiIO3 with pressure has been studied by X-ray powder diffraction [1]. It was shown that, at room temperature, α-LiIO3 is stable up to 75 GPa; only compression of the lattice parameters with pressure was observed. In this work, we present a new phase of silver iodate obtained at high pressure from α-AgIO3 and characterized by X-ray powder diffraction. The α-AgIO3 to β-AgIO3 transition was characterized by differential thermal analysis (DTA) at high pressure [2-3]. The thermal behaviors of α-AgIO3 and β-AgIO3 were studied by differential scanning calorimetry (DSC) at ambient pressure and in situ temperature-dependent X-ray powder diffraction. Structural studies of these two phases were carried out to understand the formation of β-AgIO3.

Crystallisation of caesium borosilicate glasses with approximate boroleucite composition

2002 ◽  
Vol 217 (6) ◽  
Author(s):  
R. Hübner ◽  
A. Belger ◽  
D. C. Meyer ◽  
P. Paufler ◽  
I. G. Polyakova
Keyword(s):  
Differential Scanning Calorimetry ◽  
Powder Diffraction ◽  
Borosilicate Glass ◽  
Orthorhombic Phase ◽  
Borosilicate Glasses ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Annealing Behaviour ◽  
Profile Fitting

AbstractCrystallisation and annealing behaviour of two caesium borosilicate glass samples with approximate boroleucite composition were characterised by means of differential scanning calorimetry measurements as well as X-ray powder diffraction investigations with subsequent profile fitting of the observed patterns according to the Rietveld and/or Pawley method. While one sample crystallised primarily in an orthorhombic phase (

scholarly journals Synthesis, crystal structure and thermal properties of poly[bis[μ2-3-(aminomethyl)pyridine]bis(thiocyanato)cobalt(II)]

2021 ◽  
Vol 77 (4) ◽  
pp. 428-432
Author(s):  
Christoph Krebs ◽  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Hydrogen Bonding ◽  
Thermal Properties ◽  
Powder Diffraction ◽  
Title Compound ◽  
Three Dimensional ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dimensional Network

The reaction of Co(NCS)2 with 3-(aminomethyl)pyridine as coligand leads to the formation of crystals of the title compound, [Co(NCS)2(C6H8N2)2] n , that were characterized by single-crystal X-ray analysis. In the crystal structure, the CoII cations are octahedrally coordinated by two terminal N-bonded thiocyanate anions as well as two pyridine and two amino N atoms of four symmetry-equivalent 3-(aminomethyl)pyridine coligands with all pairs of equivalent atoms in a trans position. The CoII cations are linked by the 3-(aminomethyl)pyridine coligands into layers parallel to the ac plane. These layers are further linked by intermolecular N—H...S hydrogen bonding into a three-dimensional network. The purity of the title compound was determined by X-ray powder diffraction and its thermal behavior was investigated by differential scanning calorimetry and thermogravimetry.

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