Quantification of losartan potassium polymorphs using powder X-ray diffraction

2020 ◽  
Author(s):  
Yongjun Lou ◽  
Lili Zuo
Keyword(s):  
Calibration Curve ◽  
Diffraction Method ◽  
Crystal Form ◽  
Losartan Potassium ◽  
X Ray Diffraction ◽  
Limit Of Quantification ◽  
X Ray ◽  
Weight Percentage ◽  
Using Data

Abstract Background Losartan potassium, a common antihypertensive drug on the market, has multiple polymorphs, of which form I is used as a pharmaceutical crystal form. Form I can be partially converted to form III under some circumstances. The quantification of losartan potassium polymorphs is important to control the quality of pharmaceuticals. Objective To establish a method to determine the contents of losartan potassium polymorphs. Methods Pure form I and form III of losartan potassium were obtained by recrystallization, and characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and thermal analysis. A powder X-ray diffraction method was developed to characterize form I and form III of losartan potassium. Peak area and weight percentage were used to establish calibration curve. Results The calibration curve was linear over the range of 1–50% (w/w), using the characteristic peak area ratio of form I at 11.13° 2θ and form III at 5.64° 2θ as the quantitative parameter. The precisions were excellent between 0.6–4.9%, and the limit of quantification (LoQ) was 2.02% (w/w). Conclusions This PXRD method can be used to analyze mixtures of losartan potassium polymorphs (forms I and III) quantitatively and control the quality of bulk drug. Highlights New method of quantifying the amount of form III in polymorphic forms of LP using data obtained by PXRD. Consistent, sensitive and accurate.

Study of the quality of GaAs thin film on Si substrate by X-ray diffraction method

1990 ◽  
Vol 7 (7) ◽  
pp. 308-311
Author(s):  
Li Chaorong ◽  
Mai Zhenhong ◽  
Cui Shufan ◽  
Zhou Junming ◽  
Yutian Wang
Keyword(s):  
Thin Film ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray

A New X-Ray Diffraction Method for Quantitative Multicomponent Analysis

1973 ◽  
Vol 17 ◽  
pp. 106-115 ◽  
Author(s):  
Frank H. Chung
Keyword(s):  
Calibration Curve ◽  
Fundamental Matrix ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Absorption Effect ◽  
Multicomponent Analysis ◽  
X Ray ◽  
Practical Applications ◽  
The Matrix

AbstractA unified matrix-flushing theory and its practical applications for quantitative multicomponent analysis by X-ray diffraction are presented.In this method, a fundamental “matrix-flushing” concept is introduced; the calibration curve procedure is shunted; the matrix (absorption) effect is totally eliminated; all components, crystalline or amorphous, can be determined.

Crystals M2Ni (SO4)2.XH2O (M=Na, X=4; M=K, NH4, Rb, Cs, X=6): Crystal Structures, Spectrum and Thermal Stability Characterizations

2011 ◽  
Vol 332-334 ◽  
pp. 1687-1690
Author(s):  
Xia Wang ◽  
Ming Qing Xing
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Relative Size ◽  
Diffraction Method ◽  
Electron Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Crystal Structures ◽  
Average Bond

Single crystal structures of M2Ni (SO4)2.XH2O (M=Na, X=4; M=K, NH4, Rb, Cs, X=6) were investigated using the single crystal X-ray diffraction method. They crystallize isotypic (space group P2 (1)/c). Many structure features exhibit regularity with the relative size of radius, such as a, b, c, V. But to ANSH, the regularity of average bond lengths of violets from others. Their optical transmission spectrums were recorded on PE-lambda 900 with performing wavelengths ranging from 200 to 1100 nm, they have the similar optical characters in tested wavelength range. This phenomenon arises from the electron transition of d orbits in the octahedral field. The similarity in optical spectrum is consistent with the comparability of structures. We also investigated the thermal-gravimetric quality of above single crystals under same experiment conditions. We found that the dehydration temperatures increase with increasing of radius of the M+ when M =K, Rb, Cs. When M=Na, the dehydration temperature (tdh) is above the others pronouncedly due to the specialty of structure. To NH4-, the so-called compound is also with exception of the regularity.

scholarly journals Crystallization and preliminary X-ray crystallographic studies of dipeptidyl aminopeptidase BII fromPseudoxanthomonas mexicanaWO24

2014 ◽  
Vol 70 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Yasumitsu Sakamoto ◽  
Yoshiyuki Suzuki ◽  
Ippei Iizuka ◽  
Chika Tateoka ◽  
Saori Roppongi ◽  
...  
Keyword(s):  
Diffraction Method ◽  
Crystal Form ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Hanging Drop ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Cell Parameters ◽  
Multi Wavelength ◽  
Dipeptidyl Aminopeptidase

Dipeptidyl aminopeptidase BII fromPseudoxanthomonas mexicanaWO24 (DAP BII) is able to cleave a variety of dipeptides from the amino-terminus of substrate peptides. For crystallographic studies, DAP BII was overproduced inEscherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data to 2.3 Å resolution were collected using an orthorhombic crystal form belonging to space groupP212121, with unit-cell parametersa= 76.55,b= 130.86,c= 170.87 Å. Structural analysis by the multi-wavelength anomalous diffraction method is in progress.

scholarly journals Crystallization and preliminary X-ray crystallographic studies of dipeptidyl peptidase 11 fromPorphyromonas gingivalis

2015 ◽  
Vol 71 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Yasumitsu Sakamoto ◽  
Yoshiyuki Suzuki ◽  
Ippei Iizuka ◽  
Chika Tateoka ◽  
Saori Roppongi ◽  
...  
Keyword(s):  
Diffraction Method ◽  
Crystal Form ◽  
Dipeptidyl Peptidase ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Hanging Drop ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Cell Parameters ◽  
Multi Wavelength

Dipeptidyl peptidase 11 fromPorphyromonas gingivalis(PgDPP11) preferentially cleaves substrate peptides with Asp and Glu at the P1 position [NH2–P2–P1(Asp/Glu)–P1′–P2′…]. For crystallographic studies, PgDPP11 was overproduced inEscherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data to 1.82 Å resolution were collected from an orthorhombic crystal form belonging to space groupC2221, with unit-cell parametersa= 99.33,b= 103.60,c= 177.33 Å. Structural analysis by the multi-wavelength anomalous diffraction method is in progress.

scholarly journals X-ray diffraction analysis of kaolin M1 and M2 via the Williamson–Hall and Warren–Averbach methods

2021 ◽  
pp. 174751982098472
Author(s):  
Lalmi Khier ◽  
Lakel Abdelghani ◽  
Belahssen Okba ◽  
Djamel Maouche ◽  
Lakel Said
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Low Temperature ◽  
Diffraction Analysis ◽  
Mechanical Resistance ◽  
X Ray Diffraction ◽  
Integral Breadth ◽  
X Ray ◽  
Mullite Phase

Kaolin M1 and M2 studied by X-ray diffraction focus on the mullite phase, which is the main phase present in both products. The Williamson–Hall and Warren–Averbach methods for determining the crystallite size and microstrains of integral breadth β are calculated by the FullProf program. The integral breadth ( β) is a mixture resulting from the microstrains and size effect, so this should be taken into account during the calculation. The Williamson–Hall chart determines whether the sample is affected by grain size or microstrain. It appears very clearly that the principal phase of the various sintered kaolins, mullite, is free from internal microstrains. It is the case of the mixtures fritted at low temperature (1200 °C) during 1 h and also the case of the mixtures of the type chamotte cooks with 1350 °C during very long times (several weeks). This result is very significant as it gives an element of explanation to a very significant quality of mullite: its mechanical resistance during uses at high temperature remains.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

scholarly journals Born out of Fire and Ice: Polymorph Studies of the Antiviral Famciclovir

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 129
Author(s):  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Variable Temperature ◽  
Chemical Properties ◽  
Crystal Form ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Physical Chemical ◽  
Diffraction Patterns ◽  
Crystalline Forms

There is much interest and focus on solid forms of famciclovir. However, in spite of the abundance of reported differences in oral bioavailability, compressibility, and other physical–chemical properties of the various crystal forms of this drug, very little precise structural analysis is available in the literature to date. The form used in the commercial formulation is the anhydrous form I. Patents and patent applications report three different anhydrous crystalline forms on the basis of unindexed powder diffraction patterns. Single-crystal and variable-temperature X-ray diffraction experiments using the commercially available anhydrous form of famciclovir were carried out and led not only to the crystal structure determination of the anhydrous form I, but also to discovery of a new crystal form of anhydrous famciclovir from powder data.

scholarly journals Study of Corrosion Resistance and Degradation Mechanisms in LiTiO2-Li2TiO3 Ceramic

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 753
Author(s):  
Dmitriy Shlimas ◽  
Artem L. Kozlovskiy ◽  
Maxim Zdorovets
Keyword(s):  
Degradation Mechanism ◽  
Diffraction Method ◽  
Large Mass ◽  
Time Frame ◽  
X Ray Diffraction ◽  
Acidic Media ◽  
X Ray ◽  
Mass Losses ◽  
The Stability ◽  
Thermal Sintering

The interest in lithium-containing ceramics is due to their huge potential as blanket materials for thermonuclear reactors for the accumulation of tritium. However, an important factor in their use is the preservation of the stability of their strength and structural properties when under the influence of external factors that determine the time frame of their operation. This paper presents the results of a study that investigated the influence of the LiTiO2 phase on the increasing resistance to degradation and corrosion of Li2TiO3 ceramic when exposed to aggressive acidic media. Using the X-ray diffraction method, it was found that an increase in the concentration of LiClO4·3H2O during synthesis leads to the formation of a cubic LiTiO2 phase in the structure as a result of thermal sintering of the samples. During corrosion tests, it was found that the presence of the LiTiO2 phase leads to a decrease in the degradation rate in acidic media by 20–70%, depending on the concentration of the phase. At the same time, and in contrast to the samples of Li2TiO3 ceramics, for which the mechanisms of degradation during a long stay in aggressive media are accompanied by large mass losses, for the samples containing the LiTiO2 phase, the main degradation mechanism is pitting corrosion with the formation of pitting inclusions.

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