Quantifying Low Amorphous or Crystalline Amounts of Alpha‐Lactose‐Monohydrate Using X‐Ray Powder Diffraction, Near‐Infrared Spectroscopy, and Differential Scanning Calorimetry

2004 ◽  
Vol 30 (5) ◽  
pp. 513-523 ◽  
Author(s):  
I. Fix ◽  
K.‐J. Steffens
Keyword(s):  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Powder Diffraction ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Lactose Monohydrate

Metoprolol: solid forms of a top selling antihypertensive

CrystEngComm ◽  
2019 ◽  
Vol 21 (29) ◽  
pp. 4319-4328 ◽  
Author(s):  
Mariani A. Ciciliati ◽  
M. Ermelinda S. Eusébio ◽  
Manuela Ramos Silva ◽  
Éder T. G. Cavalheiro ◽  
Ricardo A. E. Castro
Keyword(s):  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Nicotinic Acid ◽  
Powder Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Base Form

A new polymorph of metoprolol base, form II, was identified and characterized by differential scanning calorimetry, X-ray powder diffraction and infrared spectroscopy. A new salt of metoprolol and nicotinic acid was also obtained and characterized.

Reactions in Molten Alkalimetal Polychalcogenides: What Happens in the Melt? A Study of the Reactions in the System K-Nb-S Using Differential Scanning Calorimetry, Infrared Spectroscopy, and X-Ray Powder Diffraction

2002 ◽  
Vol 57 (12) ◽  
pp. 1382-1386 ◽  
Author(s):  
Peter Dürichen ◽  
Wolfgang Bensch
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Powder Diffraction ◽  
Analytical Techniques ◽  
Product Formation ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Short Time

The reactions of potassium polysulfides with elemental Nb were investigated with different analytical techniques. The amount of the polysulfide applied has no influence onto product formation, i. e. the ratio K2Sx: Nb is not important. The length of the polsysulfide chain, i. e. the value of x in K2Sx determines what product is formed. In sulfur-poor melts, K3NbS4 is observed. Increasing x to 5 - 6, K4Nb2S11 is formed with a structure containing S22− anions. Finally, applying a melt with x > 6, K6Nb4S25 is found as the product with a crystal structure containing the S52− polysulfide anion. When K2Sx (x < 5) is heated with sulfur in the first step the pentasulfide K2S5 is formed. Immediately after melting of K2S5 a reaction with elemental Nb occurs. The results of FT-IR and X-ray investigations have demonstrated that after oxidation the anion [Nb2S11]4− is formed relatively fast, and after a short time crystalline K4Nb2S11 can be detected. After 24 h the reaction is complete.

PREPARATION AND CHARACTERIZATION OF AMORPHOUS CEFUROXIME AXETIL

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (10) ◽  
pp. 53-61
Author(s):  
B. V. Dhokchawle ◽  
◽  
A. B. Bhandari
Keyword(s):  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Powder Diffraction ◽  
Cefuroxime Axetil ◽  
Scanning Calorimetry ◽  
Amorphous Form ◽  
X Ray ◽  
Saturation Solubility ◽  
Fourier Transformed Infrared Spectroscopy

In the present study, amorphous form of cefuroxime axetil was prepared and characterized by various methods. The result showed that the amorphous form of cefuroxime axetil with hydrophilic carriers was successfully obtained by freeze drying. The amorphous form showed a substantially higher dissolution rate and saturation solubility than cefuroxime axetil and physical mixture. The molecular behaviour of the drug in all samples were characterized by X-ray powder diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy and differential scanning calorimetry. The dissolution and saturation solubility studies of the samples were performed. The X-ray powder diffraction, Fourier transformed infrared spectroscopy and differential scanning calorimetry provided useful information to support the amorphousness of the samples.

scholarly journals Near-infrared spectroscopy of faint discrete X-ray point sources constituting the Galactic ridge X-ray emission

2016 ◽  
Vol 68 (4) ◽  
pp. 57 ◽  
Author(s):  
Kumiko Morihana ◽  
Masahiro Tsujimoto ◽  
Pierre Dubath ◽  
Tessei Yoshida ◽  
Kensuke Suzuki ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Point Sources ◽  
X Ray

Soil subgroup prediction via portable X-ray fluorescence and visible near-infrared spectroscopy

Geoderma ◽  
2020 ◽  
Vol 365 ◽  
pp. 114212 ◽  
Author(s):  
Lucas Benedet ◽  
Wilson Missina Faria ◽  
Sérgio Henrique Godinho Silva ◽  
Marcelo Mancini ◽  
Luiz Roberto Guimarães Guilherme ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
X Ray

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 Organic Salts of Pharmaceutical Impurity p-Aminophenol

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1910
Author(s):  
U. B. Rao Khandavilli ◽  
Leila Keshavarz ◽  
Eliška Skořepová ◽  
René R. E. Steendam ◽  
Patrick J. Frawley
Keyword(s):  
Differential Scanning Calorimetry ◽  
Salicylic Acid ◽  
Infrared Spectroscopy ◽  
Efficacy And Safety ◽  
Salt Formation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Organic Salts ◽  
X Ray ◽  
Dark Color

The presence of impurities can drastically affect the efficacy and safety of pharmaceutical entities. p-Aminophenol (PAP) is one of the main impurities of paracetamol (PA) that can potentially show toxic effects such as maternal toxicity and nephrotoxicity. The removal of PAP from PA is challenging and difficult to achieve through regular crystallization approaches. In this regard, we report four new salts of PAP with salicylic acid (SA), oxalic acid (OX), l-tartaric acid (TA), and (1S)-(+)-10-camphorsulfonic acid (CSA). All the PAP salts were analyzed using single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The presence of minute amounts of PAP in paracetamol solids gives a dark color to the product that was difficult to remove through crystallization. In our study, we found that the addition of small quantities of the aforementioned acids helps to remove PAP from PA during the filtration and washings. This shows that salt formation could be used to efficiently remove challenging impurities.

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