Comparison of the mineral oil lifetime estimates obtained by differential scanning calorimetry, infrared spectroscopy, and dielectric dissipation factor measurements

2017 ◽  
Vol 647 ◽  
pp. 86-93 ◽  
Author(s):  
R. Polansky ◽  
P. Prosr ◽  
R. Vik ◽  
D. Moravcova ◽  
J. Pihera
Keyword(s):  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Dissipation Factor ◽  
Mineral Oil ◽  
Scanning Calorimetry ◽  
Dielectric Dissipation Factor

scholarly journals Thermal stability and thermal decomposition of sucralose

2018 ◽  
Vol 39 (4) ◽  
pp. 21
Author(s):  
Gilbert Bannach ◽  
Rafael R. Almeida ◽  
Luis G. Lacerda ◽  
Egon Schnitzler ◽  
Massao Ionashiro
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Differential Thermal Analysis ◽  
Infrared Spectroscopy ◽  
Scanning Calorimetry ◽  
Thermoanalytical Techniques ◽  
Thermal Stability Of

Several papers have been described on the thermal stability of the sweetener, C12H19Cl3O8 (Sucralose). Nevertheless no study using thermoanalytical techniques was found in the literature. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC) and infrared spectroscopy, have been used to study the thermal stability and thermal decomposition of sweetener.

scholarly journals Synthesis and characterization of solid 2-methoxycinnamylidenepyruvic acid

2008 ◽  
Vol 33 (4) ◽  
pp. 61-68 ◽  
Author(s):  
C. T. de Carvalho ◽  
A. B. Siqueira ◽  
E. Y. Ionashiro ◽  
M. Pivatto ◽  
M. Ionashiro
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Molecular Geometry ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Purity Determination

The 2-methoxycinnamylidenepyruvic acid (2-MeO-HCP) was synthesized and characterized for nuclear magnetic resonance (¹H and 13C NMR), mass spectrometry (MS), Infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The application of DSC for purity determination is well documented in literature and is used in the analysis of pure organic compounds. The molecular geometry and vibrational frequencies of 2-MeO-HCP have been calculated.

scholarly journals New insight into single phase formation of capric acid/menthol eutectic mixtures by Fourier-transform infrared spectroscopy and differential scanning calorimetry

2020 ◽  
Vol 19 (2) ◽  
pp. 361-369 ◽  
Author(s):  
Hiba H. Ali ◽  
Mowafaq M. Ghareeb ◽  
Mayyas Al-Remawi ◽  
Faisal T. Al-Akayleh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Hydrogen Bond ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Bond Formation ◽  
Capric Acid ◽  
Fourier Transform Infrared ◽  
Scanning Calorimetry ◽  
Hydrogen Bond Formation

Purpose: To examine the structural changes of a eutectic mixture comprising capric acid and menthol which are commonly used in pharmaceutical applications. Methods: A phase diagram was constructed by quantitative mixing of capric acid and menthol under controlled conditions until a single liquid phase was formed. Eutectic mixtures of capric acid: menthol at the ratios of 3:2, 1:4, 1:1, 2:3, and 1:4 were prepared. Hydrogen bond formation and conformational changes were analyzed using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Microscopic imaging was carried out to capture phase change events upon increasing temperature. Results: Menthol confirmed the intact structure of a hexagonal ring. The high degree of broadening of the menthol O-H groups indicates hydrogen bond formation. FTIR band changes related to capric acid suggest a break-up of the methylene arrangement structure due to changes in the C-H band frequencies. The red shift encountered in C=O stretching band emphasizes hydrogen bond formation taking place between the oxygen atom of the hydroxyl group comprising the carboxylic moiety of capric acid and the hydrogen atom of menthol hydroxyl group. DSC results indicate the presence of two polymorphs of the capric acid/ menthol complex. Both exhibited crystallization and conformational change exotherms in addition to two melting endotherms as result of transformation of crystalline components to become partially crystalline due to hydrogen bond formation. Conclusion: The interaction between capric acid and menthol results in a typical preparation of deep eutectic systems that can act as natural-based solvents in numerous pharmaceutical applications. Keywords: Eutectic system, Capric acid, Menthol, Differential scanning calorimetry, DSC, Fourier transform infrared spectroscopy, FTIR

Comparison of Electron and Infrared Spectroscopy with Thermal Analysis to Study Molecular Weight Effects in PVC-PMMA Blends

1993 ◽  
Vol 47 (10) ◽  
pp. 1636-1642 ◽  
Author(s):  
Cindy A. Burkhardt ◽  
Joseph A. Gardella
Keyword(s):  
Thermal Analysis ◽  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Lower Molecular Weight ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Solvent Cast ◽  
Pmma Blends

The effects of homopolymer molecular weight on the miscibility of PVC/PMMA solvent cast blends were studied. Two significantly different molecular weights were chosen for each of the homopolymers, and a series of blends was prepared from the four possible homopolymer-homopolymer combinations. Angle-dependent ESCA results suggest that the surfaces of the blends are enriched with PMMA. The extent of this enrichment is dependent on molecular weight, with the most enrichment seen in blends containing the lower-molecular-weight PMMA homopolymer. Differential scanning calorimetry (DSC) results are also presented.

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.

scholarly journals PREPARATION AND EVALUATION OF ORALLY DISINTEGRATING TABLETS OF DROTAVERINE HYDROCHLORIDE USING SUBLIMATION TECHNIQUE

2018 ◽  
Vol 10 (5) ◽  
pp. 85
Author(s):  
Kuralla Hari ◽  
Saripilli Rajeswari ◽  
Kolapalli Venkata Ramanamurthy
Keyword(s):  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Fourier Transformation ◽  
Taste Masking ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Orally Disintegrating Tablets ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Drotaverine Hydrochloride ◽  
Sublimation Technique

Objective: To formulate orally disintegrating taste masked tablets of drotaverine hydrochloride (HCl) by sublimation technique.Methods: Initially superdisintegrant was selected and its concentration was optimized by pre-compression and post-compression parametric evaluation. Camphor and menthol were used as sublimating agents alone and in combination to mask the taste of drotaverine hydrochloride. Prepared tablets were evaluated for physicochemical evaluation, in vitro dissolution studies and fourier transformation-infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry studies.Results: The optimised formulation DCM2 prepared with a mixture of camphor and menthol was characterised by fourier transformation-infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry studies and found no incompatibility and no major shifts were noticed.Conclusion: The results demonstrated that the prepared drotaverine HCl orally disintegrating tablets showed better taste masking. The present sublimation technique can be effectively used for taste masking and also for orally disintegrating tablets.

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