Conformational Study of Globulin from Common Buckwheat (Fagopyrum esculentumMoench) by Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimetry

2005 ◽  
Vol 53 (20) ◽  
pp. 8046-8053 ◽  
Author(s):  
Siu-Mei Choi ◽  
Ching-Yung Ma
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Conformational Study ◽  
Common Buckwheat ◽  
Scanning Calorimetry

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

Design and evaluation of topical solid dispersion composite of voriconazole for the treatment of ocular keratitis

2019 ◽  
Vol 10 (8) ◽  
pp. 481-492
Author(s):  
Monali Patil ◽  
Swati Waydande ◽  
Pravin Pawar
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Solid Dispersion ◽  
Fourier Transform Infrared ◽  
Eye Drops ◽  
Scanning Calorimetry ◽  
Saturation Solubility ◽  
Study Results

Aim: The objective of present investigation was to increases solubility of voriconazole by using solid dispersion techniques and the development of solid dispersion-based voriconazole ophthalmic solutions. Materials & methods: The saturation solubility of solid dispersion containing polyvinylpyrrolidone K90 (PVPK-90) was found to increase the solubility of voriconazole compare other carrier like polyethylene glycol and Polyvinylpyrrolidone K 30 (PVPK-30). Solid dispersion of voriconazole was characterized by saturation solubility, Fourier-transform infrared spectroscopy and Differential scanning calorimetry study. Results & conclusion: The Fourier-transform infrared spectroscopy and Differential scanning calorimetry studies of voriconazole-based solid dispersion confirmed the complete changes in original polymorphic form of voriconazole. The antifungal assay showed that the maximum zone of inhibition was produced from optimized ophthalmic formulation containing sodium alginate as compared with other formulations and marketed eye drops.

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