Non-isothermal dehydration kinetic study of aspartame hemihydrate using DSC, TGA and DSC-FTIR microspectroscopy

Hsieh, Wei-Hsien; Cheng, Wenli; Chen, Ling-chun; Lin, Shan‐Yang

doi:10.1016/j.ajps.2017.12.001

Cited by 30 publications

(29 citation statements)

References 52 publications

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“…Non-isothermal thermogravimetric analysis with a linear heating rate is a technique for studying the process kinetics that allows the kinetics parameters of isoconversional solid-state reactions to be determined through calculations. The Flynn–Wall–Ozawa (FWO) method is one approach to studying these kinetics parameters, where the activation energy (E a ) is calculated by dynamic heat thermogravimetry [20,21].…”

Section: Resultsmentioning

confidence: 99%

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Solid-State Characterization of Different Crystalline Forms of Sitagliptin

et al. 2019

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Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase-4, used for the treatment of type 2 diabetes mellitus. The crystal structure of active pharmaceutical solids determines their physical and chemical properties. The polymorphism, solvates and hydrates can influence the free energy, thermodynamic parameters, solubility, solid-state stability, processability and dissolution rate, besides directly affecting the bioavailability. Thus, the physicochemical characterization of an active pharmaceutical ingredient is required to guarantee the rational development of new dosage forms. In this context, we describe herein the solid-state characterization of three crystalline forms of sitagliptin: sitagliptin phosphate monohydrate, sitagliptin phosphate anhydrous and sitagliptin base form. The investigation was carried out using differential scanning calorimetry (DSC), thermogravimetry (TG)/derivative thermogravimetry (DTG), spectroscopic techniques, X-ray powder diffraction (XRPD) and morphological analysis by scanning electron microscopy. The thermal analysis revealed that during the dehydration of sitagliptin phosphate monohydrate (Tpeak = 134.43 °C, ΔH = −1.15 J g−1) there is a characteristic crystalline transition event, which alters the physicochemical parameters of the drug, such as the melting point and solubility. The crystalline behavior of sitagliptin base form differs from that of sitagliptin phosphate monohydrate and sitagliptin phosphate anhydrous, mainly with regard to the lower temperature of the fusion event. The melting point (Tpeak) values obtained were 120.29 °C for sitagliptin base form, 206.37 °C for sitagliptin phosphate monohydrate and 214.92 °C for sitagliptin phosphate anhydrous. In relation to the thermal stability, sitagliptin phosphate monohydrate and sitagliptin phosphate anhydrous showed a slight difference; however, both are more thermostable than the base molecule. Therefore, through this study it was possible to establish the most suitable crystalline form of sitagliptin for the development of a safe, effective and appropriate pharmaceutical dosage form.

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Section: Resultsmentioning

confidence: 99%

“…The natural logarithm of the heating rate (log A) against the inverse of the temperature (1/T) on the TG curves at different heating rates will give a straight line with a slope of −0.457 (E a /R), allowing the determination of the activation energy [21,22,23,24].…”

Section: Resultsmentioning

confidence: 99%

Solid-State Characterization of Different Crystalline Forms of Sitagliptin

et al. 2019

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“…Observed in the last 10 years, rapid development of both experimental and computational methods used in structural analysis of solid state substances has its reflection in a number of recently determined structures of hydrated APIs [ 58 , 100 , 101 , 102 , 103 , 104 , 105 , 106 ]. In the majority of cases, numerous different experimental methods (briefly described in Section 2.2 ) are used within one study in order to properly determine the structure of a substance [ 41 , 77 , 89 , 107 , 108 , 109 ].…”

Section: Hydrates Structural Analysis Selected Cases Within the Lmentioning

confidence: 99%

Pharmaceutical Hydrates Analysis—Overview of Methods and Recent Advances

et al. 2020

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This review discusses a set of instrumental and computational methods that are used to characterize hydrated forms of APIs (active pharmaceutical ingredients). The focus has been put on highlighting advantages as well as on presenting some limitations of the selected analytical approaches. This has been performed in order to facilitate the choice of an appropriate method depending on the type of the structural feature that is to be analyzed, that is, degree of hydration, crystal structure and dynamics, and (de)hydration kinetics. The presented techniques include X-ray diffraction (single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD)), spectroscopic (solid state nuclear magnetic resonance spectroscopy (ssNMR), Fourier-transformed infrared spectroscopy (FT-IR), Raman spectroscopy), thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)), gravimetric (dynamic vapour sorption (DVS)), and computational (molecular mechanics (MM), Quantum Mechanics (QM), molecular dynamics (MD)) methods. Further, the successful applications of the presented methods in the studies of hydrated APIs as well as studies on the excipients’ influence on these processes have been described in many examples.

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“…The band at 3450 cm −1 is assigned to the stretching vibration of –OH in alcohol, carboxyl acid, and phenol . Two characteristic bands at 1496 cm −1 and 1383 cm −1 are due to the stretching of C=C in aromatic benzene ring, and the bending of C–H, respectively . Moreover, the weak peak at 1545 cm −1 is because of the existence of NO 2 , which may derive from the thermal decomposition of nitrogen compounds …”

Section: Resultsmentioning

confidence: 99%

Mass loss evolution of bituminous fractions at different heating rates and constituent conformation of emitted volatiles

Xia

Wang

et al. 2019

Energy Science & Engineering

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Bitumen is frequently used as energy source. To further understand bituminous combustion and emitted volatiles during its energy generation and conversion at the fraction level including saturates, aromatics, resins, and asphaltenes (SARA), an elemental analyzer, thermogravimetry coupled with mass spectrometer and Fourier‐transform infrared spectroscopy (TG‐MS‐FTIR) were utilized to monitor the mass loss evolution, and confirm molecular structures of emitted volatiles, and track the whereabouts of main elements during each SARA fraction combustion. Results indicate that TG, DTG, and Gram‐Schmidt (G‐S) curves show two‐stage characteristics, while the total ion chromatogram (TIC) curves present one‐stage characteristic during each SARA fraction combustion. Also, as the heating rate is raised, TG, DTG, TIC, and G‐S curves are shifted to higher temperature and the total emitted volatile amount is increased from saturates to asphaltenes. Molecular weights of main volatiles are distributed in the range of 12‐64. The elemental species of volatiles are consistent with those of SARA fractions. Finally, the typical volatiles of saturates and aromatics are similar, and the release amount of CO and CO2 at stage II is larger than those at stage I. SO2 is released during the combustion of resins. SO2 and NO2 are identified in volatiles of asphaltenes.

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Non-isothermal dehydration kinetic study of aspartame hemihydrate using DSC, TGA and DSC-FTIR microspectroscopy

Cited by 30 publications

References 52 publications

Solid-State Characterization of Different Crystalline Forms of Sitagliptin

Solid-State Characterization of Different Crystalline Forms of Sitagliptin

Pharmaceutical Hydrates Analysis—Overview of Methods and Recent Advances

Mass loss evolution of bituminous fractions at different heating rates and constituent conformation of emitted volatiles

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