Investigation of thermal behavior of enoxacin and its hydrochloride

Jingyan, Shi; Wang, Zhiyong; Liu, Yuwen; Wang, Cunxin

doi:10.1007/s10973-011-1817-x

Cited by 10 publications

(2 citation statements)

References 12 publications

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“…Volatile degradation products were obtained by decomposing the samples in a TG device. Various mass samples were used, usually 10 mg [ 22 , 23 , 24 , 25 , 26 , 27 ], 12–15 mg [ 28 , 29 , 30 , 31 , 32 ] or 15–20 mg [ 24 , 33 ]. Samples in open α-alumina sample holders [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ] or ceramic crucibles [ 34 ] were heated from ambient temperature to 400 °C [ 26 , 27 ], 500 °C [ 34 ], 700 °C [ 35 ] or 800 °C [ 22 , 23 ]; at heating rates of 5 °C/min [ 34 ], 10 °C/min [ 28 , 29 , 30 , 31 , 32 ] or 20 °C/min [ 22 , 23 , 24 , 25 , 26 , 27 , 35 ]; in dry nitrogen [ 22 , 23 , 26 , 27 , 28 ...…”

Section: Coupled Tg Measurementsmentioning

confidence: 99%

“…Various mass samples were used, usually 10 mg [ 22 , 23 , 24 , 25 , 26 , 27 ], 12–15 mg [ 28 , 29 , 30 , 31 , 32 ] or 15–20 mg [ 24 , 33 ]. Samples in open α-alumina sample holders [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ] or ceramic crucibles [ 34 ] were heated from ambient temperature to 400 °C [ 26 , 27 ], 500 °C [ 34 ], 700 °C [ 35 ] or 800 °C [ 22 , 23 ]; at heating rates of 5 °C/min [ 34 ], 10 °C/min [ 28 , 29 , 30 , 31 , 32 ] or 20 °C/min [ 22 , 23 , 24 , 25 , 26 , 27 , 35 ]; in dry nitrogen [ 22 , 23 , 26 , 27 , 28 , 29 ,...…”

Section: Coupled Tg Measurementsmentioning

confidence: 99%

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Coupled and Simultaneous Thermal Analysis Techniques in the Study of Pharmaceuticals

Wesołowski

Leyk

2023

Pharmaceutics

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Reliable interpretation of the changes occurring in the samples during their heating is ensured by using more than one measurement technique. This is related to the necessity of eliminating the uncertainty resulting from the interpretation of data obtained by two or more single techniques based on the study of several samples analyzed at different times. Accordingly, the purpose of this paper is to briefly characterize thermal analysis techniques coupled to non-thermal techniques, most often spectroscopic or chromatographic. The design of coupled thermogravimetry (TG) with Fourier transform infrared spectroscopy (FTIR), TG with mass spectrometry (MS) and TG with gas chromatography/mass spectrometry (GC/MS) systems and the principles of measurement are discussed. Using medicinal substances as examples, the key importance of coupled techniques in pharmaceutical technology is pointed out. They make it possible not only to know precisely the behavior of medicinal substances during heating and to identify volatile degradation products, but also to determine the mechanism of thermal decomposition. The data obtained make it possible to predict the behavior of medicinal substances during the manufacture of pharmaceutical preparations and determine their shelf life and storage conditions. Additionally, characterized are design solutions that support the interpretation of differential scanning calorimetry (DSC) curves based on observation of the samples during heating or based on simultaneous registration of FTIR spectra and X-ray diffractograms (XRD). This is important because DSC is an inherently non-specific technique. For this reason, individual phase transitions cannot be distinguished from each other based on DSC curves, and supporting techniques are required to interpret them correctly.

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Section: Coupled Tg Measurementsmentioning

confidence: 99%

Section: Coupled Tg Measurementsmentioning

confidence: 99%

Coupled and Simultaneous Thermal Analysis Techniques in the Study of Pharmaceuticals

Wesołowski

Leyk

2023

Pharmaceutics

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The use of TG/DSC–FT-IR to assess the effect of Cr sorption on struvite stability and composition

Rouff

2011

J Therm Anal Calorim

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TG/DSC/FTIR characterization of linear geranyl diesters

Worzakowska

Ścigalski

2012

J Therm Anal Calorim

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The synthesis, thermal behavior, and characterization of the decomposition products of linear geranyl diesters: digeranyl succinate, digeranyl glutarate, digeranyl adipinate, and digeranyl sebacinate were presented. The linear geranyl diesters were prepared in direct esterification process of a molar stoichiometric ratio of geraniol and suitable acidic reagent in solvent-free medium at 130°C using butylstannoic acid as a catalyst. Their structure was confirmed based on FTIR, 1 H-and 13 C-NMR spectra. It was proved that the use of tin catalyst allowed decreasing the reaction time and increasing the final conversion of substrates when compared to non-catalyzed process. It considerably simplifies the processing by reduction of the preparation cost and thus this new method of synthesis of aroma diesters may be attractive for practical applications. The thermal behavior of prepared compounds was studied by TG/DSC/FTIR coupled method. TG analysis showed that diesters are thermally stable up to temperatures above 200°C. The DTG curves confirmed that these decomposition run as a single-stage process. The T max1 were in the range of 294.5-313.8°C depending on the aliphatic chain length (-CH 2 -) n in the structure of aroma diesters, which was in accordance with DSC data. The analysis of the gases evolved during heating of diesters in inert atmosphere indicated on the asymmetrical disrupt of their bonds. The cleavage of ester bond and O-geranyl bond was expected. It resulted in production of the mixture of derivatives of geraniol (acyclic and alicyclic monoterpene hydrocarbons) like myrcene, ocimene, or limonene as main decomposition products. In addition, the formation of anhydride, lactone, or ketone functionalities among the degradation products clearly confirmed the proposed degradation path of studied diesters.

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Investigation of thermal behavior of enoxacin and its hydrochloride

Cited by 10 publications

References 12 publications

Coupled and Simultaneous Thermal Analysis Techniques in the Study of Pharmaceuticals

Coupled and Simultaneous Thermal Analysis Techniques in the Study of Pharmaceuticals

The use of TG/DSC–FT-IR to assess the effect of Cr sorption on struvite stability and composition

TG/DSC/FTIR characterization of linear geranyl diesters

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