Thermal decomposition of some analgesic agents

Ribeiro, Y. Asakura; Oliveira, José Dilson Silva de; Leles, Maria Inês Gonçalves; Juiz, S. A.; Ionashiro, Massao

doi:10.1007/bf01980770

Cited by 29 publications

(24 citation statements)

References 7 publications

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“…We were unable to detect such sharp endothermic peaks prior to the melting peak under dynamic flow of neither He nor N 2 , and under synthetic air such peak did not appear at all. Our data contradicts the suggestion made by Ribiero et al 1) regarding a polymorphic transition at temperature 280°C. We hypothesize that this first broad based endothermic peak detected in our DSC thermograms appeared as a result of formation of a new compound during the heating process, and the chances of forming this new compound become higher when slow scanning rates are used due to kinetics of the process.…”

Section: Discussioncontrasting

confidence: 57%

“…The T m temperatures of 283-284°C and 288-289°C obtained at scanning rates of 10°C/min and 20°C/min, respectively, for the endothermic peak are in close agreement with literature reports for the melting point of diclofenac sodium. 1,6) The double peak phenomenon observed in the thermograms obtained under both He and N 2 is of specific interest. Ribeiro et al 1) reported that a sharp endothermic peak (at 280°C) occurred in DSC thermograms for samples of diclofenac sodium under static atmospheric air prior to the melting peak (at 285°C), and postulated that the peak was due to a polymorphic transition of the material.…”

Section: Discussionmentioning

confidence: 99%

“…1,6) The double peak phenomenon observed in the thermograms obtained under both He and N 2 is of specific interest. Ribeiro et al 1) reported that a sharp endothermic peak (at 280°C) occurred in DSC thermograms for samples of diclofenac sodium under static atmospheric air prior to the melting peak (at 285°C), and postulated that the peak was due to a polymorphic transition of the material. We were unable to detect such sharp endothermic peaks prior to the melting peak under dynamic flow of neither He nor N 2 , and under synthetic air such peak did not appear at all.…”

Section: Discussionmentioning

confidence: 99%

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Thermal Behaviour of Diclofenac Sodium: Decomposition and Melting Characteristics.

et al. 2001

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Diclofenac sodium is a synthetic compound and therapeutically belongs to the group of non-steroidal anti-inflammatory drugs. Although the drug is well known and commercially available on the market in various pharmaceutical dosage forms (enteric coated oral tablets, sustained release oral tablets, topical preparations, injections and others), literature reports on thermal characterization and melting behaviour of the drug substance are contradictory. Even the melting point (about 280°C) of diclofenac sodium cited in some reference literature (e.g., European Pharmacopoeia, 3rd edition) does not correspond to the melting point reported in most scientific literature (285-289°C). 1-3)A thorough investigation of the available literature data on thermal behaviour and melting characteristics of diclofenac sodium in our laboratories suggests that the anomalies observed in reported data are due to the fact that most investigators used types of equipment which are not sensitive enough to detect all the phenomena that occur during melting of the substance, and most experiments were not well designed to make comprehensive conclusions possible. It is possible that most of the investigators did not have access to all facilities required for studying the melting and decomposition characteristics of diclofenac sodium. In fact, no differential scanning calorimetric data are available on the influence of scanning rate on the thermal behaviour of diclofenac sodium, and none of the investigators performed differential scanning calorimetry (DSC) on this drug under helium. Therefore, the main objective of our study reported here was to investigate the thermal behaviour of diclofenac sodium under various conditions using a number of techniques-DSC, thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy and thin layer chromatography (TLC). ExperimentalMaterials Diclofenac sodium (lot 9911010) of British Pharmacopoeia quality was purchased from Sekhsaria Chemicals Ltd. (Mumbai, India). Gases-helium (He), nitrogen (N 2 ) and synthetic air, were purchased from SOL SPA (Monza, Italy) with stated purity of 99.9996%, 99.999% and 99.995%, respectively. A reference standard of 1-(2,6-dichlorophenyl)-indolin-2-one (Cat. No. 18881; Lot G) was purchased from the USP (Rockville, U.S.A.).DSC Analysis Perkin Elmer's Pyris 1 equipment was used to analyse the samples under various conditions. Samples weighing 4-6 mg were placed in aluminium pan, sealed and scanned (within the range 50-320°C) at various rates (1, 5, 10 and 20°C/min) to see the effect of scanning rate on the thermal behaviour of the studied substance. The scanning runs were repeated under dynamic flow of either helium (He), or nitrogen (N 2 ) or synthetic air to see the effect of environmental atmospheric condition on the thermal characteristics of the drug substance. The data were analysed using the software package "Pyris for Windows" (version 3.52). Onset temperature was considered as the temperature of the peak (T o ). The equipment was calibrated by scann...

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Section: Discussioncontrasting

confidence: 57%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Thermal Behaviour of Diclofenac Sodium: Decomposition and Melting Characteristics.

et al. 2001

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“…Wendlandt and Collins [2] used DTA and TG as aids in the characterization and identification of commercial non-preescription analgesics. Other investigations of the use of thermoanalytical techniques for the study of drug substances and for applications in routine pharmaceutical analysis and in the pharmaceutical industry have also been described [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Thermoanalytical study of purine derivatives compounds

et al. 2004

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Thermal methods of analysis are now used in a very large range of scientific investigations. In this work simultaneous thermogravimetry-differential thermal analysis (TG-DTA), X-Ray powder diffractometry and infrared spectroscopy were used to study the derivative compounds of purine, i. e. aminophylline, theophylline, caffeine and uric acid. The results led to informations about the thermal stability and thermal decomposition of these compounds.

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“…Wendlandt and Collins 2 used DTA and TG thermal analysis techniques as aids in the characterization and identification of commercial non-preescription analgesics. Other investigations of the use of thermal analysis techniques for the study of drug substances and for applications in routine pharmaceutical analysis and in the pharmaceutical industry have also been described [3][4][5][6][7][8][9][10][11][12][13][14][15][16] . No reference has been found on the application of TG and DSC in the study of trimethoprim, sulfamethoxazole, ampicillim, tetracycline hydrochloride, rifampim and association of sulfamethoxazole with trimethoprim.…”

Section: Introductionmentioning

confidence: 99%

Thermal decomposition of some chemotherapic substances

Fernandes¹,

Filho²,

Mendes³

et al. 1999

J. Braz. Chem. Soc.

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Termogravimetria, termogravimetria derivada (TG,DTG), calorimetria exploratória diferencial (DSC) e difratometria de raios X foram utilizados para estudar o trimetroprim, sulfametoxazol, ampicilina, cloridrato de tetraciclina e rifampicina. Os resultados permitiram obter informações sobre a estabilidade térmica destes compostos e a decomposição térmica em atmosfera de ar.Thermogravimetry, derivative thermogravimetry (TG, DTG), differential scanning calorimetry (DSC) and X ray diffraction powder patterns have been used to study trimethoprim, sulfamethoxazole, ampicillim, tetracycline hydrochloride and rifampim. The results revealed the extent of their thermal stability and also allowed interpretations concerning their thermal decompositions in air atmosphere.

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Thermal decomposition of some analgesic agents

Cited by 29 publications

References 7 publications

Thermal Behaviour of Diclofenac Sodium: Decomposition and Melting Characteristics.

Thermal Behaviour of Diclofenac Sodium: Decomposition and Melting Characteristics.

Thermoanalytical study of purine derivatives compounds

Thermal decomposition of some chemotherapic substances

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