共查询到20条相似文献,搜索用时 31 毫秒
1.
Edilene Pereira Lavor Marco Vinícius M. Navarro Fátima D. Freire Cícero F. S. Aragão Fernanda Nervo Raffin Euzébio Guimarães Barbosa Túlio F. A. de Lima e Moura 《Journal of Thermal Analysis and Calorimetry》2014,115(3):2303-2309
First-line drugs (rifampicin, RIF; isoniazid, INH; ethambutol, ETA; and pyrazinamide, PZA) recommended in conventional treatment of tuberculosis were analyzed in 1:1 w/w binary mixtures with microcrystalline cellulose MC 101 (CEL) and lactose supertab® (LAC) by differential scanning calorimetry (DSC), thermogravimetry (TG), differential thermal analysis (DTA), and Fourier transformed infrared analysis (FTIR) as part of development of fixed dose combination (FDC) tablets. Evidence of interaction between drug and pharmaceutical excipients was supposed when peaks disappearance or shifting were observed on DTA and DSC curves, as well as decreasing of decomposition temperature onset and TG profiles, comparing to pure species data submitted to the same conditions. LAC was showed to interact with RIF (absence of drug fusion and recrystallization events on DSC/DTA curves); INH (thermal events of the mixtures different from those observed for drug and excipient pure in DSC/DTA curves); PZA (decrease on drug fusion peak in DSC/DTA curves), and ETA (shift on drug onset fusion and absence of pure LAC events on DSC/DTA curves). In all cases, an important decrease on the temperature of drug decomposition was verified for the mixtures (TG analysis). However, FTIR analysis showed good correlation between theoretical and experimental drug-LAC spectra except for INH–LAC mixture, evidencing high incompatibility between these two species and suggesting that those interactions with PZA and RIF were thermally induced. No evidence of incompatibilities in CEL mixtures was observed to any of the four-studied drugs. 相似文献
2.
J. Zhi W. Tian-Fang L. Shu-Fen Z. Feng-Qi L. Zi-Ru Y. Cui-Mei L. Yang L. Shang-Wen Z. Gang-Zhui 《Journal of Thermal Analysis and Calorimetry》2006,85(2):315-320
The effects of aluminum (Al) and nickel (Ni) powders
of various grain sizes on the thermal decomposition of ammonium perchlorate
(AP) were investigated by TG and DSC in a dynamic nitrogen atmosphere. The
TG results show that Al powders have no effect on the thermal decomposition
of AP at conventional grain size, while the nanometer-sized Ni powders (n-Ni)
have a great influence on the thermal decomposition of AP with conventional
and superfine grain size. The results obtained by DSC and an in situ FTIR
analysis of the solid residues confirmed the promoting effects of n-Ni. The
effects of n-Ni have been ascribed to its enhancement on the gas phase reactions
during the second step decomposition of conventional grain size AP. 相似文献
3.
《European Polymer Journal》1985,21(1):81-83
The thermal behaviour was studied by DSC and TG methods for some mixtures of poly(ethyl acrylate) and poly(vinyl alcohol) with collagen to examine compatibility, glass transition temperature and thermal degradation. The mixtures of collagen hydrolysates with poly(ethyl acrylate) have a single glass transition temperature. The mixtures with poly(vinyl alcohol) show a glass transition temperature independent of composition and a melting temperature dependent on composition. The DSC and Tg data reveal partial compatibility at low temperature. By heating above 200°, the mixture separates into the two components which behave independently. 相似文献
4.
C. D. Bertol A. P. Cruz H. K. Stulzer F. S. Murakami M. A. S. Silva 《Journal of Thermal Analysis and Calorimetry》2010,102(1):187-192
Primaquine (PQ) is the drug of choice for the radical cure of Plasmodium vivax malaria, and currently being administered in solid dosage form. In this study, the compatibility studies were carried out
using differential scanning calorimetry (DSC), thermogravimetry (TG), and fourier transformed infrared (FT-IR). Non-isothermal
and isothermal methods were employed to investigate kinetic parameters under nitrogen and air atmospheres using TG. The DSC
investigations obtained by physical mixtures showed slight alterations in the melting temperatures of PQ with some excipients.
The FT-IR confirmed the possible interactions obtained by DSC for the physical mixtures with PQ and lactose, magnesium stearate
and mannitol. The results showed that the thermal decomposition followed a zero order kinetic in both atmospheres in non-isothermal
method. The activation energy in both methods using nitrogen atmosphere was similar, and in air atmosphere the activation
energy decreased. 相似文献
5.
Ana Flávia Oliveira Santos I. D. Basílio Jr F. S. de Souza A. F. D. Medeiros Márcia Ferraz Pinto D. P. de Santana R. O. Macêdo 《Journal of Thermal Analysis and Calorimetry》2008,93(2):361-364
Thermal analysis is an essential analytical tool in development of new formulations as well as to study the interaction between drugs and excipients. This work aims to investigate the possible interactions between metformin and excipients as microcrystalline cellulose (Microcel MC101®), starch sodium glycolate (Explosol®), sodium croscarmellose (Explosel®), PVP K30, magnesium stearate, starch and lactose, usually employed in pharmaceutical products. TG, DSC and DTA techniques were used for the thermal characterization to track if the thermal properties of the drug substance were modified in the mixture. Disregard of the starch and lactose systems, no changes in thermal behavior of mixtures were found. Thermogravimetric studies (TG) of metformin and its binary mixtures showed different thermal behavior. 相似文献
6.
Edilene P. Lavor Fátima Duarte Freire Cícero Flávio S. Aragão Fernanda N. Raffin Túlio Flávio A. de Lima e Moura 《Journal of Thermal Analysis and Calorimetry》2012,108(1):207-212
Worldwide Brazil is among one of the 22 countries with high rates of tuberculosis placing this disease as a priority for the
Government Health Policies in this country. Studies with the main tuberculostatic drugs rifampicin, isoniazid, pyrazinamide,
and ethambutol, aiming the development of fixed-dose combination formulations (FDCs) have been performed. The aim of this
study was to evaluate the thermal behavior of these drugs by DSC, TG/DTG, and DTA in order to predict possible physical and
chemical interactions between tuberculostatics. DSC and DTA curves suggested incompatibility and/or interactions among drug
preparations resulting from new thermal events, as well as the disappearance and shift of the melting point of the drugs.
TG/DTG curves of drug mixtures presented different profiles from those observed for the individually tested drugs, supporting
the evidence of drug incompatibility and indicating that mixtures are less stable when compared to the drugs alone. 相似文献
7.
R. O. Macêdo T. G. do Nascimento J. W. E. Veras 《Journal of Thermal Analysis and Calorimetry》2001,64(2):757-763
The compatibilities and stabilities of some binary mixtures and generic hydrochlorothiazide formulations were studied by using
TG, DSC and a DSC-photovisual system. The kinetic parameters were determined via the Arrhenius equations. Tablet B presented
higher compatibility and thermal stability than those of tablets A and C. The photovisual system demonstrated that the decomposition
of tablet A occurs before the melting point, due to the Maillard reaction between the hydrochlorothiazide and lactose present
in the formulation. The behaviour and rate constants of binary mixtures suggest that lactose can be substituted for microcrystalline
cellulose, MC(101), in tablet A. The DSC and TG data revealed different characteristics of compatibility and stability in
generic formulations from different manufacturers.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Russany Silva da Costa Charles Alberto Brito Negrão Sarah Regina Pereira Camelo Roseane Maria Ribeiro-Costa Wagner Luiz Ramos Barbosa Carlos Emmerson Ferreira da Costa José Otávio Carréra Silva Júnior 《Journal of Thermal Analysis and Calorimetry》2013,111(3):1959-1964
Thermogravimetric (TG) techniques and differential scanning calorimetry (DSC) used for the study of pre-formulation or drug–adjuvant compatibility have been gaining importance in Brazil. These techniques are being used for the verification of possible interactions between drugs and adjuvants. Aiming at studying the behavior of a plant extract and its mixture with adjuvants, using these thermoanalytical techniques the plant species Heliotropium indicum L. was used. This plant which is originally from India and has been well acclimatized in Brazil has healing and anti-inflammatory properties. The methodology for obtaining the extract followed the Brazilian Pharmacopoeia methodology. And the incorporation of the extract with adjuvants was through binary mixtures (1:1 w/w). The TG and DSC curves were obtained under nitrogen atmosphere (25 mL min?1) at a heating rate of 5 °C min?1; TG tests were analyzed within a temperature range from 25 to 600 °C and DSC from 25 to 300 °C. The TG curves show good thermal stability of the extract and its mixtures with adjuvants up to 150 °C, except the propylene glycol (PLG). The DSC curves revealed an incompatibility of the extract with methylparaben and PLG mixture. 相似文献
9.
Macêdo R. O. Gomes do Nascimento T. Veras J. W. E. 《Journal of Thermal Analysis and Calorimetry》2002,67(2):483-489
This study demonstrates the thermalanalysis applications in compatibility and stability studies of the propranolol binary
mixture sand tablets A and B. The propranolol binary mixtures were prepared in the laboratory and compared to the fully formulated
tablets using the thermogravimetric (TG) and calorimetric(DSC) methods. DSC of binary mixtures showed similar phase transition
to propranolol drug. The tablets phase transition decreased and there was no detectable significant interaction in propranolol–lactose
mixture and tablets. The DSC-photovisual test revealed an interaction similar to the Maillard reaction. The TG isothermal
study showed a difference in the profile between the drug and tablets due excipients quality and problems in manufacture process.
The kinetic parameters indicated a lower stability for the tablets than propranolol drug. The thermal techniques thermally
differentiated the propranolol preparations demonstrating the importance in the design development of pharmaceuticals solid-dosage
form.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
Carolina Lopes Leivas Fernanda Janaína Oliveira Gomes da Costa Rafael Ramirez de Almeida Renato João Sossela de Freitas Sônia Cachoeira Stertz Egon Schnitzler 《Journal of Thermal Analysis and Calorimetry》2013,111(3):2211-2216
In this work, two varieties of potato flour (Ágata and IAPAR Cristina) were studied by simultaneous thermogravimetry–differential thermal analysis (TG–DTA), differential scanning calorimetry (DSC), rapid viscoamylographic analysis (RVA), and microscopy (NC-AFM) that were compared with conventional physico-chemical analysis, according different granulometry of each flour. Flours of IAPAR Cristina showed higher levels of starch, fiber, and phosphate and it showed higher thermal stability (TG–DTA), as well as higher pasting temperature and viscosity (RVA), and lower enthalpy of gelatinization (DSC) in the two granulometries. Flours of Agata showed higher gelatinization enthalpy (DSC) and lower pasting temperature (RVA). Atomic force microscopy—non contact method (NC-AFM), was important to check for protrusions and pores of the flour surfaces. The differences between cultivars can be attributed mainly to the genotypes and growth conditions of the tubers, which can modify the flour properties. 相似文献
11.
Bogdan Tita Ionut Ledeti Geza Bandur Dumitru Tita 《Journal of Thermal Analysis and Calorimetry》2014,118(2):1293-1304
Thermal analysis is a routine method for analysis of drugs and substances of pharmaceutical interest. Thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) are thermoanalytical methods which offer important information about the physical and chemical properties of drugs (purity, stability, phase transition, polymorphism, compatibility, kinetic analysis, etc.). This work exemplifies a general method of studying the drug-excipient interactions with the aim of predicting rapidly and inexpensively the long thermal stability of their mixtures. The TG/DTG and DSC were used as screening techniques for assessing the compatibility between indomethacin (IND) and its physical associations as binary mixtures with some common excipients. Based on their frequent use in preformulations eleven different excipients: corn starch, microcrystalline cellulose (PH 101; PH 102), colloidal silicon dioxide, lactose (monohydrate and anhydre), polyvinilpyrrolidone K30, magnesium stearate, talc, stearic acid, and manitol were blended with IND. The samples were prepared by mixing the analyte and excipients in a proportion of 1:1 (w:w). In order to investigate the possible interactions between the components, the thermal curves of IND and each selected excipient were compared with those of their 1:1 (w/w) physical mixtures. FT-IR spectroscopy and X-ray powder diffraction were used as complementary techniques to adequately implement and assist in interpretation of thermal results. On the basis of thermal results, confirmed by FT-IR and X-ray analyses, a possible interaction was found between IND with polyvinylpyrrolidone K30, magnesium stearate, and stearic acid. 相似文献
12.
A. C. M. Silva D. A. Gálico R. B. Guerra A. O. Legendre D. Rinaldo M. S. Galhiane G. Bannach 《Journal of Thermal Analysis and Calorimetry》2014,115(3):2517-2520
Simultaneous thermogravimetry–differential scanning calorimetry (TG–DSC) and coupled thermogravimetry–infrared spectroscopy (TG–FTIR) analyses were used to study the antihypertensive drug atenolol. The TG–DSC curves provided information concerning the thermal stability and decomposition profiles of the compound. From the TG–FTIR coupled techniques, it was possible to identify ammonia and isopropylamine as possible volatile compounds released during the thermal decomposition of the drug. 相似文献
13.
14.
G. L. Perpétuo D. A. Gálico R. A. Fugita R. A. E. Castro M. E. S. Eusébio O. Treu-Filho A. C. M. Silva G. Bannach 《Journal of Thermal Analysis and Calorimetry》2013,111(3):2019-2028
Thermogravimetry (TG), differential scanning calorimetry (DSC), polarized light thermal microscopy (PLTM), as well as X-ray powder diffraction (XRD) and Fourier transformed infrared spectroscopy (FTIR) were used to study the thermal behavior and the chemical structure of cimetidine, famotidine, ranitidine-HCl, and nizatidine. The TG–DSC curves show that the famotidine and ranitidine-HCl suffer decomposition during melting and they are thermally less stable in comparison with cimetidine and nizatidine, the latter being the most stable of all the drugs studied in this study. The DSC curves of famotidine and ranitidine-HCl show exothermic peaks immediately after the melting, confirming the occurrence of thermal decomposition. The DSC curves also show that the cimetidine and nizatidine have some thermal stability after melting. The thermal events shown in the PLTM images are consistent with the results shown in the TG–DSC and DSC curves. The XRD patterns show that the cimetidine and famotidine are less crystalline compared with ranitidine-HCl and nizatidine. The theoretical FTIR bands are in agreement with those obtained experimentally, and in some cases, no difference is observed between the theoretical and experimental values, even being identical in one of the cases. 相似文献
15.
聚乙烯醇/纳米纤维素复合膜的渗透汽化性能及结构表征 总被引:6,自引:0,他引:6
将聚乙烯醇/纳米纤维素(PVA/NCC)复合膜应用于乙醇-水混合溶液的渗透汽化脱水过程,探讨了纳米纤维素对膜的溶胀性能、机械性能和渗透汽化性能的影响; 利用原子力显微镜(AFM)探测了纳米纤维素的形貌特征; 采用傅里叶变换红外光谱仪(FTIR)、扫描电镜(SEM)、差示扫描量热仪(DSC)和热重分析仪(TGA)对膜结构... 相似文献
16.
17.
Goldsipe A Blankschtein D 《Langmuir : the ACS journal of surfaces and colloids》2007,23(11):5942-5952
A molecular-thermodynamic (MT) theory was developed to model the micellization of mixtures containing an arbitrary number of conventional (pH-insensitive) surfactants. The theory was validated by comparing predicted and experimental cmc's of ternary surfactant mixtures, yielding results that were comparable to, and sometimes better than, the cmc's determined using regular solution theory. The theory was also used to model a commercial nonionic surfactant (Genapol UD-079), which was modeled as a mixture of 16 surfactant components. The predicted cmc agreed well with the experimental cmc, and the monomer concentration was predicted to increase significantly above the cmc. In addition, the monomer and the micelle compositions were predicted to vary significantly with surfactant concentration. These composition variations were rationalized in terms of competing steric and entropic effects and a micelle shape transition near the cmc. To understand the packing constraints imposed on ternary surfactant mixtures better, the maximum micelle radius was also examined theoretically. The MT theory presented here represents the first molecular-based theory of the micellization behavior of mixtures of three or more conventional surfactants. In article 2 of this series, the MT theory will be extended to model the micellization of mixtures of conventional and pH-sensitive surfactants. 相似文献
18.
Martin Künzel Qi-Long Yan Jakub Šelešovský Svatopluk Zeman Robert Matyáš 《Journal of Thermal Analysis and Calorimetry》2014,115(1):289-299
Erythritol tetranitrate (butane-1,2,3,4-tetrayl tetranitrate, ETN) has become one of the most synthesized improvised explosives nowadays as it can be found on public internet discussion boards. However, the low melting point, nitrocellulose gelling ability, high energy content, and availability of its precursor make the substance potentially useful in industry as an energetic component or additive in certain gun propellants. Mixtures of ETN with other high explosives are also frequently discussed on web pages dealing with improvised explosives. This article describes thermal behavior and decomposition kinetics of pure ETN and its mixtures with pentaerythritol tetranitrate and cyclonite (1,3,5-trinitro-1,3,5-triazinane, RDX). The thermal behavior and decomposition kinetics of such mixtures are described using non-isothermal DSC and TG techniques. Kissinger method, Soviet manometric method, and modified Kissinger–Akahira–Sunose method were used for data evaluation. 相似文献
19.
M. P. Sánchez -Sánchez J. M. Salas -Peregrín M. A. Romero -Molina J. Ruiz Sánchez 《Journal of Thermal Analysis and Calorimetry》1986,31(3):573-580
The following Zn(II), Cd(II), Hg(II) and Hg(I) complexes of 4-amino-1,6-dihydro-2-methylthio-5-nitroso-6-oxopyrimidine (MTH) have been prepared and their thermal behaviour studied by TG and DSC techniques: Zn(MT)2·3H2O, Cd(MT)·H2O. Cd(MTH)Cl2, Hg(MTH)Cl2 and Hg2(MT)(NO3). The dehydration and dehalogenation enthalpy values were calculated. 相似文献
20.
H. Salvio Neto Cs. Novák J. R. Matos 《Journal of Thermal Analysis and Calorimetry》2009,97(1):367-374
Differential Scanning Calorimetry (DSC), thermogravimetry/derivative thermogravimetry (TG/DTG) and infrared spectroscopy (IR) techniques were used to investigate the compatibility between prednicarbate and several excipients commonly used in semi solid pharmaceutical form. The thermoanalytical studies of 1:1 (m/m) drug/excipient physical mixtures showed that the beginning of the first thermal decomposition stage of the prednicarbate (T onset value) was decreased in the presence of stearyl alcohol and glyceryl stearate compared to the drug alone. For the binary mixture of drug/sodium pirrolidone carboxilate the first thermal decomposition stage was not changed, however the DTG peak temperature (T peak DTG) decreased. The comparison of the IR spectra of the drug, the physical mixtures and of the thermally treated samples confirmed the thermal decomposition of prednicarbate. By the comparison of the thermal profiles of 1:1 prednicarbate:excipients mixtures (methylparaben, propylparaben, carbomer 940, acrylate crosspolymer, lactic acid, light liquid paraffin, isopropyl palmitate, myristyl lactate and cetyl alcohol) no interaction was observed. 相似文献