Authors:Ana Gomes, Lidiane Correia, Mônica da Silva Simões, and R. Macêdo
The objective of this work was to develop and validate a fast and reproducible method which is able to determine the concentration
of ketoconazole in raw materials and tablets. The samples were analyzed by dynamic thermogravimetry at heating rates of 10,
20, 40, 60 and 80°C min−1 in nitrogen and nitrogen-synthetic air mixture. The concentrations of ketoconazole in the raw material and in the tablets
were obtained from the vapor pressure curves. The data showed that there is no significant difference between the vapor pressure
profiles of ketoconazole itself and in its tablet in both studied environmental conditions confirming that the process is
really vaporization. The concentration of ketoconazole was determined in the raw material and tablets of the drug.
Authors:Ana Gomes, Lidiane Correia, Mônica da Silva Simões, and Rui Macêdo
The objective of this work was to develop and validate a fast and reproducible
method able to determine the concentration of mebendazole in raw materials
and tablets. The samples were analyzed by dynamic thermogravimetry, in the
heating rates of 10, 20, 40, 60 and 80C min–1,
in the atmospheres of nitrogen and nitrogen with synthetic air. Obtained data
were used in the equations of Antoine and Langmuir, with the purpose to get
the pressure curves of those. Vapor pressure curves of drug and tablet of
mebendazole were evaluated using the mathematical indexes of difference factor, f1, and similarity factor, f2, to compare its profiles.
The data showed that there is no significant difference between the vapor
pressure profiles of drug and tablet of mebendazole in both environmental
conditions studied, what confirms that the process is really vaporization.
The concentration of mebendazole was determined in the raw material and tablets
with the drug.
Authors:Ana Medeiros, Lidiane Correia, Mônica Simões, and R. Macêdo
A number of disintegrants
are available on the market. They improve tablets’ disintegration. The
objective of this work is the comparison of the technological quality parameters
of disintegrants using different analytical techniques. Three batches of disintegrants
and their binary mixtures (water:disintegrants) were investigated. Cooling
experiments were used from –30 up to 200C. The data obtained showed
calorimetric differences between the samples. In the binary mixtures water
showed different crystallization behaviour from the one found in the literature.
According to the results DSC technique helped the quality control of different
Authors:Ana Gomes, Lidiane Correia, Mônica da Silva Simões, and R. Macêdo
The objective of this work was to develop
and validate a fast and reproducible method to determine the concentration
of metronidazole in drug substance and tablets. The samples were analyzed
by dynamic thermogravimetry, using 10, 20, 40, 60 and 80C min–1
heating rates in nitrogen and in nitrogen with synthetic air. Obtained data
were used in the Antoine and Langmuir equations in order to have the pressure
curves. Vapor pressure curves of drug and tablet of metronidazole were evaluated
using the mathematical indexes of difference factor, f1,
and similarity factor, f2,
to compare their profiles. The data showed that there is no significant difference
between the vapor pressure profiles of drug and tablet of metronidazole in
both environmental conditions, which confirms that the process is really vaporization.
The concentration of metronidazole was determined in the raw material and
tablets of the drug.
Authors:Lidiane Pinto Correia, Elisana Afonso de Moura, Hallisson Meneses Pires, and Rui Oliveira Macêdo
Water is a fundamental element of life. Its multiple uses are indispensable for a wide spectrum of human activities. This study aims to characterize water from different salinities obtained in the Cariri region of Paraíba, Brazil. The samples were analyzed using the DSC-coupled to the Peltier system (DSC-Cooling) and physical–chemical water tests performed employing reactive kits, using the Spectroquant Merck® specific for each test. The calorimetric curves showed crystallization phase transitions with different characteristics in peak format and crystallization temperatures between the samples of different salinities. The calorimetric data obtained in the process of crystallization of water is directly correlated to the physico-chemical parameters of conductivity and total dissolved solids, showing that the analytical technology DSC-cooling/heating is suitable for characterization of different salinities water.
Authors:Elisana Moura, Lidiane Correia, Márcia Pinto, José Procópio, Fábio de Souza, and Rui Macedo
This article had studied the thermal characterization of the raw material and different fluconazole crystals, obtained through
recrystallization with different solvents using thermoanalytical techniques (TG, DTA, DSC-50, DSC Photovisual, DSC-60) and
Pyr-GC/MS. The results confirmed that the fluconazole volatilizes without decomposition until 250 °C. Pyr-GC/MS showed hexachlorobenzene
like impurities in fluconazole raw material.
Authors:José Valdilânio Virgulino Procópio, Valmir Gomes de Souza, Rodrigo Albuquerque da Costa, Lidiane Pinto Correia, Fábio Santos de Souza, and Rui Oliveira Macêdo
The simvastatin (SV) is nowadays produced semi-synthetically from lovastatin. It’s one of the statins most commonly used to treat several forms of hypercholesterolemia. This study aimed to apply the thermal characterization of the SV raw material using thermoanalytical techniques and its degradation products by Pyrolysis coupled to Gas chromatography/Mass spectrometry (Pyr-GC/MS). It was studied three samples of SV (SVA, SVB, and SVC). The results showed thermal behavior differences of the samples during the melting process transition and the activation energies (Ea) of the thermal decomposition, which were correlated to the thermal stability of them. The first decomposition step of Pyr-GC/MS showed two new compounds of m/z 284 and 207, in proportions dependents according to the pyrolysis temperature.
Authors:Monica Felts de La Roca Soares, José Lamartine Soares-Sobrinho, Keyla Emanuelle Ramos de Silva, Lariza Darlene Santos Alves, Pablo Queiroz Lopes, Lidiane Pinto Correia, Fábio Santos de Souza, Rui Oliveira Macêdo, and Pedro José. Rolim-Neto
The ornidazole drug substance presents melt at approximately 90 °C (ΔT = 85–98 °C), which is critical for its use on pharmaceutical manufacturing process. This work aimed the thermal characterization of ornidazole raw-material synthesized by three different manufacturers from India, China, and Italy, using the thermoanalytical techniques of DTA, DSC, and TG, besides the verification of its stability and compatibility as a solid pharmaceutical product by the analysis of its binary mixtures (BM) with excipients and a tablet formulation. The characterization includes the thermal decomposition kinetic investigation by Ozawa model using Arrhenius equation and drug purity determination by Van't Hoff equation. The DSC purity determination and precision were compared with results from UV–Vis spectrophotometric and liquid chromatography, showing an adequate correlation before being recommended as a general method for purity assay. The drug raw-materials presented similar quality and zero-order kinetic behavior, besides showing differences on thermal stability. The drug presented compatibility with the tested excipients since the BM studied presented melting at the same temperature range as the drug and a decomposition temperature similar to the drug for two of the BM, and at a higher temperature for the others three of the BM evaluated, which presented excipients with higher molecular structure, capable of spatial coating on the small drug molecule promoting a physical interaction pharmaceutical acceptable. The tablet was processed by wet granulation and compressed under normal conditions of pressure and temperature, maintaining the physical properties of solid drug approving the manufacturing process used. In this study, the thermal analysis was used with success as an alternative method to characterize, quantify, and perform a preformulation study.