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Purpose: Thermal analysis techniques have been applied to study the thermal behavior of fenbendazole (Fen) and rafoxanide (Raf). Semi-empirical molecular orbital calculations were used to confirm these results. Methods: Thermogravimetric analysis, derivative thermogravimetry, differential thermal analysis and differential scanning calorimetry were used to determine the thermal behavior and purity of the drugs under investigation. Results: Thermal behavior of Fen and Raf were augmented using semi-empirical molecular orbital calculations. The purity values were found to be 99.17% and 99.60% for Fen and Raf, respectively. Conclusion: Thermal analysis techniques gave satisfactory results to obtain quality control parameters such as melting point and degree of purity at low cost, furthermore, its simplicity and sensitivity justifies its application in quality control laboratories.

Purpose: Thermal analysis techniques have been used to study the thermal behavior of dapoxetine and vardenafil hydrochlorides and confirmed using semi-empirical molecular orbital calculations. Methods: Thermogravimetric analysis, derivative thermogravimetry, differential thermal analysis and differential scanning calorimetry were used to determine the thermal behavior and purity of the drugs under investigation. Thermodynamic parameters such as activation energy, enthalpy, entropy and Gibbs free energy were calculated. Results: Thermal behavior of DAP and VAR were confirmed using by semi-empirical molecular orbital calculations. The purity values were found to be 99.97% and 99.95% for dapoxetine and vardenafil hydrochlorides, respectively. The purity of dapoxetine and vardenafil hydrochlorides is similar to that found by reported methods according to DSC data. Conclusion: Thermal analysis justifies its application in quality control of pharmaceutical compounds due to its simplicity, sensitivity and low operational costs.

Purpose: The aim of the present work is to study the thermal analysis of telmisartan and cilazapril. Methods: Thermogravimetry (TGA), derivative thermogravimetry (DTG) and differential thermal analysis (DTA) were used through the work to achieve the thermal analysis study of some antihypertensive drugs, telmisartan and cilazapril. Results: The results led to thermal stability data and also to the interpretation concerning the thermal decomposition. Thermogravimetry data allowed determination of the kinetic parameters such as, activation energy and frequency factor. Conclusion: The simplicity, speed and low operational costs of thermal analysis justify its application in the quality control of pharmaceutical compounds for medications.

Purpose: Thermal behavior of some antidiabetic drugs such as pioglitazone hydrochloride (PTZ), rosiglitazone maleate (RGZ), glibenclamide (GBD) and glimepiride (GMP) has been studied. Methods: Thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential thermal analysis (DTA) techniques were used to study the thermal behavior of the drugs under investigation. Results: Thermal analysis technique was used to obtain quality control parameters such as melting point 193.13 °C, 122.42 °C, 173.75 °C and 208 °C for PTZ, RGZ, GBD and GMP, respectively. The values of melting point of gave satisfactory results in comparison to that obtained by using the official method. Non-isothermal methods were employed to determine the activation energy values of the first stage of thermal decomposition. Comparison of the activation energy values suggests the following sequence of thermal stability: GMP > GBD > RGZ > PTZ. Conclusion: The results obtained are useful for the identification of these compounds and permitted interpretations concerning their thermal decomposition. Thermal stability of pharmaceutical compounds can be studied and compared by using thermal analysis techniques.

Purpose: Thermal analysis (TGA, DTG and DTA) and differential scanning calorimetry (DSC) have been used to study the thermal behavior of terazosin hydrochloride (TER). Methods: Thermogravimetric analysis (TGA/DTG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC) were used to determine the thermal behavior and purity of the used drug. Thermodynamic parameters such as activation energy (E*), enthalpy (H*), entropy (S*) and Gibbs free energy change of the decomposition (G*) were calculated using different kinetic models. Results: The purity of the used drug was determined by differential scanning calorimetry (99.97%) and specialized official method (99.85%) indicating to satisfactory values of the degree of purity. Thermal analysis technique gave satisfactory results to obtain quality control parameters such as melting point (273 ºC), water content (7.49%) and ash content (zero) in comparison to what were obtained using official method: (272 ºC), (8.0%) and (0.02%) for melting point, water content and ash content, respectively. Conclusion: Thermal analysis justifies its application in quality control of pharmaceutical compounds due to its simplicity, sensitivity and low operational costs. DSC data indicated that the degree of purity of terazosin hydrochloride is similar to that found by official method.

Purpose: Thermal analysis techniques have been applied to study the thermal behavior of fenbendazole (Fen) and rafoxanide (Raf). Semi-empirical molecular orbital calculations were used to confirm these results. Methods: Thermogravimetric analysis, derivative thermogravimetry, differential thermal analysis and differential scanning calorimetry were used to determine the thermal behavior and purity of the drugs under investigation. Results: Thermal behavior of Fen and Raf were augmented using semi-empirical molecular orbital calculations. The purity values were found to be 99.17% and 99.60% for Fen and Raf, respectively. Conclusion: Thermal analysis techniques gave satisfactory results to obtain quality control parameters such as melting point and degree of purity at low cost, furthermore, its simplicity and sensitivity justifies its application in quality control laboratories. [ABSTRACT FROM AUTHOR]

Purpose: Thermal analysis techniques have been used to study the thermal behavior of dapoxetine and vardenafil hydrochlorides and confirmed using semi-empirical molecular orbital calculations. Methods: Thermogravimetric analysis, derivative thermogravimetry, differential thermal analysis and differential scanning calorimetry were used to determine the thermal behavior and purity of the drugs under investigation. Thermodynamic parameters such as activation energy, enthalpy, entropy and Gibbs free energy were calculated. Results: Thermal behavior of DAP and VAR were confirmed using by semi-empirical molecular orbital calculations. The purity values were found to be 99.97% and 99.95% for dapoxetine and vardenafil hydrochlorides, respectively. The purity of dapoxetine and vardenafil hydrochlorides is similar to that found by reported methods according to DSC data. Conclusion: Thermal analysis justifies its application in quality control of pharmaceutical compounds due to its simplicity, sensitivity and low operational costs. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present work is to study the thermal analysis of telmisartan and cilazapril. Methods: Thermogravimetry (TGA), derivative thermogravimetry (DTG) and differential thermal analysis (DTA) were used through the work to achieve the thermal analysis study of some antihypertensive drugs, telmisartan and cilazapril. Results: The results led to thermal stability data and also to the interpretation concerning the thermal decomposition. Thermogravimetry data allowed determination of the kinetic parameters such as, activation energy and frequency factor. Conclusion: The simplicity, speed and low operational costs of thermal analysis justify its application in the quality control of pharmaceutical compounds for medications. [ABSTRACT FROM AUTHOR]

Purpose: Thermal behavior of some antidiabetic drugs such as pioglitazone hydrochloride (PTZ), rosiglitazone maleate (RGZ), glibenclamide (GBD) and glimepiride (GMP) has been studied. Methods: Thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential thermal analysis (DTA) techniques were used to study the thermal behavior of the drugs under investigation. Results: Thermal analysis technique was used to obtain quality control parameters such as melting point 193.13 °C, 122.42 °C, 173.75 °C and 208 °C for PTZ, RGZ, GBD and GMP, respectively. The values of melting point of gave satisfactory results in comparison to that obtained by using the official method. Non-isothermal methods were employed to determine the activation energy values of the first stage of thermal decomposition. Comparison of the activation energy values suggests the following sequence of thermal stability: GMP > GBD > RGZ > PTZ. Conclusion: The results obtained are useful for the identification of these compounds and permitted interpretations concerning their thermal decomposition. Thermal stability of pharmaceutical compounds can be studied and compared by using thermal analysis techniques. [ABSTRACT FROM AUTHOR]

Purpose: Thermal analysis (TGA, DTG and DTA) and differential scanning calorimetry (DSC) have been used to study the thermal behavior of terazosin hydrochloride (TER). Methods: Thermogravimetric analysis (TGA/DTG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC) were used to determine the thermal behavior and purity of the used drug. Thermodynamic parameters such as activation energy (E*), enthalpy (∆H*), entropy (∆S*) and Gibbs free energy change of the decomposition (?G*) were calculated using different kinetic models. Results: The purity of the used drug was determined by differential scanning calorimetry (99.97%) and specialized official method (99.85%) indicating to satisfactory values of the degree of purity. Thermal analysis technique gave satisfactory results to obtain quality control parameters such as melting point (273 °C), water content (7.49%) and ash content (zero) in comparison to what were obtained using official method: (272 °C), (8.0%) and (0.02%) for melting point, water content and ash content, respectively. Conclusion: Thermal analysis justifies its application in quality control of pharmaceutical compounds due to its simplicity, sensitivity and low operational costs. DSC data indicated that the degree of purity of terazosin hydrochloride is similar to that found by official method. [ABSTRACT FROM AUTHOR]