Heat capacity and enthalpy of indapamide

Skotnicki, Marcin; Drogoń, Agata; Calvin, Jason J.; Rosen, Peter F.; Woodfield, Brian F.; Pyda, M.

doi:10.1016/j.tca.2019.01.032

Cited by 11 publications

(20 citation statements)

References 33 publications

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“…On the curve obtained during heating of the amorphous sample ( Figure 2 a, curve C), a small peak corresponding to the enthalpy relaxation is observed, arising from an additional ordering of the amorphous phase during the measurement due to the nonisothermal ageing below the T g . A similar experiment was already published by us [ 47 ], but for the clarity of this work, it is shown again.…”

Section: Resultssupporting

confidence: 64%

“…As received, indapamide was white crystalline powder in the form of hemihydrate (purity: ≥99%). Degradation of the material begins around 260 °C [ 47 ]. No degradation occurs during heating and cooling cycles in the investigated temperature range, as reported by other authors [ 30 ].…”

Section: Methodsmentioning

confidence: 99%

“…Thus, to increase the biopharmaceutical properties of IND, it could be used in the amorphous form. Some thermodynamic properties of crystalline and amorphous aged and nonaged indapamide were published [ 29 , 30 , 31 , 45 , 46 , 47 , 48 ]. However, to our best knowledge, there is no report focusing on the comprehensive characterisation of isothermal and nonisothermal physical ageing in the context of absolute heat capacity and integral equilibrium enthalpy of the solid and liquid amorphous IND phases.…”

Section: Introductionmentioning

confidence: 99%

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Physical Ageing of Amorphous Indapamide Characterised by Differential Scanning Calorimetry

et al. 2020

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The objective of this study was to characterise amorphous indapamide (IND) subjected to the physical ageing process by differential scanning calorimetry (DSC). The amorphous indapamide was annealed at different temperatures below the glass transition, i.e., 35, 40, 45, 65, 75 and 85 °C for different lengths of time, from 30 min up to a maximum of 32 h. DSC was used to characterise both the crystalline and the freshly prepared glass and to monitor the extent of relaxation at temperatures below the glass transition (Tg). No ageing occurred at 35, 40 and 45 °C at the measured lengths of times. Molecular relaxation time constants (τKWW) for samples aged at 65, 75 and 85 °C were determined by the Kohlrausch-Williams-Watts (KWW) equation. The fragility parameter m (a measure of the stability below the glass transition) was determined from the Tg dependence from the cooling and heating rates, and IND was found to be relatively stable (“moderately fragile”) in the amorphous state. Temperature-modulated DSC was used to separate reversing and nonreversing processes for unaged amorphous IND. The enthalpy relaxation peak was clearly observed as a part of the nonreversing signal. Heat capacities data for unaged and physically aged IND were fitted to Cp baselines of solid and liquid states of IND, were integrated and enthalpy was presented as a function of temperature.

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Section: Resultssupporting

confidence: 64%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Physical Ageing of Amorphous Indapamide Characterised by Differential Scanning Calorimetry

et al. 2020

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“…In addition, further C p values have been found for the amines hexamethylenetetramine [15], tetra-N-phenylbenzidine and 4,4 -bis (N-carbazolyl)-1,1 -biphenyl [16], 1,3,5-triazine [17], the ethers 1,3,5-trioxane [17], diethylene glycol n-pentyl ether [18], triethylene glycol monopentyl ether [19] and diphenyl ether [20], several alcohols and aldehydes [21], derivatives of glycidol [22], carboxylic acids [23,24], aliphatic esters [24][25][26][27], benzoates [28], haloalkanes [29,30], haloaromatics [31,32], thio ethers, sulfones and sulfoxides [33,34], alkanolamines, [35][36][37] and nitriles [38] For several compounds, more recent publications have been found the following: 4-ethylmorpholine [39], methionine [40], theophylline, and caffeine [41], as well as for (-)-menthone, (+)-pulegone, and (-)-isopulegol [42]. Beyond these, experimental C p values of a number of new compounds have been published: namely 3-amino-4-amidoximinofurazan [43], 3-fluoro-5-(3-pyridinyloxy)-benzenamine and N- [46], eugenol and (+)-carvone [47], indapamide [48], and the explosives EDNH and DNTA [49]. For some silicon-containing compounds, new C p data have been found in [50].…”

Section: Sources Of Heat-capacity Datamentioning

confidence: 99%

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at 298.15K by Means of the Group-Additivity Method

Naef

2020

Molecules

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The calculation of the isobaric heat capacities of the liquid and solid phase of molecules at 298.15 K is presented, applying a universal computer algorithm based on the atom-groups additivity method, using refined atom groups. The atom groups are defined as the molecules’ constituting atoms and their immediate neighbourhood. In addition, the hydroxy group of alcohols are further subdivided to take account of the different intermolecular interactions of primary, secondary, and tertiary alcohols. The evaluation of the groups’ contributions has been carried out by solving a matrix of simultaneous linear equations by means of the iterative Gauss–Seidel balancing calculus using experimental data from literature. Plausibility has been tested immediately after each fitting calculation using a 10-fold cross-validation procedure. For the heat capacity of liquids, the respective goodness of fit of the direct (r2) and the cross-validation calculations (q2) of 0.998 and 0.9975, and the respective standard deviations of 8.24 and 9.19 J/mol/K, together with a mean absolute percentage deviation (MAPD) of 2.66%, based on the experimental data of 1111 compounds, proves the excellent predictive applicability of the present method. The statistical values for the heat capacity of solids are only slightly inferior: for r2 and q2, the respective values are 0.9915 and 0.9874, the respective standard deviations are 12.21 and 14.23 J/mol/K, and the MAPD is 4.74%, based on 734 solids. The predicted heat capacities for a series of liquid and solid compounds have been directly compared to those received by a complementary method based on the "true" molecular volume and their deviations have been elucidated.

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“…For several compounds, more recent publications have been found: in particular for 4-ethylmorpholine [38], methionine [39], theophylline and caffeine [40], as well as for (-)-menthone, (+)-pulegone and (-)-isopulegol [41]. Beyond these, experimental Cp values of a number of new compounds have been published: namely 3-amino-4-amidoximinofurazan [42] [45], eugenol and (+)-carvone [46], indapamide [47] and the explosives EDNH and DNTA [48]. For some silicon compounds, new Cp data have been found in [49].…”

Section: Sources Of Heat-capacity Datamentioning

confidence: 99%

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at 298.15K by Means of a Generally Applicable Computer Algorithm Based on the Group-Additivity Method

Naef¹

2020

Preprint

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The calculation of the isobaric heat capacities of the liquid and solid phase of molecules at 298.15 K is presented, applying a universal computer algorithm based on the atom-groups additivity method, using refined atom groups. The atom groups are defined as the molecules' constituting atoms and their immediate neighbourhood. In addition, the hydroxy group of alcohols are further subdivided to take account of the different intermolecular interactions of primary, secondary and tertiary alcohols. The evaluation of the groups' contributions has been carried out by means of a fast Gauss-Seidel fitting calculus using experimental data from literature. Plausibility has been tested immediately after each fitting calculation using a 10-fold cross-validation procedure. For the heat capacity of liquids, the respective goodness of fit of the direct (R2) and the cross-validation calculations (Q2) of 0.998 and 0.9975, and the respective standard deviations of 8.2 and 9.16 J/mol/K, together with a medium absolute percentage deviation (MAPD) of 2.69%, based on the experimental data of 1133 compounds, proves the excellent predictive applicability of the present method. The statistical values for the heat capacity of solids are only slightly inferior: for R2 and Q2, the respective values are 0.9915 and 0.9875, the respective standard deviations are 12.19 and 14.13 J/mol/K and the MAPD is 4.65%, based on 732 solids. The predicted heat capacities for a series of liquid and solid compounds has been directly compared to those received by a complementary method based on the "true" molecular volume [1] and their deviations elucidated.

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Heat capacity and enthalpy of indapamide

Cited by 11 publications

References 33 publications

Physical Ageing of Amorphous Indapamide Characterised by Differential Scanning Calorimetry

Physical Ageing of Amorphous Indapamide Characterised by Differential Scanning Calorimetry

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at 298.15K by Means of the Group-Additivity Method

Calculation of the Isobaric Heat Capacities of the Liquid and Solid Phase of Organic Compounds at 298.15K by Means of a Generally Applicable Computer Algorithm Based on the Group-Additivity Method

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