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Phase Equilibria and Thermodynamics of p-Hydroxybenzoic acid
KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Teknisk strömningslära.
KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Teknisk strömningslära.ORCID-id: 0000-0003-1790-2310
2006 (engelsk)Inngår i: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 95, nr 4, s. 748-760Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The prevalence of phases and associated solubilities of p-hydroxybenzoic acid have been investigated in methanol, acetonitrile, acetic acid, acetone, water, and ethyl acetate at temperatures from 10 to 50 degrees C. Thermodynamic data was acquired through determination of van't Hoff enthalpy of solution, enthalpy of fusion, and melting temperature. Indications of polymorphic enantiotropy were found primarily through solubility analysis and FTIR-ATR. A comprehensive thermodynamic investigation disclosed correlation between the van't Hoff enthalpy of solution and the solubility in different solvents. A higher solubility is linked to a lower van't Hoff enthalpy of solution. A thermodynamic analysis to discriminate between different solid phases is presented.

sted, utgiver, år, opplag, sider
2006. Vol. 95, nr 4, s. 748-760
Emneord [en]
p-hydroxybenzoic acid, 4-hydroxybenzoic acid, polymorphism, pseudopolymorphism, solvate, complexation, solubility, desolvation, solid state stability, van't Hoff
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-8414DOI: 10.1002/jps.20569ISI: 000236485300004PubMedID: 16447178Scopus ID: 2-s2.0-33645991201OAI: oai:DiVA.org:kth-8414DiVA, id: diva2:13728
Merknad
QC 20100831Tilgjengelig fra: 2008-05-12 Laget: 2008-05-12 Sist oppdatert: 2022-09-13bibliografisk kontrollert
Inngår i avhandling
1. Solid-liquid Phase Equilibria and Crystallization of Disubstituted Benzene Derivatives
Åpne denne publikasjonen i ny fane eller vindu >>Solid-liquid Phase Equilibria and Crystallization of Disubstituted Benzene Derivatives
2008 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

The Ph.D. project compiled in this thesis has focused on the role of the solvent in solid-liquid phase equilibria and in nucleation kinetics. Six organic substances have been selected as model compounds, viz. ortho-, meta- and para-hydroxybenzoic acid, salicylamide, meta- and para-aminobenzoic acid. The different types of crystal phases of these compounds have been explored, and their respective solid-state properties have been determined experimentally. The solubility of these crystal phases has been determined in various solvents between 10 and 50 oC. The kinetics of nucleation has been investigated for salicylamide by measuring the metastable zone width, in five different solvents under different experimental conditions.

A total of 15 different crystal phases were identified among the six model compounds. Only one crystal form was found for the ortho-substituted compounds, whereas the meta-isomeric compounds crystallized as two unsolvated polymorphs. The para-substituted isomers crystallized as two unsolvated polymorphs and as several solvates in different solvents.

It was discovered that the molar solubility of the different crystal phases was linked to the temperature dependence of solubility. In general, a greater molar solubility corresponds to a smaller temperature dependence of solubility.

The generality of this relation for organic compounds was investigated using a test set of 41 organic solutes comprising a total of 115 solubility curves. A semi-empirical solubility model was developed based on how thermodynamic properties relate to concentration and temperature. The model was fitted to the 115 solubility curves and used to predict the temperature dependence of solubility. The model allows for entire solubility curves to be constructed in new solvents based on the melting properties of the solute and the solubility in that solvent at a single temperature.

Based on the test set comprising the 115 solubility curves it was also found that the melting temperature of the solute can readily be predicted from solubility data in organic solvents.

The activity of the solid phase (or ideal solubility) of four of the investigated crystal phases was determined within a rigorous thermodynamic framework, by combining experimental data at the melting temperature and solubility in different solvents and temperatures. The results show that the assumptions normally used in the literature to determine the activity of the solid phase may give rise to errors up to a factor of 12.

An extensive variation in the metastable zone width of salicylamide was obtained during repeated experiments performed under identical experimental conditions. Only small or negligible effects on the onset of nucleation were observed by changing the saturation temperature or increasing the solution volume. The onset of nucleation was instead considerably influenced by different cooling rates and different solvents. A correlation was found between the supersaturation ratio at the average onset of nucleation and the viscosity of the solvent divided by the solubility of the solute. The trends suggest that an increased molecular mobility and a higher concentration of the solute reduce the metastable zone width of salicylamide.

sted, utgiver, år, opplag, sider
Stockholm: KTH, 2008. s. xx, 98
Serie
Trita-CHE-Report, ISSN 1654-1081 ; 2008-32
Emneord
Salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, salicylamide, m-aminobenzoic acid, p-aminobenzoic acid, solubility, solid-liquid equilibria, thermodynamics, activity of the solid phase, ideal solubility, activity coefficient, van't Hoff enthalpy of solution, solid state, solution properties, metastable zone width, primary nucleation, nucleation kinetics
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-4742 (URN)978-91-7178-949-5 (ISBN)
Disputas
2008-05-30, D3, D, Lindstedtsvägen 5, KTH, 10:00
Opponent
Veileder
Merknad
QC 20100831Tilgjengelig fra: 2008-05-12 Laget: 2008-05-12 Sist oppdatert: 2022-06-26bibliografisk kontrollert
2. Phase equilibria and thermodynamics of hydroxybenzoic acid isomers and salicylamide
Åpne denne publikasjonen i ny fane eller vindu >>Phase equilibria and thermodynamics of hydroxybenzoic acid isomers and salicylamide
2005 (engelsk)Licentiatavhandling, med artikler (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Stockholm: KTH, 2005. s. xii, 52
Serie
Trita-KET, ISSN 1104-3466 ; 217
Emneord
Chemical engineering, salicylic acid, p-hydrozybenzoic acid, m-hydrozybenzoic acid, Kemiteknik
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-348 (URN)91-7178-077-7 (ISBN)
Presentation
2005-06-16, E2, Lindstedtsvägn 3, Stockholm, 10:00
Veileder
Merknad
QC 20101217Tilgjengelig fra: 2005-08-01 Laget: 2005-08-01 Sist oppdatert: 2022-09-13bibliografisk kontrollert

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