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Skansberger, Tatyana
Publications (3 of 3) Show all publications
Lind, T. K., Nilsson, E. J., Wyler, B., Scherer, D., Skansberger, T., Morin, M., . . . Engblom, J. (2021). Effects of ethylene oxide chain length on crystallization of polysorbate 80 and its related compounds. Journal of Colloid and Interface Science, 592, 468-484, Article ID S0021-9797(21)00078-3.
Open this publication in new window or tab >>Effects of ethylene oxide chain length on crystallization of polysorbate 80 and its related compounds
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2021 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 592, p. 468-484, article id S0021-9797(21)00078-3Article in journal (Refereed) Published
Abstract [en]

As a result of the synthesis protocol polyoxyethylene sorbitan monooleate (polysorbate 80, PS80) is a highly complex mixture of compounds. PS80 was therefore separated into its main constituents, e.g. polyoxyethylene isosorbide esters and polyoxyethylene esters, as well as mono- di- and polyesters using preparative high-performance liquid chromatography. In this comprehensive study the individual components and their ethoxylation level were verified by matrix assisted laser desorption/ionization time-of-flight and their thermotropic behavior was analyzed using differential scanning calorimetry and X-ray diffraction. A distinct correlation was found between the average length of the ethylene oxide (EO) chains in the headgroup and the individual compounds' ability to crystallize. Importantly, a critical number of EO units required for crystallization of the headgroup was determined (6 EO units per chain or 24 per molecule). The investigation also revealed that the hydrocarbon tails only crystallize for polyoxyethylene sorbitan esters if saturated. PS80 is synthesized by reacting with approximately 20 mol of EO per mole of sorbitol, however, the number of EO units in the sorbitan ester in commercial PS80 products is higher than the expected 20 (5 EO units per chain). The complex behavior of all tested compounds revealed that if the amount of several of the linear by-products is reduced, the number of EO units in the chains will stay below the critical number and the product will not be able to crystallize by the EO chains.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Crystallization, Differential scanning calorimetry, Ethylene oxide chains, Liquid chromatography, Polysorbate 80, Thermotropic behavior
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-41655 (URN)10.1016/j.jcis.2021.01.065 (DOI)000634152600006 ()33711648 (PubMedID)2-s2.0-85102147545 (Scopus ID)
Available from: 2021-04-08 Created: 2021-04-08 Last updated: 2024-02-05Bibliographically approved
Nilsson, E. J., Lind, T. K., Scherer, D., Skansberger, T., Mortensen, K., Engblom, J. & Kocherbitov, V. (2020). Mechanisms of crystallisation in polysorbates and sorbitan esters. CrystEngComm, 22(22), 3840-3853
Open this publication in new window or tab >>Mechanisms of crystallisation in polysorbates and sorbitan esters
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2020 (English)In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 22, no 22, p. 3840-3853Article in journal (Refereed) Published
Abstract [en]

Polysorbates (PS), commonly known as Tween (TM), are some of the most extensively used excipients and protein stabilisers in biopharmaceutical products worldwide. It is stipulated in the pharmacopoeia specifications that these ethoxylated surfactants are complex mixtures comprised of a wealth of molecular species. While little is known about the propensity of PSs to crystallise, they are used in applications ranging from food products, cosmetics, different types of drug dosage forms like creams and oral products to parenteral applications. However, in recent years a range of issues and safety concerns have appeared when using them for stabilising biopharmaceutical products including precipitation, particle formation, and adverse biological effects. Therefore, the aim of this study was to thoroughly characterise the thermotropic behaviour and mechanism of crystallisation of polysorbates with different hydrocarbon tails and their non-ethoxylated sorbitan ester equivalents for comparison. A systematic and comprehensive product characterisation was carried out, taking advantage of a combination of complementary techniques such as differential scanning calorimetry, matrix assisted laser desorption ionisation time-of-flight and small- and wide-angle X-ray diffraction. We show that polysorbate 80, having an unsaturated hydrocarbon tail, crystallises by the ethylene oxide chains in the headgroup. Polysorbate 20, 40, and 60, containing saturated hydrocarbon esters tails, crystallise not only by the ethylene oxide chains but also by their hydrocarbon tails. An analogous behaviour was observed for the PS non-ethoxylated equivalents, the sorbitan esters. Sorbitan esters with saturated hydrocarbon tails displayed a crystallisation of the tail upon cooling, whereas the sorbitan ester with unsaturated hydrocarbon tail displayed no crystallisation.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2020
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-17855 (URN)10.1039/d0ce00236d (DOI)000540811300012 ()2-s2.0-85086182704 (Scopus ID)
Available from: 2020-07-28 Created: 2020-07-28 Last updated: 2024-06-17Bibliographically approved
Skansberger, T. & Kocherbitov, V. (2019). The Reversible and Irreversible Phenomena in Potato Starch Gelatinization (ed.). Starke (Weinheim), 71(5-6), Article ID 1800233.
Open this publication in new window or tab >>The Reversible and Irreversible Phenomena in Potato Starch Gelatinization
2019 (English)In: Starke (Weinheim), ISSN 0038-9056, E-ISSN 1521-379X, Vol. 71, no 5-6, article id 1800233Article in journal (Refereed) Published
Abstract [en]

Gelatinization of starch is a complex process and can be considered using two different approaches. In a kinetic approach it is considered as an irreversible process and described using the formalism of chemical kinetics with activation energy as the main parameter. Alternatively, in a thermodynamic approach it can be viewed as a reversible process with van't Hoff enthalpy as the main parameter. The experimental DSC data on gelatinization of native and physically modified potato starches presented in this study support the equilibrium approach. The van't Hoff enthalpy of gelatinization of native potato starch is measured to be 737 ± 13 kJ mol−1, and it is more sensitive to physical modifications of starch than the calorimetric enthalpy. Moreover, van't Hoff enthalpy has a clear correlation with the granule size, while neither gelatinization temperature, nor calorimetric enthalpy are sensitive to the size. To explain the nonequilibrium nature of starch gelatinization, the authors propose a three‐step mechanism, which includes reversible and irreversible steps.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
Starch, Gelatinization, Thermodynamics, Kinetics, Enthalpy, DSC, Calorimetry, Heat flow, van’t Hoff enthalpy, Activation energy, Equilibrium, reversible transition
National Category
Natural Sciences
Identifiers
urn:nbn:se:mau:diva-4679 (URN)10.1002/star.201800233 (DOI)000491296800016 ()2-s2.0-85060343508 (Scopus ID)27972 (Local ID)27972 (Archive number)27972 (OAI)
Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-02-05Bibliographically approved
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