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The assessment of the relaxation behaviour of frozen aqueous solutions of human serum albumin and polyvinylpyrrolidine

Barker, S.A. (2004) The assessment of the relaxation behaviour of frozen aqueous solutions of human serum albumin and polyvinylpyrrolidine. European Journal of Pharmaceutics and Biopharmaceutics, 57 (3). pp. 431-439. ISSN 0939-6411. (doi:10.1016/j.ejpb.2004.02.009) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:78864)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
https://doi.org/10.1016/j.ejpb.2004.02.009

Abstract

In this investigation, the structure and behaviour of frozen solutions of human serum albumin (HSA) alone and in combination with the cryoprotectant polyvinylpyrrolidone (PVP) have been studied using low frequency dielectric analysis and modulated temperature differential scanning calorimetry (MTDSC). Solutions of HSA (1-10w/v%) and combined solutions (from 1 to 5w/v% of each ingredient) were prepared and studied thermally and dielectrically over a frequency range of 105-10-2Hz every 10 °C from +20 to -70 °C. Dielectric data were fitted according to the Dissado-Hill theory and the relaxation times calculated. In addition, a relaxation peak was noted for the frozen HSA systems at a frequency approximately one order of magnitude lower than that seen for the PVP systems, with the PVP dominating the response of the mixed systems. The systems showed Arrhenius behaviour, with, for example, the 5% HSA solution showing an activation energy for the relaxation process of 19.34 kJ/mol. In accordance with previous studies on frozen aqueous solutions of PVP, the results suggest that unfrozen water dominated the dielectric response, with the local environment surrounding the HSA being strongly influenced by the PVP. MTDSC data indicated that the PVP and HSA interact in a complex manner in solution, with a glass transition attributable to PVP being seen only in those systems where PVP was present in sufficient excess. In conclusion, the study has suggested that MTDSC and dielectric spectroscopy may be the useful complementary tools with which the structure and molecular mobility of frozen proteinaceous systems may be studied.

Item Type: Article
DOI/Identification number: 10.1016/j.ejpb.2004.02.009
Uncontrolled keywords: Dielectric spectroscopy, Frozen, Human serum albumin, Modulated temperature differential scanning calorimetry, Polyvinylpyrrolidone, Relaxation, Solution, cryoprotective agent, human serum albumin, povidone, water, aqueous solution, article, calculation, complex formation, dielectric constant, differential scanning calorimetry, drug formulation, drug stability, drug structure, energy, molecular weight, temperature, Freezing, Humans, Povidone, Serum Albumin, Solutions, Water
Divisions: Faculties > Sciences > Medway School of Pharmacy
Depositing User: Susan Barker
Date Deposited: 27 Nov 2019 12:41 UTC
Last Modified: 27 Nov 2019 12:41 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/78864 (The current URI for this page, for reference purposes)
Barker, S.A.: https://orcid.org/0000-0003-4880-0253
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