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Molecular Information on the Dissolution of Polydisperse Polymers: Mixtures of Long and Short Poly(ethylene oxide).

Anna Körner ; Anette Larsson (Institutionen för kemi- och bioteknik, Farmaceutisk teknologi) ; Lennart Piculell ; Bengt Wittgren
Journal of Physical Chemistry B Vol. 109 (2005), 23, p. 11530-11537.
[Artikel, refereegranskad vetenskaplig]

Abstract: A systematic study of the dissolution of dry, polydisperse poly(ethylene oxide) (PEO) samples, obtained from mixtures of low-molecular-weight and high-molecular-weight PEO, was made. During the dissolution process, the individual release of the low- and high-molecular-weight fractions was monitored. The high-molecular-weight/low-molecular-weight ratio controls the release rate, and the fraction of high-molecular-weight polymers dominates the effect on the overall release rate in mixed PEO tablets. Both fractions are released at the same rate during the main part of the dissolution process; however, during the initial dissolution period a fractionation occurs. The release rate is not a unique function of the average molecular weight of the polymer, but also depends on the polydispersity. By contrast, the average dimension of a polymer coil, as given by the intrinsic viscosity, gives a good prediction of the release rate irrespective of the polydispersity or details of the molecular weight distribution.



Denna post skapades 2006-08-25. Senast ändrad 2011-01-13.
CPL Pubid: 11635

 

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Institutioner (Chalmers)

Institutionen för kemi- och bioteknik, Farmaceutisk teknologi (2005-2014)

Ämnesområden

Galenisk farmaci

Chalmers infrastruktur