Skip to main content
placeholder image

Drug diffusion from polymeric delivery devices: a problem with two moving boundaries

Journal Article


Download full-text (Open Access)

Abstract


  • An existing model for solvent penetration and drug release from a spherically

    shaped polymeric drug delivery device is revisited. The model has two moving

    boundaries, one that describes the interface between the glassy and rubbery

    states of the polymer, and another that defines the interface between the

    polymer ball and the pool of solvent. The model is extended so that the

    nonlinear diffusion coefficient of drug explicitly depends on the

    concentration of solvent, and the resulting equations are solved numerically

    using a front fixing transformation together with a finite difference spatial

    discretisation and the method of lines. We present evidence that our scheme is

    much more accurate than a previous scheme. Asymptotic results in the small

    time limit are presented, which show how the use of a kinetic law as a

    boundary condition on the innermost moving boundary dictates qualitative

    behaviour, the scalings being very different to the similar moving boundary

    problem that arises from modelling the melting of an ice ball. The implication

    is that the model considered here exhibits what is referred to as non-Fickian

    or Case~II diffusion which, together with the initially constant rate of drug

    release, has certain appeal from a pharmaceutical perspective.

Authors


  •   Hsieh, Mike (external author)
  •   McCue, Scott (external author)
  •   Moroney, Timothy J. (external author)
  •   Nelson, Mark I.

Publication Date


  • 2011

Citation


  • Hsieh, M., McCue, S., Moroney, T. J. & Nelson, M. I. (2011). Drug diffusion from polymeric delivery devices: a problem with two moving boundaries. ANZIAM Journal, 52 (2010), C549-C566.

Scopus Eid


  • 2-s2.0-84870923372

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=9954&context=infopapers

Ro Metadata Url


  • http://ro.uow.edu.au/infopapers/2618

Start Page


  • C549

End Page


  • C566

Volume


  • 52

Issue


  • 2010

Place Of Publication


  • http://journal.austms.org.au/ojs/index.php/ANZIAMJ/article/view/3940

Abstract


  • An existing model for solvent penetration and drug release from a spherically

    shaped polymeric drug delivery device is revisited. The model has two moving

    boundaries, one that describes the interface between the glassy and rubbery

    states of the polymer, and another that defines the interface between the

    polymer ball and the pool of solvent. The model is extended so that the

    nonlinear diffusion coefficient of drug explicitly depends on the

    concentration of solvent, and the resulting equations are solved numerically

    using a front fixing transformation together with a finite difference spatial

    discretisation and the method of lines. We present evidence that our scheme is

    much more accurate than a previous scheme. Asymptotic results in the small

    time limit are presented, which show how the use of a kinetic law as a

    boundary condition on the innermost moving boundary dictates qualitative

    behaviour, the scalings being very different to the similar moving boundary

    problem that arises from modelling the melting of an ice ball. The implication

    is that the model considered here exhibits what is referred to as non-Fickian

    or Case~II diffusion which, together with the initially constant rate of drug

    release, has certain appeal from a pharmaceutical perspective.

Authors


  •   Hsieh, Mike (external author)
  •   McCue, Scott (external author)
  •   Moroney, Timothy J. (external author)
  •   Nelson, Mark I.

Publication Date


  • 2011

Citation


  • Hsieh, M., McCue, S., Moroney, T. J. & Nelson, M. I. (2011). Drug diffusion from polymeric delivery devices: a problem with two moving boundaries. ANZIAM Journal, 52 (2010), C549-C566.

Scopus Eid


  • 2-s2.0-84870923372

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=9954&context=infopapers

Ro Metadata Url


  • http://ro.uow.edu.au/infopapers/2618

Start Page


  • C549

End Page


  • C566

Volume


  • 52

Issue


  • 2010

Place Of Publication


  • http://journal.austms.org.au/ojs/index.php/ANZIAMJ/article/view/3940