An investigation of mucus/polymer rheological synergism using synthesised and characterised poly(acrylic acid)s

R.G. Riley, John Smart, J. Tsibouklis, P.W. Dettmar, F. Hampson, J.A. Davis, G. Kelly, W.R. Wilber

Research output: Contribution to journalArticle

Abstract

A range of poly(acrylic acid)s with different average degrees of polymerisation and cross-linking densities were synthesised using a solution polymerisation process. The rheological characteristics of aqueous dispersions of these materials and those of mixtures with homogenised pigs gastric mucus were investigated using dynamic oscillatory rheology, and compared to the known mucoadhesive Carbopol 934P. From the storage moduli, the rheological synergy and relative rheological synergy were calculated, and the effects of concentration and pH on this considered. Generally, the larger the molecular weight (and degree of cross-linking), the greater the rheological synergy, with Carbopol 934P giving the most pronounced effect. Rheological synergy was seen to be concentration-dependent, and a maximum concentration to produce an optimum effect was evident. Acid pHs were seen to favour synergy, although in marked contrast to previous literature reports, the optimum mucus–polymer interaction was not observed at the half ionised value (pH=pKa) but at pH regimes that were unique to each polymer type. This could be influenced by the structural constrains imposed on potential hydrogen bonded interactions. It was concluded that synthesising poly(acrylic acid)s with better defined physicochemical properties than commercially available polymers will advance the study of the phenomenon of rheological synergy.
Original languageEnglish
Pages (from-to)87-100
Number of pages14
JournalInternational Journal of Pharmaceutics
Volume217
Issue number1-2
DOIs
Publication statusPublished - Apr 2001

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carbopol 940
Polymers
Polymerization
Dispersions
Rheology
Hydrogen
Elastic moduli
Molecular weight
Acids
carbopol 934P

Keywords

  • Bioadhesion
  • Homogenised mucus
  • Mucoadhesion
  • Poly(acrylic acid)
  • Rheological synergy

Cite this

Riley, R.G. ; Smart, John ; Tsibouklis, J. ; Dettmar, P.W. ; Hampson, F. ; Davis, J.A. ; Kelly, G. ; Wilber, W.R. / An investigation of mucus/polymer rheological synergism using synthesised and characterised poly(acrylic acid)s. In: International Journal of Pharmaceutics. 2001 ; Vol. 217, No. 1-2. pp. 87-100.
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An investigation of mucus/polymer rheological synergism using synthesised and characterised poly(acrylic acid)s. / Riley, R.G.; Smart, John; Tsibouklis, J.; Dettmar, P.W.; Hampson, F.; Davis, J.A.; Kelly, G.; Wilber, W.R.

In: International Journal of Pharmaceutics, Vol. 217, No. 1-2, 04.2001, p. 87-100.

Research output: Contribution to journalArticle

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AU - Smart, John

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