Rheological evaluation of dispersions, prepared with different non- and gamma-irradiated bioadhesive cospray dried powder mixtures

Bozdag S., Weyenberg W., Ludwig A.

Pharmazie, vol.60, no.8, pp.593-597, 2005 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 60 Issue: 8
  • Publication Date: 2005
  • Journal Name: Pharmazie
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.593-597
  • Hacettepe University Affiliated: Yes


Various polymer mixtures were used to prepare gels: native drum dried waxy maize starch®, Amioca® starch, Carbopol® 974P NF and powder mixtures obtained by cospray drying Amioca® starch and Carbopol® 974P NF, and by blending Carbopol® 974P NF with Amioca® starch or drum dried waxy maize starch®. Oscillatory rheology was employed to investigate the influence of gamma-irradiation, but also of the different compositions (i.e. Carbopol® 974P NF varied from 5 to 25% w/w in the powder mixtures tested) and the preparation procedures of the powder mixtures on the viscoelastic properties of the polymer dispersions. The rheological data showed that gamma-irradiation has a significant influence on the rheological behaviour of the polymers dispersed. More elastic properties were obtained when the concentration of Carbopol® 974P NF was increased. The dispersions containing at least an amount of 15% Carbopol® 974P NF (w/w) are mainly elastic. Contrary to cospray drying the powders, blending the powders leads to higher elastic and gel properties of the dispersed polymers.