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Faculty of Pharmacy, Lj. (FFALJ)
  • Mucoadhesion on pig vesical mucosa: influence of polycarbophil/calcium interactions
    Kerec, Mojca ...
    The influence of polycarbophil/calcium interactions on the mucoadhesive properties of polycarbophil has been examined. Polycarbophil dispersions and films with different concentrations of calcium or ... sodium ions were prepared and the following parameters were measured: detachment force on pig vesical mucosa, zeta potential, pH and viscosity. Polycarbophil detachment force decreased significantly in the presence of calcium but not sodium. Both ions decrease the pH of polycarbophil dispersions. On the other hand, altering the pH of hydrated polycarbophil films in the absence of added ions had an insignificant effect on detachment force. Both ions reduce the absolute valuesof polycarbophil zeta potential, calcium more efficiently than sodium. We could conclude that decreased mucoadhesion strength of polycarbophil in thepresence of calcium is due to the chelation of polycarbophil carboxylic groups by calcium and crosslinking of polymer. The crosslinked polymer chains would be expected to be less flexible, and therefore, interpenetrate to a lesser extent with the glycosaminoglycans of mucus. Additionally, the interactions between functional groups of polycarbophil and mucus glycosaminoglycans are lowered due to the calcium, blocking the carboxylic groups. The mechanism of calcium influence on viscosity of polycarbophil dispersions appears to be different: repulsion between ionised carboxylic groups of polycarbophil prevails over the crosslinking of polycarbophil by calcium.
    Source: International journal of pharmaceutics. - ISSN 0378-5173 (Vol. 241, no. 1-2, 2002, str. 135-143)
    Type of material - article, component part
    Publish date - 2002
    Language - english
    COBISS.SI-ID - 1128817

source: International journal of pharmaceutics. - ISSN 0378-5173 (Vol. 241, no. 1-2, 2002, str. 135-143)

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