Cissus stem gum as potential dispersant in pharmaceutical liquid systems: rheological characterization

A Co-axial viscometer, the Haake-Rotovisco, was used studying the rheological behaviour of aqueous dispersion of cissus stem gum. At concentrations of 4% w/v and above, the mucilage is both pseudoplastic and thixotropic. Two equations derived from a power law expression for apparent viscosity(h): h = ekc + b were solved simultaneously (c = 4 and 8% w/v) in the determination of material constants k and b for cissus gum. The apparent viscosity of the polymeric liquid system was affected by concentration of the gum, pH, temperature and aging.