Compression pressure-induced synergy in xanthan and locust bean gum hydrogels. Effect in drug delivery

The study assesses the potential of combining xanthan gum and locust bean gum to create controlled-release hydrogels and also examines how compressing the polysaccharide blends affects their behavior. The research involved evaluating the rheological properties of aqueous dispersion of these gums and their mixtures using a rotational rheometer. Xanthan gum displayed a pseudoplastic Bingham behavior, while locust bean gum exhibited lower viscosity and shear thinning behavior. Gum blends showed an intermediate behavior with varying yield shear stress based on the gum proportions in the mixture. The flow index (n) and the consistency index (K) were calculated using the Power Law model (Ostwald de Waele relationship). The values of n are between 0.6 (Xanthan gum) and 0.1 (locust bean gum), with the blends showing intermediate values. These values are characteristic of shear-thinning systems and show a higher deviation of Xanthan gum from Newtonian behavior than LBG. Additionally, the k values indicate higher consistency for the Xanthan dispersions and similar behavior for the mixtures of the two polysaccharides, regardless of their proportion.