Rheology of thickeners in pharmaceuticals: xanthan gum

Viscosity-increasing ingredients such as xanthan gum are widely used in complex products such as pharmaceuticals, creams, health-care products, food ingredients and dietary supplements. Their use is regulated by standards, such as the Pharmacopoeia (e.g. United States Pharmacopoeia and the European Pharmacopoeia). Although the applications of these ingredients are diverse, absolute and trustworthy rheological data are constantly required for the production and quality management of such products.

Measurements using a relative measuring system, such as a spindle, can only provide relative viscosity values because of the undefined gap dimension and thus an undefined shear field. Such results are only comparable when using the same measuring system at the same measuring height and constant temperature and, thus, can only give information about relative viscosity values.

By using modern rheometers with absolute measuring systems, complex structures can be investigated in diverse ways with high precision, measurements for quality control under process parameters can be made quickly, and can then be easily compared between laboratories.

Download the application report (above) from Anton Paar to learn how modern rheometers in combination with absolute measuring systems can provide absolute viscosity values.