Carrageenan is a naturally occurring family of hydrophilic polysaccharides extracted from several closely related species of red seaweeds. They are high molecular weight, highly sulfated, linear molecules with a galactose backbone. They are made up of sulfated and non-sulfated repeating units of galactose and 3,6-anhydrogalactose.
The range of products includes three basic types of carrageenan – kappa, iota and lambda from various species of red seaweed. They are differentiated from each other by the amount of 3,6-anhydrogalactose as well as the number and position of ester sulfate groups present.
Natural rate modifying polymers
Various Gelcarin® carrageenan and Viscarin® carrageenan grades are used by the pharmaceutical industry to achieve specific gelling for controlled release thickening, and stabilizing properties desired in various formulations.