Viscosimetric behaviour of hyaluronic acid in different aqueous solutions

Rheological properties of aqueous solutions of hyaluronic acid (HA), of interest for the medical and cosmetics industry, have been studied. The value of the intrinsic viscosity of hyaluronic acid has been determined using Huggins and Kramer equations, and the value of molecular weight of this polymer has been calculated on the basis of intrinsic viscosity. The apparent viscosity value and the influence of the shear rate upon this physical property and the polymer concentration in aqueous solution have been determined. The effects caused by temperature, the concentration and nature of alcohols, as well as the electrolyte presence on the theological behaviour have been also studied. These results are expected to offer enough information to obtain the theological behaviour and to have a better understanding of HA-based mixtures for different purposes. (C) 2011 Elsevier Ltd. All rights reserved.