Hansen solubility parameters for selected cellulose ether derivatives and their use in the pharmaceutical industry

The paper describes a laboratory method used for determining the partial solubility parameters of five METHOCEL^* and six ETHOCEL^* cellulose ether products. A simple computer spreadsheet has also been devised to calculate the partial solubility parameters from the laboratory data. These new laboratory derived values extend the data base of solubility parameters that have been used to explore certain cellulose ether applications. The cellulose ethers are characterized in terms of non-polar, polar, and hydrogen bonding behavior. METHOCEL A, E, F, K and J cellulose ethers all have similar solubilities and are thus assigned solubility parameters in the range of non-polar (δ d) = 17.4 - 18.2, polar (δ p) = 14.6 - 16.5, hydrogen bond (δ h) = 15.5 - 19.4 with a radius of interaction of 10.3

More organic like solubility is shown by the six ethoxy cellulose ether derivatives. The range of Hansen partial solubility parameters are non-polar (δd) 16.6 - 17.3, polar (δp) = 6.6 - 8.3, and hydrogen bond (δh) = 8.5 - 10.0.