Patent ID: 6683143
Filing Date: 2004-01-27
Classification: A61K,A61Q,C08F

Abstract:
An ion-sensitive polymer, wherein the polymer is insoluble in a neutral salt solution containing at least about 0.3 weight percent salt, said salt comprising one or more monovalent or multivalent ions; and wherein the polymer is soluble in tap water containing up to about 500 ppm of one or more multivalent ions and wherein the polymer is formed from (a) about 35 to about 80 mol % acrylic acid, methacrylic acid, or a combination thereof; (b) from greater than 0 to about 20 mol % 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS), sodium salt of 2-acrylamido-2-methyl-1-propanesulfonic acid (NaAMPS), or a combination thereof; and (c) greater than 0 to about 65 mol % one or more alkyl acrylates.