STRONG BUFFERING CHARACTERISTICS AND SWELLING BEHAVIOR OF CATIONIC COPOLYMERS

The swelling behavior of crosslinked cationic copolymers of 2-hydroxye thyl methacrylate with (3-methacryloylamino propyl) trimethylammonium chloride was investigated in various buffered solutions as a function of ionic strength and pH. The equilibrium degree of swelling increased as the pH decreased or as the cationic group-containing comonomer in the polymer increased. The water transport in such copolymers was cont rolled by a non-Fickian mechanism. These results can be used in the de velopment of physiologically sensitive controlled drug delivery system s. (C) 1994 John Wiley & Sons, Inc.