g distinct pattern of drug release based on combination of controlled release layers, swelling agents and coatings; controlled release layer of slightly crosslinked polyacrylic acid and water soluble polymerUS5902832 *Aug 20, 1996May 11, 1999Menlo Care, Inc.Contacting a plurality of hydrophilic crosslinked particles formed from a polymer including polyoxyethylene glycol, polyvinylpyrrolidone, poly