ABSTRACT
In this chapter, the authors report the release properties of two new polyelectrolyte materials poly (acrylamido-methyl-propanesulfonate) and poly (diallydimethyl ammonium chloride), which were used as anionic and cationic carriers, respectively, for oppositely charged drugs. Swellable polyelectrolyte gel matrices of both anionic and cationic types have been investigated for their drug release properties. Such materials release drugs over an extended period of time by an ion-exchange mechanism but usually provide square root of time drug release kinetics with a tailing toward the end of release. The release kinetics from the tablets of the drug-polymer complexes were carried out in buffered release media containing 0.01 M phosphate and NaCl ranging from 0.2 M to 0.02 M at 37°C by the USP basket method at 100 rpm. When an excess drug solution was poured into an aqueous polymer solution, a water-insoluble complex formed, and precipitated as a white, agglomerated mass, which was collected, washed, and dried.
