Basic butylated methacrylate copolymer/kappa-carrageenan interpolyelectrolyte complex: preparation, characterization and drug release behaviour.

The formation of a novel interpolyelectrolyte complex (IPEC) between basic butylated methacrylate copolymer and kappa-carrageenan was investigated and the product formed was characterized. Turbidity measurements and elemental analyses pointed to a 1:1 interaction of the repeating units. These results and FT-IR confirmed IPEC formation. Electronic microscopy images, particle size determination by image analysis and N(2) (77K) adsorption measurements were consistent with a porous material. This IPEC formed presented very good flowability and compactibility. Two maxima were observed in the swelling behaviour as a function of pH. The performance of the IPEC as a matrix for controlled release of drugs was evaluated, using ibuprofen as a model drug. Release profiles were properly represented by a mathematical model, which indicates that the system releases ibuprofen in a zero-order manner. These profiles could be controlled by conveniently modifying the proportion of the IPEC in the tablets.