Macromolecular drug conjugates - Metronidazol and quinidine/cation exchange systems

'The paper discusses the formation of conjugates between the basic drugs me tronidazole and quinidine and polysaccharide-based cation exchangers, conta ining sulfopropyl functional groups, as well as their in vitro release beha viour. The amount of the drug absorbed through ionic forces on the macromol ecular support depends on the amount and the accessibility of reactive site s on the cation exchanger as well as on the basicity of the drug. The in vi tro studies showed that the drugs were released in amounts that were high e nough in a short time. To improve the release behaviour of the drugs from t hese systems, a hydrophobized cation exchanger was synthesised. Its conjuga tes with the drugs release the biologically active substance slowly. Langmu ir and Freundlich isotherms were plotted and Langmuir's constants calculate d for the studied systems.