Structure and properties of interpolymer complexes as polymer carriers of biologically active substances

Structure and properties of interpolymer complexes (IPC) composed of poly(methacrylic acid) (PMAA) and poly(ethylene glycol) (PEG) as polymer carriers for biologically active substances were studied using high-resolution solution 1H and 13C NMR and 13C solid-state CP/MAS NMR methods. Release of drugs from polymer matrix of IPC into the environment was studied using the IPC-theophilline composition as an example. It was demonstrated that information on specific features of the association of complementary chains of PMAA and PEG both for the solid state of polymer matrix and for its aqueous solution may be basically obtained by NMR methods. It was revealed that various synthesis procedures result in the formation of IPCs differing by their structures. A scheme of quantitative estimation of the fraction of the hydrogen bonds that are formed between IPC components was proposed. The results obtained allow us to assume that the synthesis procedure and composition of the forming complex are interrelated due to the mechanism of the formation of interpolymer complexes. © 1996 MAHK Hayka/Interperiodica Publishing