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New interpolyelectrolyte complexes (IPECs) between oppositely charged types of Eudragit EPO and Eudragit L100 - 55 were investigated with a view to their application in oral controlled drug delivery systems. Monitoring of microenvironmental changes of polycomplex matrices in simulated gastro-intestinal fluids showed that all IPECs could have different pH-sensitivity characteristics. Evaluation of the diffusion transport properties of the investigated IPECs with diclofenac sodium confirmed that their swellability and release characteristics were closely correlated. The main possible mechanisms of control over the delivery of drugs to the desired regions of the gastro-intestinal tract are found. The results confirm that the proposed IPEC matrices have great potential to be used for controlled drug delivery. [ABSTRACT FROM AUTHOR]

New interpolyelectrolyte complexes (IPEC) between oppositely charged types of Eudragit, EPO and L100-55, with different molar ratios were synthesized with the aim of seeking potential carriers for oral delivery systems. Elemental analysis showed that the resulting polycomplexes had different compositions, with 0.36 < Z = [EPO]/[L100] < 1.81. The structural properties of the materials assessed by IR spectroscopy and modulated-temperature differential scanning calorimetry showed that all IPEC were stabilized by a cooperative system of ionic bonds, were chemically homogeneous, and were characterized by the presence of a single glass transition temperature. These properties suggest that the polycomplexes synthesized here have potential for further study as carriers for controlled drug release in specified parts of the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

The formation of interpolyelectrolyte complexes (IPEC) between Eudragit EPO (EPO) and Carbomer 940 (C940) was investigated with a view to their use in peroral controlled-release drug delivery systems. The structure of the synthesized products was investigated using FTIR spectroscopy and MT-DSC methods, which indicated that the synthesized product can be considered to be an IPEC stabilized by a cooperative system of ionic bonds. Based on results of capillary viscosimetry and elemental analysis, the IPEC prepared at pH 4.0 has a characteristic composition with a C940:EPO mole ratio of 1.75:1. [ABSTRACT FROM AUTHOR]