Synthesis and characterization of a new carrier based on Eudragit® EPO/S100 interpolyelectrolyte complex for controlled colon-specific drug delivery

With a view to the development of peroral controlled drug delivery systems, a new interpolyelectrolyte complex (IPEC) between oppositely charged types of Eudragit®, EPO and S100, has been synthesized and investigated at neutral pH values. According to data of turbidimetry, capillary viscometry, gravimetry, and elemental analysis, the obtained IPEC has a composition of Z = [EPO]/[S100] = 1.26. Structural features of the IPEC samples have been evaluated by FTIR spectroscopy and modulated-temperature differential scanning calorimetry. The results confirmed that the IPEC is stabilized by cooperative intermacromolecular ionic bonds, is chemically homogeneous, and is characterized by a single glass transition temperature. The observed features of the carrier swelling and diclofenac sodium release from the matrix system confirm that the proposed IPEC has great potential to be used as a carrier for controlled colon-specific drug delivery.