Novel network polymers possessing cation-exchange properties have been synthesized by the catalytic resol polycondensation of calix[4]resorcinarene derivatives with formaldehyde or with furfural and formaldehyde. The ion-exchange capacities of the polymers with respect to Na+, Me4N+, Et4N+, Bu4N+cations have been determined. It is shown that the potentiometric titration curves of the polymers are similar to the titration curve of the resorcinol-formaldehyde resin, but they are shifted toward lower pH values and have inflections. The formation enthalpies of calix[4]resorcinarene derivatives and their salts with Na+, Me4N+have been calculated by the MNDO/PM3 method. The heat of the reaction simulating the interaction of the polymers with NaOH and Me4NOH has been determined. It is found out that the inflections of the potentiometric titration curves of the cationites appear when appreciable differences in the changes of the enthalpies of modeling reaction stages are observed.

The paper is devoted to the study of the ion exchange encapsulation of nicotinic acid in nanocontainers on polymer matrices. Dowex-50 cation exchanger, sulphonated polymer based on metacyclophanoctol, polymer zirconium phosphate, and strongly basic Dowex-1 anion exchanger are used as polymer matrices. It was confirmed that commercial ion exchangers can encapsulate up to 0.64 g of nicotinic acid per gram of polymer. The high elution rate of nicotinic acid from nanocontainers via the ion exchange mechanism makes it possible to achieve the desired pharmacokinetics of drug release in vivo.