Sorption of the antitumor drug prospidinum on microgels of polysaccharide phosphates

The intermolecular interaction of prospidinum with gel-forming dextran and starch phosphates has been studied. The sorption equilibria have been studied for cytostatic and the biodegradable hydrogels of polysaccharide phosphates. The concentration coefficients of ion exchange equilibrium and distribution coefficients of prospidinum have been calculated at different degrees of microgel phase filling with the cytostatic, and the relations between the coefficients and the degree of hydrogel swelling have been determined. The ion-exchange and nonexchange contributions to sorption values have been found. The analysis of the distribution coefficients has demonstrated that the concentration of prospidinum sorbed through the nonexchange mechanism is higher than its concentration in an external solution due to the van der Waals interactions between prospidinum cations and macromolecules of polysaccharide phosphates. The Na form of polysaccharide phosphates is the optimal carrier for prospidinum, because this form has a higher density of the total negative charge than their H form has.