Characterization and differentiation of some complex dextran sulfate preparations of medicinal interest

Dextran sulfate samples from different sources were examined by 1H and 13C NMR spectroscopy to differentiate the samples on the basis of extent and sites of sulfation. The anomeric (H-1) signal proved to be a good indicator ranging from no sulfation (as in dextran) to virtually complete sulfation at positions 2 and 3, whereas the relative intensity of the H-4 signal afforded a measure, conversely, of the degree of sulfation at position 4. Three different dextran sulfate tablet formulations were found by NMR to contain similar dextran sulfate material that was characterized by a high degree of sulfation at positions 2 and 3. Position 4 of dextran appears to be less readily amenable to substitution. Quasi-elastic light scattering (QELS) analysis of aqueous dispersions of the bulk dextran sulfate samples and formulated tablets permitted additional particle size and homogeneity differentiation. None of the dextran sulfate materials showed either anti-factor Xa activity or marked anticoagulant activity.