In order to estimate the impact of the low molecular mass (lmm) VO (IV) binders of blood serum on the potentially insulin-enhancing drug [VO (DHP) 2][DHP= 1, 2-dimethyl-3-hydroxy- 4 (1H)-pyridinone], the speciation in the binary system VO (IV)–DHP and in the ternary systems VO–DHP–ligand B (B= oxalate, lactate, citrate or phosphate) was studied by pH- potentiometry at 25.0° C and at an ionic strength I= 0.2 mol dm− 3 (KCl). The binding ...