Speciation studies of a bisphosphonate drug. New thermodynamic insights of sodium alendronate with Ca2+ and Mg2+ in NaCl aqueous solution (0.10 ≤ I/mol kg−1 ≤ 1.02)

•The ionic strength and temperature dependence of the equilibrium constants were modeled using Specific Ion Interaction theory (SIT) and a modified Debye-Hückel equation containing a Van't Hoff term.•Sequestering ability of alendronate toward Mg2+ and Ca2+ has been evaluated by means of the pL0.5 parameter.•Simulation of the Mg2+ and Ca2+/alendronate species in human blood plasma.