Previously [JCT: 97 (2016) 341 - 347], we have discussed the temperature-dependent enthalpies of dissolution of a chiral drug Albicar or 1,4-diethyl-3,6-dimethyltetrahydroimidazo[4,5-d] imidazole-2,5 (1H, 3H)-dione in ordinary (H2O) and heavy (D2O) water in comparison with those for Mebicar (1,3,4,6-tetramethyl-derivative) and Bicaret (1,3,4,6-tetraethyl-derivative). It was concluded that the Albicar hydration is dualistic (hydrophobic-hydrophilic) in nature and enhanced in the D2O medium. In the present report, the missing thermochemical data for solutions of Albicar (as a racemate) in the H/D isotopically distinguishable aqueous media have been analyzed to understand the situation more clearly. Such additional data are the enthalpies of dilution of Albicar solutions in H2O and D2O and the enthalpic coefficients of pairwise interaction (h(22)) for the title compound in both water isotopologues. Based on the results derived from calorimetric experiments, we have made it clear that the Albicar is a predominantly hydrophilic-hydrated compound despite the presence of two methyl and two ethyl radicals in the molecule of this heterocyclic chiral compound. (C) 2016 Elsevier Ltd.