Study of molecular interactions in drug mixtures

Molecular drug/coformer interactions were deduced from thermodynamic and thermophysical properties. Measurements of the liquid-solid equilibrium diagrams of two binary systems M.HCl + L-Proline and or + L-Arginine revealed single and double eutectic systems respectively. The diagram for the M.HCl + L-Arginine binary system also shows a defined compound. This corresponds to a P.A/Coformer cocrystallization facilitated by the existence of several functional groups. XRD, SEM and IR analysis confirmed the existence of a new compound with chemical formula C10H26N9ClO2The densities of the ternary systems [M.HCl + H2O + L-Proline and or L-Arginine] were measured at different temperatures from 288.15 to 303.15 K and at atmospheric pressure. The apparent molar volumes determined from the density measurements are positive throughout the molar range of M.HCl. These positive values may be due to the establishment of strong Keesom electrostatic interactions and intermolecular hydrogen bonding.