title: Liquid-liquid miscibility gaps and hydrate formation in drug-water binary systems: pressure-temperature phase diagram of lidocaine and pressure-temperature-composition phase diagram of the lidocaine-water system.
abstract: The pressure-temperature (P-T) melting curve of lidocaine was determined (dP/dT = 3.56 MPa K(-1)), and the lidocaine-water system was investigated as a function of temperature and pressure. The lidocaine-water system exhibits a monotectic equilibrium at 321 K (ordinary pressure) whose temperature increases as the pressure increases until the two liquids become miscible. A hydrate, unstable at ordinary pressure, was shown to form, on increasing the pressure, from about 70 MPa at low temperatures (200-300 K). The thermodynamic conditions of its stability were inferred from the location of the three-phase equilibria involving the hydrate in the lidocaine-water pressure-temperature-mole fraction (P-T-x) diagram.
authors.affiliation: Grup de Caracterizació de Materials, Department de Física i Enginyeria Nuclear, ETSEIB, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalunya, Spain.
authors.forename: René
authors.initials: R
authors.lastname: Ceolin
authors.forename: Maria
authors.initials: M
authors.lastname: Barrio
authors.forename: Josep-Lluis
authors.initials: JL
authors.lastname: Tamarit
authors.forename: Nestor
authors.initials: N
authors.lastname: Veglio
authors.forename: Marc-Antoine
authors.initials: MA
authors.lastname: Perrin
authors.forename: Philippe
authors.initials: P
authors.lastname: Espeau
mesh_terms: D004304:Dosage Forms; D006878:Hydroxides; D008012:Lidocaine; D010087:Oxides; D011312:Pressure; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D004304:Dosage Forms; D006878:Hydroxides; D010087:Oxides; D014867:Water; D008012:Lidocaine