title: Phase behavior of reverse microemulsions based on Peceol(®).
abstract: The phase diagram of the four component system Peceol®/lecithin/ethanol/water was studied at 25°C and at a fixed fraction of ethanol. It shows an isotropic W/O microemulsion phase, biphasic liquid system and Liquid crystalline phases. The stabilizing effect of lecithin with the fluidifying effect of ethanol on the microemulsion based on long chain glycerides provides an effective combination to solubilize a large amount of water. Some structural transitions in the phase diagram were investigated as a function of water content using conductivity, rheology, Karl Fisher titration, optical microscopy and SAXS measurements. The results show no change in the microstructure of the isotropic liquid upon phase separation in the liquid biphasic area. However, in the water rich region, migration of ethanol to the external aqueous phase at the expense of the saturated microemulsion promotes the formation of liquid crystalline phases. As a function of water content, the structural change to the liquid crystalline phases follows: isotropic phase L2 → Inverted hexagonal phase H2 → Inverted hexagonal H2/lamellar Lα phases.
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-ENSCM-UM2-UM1, Equipe MACS, 8 rue de l'Ecole Normale, 34296 Montpellier, France; Medesis Pharma, Avenue du Golf, L'Orée des Mas, Les Cyprès, 34670 Baillargues, France.
authors.forename: Abdelkader
authors.initials: A
authors.lastname: Mouri
authors.affiliation: Institut de Chimie Séparative de Marcoule, ICSM UMR 5257 (CEA/CNRS/UM2/ENSCM), 30206 Bagnols sur Cèze, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Diat
authors.affiliation: Institut des Biomolécules Max Mousseron, UMR CNRS 5247, Université de Montpellier I, 34060 Montpellier, France.
authors.forename: Abdeslam
authors.initials: A
authors.lastname: El Ghzaoui
authors.affiliation: Medesis Pharma, Avenue du Golf, L'Orée des Mas, Les Cyprès, 34670 Baillargues, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Bauer
authors.affiliation: Medesis Pharma, Avenue du Golf, L'Orée des Mas, Les Cyprès, 34670 Baillargues, France.
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Maurel
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-ENSCM-UM2-UM1, Equipe MACS, 8 rue de l'Ecole Normale, 34296 Montpellier, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Devoisselle
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-ENSCM-UM2-UM1, Equipe MACS, 8 rue de l'Ecole Normale, 34296 Montpellier, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Dorandeu
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-ENSCM-UM2-UM1, Equipe MACS, 8 rue de l'Ecole Normale, 34296 Montpellier, France. Electronic address: philippe.legrand@univ-montp1.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Legrand
mesh_terms: D003460:Crystallization; D004553:Electric Conductivity; D004655:Emulsions; D000431:Ethanol / Q000737:chemistry*; D006801:Humans; D054709:Lecithins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D009829:Oleic Acids / Q000737:chemistry*; D019999:Pharmaceutical Solutions / Q000737:chemistry*; D044367:Phase Transition; D012212:Rheology; D053838:Scattering, Small Angle; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004655:Emulsions; D054709:Lecithins; D008823:Micelles; D009829:Oleic Acids; C482692:Peceol; D019999:Pharmaceutical Solutions; D014867:Water; D000431:Ethanol
keywords: Microemulsion; Phase diagram; Phase transitions; Polar lipids; Rheology; SAXS