title: Formulation, physicochemical characterization and stability study of lithium-loaded microemulsion system.
abstract: Lithium biocompatible microemulsion based on Peceol(®), lecithin, ethanol and water was studied in attempt to identify the optimal compositions in term of drug content, physicochemical properties and stability. Lithium solubilization in microemulsion was found to be compatible with a drug-surfactant binding model. Lithium ions were predominantly solubilized within lecithin head group altering significantly the interfacial properties of the system. Pseudo-ternary phase diagrams of drug free and drug loaded microemulsions were built at constant ethanol/lecithin weight ratio (40/60). Lithium loaded microemulsion has totally disappeared in the Peceol(®) rich part of phase diagram; critical fractions of lecithin and ethanol were required for the formation of stable microemulsion. The effect of lithium concentration on the properties and physical stability of microemulsions were studied using microscopy, Karl Fischer titrations, rheology analyses, conductivity measurements and centrifugation tests. The investigated microemulsions were found to be stable under accelerated storage conditions. The systems exhibited low viscosity and behaved as Newtonian fluid and no structural transition was shown.
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253CNRS-ENSCM-UM2-UM1, Equipe MACS, 8 rue de l'Ecole Normale, 34296 Montpellier, France; Medesis Pharma, S.A, Avenue du Golf, L'Orée des Mas, Les Cyprès, 34670 Baillargues, France.
authors.forename: Abdelkader
authors.initials: A
authors.lastname: Mouri
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253CNRS-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
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: Institut Charles Gerhardt Montpellier, UMR 5253CNRS-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: Medesis Pharma, S.A, 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 5253CNRS-ENSCM-UM2-UM1, Equipe MACS, 8 rue de l'Ecole Normale, 34296 Montpellier, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Devoisselle
mesh_terms: D002626:Chemistry, Pharmaceutical; D002951:Citrates / Q000737:chemistry*; D004355:Drug Stability; D004655:Emulsions; D000431:Ethanol / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D054709:Lecithins / Q000737:chemistry; D009829:Oleic Acids / Q000737:chemistry; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D002951:Citrates; D004655:Emulsions; D005079:Excipients; D054709:Lecithins; D009829:Oleic Acids; C482692:Peceol; D014867:Water; D000431:Ethanol; C070669:lithium citrate
keywords: Binding process; Lecithin; Lithium; Phase diagram; W/O microemulsion