title: Studies on the formation of O/W nano-emulsions, by low-energy emulsification methods, suitable for pharmaceutical applications.
abstract: The formation of O/W nano-emulsions suitable for pharmaceutical application and the solubilisation of a practically non-water-soluble drug, lidocaine, have been studied in water/non-ionic surfactant/oil systems. Nano-emulsions were prepared by using low-energy emulsification methods, changing the composition at constant temperature. Kinetic stability was assessed by measuring droplet diameter as a function of time. Lidocaine solubilisation was studied in nano-emulsions with high water content. In the water/Cremophor EL/Miglyol 812 system the lowest droplet sizes, from 14 to 39nm at 10/90 and 40/60 oil/surfactant ratios, respectively, and 90% of water content, were obtained with an emulsification method consisting of stepwise addition of water to oil/surfactant mixtures at 70 degrees C. Nano-emulsions of this system showed high kinetic stability. Droplet diameters did not exceed 67nm after a period of at least 7 months. The maximum lidocaine concentration solubilised in nano-emulsions of the water/Cremophor EL/Miglyol 812 system with 90 and 95% of water content was 3.5 and 2.1%, respectively. These values are within the therapeutic range of lidocaine.
authors.affiliation: Department of Surfactant Technology, IIQAB-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Sadurní
authors.forename: Conxita
authors.initials: C
authors.lastname: Solans
authors.forename: Núria
authors.initials: N
authors.lastname: Azemar
authors.forename: Maria José
authors.initials: MJ
authors.lastname: García-Celma
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D004655:Emulsions; D007700:Kinetics; D008012:Lidocaine / Q000737:chemistry; D036103:Nanotechnology; D004364:Pharmaceutical Preparations; D012542:Scattering, Radiation
chemical_list: D004655:Emulsions; D004364:Pharmaceutical Preparations; D008012:Lidocaine