title: Preparation of solid lipid nanoparticles from W/O/W emulsions: preliminary studies on insulin encapsulation.
abstract: A method to produce solid lipid nanoparticles (SLN) from W/O/W multiple emulsions was developed applying the solvent-in-water emulsion-diffusion technique. Insulin was chosen as hydrophilic peptide drug to be dissolved in the acidic inner aqueous phase of multiple emulsions and to be consequently carried in SLN. Several partially water-miscible solvents with low toxicity were screened in order to optimize emulsions and SLN composition, after assessing that insulin did not undergo any chemical modification in the presence of the different solvents and under the production process conditions. SLN of spherical shape and with mean diameters in the 600-1200 nm range were obtained by simple water dilution of the W/O/W emulsion. Best results, in terms of SLN mean diameter and encapsulation efficiencies, were obtained using glyceryl monostearate as lipid matrix, butyl lactate as a solvent, and soy lecithin and Pluronic F68 as surfactants. Encapsulation efficiencies up to 40% of the loaded amount were obtained, owing to the actual multiplicity of the system; the use of multiple emulsion-derived SLN can be considered a useful strategy to encapsulate a hydrophilic drug in a lipid matrix.
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, via Pietro Giuria 9, Turin, Italy. marina.gallarate@unito.it
authors.forename: Marina
authors.initials: M
authors.lastname: Gallarate
authors.forename: Michele
authors.initials: M
authors.lastname: Trotta
authors.forename: Luigi
authors.initials: L
authors.lastname: Battaglia
authors.forename: Daniela
authors.initials: D
authors.lastname: Chirio
mesh_terms: D000818:Animals; D002417:Cattle; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods*; D016503:Drug Delivery Systems; D004655:Emulsions; D005989:Glycerides / Q000737:chemistry; D007328:Insulin / Q000008:administration & dosage / Q000737:chemistry*; D007773:Lactates / Q000737:chemistry; D054709:Lecithins / Q000737:chemistry; D008055:Lipids / Q000138:chemical synthesis* / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D020442:Poloxamer / Q000737:chemistry; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D004655:Emulsions; D005989:Glycerides; D007328:Insulin; D007773:Lactates; D054709:Lecithins; D008055:Lipids; D012997:Solvents; D013501:Surface-Active Agents; D014867:Water; D020442:Poloxamer; C048159:glyceryl monostearate