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.

Design of cationic lipid nanoparticles for ocular delivery: Development, characterization and cytotoxicity

“…The two surfactants are needed to stabilize the two existing interfaces in this type of emulsion. A variety of surfactants can be applied, such as phospholipids, bile salts, polysorbates, polyoxyethylene ethers (Gallarate et al, 2009;Fangueiro et al, 2012). Materials used for LN production are largely used in pharmaceutical industry with proved biocompatibility (Severino et al, 2012).…”

Formulation and evaluation of gemcitabine-loaded solid lipid nanoparticles

“…In order to obtain optimum nanoemulsion, the needle was placed 4 cm from the surface of the water and mixture stirred at 3000 rpm. After the complete addition of multiple emulsion, the SLN dispersion was further stirred for 3 h. After stirring, the SLN dispersion was subjected to ultra sonication for a period of 10 min (Sarmento et al, 2007;Doijad et al, 2008;Gallarate et al, 2009;Jelvehgari et al, 2010).…”

Design of solid lipid nanoparticles for caffeine topical administration

“…Conversely, the entrapment of a hydrophilic drug inside the hydrophobic matrix of SLN is a real challenge, in fact most of the examples reported in literature, regarding hydrophilic molecules, show lipid nanoparticles characterized by a low payload and often realized using toxic organic solvents, which could compromise the safety profile of the formulated nanocarriers (Hu et al, 2004;Trotta et al, 2005;Gallarate et al, 2009;Kang et al, 2009).…”