title: Liposomes Size Engineering by Combination of Ethanol Injection and Supercritical Processing.
abstract: Supercritical fluid extraction using a high-pressure packed tower is proposed not only to remove the ethanol residue from liposome suspensions but also to affect their size and distribution leading the production of nanosomes. Different operating pressures, temperatures, and gas to liquid ratios were explored and ethanol was successfully extracted up to a value of 400 ppm; liposome size and distribution were also reduced by the supercritical processing preserving their integrity, as confirmed by Z-potential data and Trasmission Electron Microscopy observations. Operating at 120 bar and 38°C, nanosomes with a mean diameter of about 180 ± 40 nm and good storage stability were obtained. The supercritical processing did not interfere on drug encapsulation, and no loss of entrapped drug was observed when the water-soluble fluorescein was loaded as a model compound. Fluorescein encapsulation efficiency was 30% if pure water was used during the supercritical extraction as processing fluid; whereas an encapsulation efficiency of 90% was obtained if the liposome suspension was processed in water/fluorescein solution. The described technology is easy to scale up to an industrial production and merge in one step the solvent extraction, liposome size engineering, and an excellent drug encapsulation in a single operation unit.
authors.affiliation: Department of Industrial Engineering, University of Salerno Fisciano Salerno 84084 Italy; Industrial Engineering Program, Polytechnic School, Federal University of Bahia Salvador Bahia 40210-630 Brazil.
authors.forename: Islane Espirito
authors.initials: IE
authors.lastname: Santo
authors.affiliation: Department of Industrial Engineering, University of Salerno Fisciano Salerno 84084 Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Campardelli
authors.affiliation: Industrial Engineering Program, Polytechnic School, Federal University of Bahia Salvador Bahia 40210-630 Brazil.
authors.forename: Elaine Cabral
authors.initials: EC
authors.lastname: Albuquerque
authors.affiliation: Industrial Engineering Program, Polytechnic School, Federal University of Bahia Salvador Bahia 40210-630 Brazil.
authors.forename: Silvio A B
authors.initials: SAB
authors.lastname: Vieira De Melo
authors.affiliation: Department of Industrial Engineering, University of Salerno Fisciano Salerno 84084 Italy.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Reverchon
authors.affiliation: Department of Industrial Engineering, University of Salerno Fisciano Salerno 84084 Italy. Electronic address: gdellaporta@unisa.it.
authors.forename: Giovanna Della
authors.initials: GD
authors.lastname: Porta
mesh_terms: D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D000431:Ethanol / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size
chemical_list: D008081:Liposomes; D000431:Ethanol
keywords: drug delivery systems; liposomes; particle size; processing; supercritical fluids