title: Volatile fluorinated nanoemulsions: a chemical route to controlled delivery of inhalation anesthesia.
abstract: Novel dispersions of the volatile inhalation anesthetic sevoflurane have been formulated that can provide controlled, sustainable release of anesthetic over clinically useful timescales. The emulsions can be simply formed with manual shaking, reproducibly yielding droplets of the order of 250 nm diameter, i.e. within the nanoemulsion range. Using a custom flow-rig, release of anesthetic gas from the emulsion has been evaluated, and clinically useful levels achieved through appropriate stirring of the formulation. Stirring can also be used to temporarily increase or decrease the amount of anesthetic released. Once consideration of the unusual nature of the fluorinated systems (phase separation by sedimentation rather than creaming), and the highly perturbed environment of their evaluation (under stirring and flow of gas), the observed behavior regarding sevoflurane evaporation can be reasonably well explained by existing theoretical models. Links between anesthetic release and emulsion structure have been defined, providing the basis for future development.
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UK.
authors.forename: Ibrahim E
authors.initials: IE
authors.lastname: Salama
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UK.
authors.forename: Claire L
authors.initials: CL
authors.lastname: Jenkins
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UK.
authors.forename: Alun
authors.initials: A
authors.lastname: Davies
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UK; Department of Anesthetics, Intensive Care and Pain Medicine, School of Medicine, Cardiff University, Cardiff, UK.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Clark
authors.affiliation: Department of Anesthetics, Intensive Care and Pain Medicine, School of Medicine, Cardiff University, Cardiff, UK.
authors.forename: Antony R
authors.initials: AR
authors.lastname: Wilkes
authors.affiliation: Department of Anesthetics, Intensive Care and Pain Medicine, School of Medicine, Cardiff University, Cardiff, UK.
authors.forename: Judith E
authors.initials: JE
authors.lastname: Hall
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, UK. Electronic address: paula3@cardiff.ac.uk.
authors.forename: Alison
authors.initials: A
authors.lastname: Paul
mesh_terms: D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D004655:Emulsions; D005461:Fluorine / Q000737:chemistry*; D008738:Methyl Ethers / Q000008:administration & dosage*; D000077149:Sevoflurane; D014835:Volatilization
chemical_list: D018685:Anesthetics, Inhalation; D004655:Emulsions; D008738:Methyl Ethers; D005461:Fluorine; D000077149:Sevoflurane
keywords: Anesthesia; Drug-delivery; Fluorocarbon; Nanoemulsions; Nanotechnology