title: A dynamic topical hydrofluoroalkane foam to induce nanoparticle modification and drug release in situ.
abstract: Topical nanoparticles are usually applied using semi-solid formulations, but the delivery process is often inefficient due to the poor drug release from the particles. The aim of this study was to investigate the capability of a dynamic foam to break open nanoparticles upon application to the skin and enhance drug delivery efficiency. Vitamin E acetate (VEAc) was selected as a model drug and loaded into lipid nanoparticles (50-60 nm) prepared by phase inversion. The highest drug loading was 18.9+/-1.2 mg/ml and the corresponding encapsulation efficiency was 81.5+/-4.1%. Dynamic foams were generated by emulsifying VEAc-loaded nanoparticle suspensions with hydrofluoroalkane using pluronic L62D. An in vitro permeation study demonstrated that VEAc did not release from the nanoparticles when administered as an aqueous suspension, but attained a flux of 18.0+/-2.1 (microg cm(-2) h(-1)) when applied using the foam. Drug release from the foam was shown to be a consequence of nanoparticle modification after dose administration and this led to the foam delivering 0.7+/-0.3% VEAc into the stratum corneum (SC) when applied to human skin.
authors.affiliation: Pharmaceutical Science Division, King's College London, London, UK.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Zhao
authors.forename: Mojgan
authors.initials: M
authors.lastname: Moddaresi
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Jones
authors.forename: Marc B
authors.initials: MB
authors.lastname: Brown
mesh_terms: D000287:Administration, Topical; D000335:Aerosol Propellants / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000008:administration & dosage* / Q000493:pharmacokinetics; D066298:In Vitro Techniques; D053758:Nanoparticles / Q000008:administration & dosage*; D012869:Skin Absorption / Q000187:drug effects / Q000502:physiology; D005466:Fluorocarbons
chemical_list: D000335:Aerosol Propellants; D004337:Drug Carriers; D006845:Hydrocarbons, Fluorinated; C094049:apaflurane; D005466:Fluorocarbons