title: Anandamide-loaded nanoparticles: preparation and characterization.
abstract: OBJECTIVE
  Preparation and characterization of anandamide (N-arachidonoyl-ethanolamine, AEA) loaded polycaprolactone nanoparticles (PCL NP) as a research tool to clarify the presence of an AEA transporter in cell membranes and to avoid AEA plastic adsorption and instability.
  
  
  METHODS
  High performance liquid chromatography and light scattering were used to determine encapsulation efficiency, particle size, drug release, permeability and stability.
  
  
  RESULTS
  A high encapsulation efficiency 96.05 ± 1.77% and a particle size of 83.52 ± 21.38 nm were obtained. Nearly 40% of AEA remained in the NP after a 99.9% dilution and only 50% was released after 24 h at 37 °C with a 99% dilution. PCL NP prevented the adsorption of the drug to polypropylene or polystyrene, but not to acrylic multiwell plates. Drug permeability through artificial membranes was low (10⁻⁷ to 10⁻⁸ cm/s) and was affected by the presence of NP. NP increased AEA stability in suspension (drug half-life 431 h vs. 12 h) and freeze-dried with 5% sucrose.
  
  
  CONCLUSIONS
  This article presents the first study where stable AEA-loaded NP with high encapsulation efficiencies have been obtained.
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, University of Alcalá, Alcalá de Henares, Spain.
authors.forename: M R
authors.initials: MR
authors.lastname: Aberturas
authors.forename: D
authors.initials: D
authors.lastname: Hernán Pérez de la Ossa
authors.forename: M E
authors.initials: ME
authors.lastname: Gil
authors.forename: A
authors.initials: A
authors.lastname: Ligresti
authors.forename: L
authors.initials: L
authors.lastname: Ligresti
authors.forename: L
authors.initials: L
authors.lastname: De Petrocellis
authors.forename: A I
authors.initials: AI
authors.lastname: Torres
authors.forename: V
authors.initials: V
authors.lastname: Di Marzo
authors.forename: J
authors.initials: J
authors.lastname: Molpeceres
mesh_terms: D000042:Absorption / Q000187:drug effects; D001095:Arachidonic Acids / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D002462:Cell Membrane / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D063388:Endocannabinoids; D008567:Membranes, Artificial; D053758:Nanoparticles / Q000737:chemistry*; D010539:Permeability / Q000187:drug effects; D011091:Polyesters / Q000737:chemistry; D053284:Polyunsaturated Alkamides / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D001095:Arachidonic Acids; D004337:Drug Carriers; D063388:Endocannabinoids; D008567:Membranes, Artificial; D011091:Polyesters; D053284:Polyunsaturated Alkamides; C016240:polycaprolactone; C078814:anandamide