title: Preparation and anti-inflammatory activity of triptolide ethosomes in an erythema model.
abstract: BACKGROUND
  The aim of this work was to evaluate the suitability of ethosomes as carriers for the topical application of triptolide in a rat model of erythema.
  
  
  OBJECTIVE
  We determined the optimal conditions for preparing ethosomes, and we measured their vesicle size by a laser particle-size analyzer and the efficiency of entrapment of triptolide by ultracentrifugation.
  
  
  METHODS
  The in vitro percutaneous permeation of triptolide-loaded ethosomes was investigated by measuring diffusion across a sample of rat skin. To explore the transdermal delivery in vivo, we used a model in which erythema was induced in rats by methyl nicotinate and determined the change in erythema index caused by the anti-inflammatory activity of triptolide by a reflection spectrophotometer.
  
  
  RESULTS
  The optimal conditions for preparing triptolide ethosomes consisted of ultrasonication of 45% (v/v) ethanol and 2% (w/v) DPPC for 5 minutes, which produced an average vesicle size of 51.4 nm and an entrapment efficiency of 98%. This ethosomal formulation of triptolide caused the greatest in vitro 24-hour accumulation of triptolide (83.7%) with no permeation time delay, and it reduced erythema in vivo more rapidly and more completely than other formulations.
  
  
  CONCLUSIONS
  Ethosomes might be a promising carrier that would enable the beneficial properties of triptolide to be safely delivered in a topical formulation.
authors.affiliation: Department of Dermatology, Xi Jing Hospital, the Fourth Military Medical University, Xi An, China.
authors.forename: Jin-Guang
authors.initials: JG
authors.lastname: Chen
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Liu
authors.forename: Tian-Wen
authors.initials: TW
authors.lastname: Gao
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use; D004058:Diffusion; D004195:Disease Models, Animal; D004224:Diterpenes / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism; D016503:Drug Delivery Systems; D004852:Epoxy Compounds / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use; D004890:Erythema / Q000188:drug therapy*; D000431:Ethanol / Q000737:chemistry*; D005260:Female; D008081:Liposomes / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D008297:Male; D010316:Particle Size; D010539:Permeability; D010616:Phenanthrenes / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000893:Anti-Inflammatory Agents; D004224:Diterpenes; D004337:Drug Carriers; D004852:Epoxy Compounds; D008081:Liposomes; D010616:Phenanthrenes; C001899:triptolide; D000431:Ethanol