Preparation and anti-inflammatory activity of triptolide ethosomes in an erythema model.
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.
Chen
Jin-Guang
JG
Department of Dermatology, Xi Jing Hospital, the Fourth Military Medical University, Xi An, China.
Liu
Yu-Feng
YF
Gao
Tian-Wen
TW
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
D000893:Anti-Inflammatory Agents; D004224:Diterpenes; D004337:Drug Carriers; D004852:Epoxy Compounds; D008081:Liposomes; D010616:Phenanthrenes; C001899:triptolide; D000431:Ethanol