Preparation and anti-inflammatory activity of triptolide ethosomes in an erythema model

• Published in: Journal of liposome research Vol. 20; no. 4; pp. 297 - 303
• Main Authors: Chen, Jin-Guang, Liu, Yu-Feng, Gao, Tian-Wen
• Format: Journal Article
• Language: English
• Published: England Informa Healthcare 01.12.2010; Taylor & Francis
• Subjects: Administration, Cutaneous; Animals; Anti-Inflammatory Agents - administration & dosage; Anti-Inflammatory Agents - chemistry; Anti-Inflammatory Agents - therapeutic use; Diffusion; Disease Models, Animal; Diterpenes - administration & dosage; Diterpenes - chemistry; Diterpenes - therapeutic use; Drug Carriers - chemistry; Drug Carriers - metabolism; Drug Delivery Systems; Epoxy Compounds - administration & dosage; Epoxy Compounds - chemistry; Epoxy Compounds - therapeutic use; Erythema - drug therapy; Ethanol - chemistry; Female; Liposomes - administration & dosage; Liposomes - chemistry; Liposomes - metabolism; Male; Particle Size; Percutaneous permeation; Permeability; Phenanthrenes - administration & dosage; Phenanthrenes - chemistry; Phenanthrenes - therapeutic use; Rats; Rats, Sprague-Dawley; rodent model; transdermal delivery; triptolide
• ISSN: 0898-2104; 1532-2394
• DOI: 10.3109/08982100903544144

Context: 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.