The purpose of this work was to explore the feasibility of ethosomes for improving the anti-arthritic efficacy of topically administered tetrandrine, a bisbenzylisoquinoline alkaloid. Ethosomes were prepared by using the transmembrane pH-gradient loading method and characterized by mean diameter, morphology and entrapment efficiency. The prepared tetrandrine-loaded ethosomes exhibited spherical shape with about 78 nm of average diameter and entrapment efficiency of （52.87±3.81）%, whereas the liposomes had bigger size （99 nm） and higher entrapment efficiency （98.80±0.01）%. In addition, ethosomes exhibited favorable and enhanced penetration behavior as compared with liposomes. More importantly, tetrandrine-loaded ethosomes had a significantly better anti-adjuvant arthritis efficacy in rats compared to liposomes formulation, but no significant difference in the anti-arthritic efficacy between tetrandrine-loaded ethosomes and commercial dexamethasone ointment was observed. These results suggest that ethosomes would be a promising nanocarrier for topical delivery of tetrandrine across skin.
