Triptolide exerts strong anti-inflammatory and immunomodulatory effects; however, its oral administration might be associated with side effects. Transdermal administration can improve the safety of triptolide. In this study, glycerosomes were prepared as the transdermal vehicle to enhance the transdermal delivery of triptolide. With entrapment efficiency and drug loading as dependent variables, the glycerosome formulation was optimized using an orthogonal experimental design. Phospholipid-to-cholesterol and phospholipid-to-triptolide mass ratios of 30:1 and 5:1, respectively and a glycerol concentration of 20 % (