Abstract: OBJECTIVE To design a transdermal patch of trantinterol with good skin permeability for the treatment of bronchial asthma by adopting the combination of ionpair and permeation enhancer strategy. METHODS The transdermal patch of trantinterol was prepared by the organic solvent evaperation method, and the full thickness skin of Wistar rat was used as a model to investigate the effect of ionpair and permeation enhancer on the skin permeation behavior of trantinterol by single factor investigation method in the in vitro skin permeation study. The molecular mechanism of ionpair and permeation enhancer on the skin permeation behavior of trantinterol were investigated through the in vitro drug release experiments and FTIR experiments. RESULTS The optimized formulation of the patch were the ionpair of trantinterol-p-aminobenzoic acid as the main drug, drug loading of 5%, DURO-TAK^®87-4098 as the pressure sensitive adhesive, and 8% polyglycerol oleate (POCC) as the permeation enhancer. The formation of ionpair increased the skin permeation of trantinterol, and the addition of POCC promoted both the release process of trantinterol from the patch and the skin permeation process. The combined application of the technologies increased the cumulative skin permeation of trantinterol. CONCLUSION In this study, by adopting both ionpair and permeation enhancer strategys, a drug-in-adhesive patch of trantinterol is successfully designed, and the molecular mechanism of ionpair and permeation enhancer is discussed from the two processes of release and percutaneous absorption. This study provides a reference for the development of trantinterol transdermal patch.