Patent ID: 7883719

Claim:
A patch comprising a backing layer and an adhesive layer disposed on the backing layer, the adhesive layer consisting of an adhesive agent; oxybutynin and/or a pharmaceutically acceptable salt thereof; one or more pharmaceutically acceptable excipient selected from the group consisting of an organic acid, a skin permeation enhancer, an absorption enhancer, a plasticizer, a tackifier, an antioxidant, a filler and an ultraviolet absorber; 1-5% by weight of a 2-ethylhexyl acrylate-vinyl acetate copolymer based on the total weight of the adhesive agent, the 2-ethylhexyl acrylate-vinyl acetate copolymer being substantially free of both carboxyl groups and hydroxyl groups in the molecule; and 10-25% by weight of a styrene-isoprene-styrene block copolymer based on the total weight of the adhesive agent, wherein the weight ratio of the 2-ethylhexyl acrylate-vinyl acetate copolymer to the styrene-isoprene-styrene block copolymer is from 1:4 to 1:19.