Method for producing a patch comprising a support layer and an adhesive agent layer disposed on at least one surface of the support layer, the method comprising: a step A of obtaining an adhesive agent layer composition comprising: at least one selected from the group consisting of oxybutynin and a pharmaceutically acceptable salt thereof as a drug, a polymer based on acrylic material and a rubber based polymer as an adhesive base agent, liquid paraffin, an organic acid, and an alicyclic saturated hydrocarbon resin as a tack agent； a step B of heating the adhesive agent layer composition at a temperature in a range from the melting point (° C) of the drug to a temperature greater than the melting point at 10 ° C for 2 to 24 hours； and a step C of cooling the heated adhesive agent layer composition to a temperature lower than the melting point of the drug at an average temperature decrease rate of 1 to 20 ° C / hour, thereby obtaining the layer of adhesive agent that It comprises the drug at a dissolved supersaturated concentration, in which the content of oxybutynin and the pharmaceutically acceptable salt thereof in the adhesive agent layer composition in terms of free oxybutynin is an amount that results in 10 to 50% by mass in the adhesive agent layer obtained, the adhesive agent layer composition comprises the polymer based on acrylic material and the rubber based polymer at a mass ratio (mass of the polymer based on acrylic material: mass of the polymer based in rubber) from 1: 4 to 1:19, the polymer content based on acrylic material in the adhesive agent layer composition is an amount that gives co As a result of 0.5 to 10% by mass in the adhesive agent layer obtained, the content of the rubber-based polymer in the adhesive agent layer composition is an amount that results in 5 to 40% by mass in the adhesive layer obtained, the content of the organic acid in the adhesive agent layer composition is an amount that results in 0.01 to 20% by mass in the layer of a
