A method for producing a patch comprising a support layer and an adhesive agent layer arranged 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, an acrylic-based polymer and a rubber-based polymer as an adhesive base agent, liquid paraffin, an organic acid, and an alicyclic saturated hydrocarbon resin as a tackifier; a step B of heating the adhesive agent layer composition at a temperature in a range from a melting point (°C) of the drug to a temperature higher than the melting point by 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 rate of temperature drop of 1 to 20°C/hour, thereby obtaining the adhesive agent layer comprising the drug at a supersaturated concentration in a dissolved form, wherein the content of the oxybutynin and the pharmaceutically acceptable salt thereof in the adhesive agent layer composition in terms of free oxybutynin is an amount which results in 10 to 50% by mass in the obtained adhesive agent layer, the adhesive agent layer composition comprises the acrylic-based polymer and the rubber-based polymer at a mass ratio (a mass of the acrylic-based polymer:a mass of the rubber-based polymer) of 1:4 to 1:19, the content of the acrylic-based polymer in the adhesive agent layer composition is an amount which results in 0.5 to 10% by mass in the obtained adhesive agent layer, the content of the rubber-based polymer in the adhesive agent layer composition is an amount which results in 5 to 40% by mass in the obtained adhesive agent layer, the content of the organic acid in the adhesive agent layer composition is an amount which results in 0.01 to 20% by mass in the obtained adhesive agent layer, the content of the alicyclic saturated hydrocarbon resin in the adhesive agent layer composition is an amount which results in 10 to 60% by mass in the obtained adhesive agent layer, the mass ratio of the oxybutynin and the pharmaceutically acceptable salt thereof to the liquid paraffin (a mass in terms of free oxybutynin:a mass of liquid paraffin) is 0.5:1 to 1.2:1 in the adhesive agent layer composition, and the mass ratio of the total mass of the acrylic-based polymer and the rubber-based polymer to the mass of the alicyclic saturated hydrocarbon resin in the adhesive agent layer composition is 1:1 to 1:3. 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, an acrylic-based polymer and a rubber-based polymer as an adhesive base agent, liquid paraffin, an organic acid, and an alicyclic saturated hydrocarbon resin as a tackifier; at least one selected from the group consisting of oxybutynin and a pharmaceutically acceptable salt thereof as a drug, an acrylic-based polymer and a rubber-based polymer as an adhesive base agent, liquid paraffin, an organic acid, and an alicyclic saturated hydrocarbon resin as a tackifier; a step B of heating the adhesive agent layer composition at a temperature in a range from a melting point (°C) of the drug to a temperature higher than the melting point by 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 rate of temperature drop of 1 to 20°C/hour, thereby obtaining the adhesive agent layer comprising the drug at a supersaturated concentration in a dissolved form, wherein the content of the oxybutynin and the pharmaceutically acceptable salt thereof in the adhesive agent layer composition in terms of free oxybutynin is an amount which results in 10 to 50% by mass in the obtained adhesive agent layer, the adhesive agent layer composition comprises the acrylic-based polymer and the rubber-based polymer at a mass ratio (a mass of the acrylic-based polymer:a mass of the rubber-based polymer) of 1:4 to 1:19, the content of the acrylic-based polymer in the adhesive agent layer composition is an amount which results in 0.5 to 10% by mass in the obtained adhesive agent layer, the content of the rubber-based polymer in the adhesive agent layer composition is an amount which results in 5 to 40% by mass in the obtained adhesive agent layer, the content of the organic acid in the adhesive agent layer composition is an amount which results in 0.01 to 20% by mass in the obtained adhesive agent layer, the content of the alicyclic saturated hydrocarbon resin in the adhesive agent layer composition is an amount which results in 10 to 60% by mass in the obtained adhesive agent layer, the mass ratio of the oxybutynin and the pharmaceutically acceptable salt thereof to the liquid paraffin (a mass in terms of free oxybutynin:a mass of liquid paraffin) is 0.5:1 to 1.2:1 in the adhesive agent layer composition, and the mass ratio of the total mass of the acrylic-based polymer and the rubber-based polymer to the mass of the alicyclic saturated hydrocarbon resin in the adhesive agent layer composition is 1:1 to 1:3.