Fentanyl-containing patch for external use

An external patch consisting essentially of an adhesive layer laminated on a support,

• wherein said adhesive layer consists essentially of:
• a styrene-isoprene-styrene block copolymer (SIS) base component;
• a tackifier component, wherein the tackifier component consists essentially of a hydrogenated rosin glycerol ester and an alicyclic saturated hydrocarbon resin;
• a softening component consisting of poly-butene and liquid paraffin;
• a fatty acid ester component, wherein the fatty acid ester component is isopropyl myristate;
• fentanyl;
• and
• optionally one or more ingredients selected from the group consisting of polyvinylpyrrolidone, polyvinylpyrrolidone/vinyl acetate copolymers, titanium dioxide, silica species, and dibutylhydroxytoluene,
• wherein:
• (1) the amount of said rosin resin is 1 to 5 times as much as the amount by weight of fentanyl,
• (2) the amount of said rosin resin is 0.1 to 0.6 times as much as the total amount by weight of the tackifier component,
• (3) the amount of said tackifier component is 30 to 60% by weight based upon the total amount of components in the adhesive layer,
• (4) the ratio by weight of liquid paraffin to poly-butene is 11:10 to 3:1, and
• (5) the amount of said styrene-isoprene-styrene block copolymer (SIS) base component is 10 to 30% by weight, the amount of said softening component is 5 to 40% by weight, the amount of said fatty acid ester component is 1 to 20% by weight, and the amount of said fentanyl is 0.1 to 10% by weight, based upon the total amount of components in the adhesive layer.