[Problem] The purpose of the present invention is to provide a formulation technique for improving the percutaneous absorption of diclofenac and/or a pharmaceutically acceptable salt thereof with respect to a pharmaceutical composition for external application, which contains diclofenac and/or a pharmaceutically acceptable salt thereof. [Solution] A pharmaceutical composition for external application, which contains a monoterpene and lactic acid and/or a salt thereof together with diclofenac and/or a pharmaceutically acceptable salt thereof exhibits dramatically improved percutaneous absorption of diclofenac and/or a pharmaceutically acceptable salt thereof. In addition, by having this pharmaceutical composition for external application additionally contain a polar oil, the percutaneous absorption of diclofenac and/or a pharmaceutically acceptable salt thereof is further improved.
