PURPOSE: To obtain an application agent, by extending a crosslinked hydrous gel prepared by dispersing diclofenac sodium and 1,3-butylene glycol on a support and capable of sustainedly and stably exhibiting effects of the diclofenac sodium.

CONSTITUTION: An application agent obtained by extending a crosslinked hydrous gel containing dispersed diclefenac sodium which is a nonsteroidal anti- inflammatory and analgesic actin and 1,3-butylene glycol, preferably containing CMC-Na, polyvinylpyrrolidone and gelatin coexisting in crosslinked polyacrylic acid. The ingredients are preferably blended in amounts based on the total plaster as follows. 0.2W4wt% diclofenac sodium, 2.0W20wt% 1,3-butylene glycol and 30W80wt% crosslinked hydrous gel. The above-mentioned application agent has excellent self-adhesive property to affected parts without remaining therein on peeling.