To produce a hydrogel material suppressing rapid increase of an agent concentration which occurs immediately after administration and slowly releasing the agent over a long time from the interior of gel.
The hydrogel material capable of slowly releasing the agent is produced by (a) a step for obtaining the hydrogel material composed of a mixed monomer solution containing a monomer having a functional group capable of forming a physical crosslinking structure with a metallic ion having a divalent or higher valency as a polymerization component, (b) a step for incorporating a target agent into the hydrogel material and (c) a step for adding the metallic ion having a divalent or higher valency thereto and carrying the target agent by the physical crosslinking structure formed between the metallic ion and the functional group.
Kei Saki
Fumio Akiyama
Hiromu Tanaka