A pharmaceutical composition for relieving pain in a jointdisease, including a hyaluronic acid and a pharmaceuticallyacceptable carrier, in which the hyaluronic acid is cross-linkedby cyclizing a double bond in the moiety of a cinnamic acid ina partially amidated hyaluronic acid represented by Formula (1):[Ar-CH=CH-COO-(CH2)n-NH-]m-HA, to form a cycloubutane ring, inwhich Ar represents an optionally substituted phenyl group, nrepresents an integer of 2 or 3, HA represents a carboxy residueof the hyaluronic acid, and m represents an amidation ratio ofthe hyaluronic acid to the total carboxyl group and is in the rangeof 3 to 50% relative to the total carboxyl group is taught.The pharmaceutical composition is an intra-articularformulation that exerts rapid analgesic effects afteradministration, and shows extremely long durable effects for ahuman joint disease with only a single administration rather thanmultiple administrations of a conventional way.
