Provided is a pharmaceutical composition comprising a cross-linked hyaluronic acid and a pharmaceutical acceptable carrier for inhibiting pain of joint disease. The cross-linked hyaluronic acid is obtained by cyclizing the double bond of the cinnamic acid moiety of the partially amidated hyaluronic acid represented by the following formula (1): [Ar-CH=CH-COO-(CH2)n-NH-]m-HA (1) (wherein, Ar represents an optionally substituted phenyl group, n represents 2 or 3, HA represents the carboxyl residue of hyaluronic acid, m represents the ratio of amidated carboxy group to total carboxyl group of hyaluronic acid, m is 3 to 50% of total carboxyl group).The pharmaceutical composition of this invention is a medicine administrated to joint, exhibiting analgesic effect rapidly after administration, and only one administration being able to maintain an extremely long period of the effect to human joint disease, comparing to the conventional several times administration.本發明係關於一種關節疾病之疼痛抑制用醫藥組成物,係包含經交聯之玻尿酸、及製藥上所容許之載體而構成者;該經交聯之玻尿酸係使下述通式(1)所表示之部分醯胺化玻尿酸之桂皮酸部分之雙鍵經環化形成環丁烷環而交聯者;[Ar-CH=CH-COO-(CH2)n-NH-]m-HA (1)(式中,Ar表示亦可具有取代基之苯基,n表示2或3,HA表示玻尿酸之羧基殘基,m表示對於玻尿酸之總羧基之醯胺化比例,m為總羧基的3至50%)。本發明之醫藥組成物為一種關節內投與製劑,其於投與後可迅速發揮鎮痛效果,且僅以1次投與而非以往之複數次投與的方式,即對人類關節疾病持續極長時間的效果。
