Denki Kagaku Kogyo Kabushiki Kaisha

Toshihiko Umeda

Kazuhiko Arai

Yoshiaki Miyata

Yasukazu Himeda

Teruzou Miyoshi

Hiroshi Kaneko

Osamu Yamamoto

Masamichi Hashimoto

Hironoshin Kitagawa

Akio Okamoto

Masatoshi Kawata

Kazuhiro Ohshima

A separate type medical material containing a hyaluronic acid ester derivative, which satisfies the storage stability of a hyaluronic acid ester derivative and avoidance of irritation and pain at the time of injecting a therapeutic agent for joints, is provided. A separate type medical material comprising liquid (A) which is an aqueous solution containing a hyaluronic acid ester derivative and buffered to a pH of from 4.5 to 6.5, and liquid (B) which is an aqueous solution having such a buffering power that when it is mixed with the liquid (A), the mixed liquid has a pH within a range of from 6.8 to 7.8, kept separately from each other.

Separate type medical material

(1) A tissue-covering medical material which comprises a soluble cellulose derivative having been made hardly soluble in water, which is used with a purpose of being embedded in the body or applied to the tissue, and (2) a method for producing the tissue-covering medical material as defined in (1), which comprises, as a method to make a soluble cellulose derivative hardly soluble in water, freezing and thawing an acidic solution of the soluble cellulose derivative, are provided.

Use of soluble cellulose derivative having been made hardly soluble in water and process for producing the same

Production of a hyaluronic acid gel, which comprises keeping hyaluronic acid in water at a hyaluronic acid concentration of at least 5 wt % in the presence of an acid component in an amount at least equimolar with the carboxyl groups in the hyaluronic acid.

Hyaluronic acid gel, process for producing the same, and medical material containing the same

A hyaluronic acid gel composition comprising hyaluronic acid and a polymer, which is substantially unmodified with a chemical cross-linking agent or a chemical modifying agent and which has a percentage dissolution of hyaluronic acid of 50% or lower in 12 hours in a neutral aqueous solution of 37&deg; C.

Hyaluronic acid gel composition, process for producing the same, and medical material containing the same

A gel made of hyaluronic acid alone which is hardly soluble in a neutral aqueous solution and has fluidity enough to be easily ejectable from an injector.

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Tokyo, Japan

Toshihiko Umeda