JP2004123672A

JP2004123672A - Peroral therapeutic or prophylactic agent for liver disease

Info

Publication number: JP2004123672A
Application number: JP2002293906A
Authority: JP
Inventors: Hideyuki Yamato; 大和　英之; Satoshi Mihashi; 三橋　智; Michihito Ise; 伊勢　道仁
Original assignee: Kureha Corp
Current assignee: Kureha Corp
Priority date: 2002-10-07
Filing date: 2002-10-07
Publication date: 2004-04-22
Anticipated expiration: 2022-10-07
Also published as: JP4311923B2

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a peroral therapeutic or prophylactic agent for liver diseases having excellent selective absorption property for toxic substances and useful substances. <P>SOLUTION: This peroral therapeutic or prophylactic agent for liver diseases comprises a porous spherical carbonaceous substance having 0.01-1 mm diameter, ≥700 m<SP>2</SP>/g specific surface area obtained by a BET method, having ≥0.04 and <0.10 mL/g pore volume of 20-1,500 nm pore diameter, having 0.30-1.20 meq/g total acidic group and 0.20-1.00 meq/g total basic group as an active ingredient. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、経口投与用肝疾患治療又は予防剤に関する。本発明による経口投与用肝疾患治療又は予防剤は、特定範囲の細孔容積を有する多孔性球状炭素質物質を有効成分として含有し、経口服用した場合に、消化酵素等の体内の有益成分の吸着性が少ないにもかかわらず、有毒な毒性物質（Ｔｏｘｉｎ）の消化器系内における吸着性能が優れるという特性を有する。従って、肝疾患者に対して経口的に服用させると、顕著な治癒効果を示す。
【０００２】
【従来の技術】
腎機能や肝機能の欠損患者らは、それらの臓器機能障害に伴って、血液中等の体内に有害な毒性物質が蓄積したり生成したりするので、尿毒症や意識障害等の脳症をひきおこす。これらの患者数は年々増加する傾向を示しているため、これら欠損臓器に代わって毒性物質を体外へ除去する機能をもつ臓器代用機器或いは治療薬の開発が重要な課題となっている。現在、人工腎臓としては、血液透析による有毒物質の除去方式が最も普及している。しかしながら、このような血液透折型人工腎臓では、特殊な装置を用いるために、安全管理上から専門技術者を必要とし、また血液の体外取出しによる患者の肉体的、精神的及び経済的負担が高いなどの欠点を有していて、必ずしも満足すべきものではない。
【０００３】
近年、これらの欠点を解決する手段として、経口的な服用が可能で、腎臓や肝臓の機能障害を治療することができる経口吸着剤が注目されている。具体的には、特公昭６２−１１６１１号公報（特許文献１）に記載の吸着剤は、特定の官能基を有する多孔性球状炭素質物質からなり、生体に対する安全性や安定性が高く、同時に腸内での胆汁酸の存在下でも有毒物質の吸着性に優れ、しかも、消化酵素等の腸内有益成分の吸着が少ないという有益な選択吸着性を有し、また、便秘等の副作用の少ない経口治療薬として、例えば、肝腎機能障害患者に対して広く臨床的に利用されている。
【０００４】
【特許文献１】
特公昭６２−１１６１１号公報
【０００５】
【発明が解決しようとする課題】
しかしながら、本発明者は、前記の多孔性球状炭素質物質からなる経口吸着剤よりも一層優れた選択的吸着性を示す経口吸着剤の探求を進めていたところ、驚くべきことに、特定範囲の細孔容積を有する多孔性球状炭素質物質は、腎臓病での毒性物質であるβ−アミノイソ酪酸の吸着性に優れているにもかかわらず、有益物質である消化酵素（例えば、α−アミラーゼ）等に対する吸着性が、前記特公昭６２−１１６１１号公報に記載の吸着剤よりも少ないという優れた選択吸着性を有することを見出した。
更に、本発明者が新たに見出した多孔性球状炭素質物質は、前記特公昭６２−１１６１１号公報に記載の吸着剤と同様に、便秘等の副作用が少なく、優れた経口肝疾患治療薬としての作用も示すことが分かった。
本発明はこうした知見に基づくものである。
【０００６】
【課題を解決するための手段】
従って、本発明は、直径が０．０１〜１ｍｍであり、ＢＥＴ法により求められる比表面積が７００ｍ^２／ｇ以上であり、細孔直径２０〜１５０００ｎｍの細孔容積が０．０４ｍＬ／ｇ以上で０．１０ｍＬ／ｇ未満であり、全酸性基が０．３０〜１．２０ｍｅｑ／ｇであり、全塩基性基が０．２０〜１．００ｍｅｑ／ｇである多孔性球状炭素質物質を有効成分として含有する、経口投与用肝疾患治療又は予防剤に関する。
【０００７】
【発明の実施の形態】
本発明による経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質は、前記のとおり、特定範囲の細孔容積を有する。すなわち、細孔直径２０〜１５０００ｎｍの細孔容積が０．０４ｍＬ／ｇ以上で０．１０ｍＬ／ｇ未満である。一方、前記特公昭６２−１１６１１号公報には、細孔半径１００〜７５０００オングストロームの空隙容積（すなわち、細孔直径２０〜１５０００ｎｍの細孔容積）が０．１〜１ｍＬ／ｇの多孔性球状炭素質物質からなる吸着剤が記載されており、胆汁酸中で、肝性脳症原因物質であるオクトパミンやα−アミノ酪酸、更に腎臓病での毒性物質及びその前躯体であるジメチルアミン、β−アミノイソ酪酸、アスパラギン酸、あるいはアルギニン等の水溶性の塩基性及び両性物質の吸着性に優れており、しかも有益物質である消化酵素等に対する吸着性は少ないことが記載されている。また、前記特公昭６２−１１６１１号公報の実施例１〜３では、細孔半径３７．５〜７５０００オングストロームの空隙容積が０．２０〜０．２３ｍＬ／ｇの吸着剤が実際に調製されており、β−アミノイソ酪酸、γ−アミノ−ｎ−酪酸、ジメチルアミン、及びオクトパミンの吸着性に優れていることが実際に確認されている。
【０００８】
これに対し、本発明者が見出したところによると、本明細書の実施例に示すとおり、細孔直径２０〜１５０００ｎｍの細孔容積を０．０４ｍＬ／ｇ以上で０．１０ｍＬ／ｇ未満に調整すると、毒性物質であるβ−アミノイソ酪酸に対する高い吸着特性を維持しつつ、有益物質であるα−アミラーゼに対する吸着特性が有意に低下する。多孔性球状炭素質吸着剤の細孔直径２０〜１５０００ｎｍの細孔容積が大きくなればなるほど消化酵素等の有益物質の吸着が起こりやすくなるため、有益物質の吸着を少なくする観点からは、前記細孔容積は小さいほど好ましい。しかしながら、一方で、細孔容積が小さすぎると毒性物質の吸着量も低下する。従って、経口投与用吸着剤においては、毒性物質の吸着量（Ｔ）の有益物質の吸着量（Ｕ）に対する比（Ｔ／Ｕ）、すなわち、選択吸着率が重要である。例えば、多孔性球状炭素質物質の選択吸着率を、ＤＬ−β−アミノイソ酪酸（毒性物質）の吸着量（Ｔｂ）のα−アミラーゼ（有益物質）の吸着量（Ｕａ）に対する比（Ｔｂ／Ｕａ）として評価することができる。すなわち、選択吸着率は、例えば、以下の式：
Ａ＝Ｔｂ／Ｕａ
（ここで、Ａは選択吸着率であり、ＴｂはＤＬ−β−アミノイソ酪酸の吸着量であり、Ｕａはα−アミラーゼの吸着量である）
によって評価することができる。
本発明の経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質吸着剤は、細孔直径２０〜１５０００ｎｍの細孔容積が０．０４ｍＬ／ｇ以上で０．１０ｍＬ／ｇ未満の範囲内で優れた選択吸着率を示し、前記細孔容積が０．０５ｍＬ／ｇ以上で０．１０ｍＬ／ｇ未満の範囲内で一層優れた選択吸着率を示す。
【０００９】
本発明による経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質は、直径が０．０１〜１ｍｍである。多孔性球状炭素質物質の直径が０．０１ｍｍ未満になると、多孔性球状炭素質物質の外表面積が増加し、消化酵素等の有益物質の吸着が起こり易くなるので好ましくない。また、直径が１ｍｍを越えると、多孔性球状炭素質物質内部への毒性物質の拡散距離が増加し、吸着速度が低下するので好ましくない。直径は、好ましくは０．０２〜０．８ｍｍである。なお、本明細書で「直径がＤｌ〜Ｄｕである」という表現は、ＪＩＳＫ　１４７４に準じて作成した粒度累積線図（平均粒子径の測定方法に関連して後で説明する）において、ふるいの目開きＤｌ〜Ｄｕの範囲に対応するふるい通過百分率（％）が９０％以上であることを意味する。
【００１０】
本発明による経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質は、ＢＥＴ法により求められる比表面積（以下「ＳＳＡ」と省略することがある）が７００ｍ^２／ｇ以上である。ＳＳＡが７００ｍ^２／ｇより小さい多孔性球状炭素質物質では、毒性物質の吸着性能が低くなるので好ましくない。ＳＳＡは、好ましくは８００ｍ^２／ｇ以上である。ＳＳＡの上限は特に限定されるものではないが、嵩密度及び強度の観点から、ＳＳＡは、２５００ｍ^２／ｇ以下であることが好ましい。
【００１１】
更に、本発明の経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質では、官能基の構成において、全酸性基が０．３０〜１．２０ｍｅｑ／ｇであり、全塩基性基が０．２０〜１．００ｍｅｑ／ｇである。官能基の構成において、全酸性基が０．３０〜１．２０ｍｅｑ／ｇであり、全塩基性基が０．２０〜１．００ｍｅｑ／ｇの条件を満足しない多孔性球状炭素質物質では、上述した有毒物質の吸着能が低くなるので好ましくない。官能基の構成において、全酸性基は０．３０〜１．００ｍｅｑ／ｇであることが好ましく、全塩基性基は０．３０〜０．６０ｍｅｑ／ｇであることが好ましい。本発明の経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質では、その官能基の構成は、全酸性基が０．３０〜１．２０ｍｅｑ／ｇ、全塩基性基が０．２０〜１．００ｍｅｑ／ｇ、フェノール性水酸基が０．２０〜０．７０ｍｅｑ／ｇ、及びカルボキシル基が０．１５ｍｅｑ／ｇ以下の範囲にあり、且つ全酸性基（ａ）と全塩基性基（ｂ）との比（ａ／ｂ）が０．４０〜２．５であり、全塩基性基（ｂ）とフェノール性水酸基（ｃ）とカルボキシル基（ｄ）との関係〔（ｂ＋ｃ）−ｄ〕が０．６０以上であることが好ましい。
【００１２】
本発明の経口投与用肝疾患治療又は予防剤の有効成分の有効成分として用いる多孔性球状炭素質物質は、例えば、以下の方法によって製造することができる。最初に、石油ピッチ又は石炭ピッチ等のピッチに対し、添加剤として、沸点２００℃以上の２環式又は３環式の芳香族化合物又はその混合物を加えて加熱混合した後、成形してピッチ成形体を得る。なお、前記の多孔性球状炭素質物質は経口投与用であるので、その原料も、安全上充分な純度を有し、且つ品質的に安定であることが必要である。
【００１３】
次に、７０〜１８０℃の熱水中で、前記のピッチ成形体を撹拌下に分散造粒して微小球体化する。更に、ピッチに対して低溶解度を有し、かつ前記添加剤に対して高溶解度を有する溶剤で、ピッチ成形体から添加剤を抽出除去し、得られた多孔性ピッチを、酸化剤を用いて酸化すると、熱に対して不融性の多孔性ピッチが得られる。こうして得られた不融性多孔性ピッチを、更に炭素と反応性を有する気流（例えば、スチーム又は炭酸ガス）中で、８００〜１０００℃の温度で処理すると、多孔性炭素質物質を得ることができる。
【００１４】
こうして得られた多孔性炭素質物質を、続いて、酸素含有量０．１〜５０ｖｏｌ％（好ましくは１〜３０ｖｏｌ％、特に好ましくは３〜２０ｖｏｌ％）の雰囲気下、３００〜８００℃（好ましくは３２０〜６００℃）の温度で酸化処理し、更に８００〜１２００℃（好ましくは８００〜１０００℃）の温度下、非酸化性ガス雰囲気下で加熱反応による還元処理をすることにより、本発明の経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質を得ることができる。
【００１５】
前記の製造方法において、特定量の酸素を含有する雰囲気としては、純粋な酸素、酸化窒素又は空気等を酸素源として用いることができる。また、炭素に対して不活性な雰囲気としては、例えば、窒素、アルゴン、又はへリウム等を単独で用いるか、あるいはそれらの混合物を用いることができる。
【００１６】
前記の原料ピッチに対して、芳香族化合物を添加する目的は、原料ピッチの軟化点を降下させることにより流動性を向上させて微小球体化を容易にすること及び成形後のピッチ成形体からその添加剤を抽出除去させることにより成形体を多孔質とし、その後の工程の酸化による炭素質材料の構造制御並びに焼成を容易にすることにある。このような添加剤としては、例えば、ナフタレン、メチルナフタレン、フェニルナフタレン、ベンジルナフタレン、メチルアントラセン、フェナンスレン、又はビフェニル等を単独で、又はそれらの２種以上の混合物を用いることができる。ピッチに対する添加量は、ピッチ１００重量部に対し芳香族化合物１０〜５０重量部の範囲が好ましい。
【００１７】
ピッチと添加剤との混合は、均一な混合を達成するために、加熱して溶融状態で行うのが好ましい。ピッチと添加剤との混合物は、得られる多孔性球状炭素質の粒径（直径）を制御するため、粒径約０．０１〜１ｍｍの粒子に成形することが好ましい。成形は溶融状態で行ってもよく、また混合物を冷却後に粉砕する等の方法によってもよい。
ピッチと添加剤との混合物から添加剤を抽出除去するための溶剤としては、例えば、ブタン、ペンタン、ヘキサン、又はヘプタン等の脂肪族炭化水素、ナフサ、又はケロシン等の脂肪族炭化水素を主成分とする混合物、あるいはメタノール、エタノール、プロパノール、又はブタノール等の脂肪族アルコール類等が好適である。
このような溶剤でピッチと添加剤との混合物成形体から添加剤を抽出することによって、成形体の形状を維持したまま、添加剤を成形体から除去することができる。この際に、成形体中に添加剤の抜け穴が形成され、均一な多孔性を有するピッチ成形体が得られるものと推定される。
なお、添加剤の抜け穴サイズ（すなわち、細孔容積）の制御は、常法、例えば、添加剤の量、ピッチ成形体の微小球体化工程における添加剤の析出温度（冷却温度）を制御することによって実施することができる。また、添加剤の抽出により生成した細孔容積は不融化条件によっても影響を受ける。例えば、不融化処理が強ければ熱処理による熱収縮が小さくなり、添加剤の抽出により得られた細孔が維持されやすい傾向にある。
【００１８】
こうして得られた多孔性ピッチ成形体を、次いで不融化処理、すなわち酸化剤を用いて、好ましくは常温から３００℃までの温度で酸化処理することにより、熱に対して不融性の多孔性不融性ピッチ成形体を得ることができる。ここで用いる酸化剤としては、例えば、酸素ガス（Ｏ_２）、あるいは酸素ガス（Ｏ_２）を空気や窒素等で希釈した混合ガスを挙げることができる。
【００１９】
本発明の経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質が有する各物性値、すなわち、平均粒子径、比表面積、細孔容積、全酸性基、及び全塩基性基は、以下の方法によって測定する。
（１）平均粒子径
多孔性球状炭素質物質についてＪＩＳ　Ｋ　１４７４に準じて粒度累積線図を作成する。平均粒子径は、粒度累積線図において、横軸の５０％の点の垂直線と粒度累積線との交点から、横軸に水平線を引いて交点の示すふるいの目開き（ｍｍ）を求めて、平均粒子径とする。
【００２０】
（２）比表面積
連続流通式のガス吸着法による比表面積測定器（例えば、ＭＩＣＲＯＭＥＲＩＴＩＣＳ社製「Ｆｌｏｗ　Ｓｏｒｂ　ＩＩ　２３００」）を用いて、多孔性球状炭素質物質試料のガス吸着量を測定し、ＢＥＴの式により比表面積を計算することができる。具体的には、試料である多孔性球状炭素質物質を試料管に充填し、その試料管に窒素３０ｖｏｌ％を含有するヘリウムガスを流しながら以下の操作を行い、多孔性球状炭素質物質試料への窒素吸着量を求める。すなわち、試料管を−１９６℃に冷却し、多孔性球状炭素質物質試料に窒素を吸着させる。次に、試料管を室温に戻す。このとき多孔性球状炭素質物質試料から脱離してくる窒素量を熱伝導度型検出器で測定し、吸着ガス量（ｖ）とする。
ＢＥＴの式から誘導された近似式：
ｖ_ｍ＝１／（ｖ・（１−ｘ））
を用いて液体窒素温度における、窒素吸着による１点法（相対圧力ｘ＝０．３）によりｖ_ｍを求め、次式：
比表面積＝４．３５×ｖ_ｍ（ｍ^２／ｇ）
により試料の比表面積を計算する。前記の各計算式で、ｖ_ｍは試料表面に単分子層を形成するのに必要な吸着量（ｃｍ^３／ｇ）であり、ｖは実測される吸着量（ｃｍ^３／ｇ）であり、ｘは相対圧力である。
【００２１】
（３）水銀圧入法による細孔容積
水銀ポロシメーター（例えば、ＭＩＣＲＯＭＥＲＩＴＩＣＳ社製「ＡＵＴＯＰＯＲＥ　９２００」）を用いて細孔容積を測定することができる。試料である多孔性球状炭素質物質を試料容器に入れ、２．６７Ｐａ以下の圧力で３０分間脱気する。次いで、水銀を試料容器内に導入し、徐々に加圧して水銀を多孔性球状炭素質物質試料の細孔へ圧入する（最高圧力＝４１４ＭＰａ）。このときの圧力と水銀の圧入量との関係から以下の各計算式を用いて多孔性球状炭素質物質試料の細孔容積分布を測定する。
具体的には、細孔直径１５μｍに相当する圧力（０．０７ＭＰａ）から最高圧力（４１４ＭＰａ：細孔直径３ｎｍ相当）までに多孔性球状炭素質物質試料に圧入された水銀の体積を測定する。細孔直径の算出は、直径（Ｄ）の円筒形の細孔に水銀を圧力（Ｐ）で圧入する場合、水銀の表面張力を「γ」とし、水銀と細孔壁との接触角を「θ」とすると、表面張力と細孔断面に働く圧力の釣り合いから、次式：
−πＤγｃｏｓθ＝π（Ｄ／２）^２・Ｐ
が成り立つ。従って
Ｄ＝（−４γｃｏｓθ）／Ｐ
となる。
本明細書においては、水銀の表面張力を４８４ｄｙｎｅ／ｃｍとし、水銀と炭素との接触角を１３０度とし、圧力ＰをＭＰａとし、そして細孔直径Ｄをμｍで表示し、下記式：
Ｄ＝１．２７／Ｐ
により圧力Ｐと細孔直径Ｄの関係を求める。本発明における細孔直径２０〜１５０００ｎｍの範囲の細孔容積とは、水銀圧入圧０．０７ＭＰａから６３．５ＭＰａまでに圧入された水銀の体積に相当する。
【００２２】
（４）全酸性基
０．０５規定のＮａＯＨ溶液５０ｍＬ中に、２００メッシュ以下に粉砕した多孔性球状炭素質物質試料１ｇを添加し、４８時間振とうした後、多孔性球状炭素質物質試料をろ別し、中和滴定により求められるＮａＯＨの消費量である。
【００２３】
（５）全塩基性基
０．０５規定のＨＣｌ溶液５０ｍＬ中に、２００メッシュ以下に粉砕した多孔性球状炭素質物質試料１ｇを添加し、２４時間振とうした後、多孔性球状炭素質物質試料をろ別し、中和滴定により求められるＨＣｌの消費量である。
【００２４】
本発明の経口投与用肝疾患治療又は予防剤の有効成分として用いる多孔性球状炭素質物質は、前記のように両イオン性基（すなわち、酸性基及び塩基性基）を有し、且つ腸内での毒性物質の選択吸着性に優れているので、肝疾患の治療用又は予防用経口投与用吸着剤として用いることができる。
肝疾患としては、例えば、劇症肝炎、慢性肝炎、ウイルス性肝炎、アルコール性肝炎、肝線維症、肝硬変、肝癌、自己免疫性肝炎、薬剤アレルギー性肝障害、原発性胆汁性肝硬変、振せん、脳症、代謝異常、又は機能異常を挙げることができる。その他、体内に存在する有害物質による病気、すなわち、精神病等の治療にも用いることができる。
【００２５】
本発明による経口投与用肝疾患治療又は予防剤の投与量は、投与対象がヒトであるかあるいはその他の動物であるかにより、また、年令、個人差、又は病状などに影響されるので、場合によっては下記範囲外の投与量が適当なこともあるが、一般にヒトを対象とする場合の経口投与量は１日当り１〜２０ｇを３〜４回に分けて服用し、更に症状によって適宜増減することができる。投与形態は、散剤、顆粒、錠剤、糖衣錠、カプセル剤、懸濁剤、スティック剤、分包包装体、又は乳剤等であることができる。カプセル剤として服用する場合は、通常のゼラチンの他に、必要に応じて腸溶性のカプセルを用いることもできる。錠剤として用いる場合は、体内でもとの微小粒体に解錠されることが必要である。更に他の薬剤であるアルミゲルやケイキサレートなどの電解質調節剤と配合した複合剤の形態で用いることもできる。
【００２６】
【実施例】
以下、実施例によって本発明を具体的に説明するが、これらは本発明の範囲を限定するものではない。
以下の実施例において、α−アミラーゼ吸着試験及びＤＬ−β−アミノイソ酪酸吸着試験は以下の方法で実施し、選択吸着率は以下の方法で計算した。
（１）α−アミラーゼ吸着試験
多孔性球状炭素質物質試料を乾燥した後、乾燥試料０．１２５ｇを正確に量って共栓付三角フラスコにとる。一方、α−アミラーゼ（液化型）０．１００ｇを正確に秤量して、ｐＨ７．４のリン酸塩緩衝液を加えて溶かし、正確に１０００ｍＬとした液（原液）５０ｍＬを、前記の共栓付三角フラスコに正確に加え、３７±１℃で３時間振り混ぜる。フラスコの内容物をろ孔０．６５μｍのメンブランフィルターで吸引ろ過し、はじめのろ液約２０ｍＬを除き、つぎのろ液約１０ｍＬを取って試料溶液とする。
一方、ｐＨ７．４のリン酸塩緩衝液を用いて同じ操作を行い、そのろ液を補正液とする。試料溶液及び補正液につき、ｐＨ７．４のリン酸塩緩衝液を対照とし、吸光度測定法により試験を行い、波長２８２ｎｍにおける吸光度を測定する。試料溶液の吸光度と補正液の吸光度の差を試験吸光度とする。
【００２７】
検量線はα−アミラーゼ原液を０ｍＬ、２５ｍＬ、５０ｍＬ、７５ｍＬ、及び１００ｍＬの量でメスフラスコに正確に分取し、ｐＨ７．４リン酸塩緩衝液で１００ｍＬにメスアップして波長２８２ｎｍにおける吸光度を測定することにより作成した。
試験吸光度と検量線より、α−アミラーゼ残存量（ｍｇ／ｄＬ）を計算した。多孔性球状炭素質物質試料の量の依存性を測定するため、多孔性球状炭素質物質試料の量を０．５００ｇとし、上記方法と同様の方法で試験吸光度を測定し、α−アミラーゼ残存量を計算した。
【００２８】
（２）ＤＬ−β−アミノイソ酪酸吸着試験
多孔性球状炭素質物質試料を乾燥した後、乾燥試料２．５００ｇを正確に量って共栓付三角フラスコにとる。一方、ＤＬ−β−アミノイソ酪酸０．１００ｇを正確に量り、ｐＨ７．４のリン酸塩緩衝液を加えて溶かし、正確に１０００ｍＬとした液（原液）５０ｍＬを、前記の共栓付三角フラスコに正確に加え、３７±１℃で３時間振り混ぜる。フラスコの内容物をろ孔０．６５μｍのメンブランフィルターで吸引ろ過し、はじめのろ液約２０ｍＬを除き、つぎのろ液約１０ｍＬを取って試料溶液とする。
試料溶液０．１ｍＬを試験管に正確に取り、ｐＨ８．０のリン酸塩緩衝液５ｍＬを正確に加えて混合した後、フルオレスカミン０．１００ｇを非水滴定用アセトン１００ｍＬに溶かした液１ｍＬを正確に加えて混合した後で、１５分間静置する。この液につき、蛍光光度法により試験を行い、励起波長３９０ｎｍ、及び蛍光波長４７５ｎｍで蛍光強度を測定する。
【００２９】
ＤＬ−β−アミノイソ酪酸原液を０ｍＬ、１５ｍＬ、５０ｍＬ、７５ｍＬ、及び１００ｍＬの量とｐＨ７．４リン酸塩緩衝液とで１００ｍＬにして攪拌し、ろ過し、ろ液０．１ｍＬを試験管に正確に取り、ｐＨ８．０のリン酸塩緩衝液５ｍＬを正確に加えて混合した後、フルオレスカミン０．１００ｇを非水滴定用アセトン１００ｍＬに溶かした液１ｍＬを正確に加えて混合した後で、１５分間静置する。これらの液につき、蛍光光度法により試験を行い、励起波長３９０ｎｍ、及び蛍光波長４７５ｎｍで蛍光強度を測定し、検量線を作成する。最後にＤＬ−β−アミノイソ酪酸の残存量（ｍｇ／ｄＬ）を上記検量線を用いて計算する。
多孔性球状炭素質物質試料の量の依存性を測定するため、多孔性球状炭素質物質試料の量を０．５００ｇとして上記方法と同様の方法で試験蛍光強度を測定し、ＤＬ−β−アミノイソ酪酸の残存量を計算した。
【００３０】
（３）選択吸着率
炭素質吸着剤の使用量が０．５００ｇの場合のα−アミラーゼ吸着試験におけるα−アミラーゼ残存量、及び同様に、炭素質吸着剤の使用量が０．５００ｇの場合のＤＬ−β−アミノイソ酪酸吸着試験におけるＤＬ−β−アミノイソ酪酸残存量のそれぞれのデータに基づいて、以下の計算式：
Ａ＝（１０−Ｔｒ）／（１０−Ｕｒ）
（ここで、Ａは選択吸着率であり、ＴｒはＤＬ−β−アミノイソ酪酸の残存量であり、Ｕｒはα−アミラーゼの残存量である）
から計算した。
【００３１】
【実施例１】
石油系ピッチ（軟化点＝２１０℃；キノリン不溶分＝１重量％以下；Ｈ／Ｃ原子比＝０．６３）６８ｋｇと、ナフタレン３２ｋｇとを、攪拌翼のついた内容積３００Ｌの耐圧容器に仕込み、１８０℃で溶融混合を行った後、８０〜９０℃に冷却して押し出し、紐状成形体を得た。次いで、この紐状成形体を直径と長さの比が約１〜２になるように破砕した。
０．２３重量％のポリビニルアルコール（ケン化度＝８８％）を溶解して９３℃に加熱した水溶液中に、前記の破砕物を投入し、攪拌分散により球状化した後、前記のポリビニルアルコール水溶液を水で置換することにより冷却し、２０℃で３時間冷却し、ピッチの固化及びナフタレン結晶の析出を行い、球状ピッチ成形体スラリーを得た。
大部分の水をろ過により除いた後、球状ピッチ成形体の約６倍重量のｎ−ヘキサンでピッチ成形体中のナフタレンを抽出除去した。このようにして得た多孔性球状ピッチを、流動床を用いて、加熱空気を通じながら、２３５℃まで昇温した後、２３５℃にて１時間保持して酸化し、熱に対して不融性の多孔性球状酸化ピッチを得た。
続いて、多孔性球状酸化ピッチを、流動床を用い、５０ｖｏｌ％の水蒸気を含む窒素ガス雰囲気中で９００℃で１７０分間賦活処理して多孔性球状活性炭を得、更にこれを流動床にて、酸素濃度１８．５ｖｏｌ％の窒素と酸素との混合ガス雰囲気下で４７０℃で３時間１５分間、酸化処理し、次に流動床にて窒素ガス雰囲気下で９００℃で１７分間還元処理を行い、多孔性球状炭素質物質、すなわち、経口投与用吸着剤を得た。この吸着剤を、本発明の経口投与用肝疾患治療又は予防剤として、以下の安全性確認試験例及び薬理試験例で使用した。
得られた炭素質材料の特性を表１及び表２に示す。
【００３２】
【実施例２】
多孔性球状酸化ピッチの賦活処理時間を８０分間としたこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び表２に示す。
【００３３】
【実施例３】
多孔性球状酸化ピッチの賦活処理時間を１２０分間としたこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び表２に示す。
【００３４】
【実施例４】
多孔性球状酸化ピッチの賦活処理時間を２４０分間としたこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び表２に示す。
【００３５】
【実施例５】
球状化ピッチの析出及びナフタレン結晶析出のための冷却水の温度を２５℃としたこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び表２に示す。
【００３６】
【比較例１】
多孔性球状酸化ピッチの賦活処理を行う代わりに、流動床にて窒素気流下で９０分間で９００℃まで昇温したこと、及び９００℃に達した後に放冷したこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び表２に示す。
【００３７】
【比較例２】
球状化ピッチの析出及びナフタレン結晶析出のための冷却水の温度を３０℃としたこと、及び多孔性球状ピッチを多孔性球状酸化ピッチとするための酸化処理温度を２６０℃としたこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び表２に示す。
【００３８】
【比較例３】
実施例１の多孔性球状炭素質物質を粉砕機にて平均粒子径２０μｍに粉砕し、粉末状多孔性炭素質物質とした。得られた炭素質材料の特性を表１及び表２に示す。
【００３９】
【比較例４】
多孔性球状活性炭の還元処理を行わないこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び表２に示す。
【００４０】
【比較例５】
多孔性球状活性炭の酸化処理及び還元処理を行わないこと以外は、実施例１に記載の方法を繰り返して、多孔性球状炭素質物質を得た。得られた炭素質材料の特性を表１及び媛に示す。
【００４１】
【比較例６】
比較のため、日本薬局方記載の「薬用炭」を使用し、同様の評価を行った。なお、前記「薬用炭」は粉末状である。得られた結果を表１及び表２に示す。
【表１】

表１中の細孔容積は、水銀圧入法により求めた細孔直径２０〜１５０００ｎｍの範囲の細孔容積に相当する。
【００４２】
【表２】

【００４３】
細孔容積以外の特性や製造方法が類似している実施例１〜５及び比較例１〜２の７種類の炭素質吸着剤について、選択吸着率と炭素質吸着剤の細孔容積との関係を図１に示す。図１より、細孔容積が０．０４〜０．１０ｍＬ／ｇの範囲の炭素質吸着剤が、優れた選択吸着率を示すことがわかる。
また、表２及び図１より、本発明の経口投与用肝疾患治療又は予防剤の有効成分として用いることのできる多孔性球状炭素質吸着剤は選択吸着率が優れていることが理解される。
【００４４】
【安全性確認試験例】
（１）単回投与による安全性確認
前記実施例１で得られた吸着剤（すなわち、本発明の経口投与用肝疾患治療又は予防剤）を試料として用いた。雄性のＳＤラット（６週齢）を５匹使用し、ラット用フレキシブルディスポーザブルゾンデを用いて５ｇ／ｋｇ／ｄａｙに相当する試料を強制経口投与した。投与日から８日間、動物の生死、行動、外観、及び体重の変化等について観察を行った。投与後９日目に剖検を行い、肝臓、腎臓、及び消化管について肉眼的に観察するとともに、肝臓及び腎臓については臓器重量測定を行った。
各個体とも投与直後及び観察期間中に、一般状態に異常は認められなかった。体重増加抑制及び臓器重量等の変化も認められなかった。また、各個体とも剖検所見において肉眼的変化はみられず、消化管内肉眼的検査でも異常は観察されなかった。これらのことから、実施例１で得られた吸着剤を用いた単回投与試験において、毒性学的変化は認められなかった。
【００４５】
（２）反復投与による安全性確認
前記実施例１で得られた吸着剤を試料として用いた。雄性のＳＤラット（６週齢）を５匹使用し、５ｇ／ｋｇ／ｄａｙの投与量になるように混餌飼料を作製し、２４時間自由摂取により２８日間投与した。投与期間において、動物の生死、行動、外観、体重、及び摂餌量の変化等について観察を行った。投与後２９日目に採血・剖検を行い、肝臓、腎臓、及び消化管について肉眼的に観察するとともに、肝臓及び腎臓については臓器重量測定を行った。また、血液化学的検査として、血清中タンパク分画、総コレステロール及び無機リンについて測定した。
各個体とも試験期間中に一般状態に変化はみられず、体重量及び摂餌量についても順調に推移した。摂餌量より平均投薬量を求めたところ、試験期間中に５ｇ／ｋｇ／ｄａｙ前後の投与が行われていた。臓器重量及び血液化学的検査においても特記すべき変化はなかった。各個体とも剖検所見において本件試料投与によると考えられる肉眼的変化、及び消化管内肉眼的検査の異常は観察されなかった。これらのことから、実施例１で得られた吸着剤を用いた２８日間反復投与試験において、毒性学的変化は認められなかった。
【００４６】
【薬理試験例】
【肝疾患の改善作用】
前記実施例１で得られた吸着剤を試料として用いた。四塩化炭素誘発肝炎ラット１４匹を群間に隔たりのないように、対照群（７匹）と吸着剤投与群（７匹）とに分けた。これ以降１０週間に亘り、対照群には通常飼料を与え、投与群には吸着剤５％を混合した混餌を摂取させた。肝線維化の指標として、血清中プロリルヒドロキシラーゼ（ＰＨ）を測定し、肝機能の検査を目的にＩＣＧ（ｉｎｄｏｃｙａｎｉｎｅ　ｇｒｅｅｎ；インドシアニングリーン）負荷試験を０週、９週間経過後、及び１０週間経過後に検討した。群間の統計学的検定は、ｔ検定を用いた。
対照群の血清中プロリルヒドロキシラーゼ（ＰＨ）は、９週間経過後、及び１０週間経過後において、各々８３２．３±５１７．５（平均±ＳＤ）ｎｇ／ｍＬ、及び８５４．６±５７５．６ｎｇ／ｍＬであったのに対し、吸着剤投与群の各々の値は、４３５．０±１３８．０（平均±ＳＤ）ｎｇ／ｍＬ、及び４１７．２±２５５．６ｎｇ／ｍＬであり、統計学的に有意差はなかったものの、対照群に比べ低値を示す傾向が認められた。対照群のＩＣＧ負荷試験は、９週経過後及び１０週経過後において、各々１．０２±０．１６（平均±ＳＤ）ｍｇ／ｄＬ、及び０．７８±０．１４ｍｇ／ｄＬであったのに対し、吸着剤投与群の各々の値は、０．４９±０．０２（平均±ＳＤ）ｍｇ／ｄＬ、０．４４±０．０６ｍｇ／ｄＬであり、対照群では血中に負荷したＩＣＧの停滞が認められたが、吸着剤投与群では、その停滞は有意に抑制された。
以上の結果、実施例１で得られた吸着剤は、本モデルにおいて肝の線維化を遅延し、線維化に伴う肝機能障害を改善して肝炎から肝硬変への進展を抑制する可能性が強く示唆された。
【００４７】
【肝臓障害への作用】
（１）肝機能障害を生じていた男性（７９歳）の患者で、ＧＯＴ（ｇｌｕｔａｍｉｃ−ｏｘａｌｏａｃｅｔｉｃ　ｔｒａｎｓａｍｉｎａｓｅ；グルタミン酸−オキサロ酢酸トランスアミナーゼ）が４７Ｕで、ＧＰＴ（ｇｌｕｔａｍｉｃ−ｐｙｒｕｖｉｃ　ｔｒａｎｓａｍｉｎａｓｅ；グルタミン酸−ピルビン酸トランスアミナーゼ）が６６Ｕの高値を示していたが、実施例１で得られた吸着剤３ｇ／日の用量で経口投与を続けた結果、投与開始から４ヶ月後でＧＯＴが２１Ｕへ低下し、ＧＰＴが２４Ｕへ低下した。更に投与を継続すると投与開始から７ヶ月経過後にはＧＯＴが１８Ｕへ低下し、ＧＰＴが２１Ｕまで低下し、肝機能障害の回復がみられた。
【００４８】
（２）慢性肝炎を有する男性（４６歳）の患者で、ＧＯＴが１６９Ｕで、ＧＰＴが３５３Ｕの高値を示していたが、実施例１で得られた吸着剤６ｇ／日の用量で経口投与を続けた結果、投与開始１ヶ月後でＧＯＴが１５Ｕへ、ＧＰＴが１５Ｕへと低下し、投与開始から６ヶ月後まで、ＧＯＴが１４〜２２Ｕへ、ＧＰＴが１４〜２１Ｕと安定的に推移し、肝機能障害の回復がみられた。
【００４９】
【肝線維化に対する効果】
（ａ）試験方法
体重１３０〜１５０ｇの６週齢雄Ｗｉｓｔａｒ系ラット（ＳＬＣ）１０匹にコリン欠乏アミノ酸粉末食（Ｄｙｅｔｓ社製：ＵＳＡ）を与え、２週間後にＧＯＴ及びＧＰＴの測定値に基づいて、肝線維化発症ラット８匹を選び、それらを群間に偏りを生じないように対照群４匹と、実施例１で得られた吸着剤投与群４匹とに分けた。
対照群ラットにはコリン欠乏アミノ酸粉末食を与え、吸着剤投与群には、コリン欠乏アミノ酸粉末食に前記実施例１で得られた吸着剤４％（重量／重量％）の割合で混合した飼料を与え、それぞれ１６週間観察した。
【００５０】
摂餌量を１週間に３回、及び体重を１週間に１回の割合で測定し、ＧＯＴ及びＧＰＴを２週間に１回の割合で測定した。更に、ＩＣＧ（インドシアニングリーン）テストを１１週目（吸着剤投与から）に実施し、肝線維化率測定を１６週目（吸着剤投与から）に実施した。
ＧＯＴ及びＧＰＴは、二波長反射光度法によるエンドポイント法（全自動スパードライシステム・スポットケムＳＰ−４４１０）により測定した。ＩＣＧテストは、インドシアニングリーン（ジアグノグリーン；第一製薬）を５ｍｇ／ｋｇ体重で投与し、１５分後に採血を行い、インドシアニングリーン投与前後の吸光度の差によって算出した。肝線維化率は、アザン染色された病理組織を顕微鏡下画像処理システム（Ｉｍａｇｅ　Ａｎａｌｙｚｅｒ　Ｖ１０；東洋紡）を用いて識別し、測定した。
【００５１】
（ｂ）試験結果
吸着剤投与は、体重、摂餌量、ＧＯＴ、及びＧＰＴに影響を及ぼさなかった。吸着剤投与群は、１１週目のＩＣＧテストにおいて、対照群に比較し、統計学的に有意な低値を示した。表３に各群のＩＣＧ値を平均±標準誤差で示す。
【００５２】
【表３】

対照ラットのＩＣＧ値に対する統計学的有意性（スチューデントのｔ検定）
＊ｐ＜０．０１（対照ラットに対する有意性）
【００５３】
吸着剤投与群は、１６週目の肝線維化率において対照群に比較し統計学的に有意な低値を示し肝線維化を抑制した。表４に各群の肝線維化率を平均±標準誤差で示す。
【００５４】
【表４】

対照ラットの肝線維化率に対する統計学的有意性（スチューデントのｔ検定）
＊ｐ＜０．００２（対照ラットに対する有意性）
【００５５】
【発明の効果】
本発明の経口投与用肝疾患治療又は予防剤は、特公昭６２−１１６１１号公報に記載の従来公知の吸着性と比べ、腎臓病での毒性物質であるβ−アミノイソ酪酸の吸着性を実質的に維持したまま、有益物質である消化酵素等に対する吸着性が低下する。また、前記特公昭６２−１１６１１号公報に記載の吸着剤と同様に、便秘等の副作用が少なく、優れた経口肝疾患治療薬としての作用も示す。
【図面の簡単な説明】
【図１】実施例１〜５及び比較例１〜２で調製した７種類の炭素質吸着剤について、選択吸着率と炭素質吸着剤の細孔容積との関係を示すグラフである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an agent for treating or preventing liver disease for oral administration. The therapeutic or preventive agent for liver disease for oral administration according to the present invention contains a porous spherical carbonaceous substance having a specific range of pore volume as an active ingredient, and when taken orally, is useful for in vivo beneficial ingredients such as digestive enzymes. Despite its low adsorptivity, it has the characteristic of excellent adsorption performance of toxic substances (Toxin) in the digestive system. Therefore, when taken orally to a liver disease patient, it shows a remarkable healing effect.
[0002]
[Prior art]
Patients with deficits in renal and hepatic functions accumulate or produce harmful toxic substances in the body, such as in the blood, in association with their organ dysfunction, causing encephalopathy such as uremia and consciousness disturbance. Since the number of these patients tends to increase year by year, development of organ replacement devices or therapeutic agents having a function of removing toxic substances outside the body in place of these defective organs has become an important issue. At present, as an artificial kidney, a method of removing toxic substances by hemodialysis is most widely used. However, such a blood-through-flow type artificial kidney requires special technicians from the viewpoint of safety management because of the use of a special device, and the physical, mental and economic burden on the patient due to the removal of blood from the body. It has disadvantages such as high and is not always satisfactory.
[0003]
In recent years, as a means for solving these drawbacks, an oral adsorbent that can be taken orally and can treat dysfunction of the kidneys and liver has attracted attention. Specifically, the adsorbent described in Japanese Patent Publication No. 62-11611 (Patent Document 1) is made of a porous spherical carbonaceous material having a specific functional group, and has high safety and stability to living organisms, It has excellent adsorptivity of toxic substances even in the presence of bile acids in the intestine, and has beneficial selective adsorptivity of less intestinal beneficial components such as digestive enzymes, and less side effects such as constipation As an oral therapeutic agent, for example, it is widely and clinically used for patients with hepatorenal dysfunction.
[0004]
[Patent Document 1]
JP-B-62-11611
[0005]
[Problems to be solved by the invention]
However, the present inventor has been pursuing an oral adsorbent exhibiting more selective adsorption than the oral adsorbent comprising the porous spherical carbonaceous material, and surprisingly found that the specific range of the adsorbent was surprising. Porous spheroidal carbonaceous materials having a pore volume are excellent in the ability to absorb β-aminoisobutyric acid, a toxic substance in kidney disease, but are beneficial substances such as digestive enzymes (eg, α-amylase). It has been found that it has an excellent selective adsorptivity such that the adsorptivity to the like and the like is lower than that of the adsorbent described in JP-B-62-11611.
Furthermore, the porous spherical carbonaceous substance newly discovered by the present inventors has a low side effect such as constipation, similar to the adsorbent described in JP-B-62-11611, and is an excellent therapeutic drug for oral liver disease. It was also found that the action of
The present invention is based on such findings.
[0006]
[Means for Solving the Problems]
Therefore, the present invention has a diameter of 0.01 to 1 mm and a specific surface area of 700 m ² / G or more, the pore volume with a pore diameter of 20 to 15000 nm is 0.04 mL / g or more and less than 0.10 mL / g, and the total acidic group is 0.30 to 1.20 meq / g. The present invention relates to a therapeutic or preventive agent for liver disease for oral administration, comprising a porous spherical carbonaceous substance having a basic group of 0.20 to 1.00 meq / g as an active ingredient.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
As described above, the porous spherical carbonaceous material used as an active ingredient of the therapeutic or prophylactic agent for liver disease for oral administration according to the present invention has a specific range of pore volume. That is, the volume of pores having a pore diameter of 20 to 15000 nm is 0.04 mL / g or more and less than 0.10 mL / g. On the other hand, Japanese Patent Publication No. 62-11611 discloses a porous spherical carbon having a pore volume with a pore radius of 100 to 75000 angstroms (that is, a pore volume with a pore diameter of 20 to 15000 nm) of 0.1 to 1 mL / g. Adsorbents consisting of toxic substances in hepatic encephalopathies, octopamine and α-aminobutyric acid, toxic substances in kidney disease and their precursors, dimethylamine, β-aminoiso It describes that the compound has excellent adsorptivity to water-soluble basic and amphoteric substances such as butyric acid, aspartic acid, and arginine, and has little adsorption property to digestive enzymes and the like, which are beneficial substances. In Examples 1 to 3 of JP-B-62-11611, an adsorbent having a pore radius of 37.5 to 75000 angstroms and a void volume of 0.20 to 0.23 mL / g was actually prepared. , Β-aminoisobutyric acid, γ-amino-n-butyric acid, dimethylamine, and octopamine.
[0008]
On the other hand, according to the findings of the present inventor, as shown in the examples of the present specification, the pore volume having a pore diameter of 20 to 15000 nm was adjusted to 0.04 mL / g or more and less than 0.10 mL / g. Then, while maintaining high adsorption characteristics for β-aminoisobutyric acid, which is a toxic substance, adsorption characteristics for α-amylase, which is a beneficial substance, are significantly reduced. Since the larger the pore volume of the porous spherical carbonaceous adsorbent having a pore diameter of 20 to 15000 nm is, the more easily a beneficial substance such as a digestive enzyme is adsorbed, from the viewpoint of reducing the adsorption of the beneficial substance, The smaller the pore volume, the better. However, on the other hand, if the pore volume is too small, the amount of toxic substances adsorbed also decreases. Therefore, in the adsorbent for oral administration, the ratio (T / U) of the adsorption amount (T) of the toxic substance to the adsorption amount (U) of the beneficial substance, that is, the selective adsorption rate is important. For example, the selective adsorption rate of the porous spherical carbonaceous substance is determined by the ratio (Tb / Ua) of the adsorption amount (Tb) of DL-β-aminoisobutyric acid (toxic substance) to the adsorption amount (Ua) of α-amylase (beneficial substance). ) Can be evaluated. That is, the selective adsorption rate is calculated by, for example, the following equation:
A = Tb / Ua
(Where A is the selective adsorption rate, Tb is the adsorption amount of DL-β-aminoisobutyric acid, and Ua is the adsorption amount of α-amylase)
Can be evaluated by:
The porous spherical carbonaceous adsorbent used as an active ingredient of the therapeutic or preventive agent for liver disease for oral administration of the present invention has a pore volume of 20 to 15000 nm having a pore volume of 0.04 mL / g or more and less than 0.10 mL / g. And the pore volume is more than 0.05 mL / g and less than 0.10 mL / g.
[0009]
The porous spherical carbonaceous material used as an active ingredient of the therapeutic or preventive agent for liver disease for oral administration according to the present invention has a diameter of 0.01 to 1 mm. If the diameter of the porous spherical carbonaceous substance is less than 0.01 mm, the outer surface area of the porous spherical carbonaceous substance increases, and the adsorption of beneficial substances such as digestive enzymes tends to occur. On the other hand, if the diameter exceeds 1 mm, the diffusion distance of the toxic substance into the porous spherical carbonaceous material increases, and the adsorption rate decreases, which is not preferable. The diameter is preferably between 0.02 and 0.8 mm. In the present specification, the expression "the diameter is Dl to Du" is used in a particle size accumulation diagram (described later in connection with the method of measuring the average particle size) created according to JIS K 1474. It means that the sieve passing percentage (%) corresponding to the range of the openings Dl to Du is 90% or more.
[0010]
The porous spherical carbonaceous substance used as an active ingredient of the therapeutic or preventive agent for liver disease for oral administration according to the present invention has a specific surface area (hereinafter sometimes abbreviated as “SSA”) of 700 m as determined by the BET method. ² / G or more. SSA is 700m ² / G of a porous spherical carbonaceous substance is not preferred because the toxic substance adsorption performance is reduced. SSA is preferably 800 m ² / G or more. The upper limit of SSA is not particularly limited, but from the viewpoint of bulk density and strength, SSA is 2500 m ² / G or less.
[0011]
Furthermore, in the porous spherical carbonaceous substance used as an active ingredient of the therapeutic or preventive agent for liver disease for oral administration of the present invention, the total number of acidic groups in the composition of the functional groups is 0.30 to 1.20 meq / g. The basic group is 0.20 to 1.00 meq / g. In the configuration of the functional group, the porous spherical carbonaceous substance in which the total acidic group is 0.30 to 1.20 meq / g and the total basic group does not satisfy the condition of 0.20 to 1.00 meq / g is as described above. It is not preferable because the ability of adsorbing toxic substances decreases. In the constitution of the functional group, the total acidic group is preferably 0.30 to 1.00 meq / g, and the total basic group is preferably 0.30 to 0.60 meq / g. In the porous spherical carbonaceous substance used as an active ingredient of the therapeutic or prophylactic agent for liver disease for oral administration of the present invention, the functional groups are composed of a total acidic group of 0.30 to 1.20 meq / g and a total basic group of Is in the range of 0.20 to 1.00 meq / g, the phenolic hydroxyl group is in the range of 0.20 to 0.70 meq / g, and the carboxyl group is in the range of 0.15 meq / g or less, and all acidic groups (a) and all bases are present. The ratio (a / b) to the basic group (b) is 0.40 to 2.5, and the relationship between the total basic group (b), phenolic hydroxyl group (c), and carboxyl group (d) [(b + c ) -D] is preferably 0.60 or more.
[0012]
The porous spherical carbonaceous substance used as an active ingredient of the active ingredient of the therapeutic or preventive agent for liver disease for oral administration of the present invention can be produced, for example, by the following method. First, a pitch such as a petroleum pitch or a coal pitch is added with a bicyclic or tricyclic aromatic compound having a boiling point of 200 ° C. or higher or a mixture thereof as an additive and heated and mixed. Get the body. Since the porous spherical carbonaceous substance is for oral administration, it is necessary that the raw material has sufficient purity for safety and is stable in quality.
[0013]
Next, the above-mentioned pitch compact is dispersed and granulated in hot water at 70 to 180 ° C. with stirring to form microspheres. Further, with a solvent having a low solubility for the pitch, and a high solubility for the additive, the additive is extracted and removed from the pitch formed body, the obtained porous pitch, using an oxidizing agent Oxidation results in a porous pitch that is infusible to heat. When the infusible porous pitch thus obtained is further treated at a temperature of 800 to 1000 ° C. in a gas stream reactive with carbon (for example, steam or carbon dioxide), a porous carbonaceous material can be obtained. it can.
[0014]
The porous carbonaceous material thus obtained is subsequently subjected to an atmosphere having an oxygen content of 0.1 to 50 vol% (preferably 1 to 30 vol%, particularly preferably 3 to 20 vol%) at 300 to 800 ° C (preferably 320 to 600 ° C.), and further subjected to a reduction treatment by a heating reaction in a non-oxidizing gas atmosphere at a temperature of 800 to 1200 ° C. (preferably 800 to 1000 ° C.), whereby the oral composition of the present invention is obtained. A porous spherical carbonaceous substance used as an active ingredient of an agent for treating or preventing liver disease for administration can be obtained.
[0015]
In the above-mentioned manufacturing method, pure oxygen, nitrogen oxide, air, or the like can be used as an oxygen source as an atmosphere containing a specific amount of oxygen. As the atmosphere inert to carbon, for example, nitrogen, argon, helium, or the like can be used alone, or a mixture thereof can be used.
[0016]
The purpose of adding the aromatic compound to the raw material pitch is to lower the softening point of the raw material pitch to improve the fluidity and facilitate the microsphere formation, and from the pitch molded body after molding. An object of the present invention is to make a molded body porous by extracting and removing additives, thereby facilitating structure control and firing of a carbonaceous material by oxidation in a subsequent step. As such an additive, for example, naphthalene, methylnaphthalene, phenylnaphthalene, benzylnaphthalene, methylanthracene, phenanthrene, biphenyl, or the like can be used alone, or a mixture of two or more thereof can be used. The amount added to the pitch is preferably in the range of 10 to 50 parts by weight of the aromatic compound per 100 parts by weight of the pitch.
[0017]
Mixing of the pitch and the additive is preferably performed in a molten state by heating in order to achieve uniform mixing. The mixture of the pitch and the additive is preferably formed into particles having a particle diameter of about 0.01 to 1 mm in order to control the particle diameter (diameter) of the obtained porous spherical carbonaceous material. The molding may be performed in a molten state, or may be performed by a method such as pulverizing the mixture after cooling.
Examples of the solvent for extracting and removing the additive from the mixture of the pitch and the additive include, for example, aliphatic hydrocarbons such as butane, pentane, hexane, or heptane, naphtha, and aliphatic hydrocarbons such as kerosene. Or an aliphatic alcohol such as methanol, ethanol, propanol, or butanol.
By extracting the additive from the mixture formed of the pitch and the additive with such a solvent, the additive can be removed from the molded body while maintaining the shape of the molded body. At this time, it is presumed that holes for the additive are formed in the molded article, and a pitch molded article having uniform porosity is obtained.
The size of the hole of the additive (that is, the pore volume) is controlled in a conventional manner, for example, by controlling the amount of the additive and the deposition temperature (cooling temperature) of the additive in the microsphere forming step of the pitch compact. Can be implemented. The pore volume generated by the extraction of the additive is also affected by the infusibilizing conditions. For example, if the infusibilization treatment is strong, the heat shrinkage due to the heat treatment is small, and the pores obtained by extracting the additive tend to be easily maintained.
[0018]
The porous pitch molded body thus obtained is then subjected to infusibilization treatment, that is, oxidation treatment using an oxidizing agent, preferably at a temperature of from room temperature to 300 ° C., to thereby form a porous infusible heat. A fusible pitch compact can be obtained. As the oxidizing agent used here, for example, oxygen gas (O ₂ ) Or oxygen gas (O ₂ ) Is diluted with air or nitrogen.
[0019]
Each physical property value of the porous spherical carbonaceous material used as an active ingredient of the therapeutic or prophylactic agent for liver disease for oral administration of the present invention, i.e., average particle diameter, specific surface area, pore volume, all acidic groups, and all basic properties The group is measured by the following method.
(1) Average particle size
For the porous spherical carbonaceous material, a particle size accumulation diagram is created according to JIS K 1474. The average particle diameter is obtained by drawing a horizontal line on the horizontal axis from the intersection of the vertical line at the 50% point on the horizontal axis and the particle size cumulative line in the particle size cumulative diagram to determine the sieve opening (mm) indicated by the intersection. , The average particle diameter.
[0020]
(2) Specific surface area
The gas adsorption amount of the porous spherical carbonaceous material sample was measured using a specific surface area measuring device (for example, “Flow Sorb II 2300” manufactured by MICROMERITICS) by a continuous flow gas adsorption method, and the specific surface area was calculated by the BET equation. Can be calculated. Specifically, a porous spherical carbonaceous material, which is a sample, is filled in a sample tube, and the following operation is performed while flowing a helium gas containing 30 vol% of nitrogen into the sample tube to perform the following operations on the porous spherical carbonaceous material sample. The amount of nitrogen adsorption is determined. That is, the sample tube is cooled to -196 ° C, and nitrogen is adsorbed on the porous spherical carbonaceous material sample. Next, the sample tube is returned to room temperature. At this time, the amount of nitrogen desorbed from the porous spherical carbonaceous material sample is measured by a thermal conductivity type detector, and is defined as the amount of adsorbed gas (v).
Approximate formula derived from BET formula:
v _m = 1 / (v · (1-x))
By the one-point method (relative pressure x = 0.3) by nitrogen adsorption at the temperature of liquid nitrogen using _m And the following equation:
Specific surface area = 4.35 × v _m (M ² / G)
To calculate the specific surface area of the sample. In each of the above equations, v _m Is the adsorption amount (cm) required to form a monolayer on the sample surface. ³ / G), and v is the actually measured adsorption amount (cm ³ / G) and x is the relative pressure.
[0021]
(3) Pore volume by mercury intrusion method
The pore volume can be measured using a mercury porosimeter (for example, “AUTOPORE 9200” manufactured by MICROMERITICS). A porous spherical carbonaceous material, which is a sample, is placed in a sample container and degassed at a pressure of 2.67 Pa or less for 30 minutes. Next, mercury is introduced into the sample container, and the pressure is gradually increased to press the mercury into the pores of the porous spherical carbonaceous material sample (maximum pressure = 414 MPa). The pore volume distribution of the porous spherical carbonaceous material sample is measured from the relationship between the pressure at this time and the amount of mercury injected using the following formulas.
Specifically, the volume of mercury injected into the porous spherical carbonaceous material sample from a pressure (0.07 MPa) corresponding to a pore diameter of 15 μm to a maximum pressure (414 MPa: equivalent to a pore diameter of 3 nm) is measured. The pore diameter is calculated by, when mercury is injected into a cylindrical pore having a diameter (D) at a pressure (P), by setting the surface tension of mercury to “γ” and setting the contact angle between mercury and the pore wall to “γ”. θ ”, from the balance between the surface tension and the pressure acting on the pore cross section,
-ΠDγcosθ = π (D / 2) ² ・ P
Holds. Therefore
D = (-4γcosθ) / P
It becomes.
In the present specification, the surface tension of mercury is 484 dyne / cm, the contact angle between mercury and carbon is 130 degrees, the pressure P is MPa, and the pore diameter D is expressed in μm.
D = 1.27 / P
To determine the relationship between the pressure P and the pore diameter D. The pore volume in the range of the pore diameter of 20 to 15000 nm in the present invention corresponds to the volume of mercury injected at a mercury injection pressure of 0.07 MPa to 63.5 MPa.
[0022]
(4) All acidic groups
In 50 mL of 0.05 N NaOH solution, 1 g of a porous spherical carbonaceous material sample pulverized to 200 mesh or less is added, and after shaking for 48 hours, the porous spherical carbonaceous material sample is filtered and neutralized. It is the consumption of NaOH determined by titration.
[0023]
(5) All basic groups
In 50 mL of 0.05N HCl solution, 1 g of a porous spherical carbonaceous material sample pulverized to 200 mesh or less is added, and after shaking for 24 hours, the porous spherical carbonaceous material sample is filtered off and neutralized. It is the consumption of HCl determined by titration.
[0024]
The porous spherical carbonaceous material used as an active ingredient of the therapeutic or preventive agent for liver disease for oral administration of the present invention has a zwitterionic group (that is, an acidic group and a basic group) as described above, and It can be used as an adsorbent for oral administration for treating or preventing liver disease because of its excellent selective adsorption of toxic substances.
As the liver disease, for example, fulminant hepatitis, chronic hepatitis, viral hepatitis, alcoholic hepatitis, liver fibrosis, cirrhosis, liver cancer, autoimmune hepatitis, drug allergic liver injury, primary biliary cirrhosis, tremor, Encephalopathy, metabolic abnormalities, or functional abnormalities can be mentioned. In addition, it can be used for treatment of diseases caused by harmful substances present in the body, ie, mental illness.
[0025]
The dose of the therapeutic or preventive agent for liver disease for oral administration according to the present invention depends on whether the administration subject is a human or another animal, and is affected by age, individual difference, or medical condition. Depending on the case, a dose outside the following range may be appropriate, but in general, the oral dose for human subjects is 1 to 20 g per day in 3 to 4 divided doses, and the dose may be adjusted according to the symptoms. can do. Dosage forms can be powders, granules, tablets, dragees, capsules, suspensions, sticks, divided packages, emulsions and the like. When taken as a capsule, enteric capsules can be used, if necessary, in addition to ordinary gelatin. When used as a tablet, it must be released into the original microparticles in the body. Furthermore, it can also be used in the form of a complex prepared by blending it with another agent such as an aluminum gel or an electrolyte regulator such as a silicate.
[0026]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but these do not limit the scope of the present invention.
In the following examples, the α-amylase adsorption test and the DL-β-aminoisobutyric acid adsorption test were performed by the following method, and the selective adsorption rate was calculated by the following method.
(1) α-amylase adsorption test
After drying the porous spherical carbonaceous material sample, 0.125 g of the dried sample is accurately measured and placed in a stoppered Erlenmeyer flask. On the other hand, 0.100 g of α-amylase (liquefied type) was accurately weighed, and a phosphate buffer solution having a pH of 7.4 was added and dissolved, and 50 mL of a solution (stock solution) accurately adjusted to 1000 mL was supplied with the above stopper. Add exactly to the Erlenmeyer flask and shake at 37 ± 1 ° C. for 3 hours. The contents of the flask are suction-filtered with a membrane filter having a filter hole of 0.65 μm, and about 20 mL of the first filtrate is removed, and about 10 mL of the next filtrate is used as a sample solution.
On the other hand, the same operation is performed using a phosphate buffer of pH 7.4, and the filtrate is used as a correction solution. For the sample solution and the correction solution, a test is performed by an absorbance measurement method using a phosphate buffer of pH 7.4 as a control, and the absorbance at a wavelength of 282 nm is measured. The difference between the absorbance of the sample solution and the absorbance of the correction solution is defined as the test absorbance.
[0027]
The calibration curve was prepared by accurately dispensing the α-amylase stock solution in 0 mL, 25 mL, 50 mL, 75 mL, and 100 mL volumes into a volumetric flask, making up to 100 mL with a pH 7.4 phosphate buffer, and measuring the absorbance at a wavelength of 282 nm. Created by measuring.
The residual amount of α-amylase (mg / dL) was calculated from the test absorbance and the calibration curve. In order to measure the dependence of the amount of the porous spherical carbonaceous material sample, the amount of the porous spherical carbonaceous material sample was set to 0.500 g, and the test absorbance was measured in the same manner as described above. Was calculated.
[0028]
(2) DL-β-aminoisobutyric acid adsorption test
After drying the porous spherical carbonaceous material sample, 2.500 g of the dried sample is accurately measured and placed in a stoppered Erlenmeyer flask. On the other hand, 0.100 g of DL-β-aminoisobutyric acid was accurately measured and dissolved by adding a phosphate buffer of pH 7.4, and 50 mL of a solution (stock solution) accurately adjusted to 1000 mL was placed in the Erlenmeyer flask with a stopper. Add exactly and shake for 3 hours at 37 ± 1 ° C. The contents of the flask are suction-filtered with a membrane filter having a filter hole of 0.65 μm. About 20 mL of the first filtrate is removed, and about 10 mL of the next filtrate is used as a sample solution.
0.1 mL of a sample solution is accurately taken in a test tube, and 5 mL of a phosphate buffer having a pH of 8.0 is accurately added and mixed. Then, 1 mL of a solution prepared by dissolving 0.100 g of fluorescamine in 100 mL of acetone for nonaqueous titration is used. After adding exactly and mixing, let stand for 15 minutes. This solution is tested by a fluorometric method, and the fluorescence intensity is measured at an excitation wavelength of 390 nm and a fluorescence wavelength of 475 nm.
[0029]
The DL-β-aminoisobutyric acid stock solution was made up to 100 mL with 0 mL, 15 mL, 50 mL, 75 mL, and 100 mL volumes and a pH 7.4 phosphate buffer, stirred, filtered, and 0.1 mL of the filtrate was accurately placed in a test tube. After accurately adding and mixing 5 mL of a phosphate buffer having a pH of 8.0, 1 mL of a solution prepared by dissolving 0.100 g of fluorescamine in 100 mL of acetone for non-aqueous titration was added accurately, and then mixed. Let stand for 15 minutes. These liquids are tested by a fluorometric method, and the fluorescence intensity is measured at an excitation wavelength of 390 nm and a fluorescence wavelength of 475 nm to prepare a calibration curve. Finally, the residual amount of DL-β-aminoisobutyric acid (mg / dL) is calculated using the above calibration curve.
In order to measure the dependence of the amount of the porous spherical carbonaceous material sample, the test fluorescence intensity was measured in the same manner as the above method with the amount of the porous spherical carbonaceous material sample being 0.500 g, The remaining amount of butyric acid was calculated.
[0030]
(3) Selective adsorption rate
Α-amylase residual amount in the α-amylase adsorption test when the amount of the carbonaceous adsorbent used is 0.500 g, and similarly, DL-β-aminoisobutyric acid when the amount of the carbonaceous adsorbent used is 0.500 g Based on each data of the residual amount of DL-β-aminoisobutyric acid in the adsorption test, the following calculation formula:
A = (10-Tr) / (10-Ur)
(Where A is the selective adsorption rate, Tr is the residual amount of DL-β-aminoisobutyric acid, and Ur is the residual amount of α-amylase)
Calculated from
[0031]
Embodiment 1
68 kg of petroleum pitch (softening point = 210 ° C .; quinoline insoluble matter = 1% by weight or less; H / C atomic ratio = 0.63) and 32 kg of naphthalene are charged into a 300 L pressure vessel equipped with stirring blades. After melt-mixing at 180 ° C., the mixture was cooled to 80 to 90 ° C. and extruded to obtain a cord-like molded body. Next, this cord-like molded body was crushed so that the ratio of the diameter to the length was about 1 to 2.
0.23% by weight of polyvinyl alcohol (degree of saponification = 88%) is dissolved in the aqueous solution heated to 93 ° C., and the crushed material is put into the aqueous solution. Was replaced with water, and cooled at 20 ° C. for 3 hours to solidify the pitch and precipitate naphthalene crystals to obtain a spherical pitch compact slurry.
After most of the water was removed by filtration, the naphthalene in the pitch molded product was extracted and removed with n-hexane about 6 times the weight of the spherical pitch molded product. The porous spherical pitch thus obtained is heated to 235 ° C. using a fluidized bed while passing heated air, and is then oxidized by holding at 235 ° C. for 1 hour to be infused with heat. Was obtained.
Subsequently, the porous spherical oxidized pitch was activated at 900 ° C. for 170 minutes in a nitrogen gas atmosphere containing 50 vol% steam using a fluidized bed to obtain a porous spherical activated carbon, which was further treated with a fluidized bed. An oxidation treatment is performed at 470 ° C. for 3 hours and 15 minutes in a mixed gas atmosphere of nitrogen and oxygen having an oxygen concentration of 18.5 vol%, and then a reduction treatment is performed in a fluidized bed at 900 ° C. for 17 minutes under a nitrogen gas atmosphere. A porous spherical carbonaceous material, that is, an adsorbent for oral administration was obtained. This adsorbent was used in the following safety confirmation test examples and pharmacological test examples as the therapeutic or preventive agent for liver disease for oral administration of the present invention.
Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0032]
Embodiment 2
A porous spherical carbonaceous material was obtained by repeating the method described in Example 1 except that the activation treatment time of the porous spherical oxide pitch was set to 80 minutes. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0033]
Embodiment 3
A porous spherical carbonaceous material was obtained by repeating the method described in Example 1 except that the activation treatment time of the porous spherical oxide pitch was set to 120 minutes. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0034]
Embodiment 4
A porous spherical carbonaceous material was obtained by repeating the method described in Example 1 except that the activation time of the porous spherical oxide pitch was set to 240 minutes. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0035]
Embodiment 5
A porous spherical carbonaceous material was obtained by repeating the method described in Example 1 except that the temperature of cooling water for precipitation of spheroidized pitch and naphthalene crystals was 25 ° C. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0036]
[Comparative Example 1]
Instead of performing the activation treatment of the porous spherical oxide pitch, the procedure of Example 1 was repeated except that the temperature was raised to 900 ° C. in a fluidized bed under a nitrogen gas stream for 90 minutes, and the temperature was lowered after reaching 900 ° C. The described method was repeated to obtain a porous spherical carbonaceous material. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0037]
[Comparative Example 2]
Except that the temperature of cooling water for precipitation of spheroidized pitch and naphthalene crystal precipitation was set to 30 ° C., and that the oxidation treatment temperature for forming porous spherical pitch to porous spherical oxide pitch was set to 260 ° C. By repeating the method described in Example 1, a porous spherical carbonaceous material was obtained. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0038]
[Comparative Example 3]
The porous spherical carbonaceous substance of Example 1 was pulverized with a pulverizer to an average particle diameter of 20 μm to obtain a powdery porous carbonaceous substance. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0039]
[Comparative Example 4]
A porous spherical carbonaceous material was obtained by repeating the method described in Example 1, except that the reduction treatment of the porous spherical activated carbon was not performed. Tables 1 and 2 show the properties of the obtained carbonaceous material.
[0040]
[Comparative Example 5]
The method described in Example 1 was repeated to obtain a porous spherical carbonaceous material, except that the oxidation treatment and the reduction treatment of the porous spherical activated carbon were not performed. The properties of the obtained carbonaceous material are shown in Table 1 and Ehime.
[0041]
[Comparative Example 6]
For comparison, the same evaluation was performed using “medicinal coal” described in the Japanese Pharmacopoeia. The “medicinal coal” is in a powder form. The obtained results are shown in Tables 1 and 2.
[Table 1]

The pore volume in Table 1 corresponds to a pore volume in the range of pore diameter of 20 to 15000 nm determined by a mercury intrusion method.
[0042]
[Table 2]

[0043]
The relationship between the selective adsorption rate and the pore volume of the carbonaceous adsorbent for the seven types of carbonaceous adsorbents of Examples 1 to 5 and Comparative Examples 1 and 2 which have similar properties and production methods other than the pore volume. Is shown in FIG. FIG. 1 shows that the carbonaceous adsorbent having a pore volume in the range of 0.04 to 0.10 mL / g shows an excellent selective adsorption rate.
Further, from Table 2 and FIG. 1, it is understood that the porous spherical carbonaceous adsorbent which can be used as an active ingredient of the therapeutic or preventive agent for liver disease for oral administration of the present invention has an excellent selective adsorption rate.
[0044]
[Example of safety confirmation test]
(1) Safety confirmation by single administration
The adsorbent obtained in Example 1 (that is, the therapeutic or preventive agent for liver disease for oral administration of the present invention) was used as a sample. Five male SD rats (6 weeks old) were used, and a sample corresponding to 5 g / kg / day was orally administered by gavage using a flexible disposable sonde for rats. For 8 days from the administration day, the animals were observed for life and death, behavior, appearance, changes in body weight, and the like. Nine days after the administration, necropsy was performed. The liver, kidney, and digestive tract were visually observed, and the liver and kidney were measured for organ weight.
Immediately after the administration and during the observation period, no abnormality was observed in the general condition of each individual. No suppression of weight gain and no change in organ weight were observed. In addition, no gross changes were observed in the autopsy findings of each individual, and no abnormalities were observed by gross examination in the gastrointestinal tract. From these, no toxicological change was observed in the single dose test using the adsorbent obtained in Example 1.
[0045]
(2) Confirmation of safety by repeated administration
The adsorbent obtained in Example 1 was used as a sample. Five male SD rats (6 weeks old) were used to prepare a mixed feed at a dose of 5 g / kg / day, and were administered freely for 24 hours for 28 days. During the administration period, the animals were observed for life and death, behavior, appearance, body weight, changes in food consumption, and the like. On day 29 after administration, blood collection and necropsy were performed, and the liver, kidney, and digestive tract were visually observed, and the liver and kidney were measured for organ weight. As a blood chemistry test, serum protein fraction, total cholesterol and inorganic phosphorus were measured.
No change was observed in the general condition of each individual during the test period, and body weight and food consumption were also favorable. When the average dosage was determined from the amount of food consumed, administration of about 5 g / kg / day was performed during the test period. There were no notable changes in organ weight and blood chemistry. Necropsy findings did not show any gross changes in each animal that could be attributed to the administration of the sample, and no abnormal gross examination in the digestive tract. From these facts, no toxicological changes were observed in a 28-day repeated administration test using the adsorbent obtained in Example 1.
[0046]
[Pharmacological test example]
[Improvement of liver disease]
The adsorbent obtained in Example 1 was used as a sample. Fourteen carbon tetrachloride-induced hepatitis rats were divided into a control group (7) and an adsorbent-administered group (7) so that there was no gap between the groups. Over the following 10 weeks, the control group was fed with a normal feed, and the administration group was fed with a mixed diet containing 5% of the adsorbent. Serum prolyl hydroxylase (PH) was measured as an indicator of liver fibrosis, and an ICG (indocyanine green) load test was performed at 0 weeks, 9 weeks, and 10 weeks for the purpose of testing liver function. Considered after the passage. Statistical test between groups used t test.
Serum prolyl hydroxylase (PH) in the control group was 832.3 ± 517.5 (mean ± SD) ng / mL and 854.6 ± 575. After 9 weeks and 10 weeks, respectively. In contrast to 6 ng / mL, the respective values of the adsorbent administration group were 435.0 ± 138.0 (mean ± SD) ng / mL and 417.2 ± 255.6 ng / mL, respectively. Although there was no significant difference, there was a tendency to show lower values compared to the control group. The ICG load test of the control group was 1.02 ± 0.16 (mean ± SD) mg / dL and 0.78 ± 0.14 mg / dL after 9 weeks and 10 weeks, respectively. On the other hand, the values of the adsorbent administration group were 0.49 ± 0.02 (mean ± SD) mg / dL and 0.44 ± 0.06 mg / dL, respectively. Stagnation was observed, but the stagnation was significantly suppressed in the adsorbent administration group.
As a result, the adsorbent obtained in Example 1 has a strong possibility of delaying liver fibrosis in this model, improving hepatic dysfunction associated with fibrosis, and suppressing progression from hepatitis to cirrhosis. It was suggested.
[0047]
[Effect on liver damage]
(1) A male (79-year-old) patient who had hepatic dysfunction had 47 U of GOT (glutamic-oxalactic transaminase; Glutamate-oxaloacetate transaminase) and GPT (glutamic-pyruvic transaminase). Although it showed a high value of 66 U, as a result of continuing oral administration at a dose of 3 g / day of the adsorbent obtained in Example 1, GOT decreased to 21 U and GPT decreased to 24 U four months after the start of administration. did. When the administration was further continued, the GOT decreased to 18 U and the GPT decreased to 21 U after 7 months from the start of the administration, and recovery of liver dysfunction was observed.
[0048]
(2) A male (46 years old) patient with chronic hepatitis had a GOT of 169 U and a high GPT of 353 U, but was orally administered at a dose of 6 g / day of the adsorbent obtained in Example 1. As a result, one month after the start of administration, the GOT decreased to 15 U and the GPT decreased to 15 U. Until six months after the start of administration, the GOT changed to 14 to 22 U and the GPT stably changed to 14 to 21 U. Recovery of liver dysfunction was observed.
[0049]
[Effect on liver fibrosis]
(A) Test method
A choline-deficient amino acid powdered diet (manufactured by Dyets: USA) was given to 10 6-week-old male Wistar rats (SLC) weighing 130 to 150 g, and two weeks later, liver fibrosis was developed based on the measured values of GOT and GPT. Eight rats were selected, and they were divided into four control groups and four adsorbent-administered groups obtained in Example 1 so as not to cause a bias between the groups.
The control group rats were fed a choline-deficient amino acid powder diet, and the adsorbent-administered group was a diet prepared by mixing the choline-deficient amino acid powder diet with the adsorbent obtained in Example 1 at a ratio of 4% (w / w). And observed for 16 weeks each.
[0050]
Food consumption was measured three times a week and body weight was measured once a week, and GOT and GPT were measured once every two weeks. In addition, an ICG (Indocyanine Green) test was performed at week 11 (from adsorbent administration), and liver fibrosis rate measurement was performed at week 16 (from adsorbent administration).
GOT and GPT were measured by an endpoint method based on a two-wavelength reflection photometric method (fully automated Spadry System Spotchem SP-4410). In the ICG test, indocyanine green (Diagno Green; Daiichi Pharmaceutical Co., Ltd.) was administered at 5 mg / kg body weight, blood was collected 15 minutes later, and the difference in absorbance before and after administration of indocyanine green was calculated. The hepatic fibrosis rate was determined by identifying an Azan-stained pathological tissue using an image processing system under a microscope (Image Analyzer V10; Toyobo).
[0051]
(B) Test results
Adsorbent administration did not affect body weight, food consumption, GOT, and GPT. The adsorbent-administered group showed a statistically significant lower value than the control group in the 11th week ICG test. Table 3 shows the ICG value of each group as mean ± standard error.
[0052]
[Table 3]

Statistical significance of control rats to ICG value (Student's t-test)
* P <0.01 (significance over control rats)
[0053]
The adsorbent-administered group showed a statistically significant lower value in the liver fibrosis rate at 16 weeks than the control group, and suppressed liver fibrosis. Table 4 shows the liver fibrosis rate of each group as mean ± standard error.
[0054]
[Table 4]

Statistical significance of control rats on liver fibrosis rate (Student's t-test)
* P <0.002 (significance over control rats)
[0055]
【The invention's effect】
The therapeutic or prophylactic agent for liver disease for oral administration of the present invention has a substantially higher adsorptivity for β-aminoisobutyric acid, a toxic substance in kidney disease, as compared with the conventionally known adsorptivity described in JP-B-62-11611. , The adsorptivity to beneficial substances such as digestive enzymes is reduced. In addition, as in the case of the adsorbent described in JP-B No. 62-11611, there are few side effects such as constipation, and it also shows an excellent action as a therapeutic drug for oral liver disease.
[Brief description of the drawings]
FIG. 1 is a graph showing a relationship between a selective adsorption rate and a pore volume of a carbonaceous adsorbent for seven types of carbonaceous adsorbents prepared in Examples 1 to 5 and Comparative Examples 1 and 2.

Claims

The diameter is 0.01 to 1 mm, the specific surface area determined by the BET method is 700 m ² / g or more, and the pore volume with a pore diameter of 20 to 15000 nm is 0.04 mL / g or more and less than 0.10 mL / g. Orally containing, as an active ingredient, a porous spherical carbonaceous substance having a total acidic group of 0.30 to 1.20 meq / g and a total basic group of 0.20 to 1.00 meq / g. For treating or preventing liver disease.

If the liver disease is fulminant hepatitis, chronic hepatitis, viral hepatitis, alcoholic hepatitis, liver fibrosis, cirrhosis, liver cancer, autoimmune hepatitis, drug-allergic liver disorder, primary biliary cirrhosis, tremor, encephalopathy, metabolism The agent for treating or preventing liver disease for oral administration according to claim 1, wherein the agent is abnormal or functionally abnormal.