JP2004530452A - Non-attractable transition viscoelastic materials for use in surgery - Google Patents

Abstract

Non-attractable viscoelastic materials, compositions, and methods of use are disclosed. This non-attractable transition viscoelastic has sufficient viscosity to be useful in the viscosurgery of the eye, but produces little or no IOP spikes (ie, acceptable in the IOP spike model). A sharp IOP spike profile) can be left in the eye. The compositions of the present invention comprise a transition viscosity or transition viscoelastic polymeric agent suitable for use in ophthalmic surgery. This composition is particularly useful in cataract surgery.

Description

（実施例２）
【００３６】
【表２】

（実施例３）
【００３７】
【表３】

（実施例４）
【００３８】
【表４】

（実施例５）
【００３９】
【表５】

（実施例６）
【００４０】
【表６】

以下の実施例７〜１８は、本発明の組成物のレオロジー特性を示す。
【００４１】
（実施例７）
本発明のＨＡ−アミド組成物のレオロジー特性を、種々の濃度にわたって、類似の非遷移のＨＡ組成物と比較した。実施例３の１０％置換されたドデシルアミド−ＨＡ処方物（０．２％、０．４％、０．６％、０．８％および１．０％ｗ／ｖ）および前駆体の非修飾ＨＡを含むコントロール組成物（０．２、０．４、０．６、０．８および１．０％）を、以下の手順に従って、調製した。種々の処方物を含む容器にふたをして、時々攪拌して、全てのドデシルアミドＨＡまたはＨＡ粉末が緩衝液中に浸されており、完全溶解が起こったことを確認しながら、５０℃で４時間加熱した。次いで、各溶液を、別個の５ｃｃシリンジに移し、ふたをして、２５００ＲＰＭで遠心分離して、泡を除いた。次いで、ロードしたシリンジを、Ｄｕａｌ−ハブアセンブリを介して各々、空の５ｃｃシリンジと、つないだ。シリンジを１時間冷却し、それぞれのアセンブリで５０の経路を用いて混合した。
【００４２】
レオロジー分析を行なうために、サンプルをＢｏｈｌｉｎ ＣＳ−１０（Ｃｏｎｓｔａｎｔ Ｓｔｒｅｓｓ Ｒｈｅｏｍｅｔｅｒ）サンプルプレート上で２７ゲージ針を通し吸引し、２７ゲージ針を通ってサンプルをおき、装置をビスコメトリーモードにセットした。サンプルの粘度を、１６℃で１．０９〜５２．８９Ｐａのせん断応力を使用して、せん断速度に対して測定した。フルせん断速度まで近づくにつれて、可能な掃引が使用され、高せん断速度終点での求心力に起因して、可能なサンプルのロスについて考慮する。各々のサンプルに関して、次いで、１０℃〜５０℃の温度範囲および２．５℃／分の加熱速度を使用して、遷移の挙動（粘度 対 温度）を特徴付けた。各サンブルを、同一のパラメータを用いて処理した。まとめた結果は、表１に含まれる。
【００４３】
（表１：１６℃での、１０％置換されたドデシルアミン−ＨＡ 対 コントロールＨＡの粘度）
【００４４】
【表７】

表１に示されるように、ドデシルアミド−ＨＡ組成物は、修飾されていないＨＡ組成物よりも非常に高い粘度であった。また、低いせん断粘度における、約５桁におよぶ増加は、デシルアミド−ＨＡ濃度の増加（すなわち、０．２％〜１．０％ｗ／ｖ）と相関関係にあった。
【００４５】
（実施例８）
実施例４の組成物を、レオロジー的に評価した。組成物を、実施例６において開示される方法と同様の方法で調製した。
【００４６】
このサンプルを、Ｂｏｈｌｉｎ ＣＳ−１０制御された応力レオメーターを用いて、実施例６に記載されるのと同じ手順を用いて、０．４１〜３２．５８Ｐａのせん断応力範囲で、粘度 対 せん断速度に関して、レオロジー的に処理した。この結果は、表２に含まれる。
【００４７】
（表２：１６℃での、３２％置換されたオクチルアミド−ＨＡに関する粘度 対 せん断応力）
【００４８】
【表８】

表２に示されるように、１％溶液は、約１０００Ｐａ−ｓの低いせん断粘度を示した。
【００４９】
類似の実験において、組成物の粘度を、１７℃〜３７℃の温度範囲にわたって、１．７８１Ｐａのせん断応力を用いて試験した。結果は、表３に報告される。
【００５０】
（表３：３２％置換されたオクチルアミド−ＨＡの１％溶液に関する、粘度 対 温度）
【００５１】
【表９】

表３に示され、そして図３に図示されるように、この物質の遷移の粘度損失挙動は、温度の増加と直線的に相関する。この温度範囲にわたる総粘度損失は、約８８％であった。
【００５２】
（実施例９）
本発明の好ましい組成物の貯蔵安定性を、保持された粘度の測定として、以下の実験において観察した。実施例２のドデシルアミド−ＨＡを、４℃および室温（「ＲＴ」、すなわち、２１〜２３℃）で５．５ヶ月にわたってインキュベートした。所定の時点で、各組成物のアリコートを取り出し、サンプルのレオロジー分析（この実施例に関するせん断応力の範囲は、０．１６〜５２．８９Ｐａであった）を行った。この結果は、表４に列挙され、図４に図示される。
【００５３】
（表４：１０％置換されたドデシルアミド−ＨＡの０．８％溶液の粘度安定性）
【００５４】
【表１０】

表４に示されるように、ゼロ時間（コントロール）と１ヶ月インキュベーション時点との間で、粘度において、ドデシルアミド−ＨＡ組成物は、低せん断条件で、１６Ｐａ−ｓの最初のシフトを受けた。しかし、粘度は、１ヶ月インキュベーション時点から５．５ヶ月インキュベーション時点まで安定であった。
【００５５】
５．５ヶ月にわたって４℃で貯蔵したヘキサデシルアミド−ＨＡ組成物の遷移の安定性もまた、試験した。結果は、表５に開示される。
【００５６】
（表５：４℃にてリン酸緩衝化生理食塩水中で保存された８％の置換ヘキサデシルアミド−ＨＡの、粘性 対 温度安定性分析）
【００５７】
【表１１】

表５および図５に示すように、全ての組成物の粘度は、２５℃から３７℃への温度変化を通じて遷移し、２．８９Ｐａのせん断応力でその粘度の７０％〜８０％を失った。このことは、同様の出発粘度のヒアルロン酸溶液に対する、約３５％のみの粘度の喪失に匹敵する。
【００５８】
（実施例１０）
本発明のドデシルアミド−ＨＡ組成物の安定性を、以下の実験を用いて観察した。実施例７の１％（ｗ／ｖ）ドデシルアミド−ＨＡ組成物を、６ヶ月間、４℃、室温（２１〜２３℃）および３７℃でインキュベートした。適切な時点で、１アリコートの組成物を取り、ドデシルアミド−ＨＡの化学的安定性を、キャピラリーガスクロマトグラフィー（ＧＣ）を使用して分析した。ＧＣを、以下のパラメータを用いて、フレームイオン化検出器（ＦＩＤ）を備えたＨｅｗｌｅｔｔ Ｐａｃｋａｒｄ ５８９０Ａ ＧＣシステムで実行した：
【００５９】
【表１２】

使用したカラムは、Ｊ＆Ｗ Ｓｃｉｅｎｔｉｆｉｃ（Ｆｏｌｓｏｍ、ＣＡ）製のＤＢ５縮合シリカキャピラリーカラム（０．３２ｍｍの内径および１．０ｍｍの薄膜厚みを有する、長さ３０メートル）であった。
【００６０】
所定のインキュベーション時間後、サンプルを、１重量部のエタノールに対して２重量部の酢酸エチルの混合物の１当量と混合し、そして５０℃で１時間インキュベートした。この混合物に、さらに３重量部の酢酸エチル−エタノール混合物をを添加した。この第二の添加は、多糖の沈殿をもたらし、この沈殿を遠心分離して、上清を、分解疎水性基であるドデシルアミンの存在について、ＧＣによって分析した。ドデシルアミン−ＨＡの側鎖の１００％の加水分解が生じた場合、１０％の置換ドデシルアミン−ＨＡの完全な沈殿によって、上清中に４２ｐｐｍのドデシルアミンを生じた。この試験結果は、１ｐｐｍ未満のドデシルアミンが、種々の温度およびインキュベート時間を通じて、処理された組成物サンプルの上清中に存在することを示した。これらの結果は、遷移粘弾性物質のアミド結合が、緩衝化された組成物中で非常に安定であることを示した。
【００６１】
（実施例１１）
疎水性に修飾されたヒアルロン酸（ＨＭ−ＨＡ）化合物の疎水性基置換レベルの決定のためのＮＭＲ分析）
４ｍＬのガラスバイアル中に、３〜５ｍｇのＨＭ−ＨＡ物質を添加した。同じバイアル中に、０．８ｍＬの水を添加し、次いでこのバイアルを５〜１０秒間ボルテックスミキサー上で攪拌した。このサンプルバイアルを５０℃に設定したオーブン中に配置し、そして一晩（１５〜２０時間）加熱して溶解させた。次の日、ヒアルロン酸リアーゼ（６００〜９００単位／密封アンプル、カタログ番号Ｈ−１１３６、Ｓｉｇｍａ Ｃｈｅｍｉｃａｌ Ｃｏ．）酵素溶液を、密封アンプルをカチッと開け、そして約９００単位の酵素（１単位／μＬ）を含むアンプルに、０．８ｍＬの水を添加することによって調製した。次いで、このバイアルに、１００μＬ（０．１ｍＬ）の酵素溶液を添加した。このバイアルにキャップをし、そして３７℃のオーブンに一晩（１５〜２０時間）配置した。
【００６２】
次の日、このバイアルをオーブンから取り出し、そして１００μＬ（０．１ｍＬ）の重水（９９．６％原子−％Ｄ、カタログ番号４２，３４５−９、Ａｌｄｒｉｃｈ Ｃｈｅｍｉｃａｌ Ｃｏ．）をこのバイアルに添加した。混合後、この溶液を、ガラスの使い捨て移動ピペットを使用して、ＮＭＲチューブに移した。次いで、このサンプルを分析して、厳密なピーク信号取り込みを用いて、湿度抑制モードで作動し得る、６００ＭＨｚのＢｒｕｋｅｒ ＮＭＲ機器で、プロトンＮＭＲスペクトルを獲得した。
【００６３】
酵素処理したＨＭ−ＨＡサンプルのＮＭＲスペクトルを使用して、疎水性置換レベルを、０．８〜１．３ｐｐｍの疎水性残基を示す３つの信号 対 Ｎ−アセチルメチル基についての２．０〜２．１ｐｐｍでの２〜４つの信号についての積分値を、一緒に加えることによって、取り込み値から計算した。
【００６４】
０．８〜１．３ｐｐｍの間の３つの信号は、疎水性基（ｎ個の炭素原子を含む）中のＣ_２〜Ｃ_ｎ炭素に結合した水素原子に由来する。このヒアルロン酸リアーゼ酵素は、疎水性基領域においてもＮ−アセチルメチル信号領域においても、干渉信号を有さない。Ｎ−アセチルメチル基は、ＨＡ構造の反復単位毎に存在するので、疎水性置換レベルは、Ｎ−アセチルメチル基の積分値に対する疎水性基の積分値の比から計算され得る。従って、ｎ個の炭素を有する、その水性置換基としての直鎖ノルマルアルキル基［−（ＣＨ_２）_ｎ−１ＣＨ_３］で置換されたＨＭ−ＨＡ物質の置換の程度の計算を、以下の式：
％疎水性置換＝［積分０．８〜１．５ｐｐｍ／（２（ｎ−１）＋１）］／［積分２．０〜２．１ｐｐｍ／３］×１００
によって与え得る。
【００６５】
（実施例１２）
以下の実施例は、本発明のあまり好ましくない粘弾性剤の、より低い安定性を実証する。実施例１〜６の組成物と類似の組成物（ここで、この粘弾性剤は、１５％のドデシルエステル−ＨＡ、ナトリウム塩（約２００ｋＤａ）または４３％もしくは５２％のベンジルエステル−ＨＡ、ナトリウム塩（約２００ｋＤａ最終、修飾された粘弾性物質）のいずれかで置換される）を、実施例７に開示の方法と類似の様式で調製した。この組成物を、４℃、室温および３７℃で、９．５週間インキュベートした。ドデシルアルコールまたはベンジルアルコール（それぞれの疎水性エステル側鎖の分解生成物）を、実施例１０のＧＣ方法を使用して定量した。
【００６６】
所定のインキュベーション時間後、サンプルを４容量のアセトン（これは、多糖の沈殿を生じる）と混合した。次いで、沈殿した多糖を遠心分離し、そして上清を、適切なアルコールの存在について、ＧＣによって分析した。
【００６７】
ドデシルエステル−ＨＡまたはベンジルエステル−ＨＡの側鎖の完全な加水分解は、それぞれ、上清中に７０ｐｐｍのドデシルアルコールまたは４００ｐｐｍのベンジルアルコールを生じた。この結果を、表６に開示する。
【００６８】
（表６：４℃にてリン酸緩衝化生理食塩水中の保存したＨＡ−エステルの％加水分解）
【００６９】
【表１３】

上に示したように、匹敵する修飾粘弾性物質の加水分解は、種々の時点において１％より高かった。粘弾性組成物が、保存安定性を有することが所望であるので（すなわち、粘弾性生成物は、代表的に、２年の有効期限満了日を必要とする）、上記の加水分解率を示す粘弾性物質は、本発明の組成物においてあまり有用でないとみなされる。
【００７０】
（実施例１３）
５０％のカルボン酸置換でのＨＡのベンジルエステル（約２００ｋＤａ）の３％溶液を、塩化ナトリウムを有するリン酸緩衝液中および平衡塩を有するクエン酸／酢酸緩衝液中で調製した。これらの溶液は、光学的に透明な粘弾性ゲル（これは、２７ゲージの針を通して容易に吸引された）を形成した。これらの溶液は、２５℃（ｋ．ｅ．、約２００Ｐａ−ｓ）で、Ｖｉｓｃｏａｔ（登録商標）またはＰｒｏｖｉｓｃ（登録商標）と匹敵する低いせん断粘弾性を有し、２５℃で、Ｐｒｏｖｉｓｃ（登録商標）またはＶｉｓｃｏａｔ（登録商標）のようにずり減粘であった。これらの溶液は、外科的温度（２５℃）で約２００Ｐａ−ｓから、体温（３７℃）で２０Ｐａ−ｓ、までの、粘度における有意な下落を示した。
【００７１】
（実施例１４）
１４．３％のカルボン酸置換でのＨＡのドデシルエステル（約２００ｋＤａ）の１％溶液を、平衡塩を有するクエン酸／酢酸緩衝液中で調製し、透明な粘弾性溶液を形成した。この溶液は、Ｐｒｏｖｉｓｃ（登録商標）またはＶｉｓｃｏａｔ（登録商標）に匹敵する流動学的プロフィールを示した。２５℃および０．０８５／ｓを下回るずり速度での粘性は、約９０Ｐａ−ｓであった。ずり減粘は、７５Ｐａ−ｓの粘度で、０．２４／ｓで開始した。５．４／ｓでの粘度は、約１６Ｐａ−ｓに低下した。３１℃で、低いずり粘度は、たった約４５Ｐａ−ｓであった。２．８９Ｐａ−ｓでの一定のせん断応力で、この処方物の粘度は、２５℃で約１００Ｐａ−ｓから、３７℃で約２５Ｐａ−ｓに下落した。
【００７２】
（実施例１５）
１４．３％のカルボン酸置換でのＨＡのドデシルエステル（約２００ｋＤａ）の０．７５％溶液を、平衡塩を有するクエン酸／酢酸緩衝液中で調製し、透明な粘弾性溶液を形成した。この溶液は、２５℃で約２５Ｐａ−ｓの低いせん断粘度を有し、そして５３４／ｓで０．１Ｐａ−ｓ未満にずり減粘であった。この処方物はまた、一定のせん断応力（１．１Ｐａ）で、２５℃で約２５Ｐａ−ｓから、３７℃で約５Ｐａ−ｓまでの粘度の減少を示した。
【００７３】
（実施例１６）
１４．３％のカルボン酸置換でのＨＡのドデシルエステル（約２００ｋＤａ）の２％溶液を、平衡塩を有するクエン酸／酢酸緩衝液中で調製し、透明な濃い溶液を形成した。この溶液（約２ｃｃ）を、１２５℃で約２０分間の露出時間にわたってオートクレーブし、ゆっくりと排気しながら冷却した。室温まで冷却した後、この処方物は、有用な粘弾性ゲルを得るに十分な粘度を維持した。
【００７４】
（実施例１７）
カルボキシメチルセルロースのヘキサデシルエーテルの５％溶液（約１００ｋＤａで、反復単糖単位の５％にエーテル結合したヘキサデシル部分を含む）を、塩化ナトリウムを有するリン酸緩衝液中で調製した。この溶液は、透明であり、そして粘性ゲルを定性的に形成した。
【００７５】
（実施例１８）
３％の硫酸コンドロイチンを有する、ＨＡ、ナトリウム塩の２０％ドデシルアミドの１．０重量％溶液を、２日間にわたって５０℃にてゆっくりと溶解させることによって、ＰＢＳ中で調製した。ＨＡ、ナトリウム塩の２０％ドデシルアミドの１．０重量％のみを含有する別のサンプルを、２日間にわたって５０℃にてゆっくりと溶解させることによって、ＰＢＳ中で同様に調製した。溶解後、これらのサンプルを各々、別個の１０ｍＬシリンジ中に移し、そして二重ハブコネクタを１００回通して別の空のシリンジに移し、適切な混合物を提供した。サンプルを遠心分離して、気泡を除去し、そして２７ゲージの針を通してＢｏｈｌｉｎ ＣＳ−１０ Ｃｏｎｓｔａｎｔ Ｓｔｒｅｓｓ Ｒｈｅｏｍｅｔｅｒのサンプルプレート上に吸引した。流動学的分析を実行し、両方のサンプルについて、粘度 対 ２５℃でのせん断速度のプロットを得た。両方のサンプルは、粘度 対 せん断速度のプロットの、低いせん断プラトー領域において、約９０Ｐａ−ｓの明らかな粘度値を与えた。
【００７６】
（実施例１９）
以下は、ＩＯＰ Ｓｐｉｋｅ Ｍｏｄｅｌの説明である。
【００７７】
（ＩＯＰ Ｓｐｉｋｅ Ｍｏｄｅｌ）
ＩＯＰ Ｓｐｉｋｅ Ｍｏｄｅｌは、（１）図７に模式的に示されるような灌流装置、ポンプおよび圧力トランスデューサー／レコーダー；（２）灌流媒体；（３）解剖されたヒトの眼；および（４）試験される粘弾性物質を使用する。
【００７８】
（１．灌流媒体）
ＩＯＰ Ｓｐｉｋｅ Ｍｏｄｅｌにおいて使用される灌流媒体を、５ｍＬのペニシリン−ストレプトマイシン溶液（ペニシリンＧからの１０，０００単位／ｍＬペニシリン（塩基）および硫酸ストレプトマイシンからの１０，０００μｇ／ｍＬストレプトマイシン（塩基））、ならびに０．８５ｍＬのゲンタマイシン溶液（１０ｍｇ／ｍＬ）を、５００ｍＬの細胞培養培地（ダルベッコ改変イーグル培地、低グルコース、Ｌ−アラニル−Ｌ−グルタミンおよびピルベートを有する（Ｌｉｆｅ Ｔｅｃｈｎｏｌｏｇｉｅｓ、Ｇｒａｎｄ Ｉｓｌａｎｄ、ＮＹ））に添加することによって調製する。次いで、この灌流媒体を、５００ｍＬの滅菌フィルター単位（０．２μｍの孔サイズ）を使用して濾過し、そして４℃で保存する（使用前に３７度にする）。
【００７９】
（２．眼調製）
ＩＯＰ Ｓｐｉｋｅ Ｍｏｄｅｌにおいて有用な死体の眼は、以下でなければならない：ｉ）このモデルにおける使用のために調製される時点で、死後２４〜３６時間より古くてはならない；ｉｉ）加湿チャンバ内で全眼として保存されなければならない；ｉｉｉ）ＨＩＶ、肝炎または他の感染症ではない；そしてｉｖ）緑内障濾過、強膜折込移植またはＩＯＰ移植のような、眼の外科手術を受けていない。ヒトの眼の前区７（図１０を参照のこと）を、以下の解剖方法によって調製する：
眼を、まっすぐな微細な鋏（Ｋａｔｅｎａ Ｎｏ．Ｋ４−７４４０）を使用して、過剰な筋肉または結合組織から、注意深く切り取り、そしてポビドンヨード溶液（１％の遊離ヨウ素）を含む容器中に、２５℃にて約２分間配置する。次いで、この眼をヨウ素溶液から取り出し、生理食塩溶液でリンスし、そして角膜３の中心が頂点にくるように配置する（図９ａを参照のこと）。図９ａおよび９ｂを参照して、次いで、強膜５に、（滅菌眼科用三日月型ナイフ（Ａｌｃｏｎ Ｎｏ．８０６５−９４０００１）を使用して）その縁から鋸状縁に放射状に伸びる、均等に間隔を開けた２４本の直線カット９（各カットは、強膜の厚さの５０％の深さを超えず、そして約５ｍｍの長さである）で切れ目をつけて、上強膜静脈を開き、そして灌流媒体の出口経路を提供する。図９ｂを参照して、次いで眼球を、赤道面１３と強膜面１５との間のほぼ中間の水平面１１に沿って、２葉に切断する。眼の前方半分（上部）を、後方半分（下部）（これは廃棄される）から分離する。この前方半分を反転させ、その結果、角膜は下向きにされ、次いで、残りの硝子体を、Ｇｒａｅｆｅ鉗子（Ｋａｔｅｎａ Ｎｏ．Ｋ５−４８２１）を使用して、前方半分から注意深く除去する。次いで、この小帯を、Ｗｅｓｃｏｔｔ鋏（Ｋａｔｅｎａ Ｎｏ．Ｋ４−４１００）を用いて切断し、そしてレンズをＧｒａｅｆｅ鉗子を使用して前区から除去する。次いで、麦粒鉗子（Ｋａｔｅｎａ Ｎｏ．Ｋ５−４０１０）を使用して、虹彩を除去し、そして脈絡膜を、Ｗｅｓｃｏｔｔ鋏を使用して、鋸状縁で円周状に切断する。次いで、強膜の内側から、全ての残りの色素を、麦粒鉗子を用いて除去する。次いで、残りの前区７を、灌流媒体で２回リンスして、色素、組織レムナントまたは他の破片を洗い流す。
【００８０】
（３．灌流装置）
ＩＯＰスパイクモデルにおいて使用した灌流装置は、ＪｏｈｎｓｏｎおよびＴｓｃｈｕｍｐｅｒならびにＣｌａｒｋらの灌流システム（ＪｏｈｎｓｏｎおよびＴｓｃｈｕｍｐｅｒ、「Ｈｕｍａｎ ｔｒａｂｅｃｕｌａｒ ｍｅｓｈｗｏｒｋ ｏｒｇａｎ ｃｕｌｔｕｒｅ：ａ ｎｅｗ ｍｅｔｈｏｄ」、Ｉｎｖｅｓｔ．Ｏｐｈｔｈａｌｍｏｌ．Ｖｉｓ．Ｓｃｉ．、２８：９４５−９５３（１９８７）；ならびにＣｌａｒｋｅら、「Ｄｅｘａｍｅｔｈａｓｏｎｅ Ｉｎｄｕｃｅｄ Ｏｃｕｌａｒ Ｈｙｐｅｒｔｅｎｓｉｏｎ ｉｎ Ｐｅｒｆｕｓｉｏｎ−Ｃｕｌｔｕｒｅｄ Ｈｕｍａｎ Ｅｙｅｓ」、Ｉｎｖｅｓｔ．Ｏｐｈｔｈａｌｍｏｌ．Ｖｉｓ．Ｓｃｉ．、３６（２）：４７８−４８９（１９９５））において記載される改変されたバージョンである。以前のシステムに対する重大な改変は、偽水晶体のヒト前部セグメント容積の容積により近づけるための、約０．８〜１．０ｍＬから約０．５〜０．６ｍＬへのチャンバー容積の減少および、灌流の間のチャンバーの反転である。容積の減少はチャンバーのプラットホーム上に形成される島によって達成され、これは、前部セグメントのドーム内の空間を減少させ、そして後部のデット空間（すなわち、小柱網に対して後方）における粘弾性溶液の停滞を防ぐかまたは減少させるはずである。灌流の間、チャンバーを（以前のシステムに対して）上下逆さにすることにより、粘弾性物質が、陥凹の方向に高くなる島を乗り越えて灌流することにより効果的に混合されるので、角膜の陥凹で生じる粘弾性物質の停滞が防止される。
【００８１】
灌流装置１を、図７、８および１０に示す。装置１は、ベース２、シリンダー４、島６、ｏ−リング８、複数のスクリュー１０およびキャップ１２を備える。使用時に、装置１はまた、前部セグメント７を備える。
【００８２】
ベース２は、上部２２、底部２４および側部２６を有し、そしてスクリュー１０を受ける形状および大きさのチャネル１４および１６、プラットホーム１８ならびにスレッド１９を備えるディスク型である。チャンネル１４は、側面２６の開口部２８と島６の開口部２０とを連絡する。チャンネル１６は、側面２６の開口部３０とプラットホーム１８の開口部３２とを連絡する。チャネル１４および１６は、装置１を往復する灌流媒体の正確なフロー（チャンネル１４）および厳密な圧力測定（チャンネル１６）を提供するような形状および大きさである。開口部２８は、接続金具を受けるような（注入ライン２９に接続するために）大きさおよび形状であり、そして開口部３０はまた、接続金具を受けるような（変換器ライン３１に接続するために）大きさおよび形状である。この接続金具は、チュービングまたは他の円筒型ラインを受けるために有用な当該分野で公知の標準的なコネクターである。プラットホーム１８はベース２から突き出て、側部３４を有し、そして前部セグメント７を受けるために円錐状の形状および大きさである。島６はプラットホーム１８の中央から突き出る。
【００８３】
図８および１０を参照して、シリンダー４は、ベース２の上部２２上に同軸状および持続的に設置され、そしてそこから同一平面状に延びる。島６は開口部２０を有し、チャネル１４の一部分を備え、そしてプラットホーム１８から伸びる。ｏ−リング８は、溝付きくぎ、凹面の内端部３６およびｏ−リング８を通ってスクリュー１０を受けるための大きさおよび形状の複数のホール３８を備える。端部３８は、装置１を使用する場合、ベース２に対するｏ−リング８の圧縮が、端部３６とプラットホーム１８の側部３４の間の前部セグメント７の周縁部をサンドイッチして、前部チャンバー４２を形成する大きさおよび形状である。上記のように、前部チャンバー４２の容積は、前部チャンバーとヒト目の水晶体レンズとを組み合わせた容積（一般に約０．５〜０．６ｍＬ）に近づけるために、本発明者らによって設計された。
【００８４】
図８および図１０に示すように、キャップ１２は、シリンダー４の一部分を受け、閉鎖した空間４０を形成する形状および大きさである。ＩＯＰスパイクモデルについての好ましい灌流装置は、ポリサルフォンのベース２、ポリサルフォンの島６、ポリサルフォンのｏ−リング８、ナイロンのスクリュー１０、透明なポリサルフォンのシリンダー４、医療用スチールのチャネル１４および１６ならびに透明なポリスチレンのキャップ１２を使用する。
【００８５】
（４．灌流装置のアセンブリおよび調製）
使用の前に、装置１を分解し、そして個々の部材をオートクレーブ処理するか、または低温度滅菌し、次いでスポリシジン（ｓｐｏｒｉｃｉｄｉｎ）滅菌溶液（５０ｍｌ／Ｌ 水）を用いて層状のフローチャンバーを浸し、続いて滅菌脱イオン水において一晩リンスした。
【００８６】
図７および１０を参照して、灌流媒体を、注入ライン２９（チャンネル１４を通ってチャンバー４２中に灌流培地を注入する）に順々に接続されるポンプで送り；そして変換器ライン３１を、校正圧力変換器およびチャンバー４２の圧力を記録し得る記録計とに接続する。次いで、開口部２８および３０に配置した接続金具を、それぞれ注入ラインおよび変換器ラインに最初に接続することによって、装置１を再組立てする。次いで、装置１を上部２２を上に面して再配置する。前部セグメント７をプラットホーム１８上に、角膜側を上にして配置する。次いで、わずかな灌流媒体フローをシリンジによってチャンネル１６を通して適用させ、プラットホーム１８上のセグメント７を適切に収容する。次いで、ｏ−リング８（これは、外周の直径が約１．５インチであり、内部の直径が０．７１０〜０．７３６インチである）を、セグメント７上に配置する。ｏ−リング８がセグメント７を十分に収容し、漏出を回避することが重要である（わずかに異なる直径のｏ−リング８が、収容を改善するために使用され得る）。スクリュー１０をホール３８を通してスレッド１９に挿入し、そして密接させ、ｏ−リング８が均一に収容されることを確実にする。ｏ−リング８はセグメント７の周縁部上に密接されるので、過剰な圧力が収容しているセグメント７に加わらないように、チャンネル１６を通して適用されたフローを解放する。セグメント７の周縁部を、プラットホーム１８とｏ−リング８の間にきつく（セグメント７が破裂するきつさではない）サンドイッチするように、ベース２に対してスクリュー１０を回転させる。次いで、シリンジを用いて、灌流媒体をチャンネル１４を通して押し出すが、同時に灌流媒体をチャンネル１６から開口部３０を通って引き抜き、存在するどんな気泡もチャンネル１６を経由してチャンバー４２から流出させるようにベース２を傾ける。気泡をパージした後、チャンネル１４および１６を閉めて、媒体フローを灌流させる。次いで、装置１を上部２２を上にして水平に反転させる。
【００８７】
次いで、キャップ１２をシリンダー４上に配置し、それによって空間４０を形成する。次いで装置１を底部２４が上を向くように反転させ、そして組織培養インキュベーター（Ｎｕａｉｒｅ）内（３７℃で加湿された雰囲気下（５％ ＣＯ２／９５％空気）を維持する）に置く。変換器ライン３１および注入ライン２９は、インキュベーター扉のシールに対して配置されるべきであり、扉が閉まっているときは、損傷も妨害も受けない。圧縮変換器は装置１のレベルを維持し続けるべきである。この形状において、装置１はＩＯＰスパイクモデルにおいて現在容易に使用され得る。
【００８８】
（５．初期の灌流）
灌流ラインを開け、ポンプを作動させ（Ｈａｒｖａｒｄ Ｍｏｄｅｌ番号９４４の場合、設定「６」）、灌流媒体を開口部２８およびチャンネル１４を通して自由にフローする。このポンプを、圧力が約５〜１０ｍｍＨｇに上昇するまで働かせ、その後ポンプの速度を約２μＬ／分（設定「１２」）に下げる。セグメント７を、粘弾性物質候補物の注入より約２４時間前までに灌流する。安定な基線（１０〜４０ｍｍＨｇの間の圧力で）が２４時間以内に確立しない場合、このフロー速度は安定な基線ＩＯＰが達成するまで、２〜３ｍｌの灌流容積ごとに繰り返し調節され得る。この問題が次の２４時間にわたって解決せず、後のフロー速度の調節およびフラッシング工程が４８時間以内に処理されない場合、前部セグメント７は信用できず、そして灌流を終了するべきである。
【００８９】
（６．粘弾性物質の注入および灌流）
一旦、前方セグメント７が、少なくとも４時間にわたって１０〜４０ｍｍＨｇの間の安定な基線ＩＯＰを生成すると（約１．７５〜２．０５μＬ／分の間の灌流速度）、ＩＯＰスパイク研究の準備が整う。代表的に、このようなポイントは最初の灌流から２４時間後に達成される。このモデルを、「ポジティブ」コントールの注入により最初に確認する。ポジティブコントロールは０．５ｍＬの希釈したヒアルロン酸ナトリウム（約７５０ｋＤａｌ Ｌｉｆｅｃｏｒｅ Ｂｉｏｍｅｄｉｃａｌ，Ｉｎｃ．製、Ｃｈａｓｋａ、ＭＮ）であり、これは、緩衝化溶液の１割の３．５％ ＨＡを、同じ緩衝化溶液の９割に希釈することによって調製する。ここで、各々１ｍＬの緩衝化溶液は約０．４５ｍｇのリン酸二水素ナトリウム水和物、２．００ｍｇのリン酸１水素２ナトリウム、４．３ｍｇの塩化ナトリウム（Ｗａｔｅｒ Ｆｏｒ Ｉｎｊｅｃｔｉｏｎ、ＵＳＰグレード、ｑ．ｓ．を用いる）を含み、中性のｐＨを有する。ポジティブコントロールの０．５ｍＬの希釈したＨＡ（０．３５％）を、灌流ライン２９上の多弁アセンブリ３３に取り付けた同じ容積のチュービングループに注入し、多弁アセンブリ３３を切り替えて、完全なサンプルの容積を灌流装置１に流入させる。従って、注入速度は灌流速度によって決定される。ＩＯＰを持続的にモニターし、記録する。基線ＩＯＰを超えた任意のＩＯＰスパイクを観察し、記録する。ポジティブコントロールが注入の２４時間以内で基線を超えて、２０〜８０ｍｍＨｇの間のＩＯＰスパイクを生じる場合、このモデルは正当であると考慮され、そして候補の遷移粘弾性物質を試験するために使用され得る。
【００９０】
一般的に、遷移粘弾性サンプルをまた、一日の間隔で単一の前部セグメントに２回注入し得る（第１の注入はポジティブコントロールである）。サンプル粘弾性物質を、コントロールサンプルを調製するために使用したのと同じ緩衝化溶液を用いて最初の濃度の１／１０に希釈すべきである。先の粘弾性物質サンプルによって生じる任意のＩＯＰスパイクの減退によって示されるように、安定であり、かつ受容可能な基線ＩＯＰが新規の各注入の前に達成されるべきである。基線ＩＯＰが１日以内に１０〜４０ｍｍＨｇの範囲内に回復しない場合、所定の前部セグメントにおけるさらなる灌流を中止するべきである。
【００９１】
上に述べたように、本発明の遷移粘弾性物質（すなわち、ＩＯＰスパイクををほとんど生じないか、または全く生じない）は、１０ｍｍＨｇの平均スパイクを示すか、または基線超えない。
【００９２】
（実施例２０）
本発明の遷移粘弾性物質（ＡＬ−１２４８８、４３％置換ベンジルエステル改変ＨＡ（約２００ｋＤａｌ））を、上記のＩＯＰスパイクモデルにおいて試験し、そしてポジティブコントロール（Ｂｅｎｃｈｍａｒｋ）および２００ｋＤａｌ ＨＡ（Ｆｉｄｉａ社製）と比較した。この研究結果を図１１に図示する。矢印は、種々の注入を示す。注入１および４はポジティブコントロールＨＡの０．３５％であり、注入２はＦｉｄｉａ無改変ＨＡの０．３５％および注入３はＡＬ−１２４８８の０．３５％であった。すべての注入サンプルは０．５ｍｌの容積であった。アスタリスクは注入から生じた個々のＩＯＰスパイクを示す。遷移粘弾性物質（ＡＬ−１２４４８）のみがＩＯＰスパイクをほとんど示さないかまたは全く示さないように特徴付けられ得る。なぜなら、ＩＯＰスパイクモデルにおいて観察されるスパイクは、基線ＩＯＰを超えて、約１０ｍｍＨｇ以下であり、実際は約１０ｍｍＨｇにかなり満たないからである。
【００９３】
外科的手順の特定の工程に対して、所定の遷移粘弾性物質の適合性は、例えば、粘弾性物質の濃度、平均分子量、粘性、偽可塑性、弾性、硬性、接着性（被覆性（ｃｏａｔａｂｉｌｉｔｙ））、粘着性（ｃｏｈｅｓｉｖｅｎｅｓｓ）、分子電荷および溶液の浸透性に依存することを、当業者は理解する。この粘性物質の適合性はさらに、粘弾性物質により発揮されることが予期される機能および外科医によって使用される外科的技術に依存する。
【００９４】
適切な緩衝液系（例えば、リン酸ナトリウム、酢酸ナトリウムまたはホウ酸ナトリウム）が、貯蔵条件下でのｐＨドリフトを防ぐために組成物に添加され得る。
【００９５】
本発明の遷移粘弾性物質の全てまたは大部分が、手術の終了した目に残され得るので、これらの粘弾性物質は、粘弾性外科手段および薬物送達装置の二重の役割を果たすことに唯一適合する。
【００９６】
本発明の組成物における使用のために適切な眼科用の薬物は、以下が挙げられるが、これらに制限されない：抗緑内障薬剤（例えば、β遮断薬（チモロール、ベタキソロール、レボベタキソロール（ｌｅｖｏｂｅｔａｘｏｌｏｌ）、カルテオロール（ｃａｒｔｅｏｌｏｌ）、ピロカルピンを含む模倣物、炭酸脱水酵素インヒビター、プロスタグランジン、セラトニン作動薬（ｓｅｒａｔｏｎｅｒｇｉｃ）、ムスカリン作動薬、ドーパミン作動性アゴニスト、アプラクロニジンおよびブリモニジンを含むアドレナリン作動性アゴニストを含む）；抗感染剤（シプロフロキサシンのようなキノロンならびにトブラマイシンおよびゲンタマイシンのようなアミノグリコシドを含む）；非ステロイドおよびステロイド抗炎症剤（例えば、スプロフェン、ジクロフェナク、ケトロラック、リメキソロン（ｒｉｍｅｘｏｌｏｎｅ）およびテトラヒドロコルチゾール；増殖因子（例えば、ＥＧＦ）；免疫抑制剤；ならびにオロパタジンを含む抗アレルギー剤）。眼科用薬物は、薬学的に受容可能な塩（例えば、マレイン酸チモロール、酒石酸ブリモニジンまたはジクロフェナクナトリウム）の形態において存在し得る。本発明の組成物はまた、以下の（ｉ）および（ｉｉ）の組み合わせのような眼科用薬物の組み合わせを含み得る：（ｉ）ベタキソロールおよびチモロールからなる群より選択されるβ遮断薬ならびに（ｉｉ）ラタノプロスト；１５−ケトラタノプラスト；フルプロステノール（ｆｌｕｐｒｏｓｔｅｎｏｌ）イソプロピルエステル（特に、ｌＲ−［ｌα（Ｚ），２β（ｌＥ，３Ｒ^＊），３α，５α］−７−［３，５−ジヒドロキシ−２−［３−ヒドロキシ−４−［３−（トリフルオロメチル）−フェノキシ］−ｌ−ブテニル］シクロペンチル］−５−ヘプテン酸，１−メチルエチルエステル）；およびイソプロピル［２Ｒ（ｌＥ，３Ｒ），３Ｓ（４Ｚ），４Ｒ］−７−［テトラヒドロ−２−［４−（３−クロロフェノキシ）−３−ヒドロキシ−１−ベテニル］−４−ヒドロキシ−３−フラニル］−４−ヘプテン酸からなる群から選択されるプロスタグランジン。
【００９７】
薬学的薬剤が遷移粘弾性物質に添加される場合には、このような薬剤は、水への溶解度を制限され得、それゆえ、組成物中に界面活性剤または他の適切な共溶媒を必要とし得る。このような共溶媒としては、代表的に以下が挙げられる：ポリエトキシ化カスター油、Ｐｏｌｙｓｏｒｂａｔｅ ２０、６０および８０；Ｐｌｕｒｏｎｉｃ（登録商標）Ｆ−６８、Ｆ−８４およびＰ−１０３（ＢＡＳＦ Ｃｏｒｐ．、Ｐａｒｓｉｐｐａｎｙ ＮＪ、ＵＳＡ）；シクロデキストリン；または当業者に公知の他の薬剤。このような共溶媒は代表的に、約０．０１〜２重量％のレベルで使用される。手術の間に粘弾性物質の可視化を改善するために、および／またはこのような組織の改善された可視化について、眼性組織（特に、白内障手術における皮膜破裂（ｃａｐｓｕｌｏｒｈｅｘｉｓ）の間の皮膜バッグ）を染色するために、薬学的に受容可能な染料を粘弾性物質に添加することがまた所望され得る。従来の粘弾性物質におけるこのような染料の使用は、ＷＯ９９／５８１６０に記載されている。好ましい染料としては、トリパンブルー、トリパンレッド、ブリリアントクライシル（ｃｒｙｓｙｌ）ブルーおよびインドシアニングリーンが挙げられる。粘弾性溶液における染料の濃度は、好ましくは約０．００１重量％と２重量％の間であり、最も好ましくは、約０．０１重量％と０．１重量％の間である。しかし、任意のこのような添加物（薬剤、共溶媒または染料）は、これらが本発明の組成物の粘弾性特性に決定的な影響を与えない程度でのみ使用され得ることが、当業者に理解される。
【００９８】
本発明の方法はまた、異なる接着特性または粘着特性を有する種々の粘弾性薬剤の使用を包含する。本発明の組成物は、種々の外科手順において熟練の外科医により使用され得ることが、当業者に認識される。
【００９９】
各々の型の粘弾性物質の利点を考慮すれば、外科医は、１回の外科手順において、本発明の種々の粘弾性組成物を使用し得る。本発明の遷移粘弾性物質の使用は、外科手術における使用についてこれまで開示されていないが、米国特許第５，２７３，０５６号（ＭｃＬａｕｇｈｌｉｎら）は、所定の眼の外科手術の間に粘弾特性が変化する粘弾性物質を含む組成物の使用を利用する方法を開示している（この文献の全内容は、本明細書中で参考として援用される）。
【０１００】
例えば、水晶体超音波吸引および／または灌注／吸引を含む外科手順の部分（例えば、白内障外科手術）のために、比較的高い接着特性および比較的低い粘着特性を有する粘弾性薬剤を使用することが一般的に好ましい。本明細書では、このような粘弾性薬剤を「接着性」薬剤と呼ぶ。溶液中の粘弾性薬剤の粘着性は、少なくとも一部、その薬剤の平均分子量に依存すると考えられる。所定の濃度において、分子量が大きくなれば、粘着性も大きくなる。デリケートな組織の操作を含む外科手順のこれらの部分は、一般的に、比較的高い粘着特性および比較的低い接着特性を有する粘弾性薬剤によってより活かされる。本明細書では、このような薬剤を、「粘着性」薬剤と呼ぶ。保護目的と反対に、主に組織操作または維持目的で主に使用される、このような粘着性薬剤について、機能的に望ましい粘度は、熟練の外科医が、このような薬剤を、実施されている外科工程の間に目的の組織を操作または支持するための柔らかいツールとして使用することを可能にするのに十分な粘度である。
【０１０１】
組織操作目的とは反対に、主に保護目的で主に使用されている他の粘弾性薬剤（「接着性」薬剤）について、機能的に望ましい粘度は、このような薬剤の保護層が、外科工程が実施される間、目的の組織または細胞上に留まることを可能にするのに十分な粘度である。このような粘度は、代表的に、約３，０００ｃｐｓ〜約６０，０００ｃｐｓ（せん断速度２秒^−１、および２５℃）であり、好ましくは、約４０，０００ｃｐｓである。このような接着性薬剤は、先に記載された保護機能を提供し得るが、保護されているデリケートな組織を危険にさらし得る不慮の除去は起こらない。残念ながら、この同一の特性により、（白内障外科手術において全てのこのような市販品に対して推奨される）外科手術の最後のこのような接着性粘弾性物質の吸引が、外科医の問題となり、そしてこの特性により、除去手順時に、コーティングされた組織が外傷にさらされ得る。本発明の遷移粘弾性物質の重要な利点は、それらが、外科手術の最後に外科部位に留められ得、それによって、罹患した柔組織に対する不必要な外傷を回避し得ることである。
【０１０２】
本発明の好ましい方法は、所定の外科手順において複数の粘弾性物質を使用し得、このような粘弾性物質の少なくとも１つは、遷移粘弾性物質である。本発明の最も好ましい実施形態において、より優れた接着特性を有する遷移粘弾性は、白内障外科手術において使用され、この外科手術の最後に、遷移粘弾性物質の一部または全てがインサイチュに留められ、そしてＩＯＰスパイクをほとんど生じないかまたは全く生じない。
【０１０３】
本発明は、特定の好ましい実施形態に言及することにより記載されているが、本発明の意図または必須の特徴から逸脱することなく、他の特定の形態またはその変形で実施され得ることが理解されるべきである。従って、上述の実施形態は、全ての局面において例示であって限定ではないとみなされ、本発明の範囲は、前述の詳細な説明ではなく添付の特許請求の範囲により示される。
【図面の簡単な説明】
【図１】
図１は、本発明のドデシルアミドＨＡおよびコントロールＨＡに関する、濃度の関数としての粘度を示すグラフである。
【図２】
図２は、本発明のオクチルアミドＨＡのせん断速度の関数としての粘度を示すグラフである。
【図３】
図３は、本発明のオクチルアミドＨＡの遷移粘度を示すグラフである。
【図４】
図４は、オートクレーブで処理された本発明のドデシルアミドＨＡの粘度安定性を示すグラフである。
【図５】
図５は、本発明のヘキサデシルアミドＨＡの遷移挙動の安定性を示すグラフである。
【図６】
図６は、本発明のエステル化ＨＡの加水分解速度を示すグラフである。
【図７】
図７は、本発明のＩＯＰスパイクモデルの略図である。
【図８】
図８は、本発明の灌流装置の分解立面図である。
【図９ａ】
図９ａは、還流装置での使用のための眼の頂部平面図である。
【図９ｂ】
図９ｂは、図９ａの眼の側面図である。
【図１０】
図１０は、図８に前方の部分を含めた、本発明の灌流装置の断面図である。
【図１１】
図１１は、本発明のＩＯＰスパイクモデルを使用したＩＯＰに対する、本発明の伝統的な粘弾性物質および遷移粘弾性物質の効果を示すグラフである。[0001]
(Field of the Invention)
The present invention relates to the field of viscous and viscoelastic materials suitable for use in surgical procedures. In particular, non-suction viscoelastics are disclosed, including transitional viscoelastics (with variable viscosities associated with non-shearing properties), which may be left in situ at the end of surgery . Also disclosed is a method of using the transition viscoelastic material in surgery, particularly eye surgery.
[0002]
(Background of the Invention)
Viscous or viscoelastic agents used in surgery can perform many different functions, including (without limitation) soft tissue maintenance and support, tissue manipulation, lubrication, tissue protection, and anti-adhesion. It is recognized that the different rheological properties of these drugs necessarily affect their ability to perform these functions and, consequently, their suitability for a particular surgical procedure. See, for example, U.S. Patent No. 5,273,056.
[0003]
Cataracts are opacity of the lens of the eye, which generally occurs in the elderly. To improve vision, the cataractous lens is surgically removed and an artificial intraocular lens is inserted in its place. During these surgical procedures, viscoelastic materials are typically injected into the anterior chamber and the capsular bag to prevent collapse of the anterior chamber and to protect tissue from damage resulting from physical manipulation.
[0004]
Numerous viscous or viscoelastic agents (hereinafter "drugs") are known for ophthalmic surgical applications. For example, the following are all useful in cataract surgery: Viscoat® (Alcon Laboratories, Inc.) (containing sodium hyaluronate and chondroitin sulfate); Healon® and Healon® GV (Pharmacia) Corp.), Amvisc® Regular and Amvisc® Plus (IOLAB), and Vitrax® (Allergan), which all contain sodium hyaluronate; and Cellugel® (Alcon). ), Which contains hydroxypropyl methylcellulose (HPMC). These may be used for several purposes, including maintenance of the anterior chamber of the eye during surgery and protection of ocular tissues, particularly corneal endothelial cells, and as an aid in manipulating ocular tissues. Used by physicians.
[0005]
All of the above agents may be used during cataract surgery, but each has certain recognized advantages and disadvantages. See U.S. Patent No. 5,273,056. In general, however, all drugs that have sufficient viscosity and pseudoplasticity to be useful in ophthalmic surgery are "IOP spiked" when left in the eye at the end of surgery. Produces a transient increase in intraocular pressure ("IOP"), known as (See Obstbaum, Postperative pressure evolution. A relational approach to it's presentation and management, J. Catalyst Refractive Surgery 18: 1 (1992). This increase in pressure contributed to the fact that these agents interfere with the normal outflow of aqueous humor through the trabecular meshwork and Schlemm's canal (Berson et al., Obstruction of Aqueous Outflow by Sodium Hyaluronate in Enc.Human Eyes. Ophthalmology, 95: 668 (1983); Olivius et al., Intraocular pressure after character surgery with Healon (registered trademark); Am. Intraocular implant Soc. J. 11: eoprotoPr. Healon Amvis, and Viscoat, J.Cataract Refractive Surgery 15: 415 (1989)). IOP spikes, depending on their amplitude and duration, can cause significant and / or irreversible damage to susceptible eye tissue, including but not limited to the optic nerve.
[0006]
Thus, the ease with which a drug can be removed from a surgical site (typically by aspiration) has traditionally been considered an important feature in the overall assessment of drug usefulness in cataract surgery. By removing this drug before the end of surgery, physicians expect to minimize or avoid any significant IOP spikes. However, unfortunately, removal of drugs that are relatively dispersive (as opposed to sticky) or adherent to ocular tissue is often difficult and can cause additional trauma to the eye.
[0007]
Extrinsic dilution of viscoelastic materials has been suggested to mitigate IOP spikes. See U.S. Patent No. 4,328,803. However, depending on the particular viscoelastic material used and the surgical technique, IOP spikes can still be a problem. More recently, it has been suggested that administering degradable agents to destroy conventional viscous or viscoelastic agents in the eye may reduce or avoid the occurrence of IOP spikes. See, for example, U.S. Patent No. 5,792,103. Such an approach involves not only the administration of a second enzyme drug (provided that it must be biocompatible) to the eye; a means to properly mix the two drugs with a special device Also need.
[0008]
Viscoelastic materials have also been recommended as drug delivery devices for pharmaceutical agents to be administered when the viscoelastic material is applied during surgery. For example, US Patent No. 5,811,453 (Yanni et al.) Discloses viscoelastic materials containing anti-inflammatory compounds and methods of using these enhanced viscoelastic materials in cataract surgery. While this approach may ameliorate ocular inflammation resulting from surgical trauma, such an approach still has significant limitations, as described above, which exhibit the problem of IOP spikes. As a result, these enhanced viscoelastic materials still need to be aspirated at the end of the surgical procedure.
[0009]
Accordingly, a need exists for improved means for reducing or avoiding IOP spikes associated with the use of conventional viscous or viscoelastic agents in ophthalmic surgery, particularly cataract surgery. More specifically, an improved viscous agent or viscosity having a variable or transitional viscosity, such that, without the addition of a disintegrant, the viscosity will be substantially lower after its purpose has been fulfilled in surgery. The present inventors have recognized the need for an elastic agent (such agents are hereinafter referred to as transition viscoelastic materials). Significant amounts of such transition viscoelastic materials can then be left in the eye by a physician and removed by the body's natural processes without causing dangerous IOP spikes.
[0010]
Transition viscosities are known to occur in certain systems. In the ophthalmic field, liquid systems are known which form a gel after being applied to the eye. For example, such gelling can be initiated by a pH change. Gurney et al., "The Development and Use of In Situ Formed Gels, Triggered by pH," Biopharm. Ocul. See Drug Delivery, (1993) pp. 81-90. Temperature sensitive gelling systems also provide for certain ethyl (hydroxyethyl) cellulose ethers (EHEC) when mixed at appropriate concentrations with certain ionic surfactants (Carlsson et al., "Thermal Gelation of Nonionic Cellulose Ethers and Ionic"). Surfactants in Water, "Colloids Surf., Vol. 47, pp. 147-65 (1990), and a system of pure methylethylcellulose (US Pat. No. 5,618,800 (Kabra et al.)). More recently, U.S. Patent No. 6,177,544 disclosed a modified collagen for ophthalmic use, which was reported to lose viscosity upon denaturation and facilitate removal. However, no commercial embodiment of such a material is considered to be available. Carrageenans that can be adjusted to control the viscous transition to different temperature ranges are also known (Verschueren et al., "Evaluation of various carrageenans as an ophthalmic viscolysers", STP Pharma Sci, Vol. 6, pp. 203-210d, Vol. 6, pp. 203-210d). See Pickellell et al., "Gelling Carrageenans," Food Polysaccharides and Their Applications, Ed: Stephen, AM, Marcel Dekker: New York, 67, 204-44 (1995). Finally, gellan gum (Gelrite®) is known to form a gel when contacted with the specification. Greaves et al., "Scintographic Assessment of an Ophthalmic Gelling Vehicle in Man and Rabbit," Curr. Eye Res. 9, Vol. 415, (1990). The gellan system has been suggested for use as a vehicle for ophthalmic dosing (Rozier et al., "Gelrite: A Novel, Ion-Activated, In Situ Gelling Polymer for Ophthalmic Vehicles Biotechnology. Biotechnology. Biotechnology. Biotechnology. Biotechnology. Pharm., 57, 163 (1989)), and certain gellans are currently marketed with timolol (a beta blocker) as a glaucoma drug.
[0011]
However, the use of non-collagen-based transition viscous viscoelastic agents as effective surgical tools, particularly in eye surgery, has not been disclosed or suggested in the art. In addition to having the desired initial viscosity transition viscosity over a given temperature range to be most effective for use as an eye surgery tool, the drug preferably meets the following requirements: physiologically Acceptable osmolality and pH; relatively short viscous transfer time; clear (no turbidity); biocompatible; and sterilizable. It is believed that the transition viscoelastic materials of the present invention meet these requirements.
[0012]
(Summary of the Invention)
The present invention relates to improved viscous or viscoelastic agents for use in surgical procedures, particularly ophthalmic surgical procedures. More particularly, the present invention relates to any agent having a desired initial viscosity that produces an acceptable IOP spike profile in the IOP spike model described below. The improved agents of the present invention include transition viscosity or transition viscoelastic polymeric agents suitable for use in ophthalmic surgery. As used herein, the term "transition viscoelastic" refers to maintaining high viscosity during a surgical procedure, but reducing or avoiding the occurrence of dangerous IOP spikes, and An agent that rapidly loses viscosity after the end of surgery to reduce or prevent the need for active removal of the viscoelastic material at the end of the procedure.
[0013]
Recognizing that the surface temperature of the ocular tissue during surgery is about room temperature or below about 25 ° C., we maintain an appropriate viscosity at this temperature, but maintain a slightly higher temperature ( That is, a drug that rapidly loses viscosity at body temperature (about 37 ° C.) was discovered. The loss of viscosity that occurs without the addition of exogenous degradants is primarily caused by warming the eye back to body temperature after the surgery is completed.
[0014]
The stability of the transition viscoelastic materials of the present invention is a particularly important feature of the present invention. If the drug undergoes substantial hydrolysis, oxidation or other degradation prior to use, the drug loses its viscous properties and yields a viscoelastic material that is not or less useful. Preferred transition viscoelastic compositions of the present invention are substantially stable, exhibiting less than 1% degradation at storage temperature for up to 6 months. These compositions are used in conventional cataract surgery and, when left in the eye after surgery, produce little or no IOP spikes (defined below).
[0015]
Materials suitable for use as transition viscoelastic materials include, without limitation, the following: hydrophobically modified polysaccharides or mucopolysaccharides (eg, hyaluronic acid and its salts) (HA) (surfactant) With or without an agent); dialyzed amphoteric polyelectrolyte or dialyzed mixture of oppositely charged polyelectrolytes; polysaccharides or mucopolysaccharides with cationic hydrophilic polymers (eg HA); temperature Polysaccharides and hydrophilic synthetic polymers that exhibit dependent conformational changes; and combinations thereof. Polysaccharides or mucopolysaccharides modified to be hydrophobic are preferred. HA modified to be hydrophobic (particularly HA-amides) is most preferred.
[0016]
(Detailed description of the present invention)
The present invention relates to viscoelastic materials, and in particular to transition viscoelastic materials, compositions and methods of use. The primary use of transition viscoelastic materials is in surgical applications where the transition viscoelastic material is applied during surgery in a more viscous state and loses substantial viscosity in situ after surgery. A preferred use for the transition viscoelastic material is in cataract surgery, where the viscoelastic material is i) in the anterior chamber to maintain the dome and protect exposed tissue; and / or ii) in capsule form It is dropped in the anterior chamber to inflate the bag. After surgery, the viscoelastic material remaining in the eye is heated by the body to the surrounding body temperature, loses its viscosity, and is more easily removed (than non-transition viscoelastic material) by ocular processes. A major advantage in this preferred application is the avoidance of IOP spikes that can occur with other systems. Thus, another advantage of this application is that it allows the physician to take advantage of the traditional benefits of viscoelastic materials without the disadvantage of having to completely aspirate the viscoelastic material from the surgical site after the surgery is completed. It is. As noted above, such aspiration is time consuming and presents additional risks to the patient.
[0017]
The transition viscoelastic materials of the present invention typically exhibit a loss of viscosity of 70% or more without substantial hydrolysis, wherein such materials are used at about room temperature or at operating temperatures (about 17- (26 ° C.) to approximately body temperature (about 35-38 ° C.).
[0018]
As noted above, the preferred transition viscoelastic materials of the present invention are substantially stable. As used herein, "substantially stable" refers to a viscoelastic material that loses less than 1% of these hydrophobic side chains due to hydrolysis, oxidation, or other degradation. The viscoelastic material is stored at a refrigeration temperature of about 4 ° C. for up to 6 months.
[0019]
The transition properties of the viscoelastic materials of the present invention are preferably reversible. The reversible viscosity properties of the preferred embodiment allow the transition viscoelastic material to be heated before use (eg, heat sterilization) and then re-cooled for surgical application.
[0020]
Additional preferred properties of the transition viscoelastic materials of the present invention include: (1) a transit time of less than about 2 hours after surgery; (2) an optical with little or no turbidity. (3) safe adhesion to ocular tissue (ie, the ability to provide a protective coating on delicate tissue); and (4) biocompatibility.
[0021]
As noted above, when used in cataract surgical procedures, the most important feature of the transition viscoelastic materials of the present invention is that they have little or no IOP spikes after such surgery. For purposes of the present invention, 0.5 ml of a 10% solution (ie, the actual product composition diluted to 10% of its original concentration, including a buffered isotonic salt solution) was identified as described below. A transition viscoelastic material is deemed to exhibit "little or no IOP spikes" if it produces an IOP spike above the baseline IOP in the failed IOP spike model ("IOP Spike Model") which does not exceed an average of about 10 mmHg. .
[0022]
Without being bound by theory, we believe that the transition viscoelastic characteristics of the compositions of the present invention may result in relatively low molecular weight molecules that, at a given concentration, result in a viscosity that exceeds that expected from such low molecular weight molecules. Assume that it can be attributed to the physical association between them. Typically, the transition viscoelastic material of the present invention is a modified viscoelastic material, wherein a hydrophobic side chain is covalently linked to the viscoelastic compound. Unmodified viscoelastic materials can be substituted, to varying degrees, with various moieties to produce the transition viscoelastic materials of the present invention. For example, the appropriate side chains of all viscoelastic materials (eg, for the ester and amide transition viscoelastic materials described further below) can be substituted (ie, 100% substituted). , Or some side chains may be substituted (eg, 15% substitution). Generally, transition viscoelastic materials are derived from known viscoelasticity or modified to exhibit the properties described above. Examples of commercially available viscoelastic materials useful in preparing transition viscoelastic materials include hyaluronic acid (eg, sodium hyaluronate (HA)), salts of chondroitin sulfate (CS) and hydroxypropyl methylcellulose (HPMC), and HA and There is a combination of CS. Other viscoelastic materials useful in preparing transition viscoelastic materials include dialyzed amphoteric polyelectrolytes (eg, carboxymethylcellulose).
[0023]
Transition viscoelastic materials can be composed of viscoelastic polymers of various molecular weights. Generally, the average molecular weight of the unmodified polymer ranges from 50,000 to 1,000,000 daltons. For HA-based transition viscoelastic materials, the average molecular weight of the unmodified HA polymer backbone is preferably from about 120,000 to about 400,000 daltons (weight average molecular weight) and from about 50,000 to about 350,000 daltons ( (Number average molecular weight). These preferred unmodified HAs at conventional concentrations exhibit insufficient viscosity for the preferred surgical purpose. The molecular weight of the viscoelastic material can be determined by gel permeation chromatography (GPC) (also known as size exclusion chromatography (SEC) using light scattering or against a standard molecular weight of known molecular weight using the detection of refractive index. )). Molecular weight typically affects the degree of viscosity of these known viscoelastic materials. All molecular weights for transition viscoelasticity described herein are, unless otherwise indicated, the number average molecular weight of the unmodified viscoelastic polymer before modification to the transition viscoelastic material.
[0024]
HA (free acid and salt form) can be modified to exhibit the above properties, and is therefore useful as the transition viscoelastic material of the present invention. For example, a dodecyl moiety can be covalently linked to a carboxylic acid group on the backbone of HA to form its dodecyl ester. As used herein, HA modified by esterification of these side chains with various moieties is referred to as "HA-ester". Examples of esters that can be substituted on the carboxylic acid group of HA include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, Alkyl groups such as dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, or any other alkyl group containing up to 30 carbons; cycloalkyl groups (eg, cyclohexyl); and aryl groups ( For example, phenyl); as well as any isomers of the foregoing groups. Such substituents may be further substituted, if desired, and may optionally include therein atoms selected from the group consisting of O, N, and S. Such HA esters are available from Fijia Advanced Biopolymers (Abano Terme, Italy) or are known in the art (eg, US Pat. Nos. 5,466,461; 5,616,568). No. 5,652,347, the contents of which are incorporated herein by reference. The degree and type of such substitution affects low or apparent viscosity and low shear tack, as well as viscosity and adhesion at elevated temperatures. Hydrophobic substituents are preferred.
[0025]
Since there are several factors that influence the hydrodynamic properties of the compositions of the present invention, such as the type and degree of substitution, the average molecular weight and concentration of the viscoelastic polymer (unmodified), various parameters of the various The composition can produce similar hydrodynamic properties. For example, a 0.88% w / v solution of 200 kDal HA substituted 14% with dodecylated carboxyl groups, a 1.2% w / v solution of 200 kDal HA substituted 11% with dodecylated carboxyl groups, and hexadecylation All 2.55% w / v solutions of 200 kDal HA substituted 4% with carboxyl groups show similar viscosity and transition behavior. Thus, the transition viscoelastic materials of the present invention can be characterized by a "viscosity factor", which is determined by the following equation:
Concentration × molecular weight × substitution% = viscosity factor
(W / v%) (unmodified polymer
(Kilodalton))
The transition viscoelastic material of the present invention has a viscosity factor ranging from about 200 to about 50,000. The preferred transition viscoelasticity of the present invention has a viscosity factor in the range of about 1000 to about 20,000. Most preferred are transition viscoelastic materials having a viscosity factor of about 2000 to about 10,000.
[0026]
As those skilled in the art will appreciate that compositions of various parameters can produce similar hydrodynamic properties (see the preceding graph), compositions having the same or similar viscosity factors will It is understood that due to the interactions, they may have significantly different hydrodynamic properties. The viscosity factor is currently the only general indicator of a viscoelastic compatible composition for its intended purpose. One of skill in the art will further appreciate that by modifying one or more parameters, optimal hydrodynamic properties for a given purpose may be achieved.
[0027]
Preferred modified hyaluronic acids include partial amide modification of the carboxylic acid group of HA with an alkyl or aryl group to form an alkyl amide or aryl amide of HA. As used herein, such a molecule is referred to as “HA-amide”. Examples of amides that can be substituted on the carboxylic acid group of HA include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, Alkyl groups such as dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, or any other alkyl group containing up to 30 carbons; cycloalkyl groups (eg, cyclohexyl); and aryl groups ( For example, phenyl); as well as any isomers of the foregoing groups. Such substituents may be further substituted, if desired, and may optionally include therein atoms selected from the group consisting of O, N, and S. The most preferred amide substituent is dodecyl.
[0028]
The degree of substitution may also vary. Generally, the substitution is about 2-60%. Preferred substitution levels are about 5-40%. Preferred amide substituents are octyl, dodecyl, and hexadecyl; dodecyl is most preferred. For octylamide HA, the preferred variables are: substitution levels of 30-40%; polymer concentrations of 1-3% by weight; and 200-350 kilodaltons ("kDal") (weight average) or 120-230 kDal (number (Average) unmodified HA molecular weight. For dodecylamide HA, the preferred variables are: substitution levels of 5-32%, more preferably 15-25%, and most preferably 10-20%; polymer concentration of 0.35-1.2% by weight And a molecular weight of unmodified HA of 200-350 kDal (weight average) or 120-230 kDal (number average). Alternatively, low molecular weight unmodified HA can be used. Preferred parameters for such low molecular weight transition viscoelastic materials are: molecular weight of 50-150 kDal (weight average), 25-40% amide (preferably dodecyl) substitution level, and 0.5-2. % (Wt./v.) Unmodified HA with polymer concentration. For hexadecylamide HA, preferred variables are: 5-15% substitution level; 0.3-0.8% by weight polymer concentration; and 200-350 kDal (weight average) or 120-230 kDal (number average). ) Unmodified HA molecular weight. The level of substitution can be determined by NMR, as described in Example 11. In many cases, the substitution levels specified in the examples herein were provided by a supplier of HA-amides (Fidia Advanced Biopolymers).
[0029]
The transition viscoelastic compositions of the present invention generally have sufficient zero shear viscosity useful in viscosurgical procedures. Typically, such a zero shear viscosity is at least 1 Pa-s at 25C. Compositions exhibiting a zero shear viscosity of about 5 to 10,000 Pa-s at 25C are preferred. Compositions that exhibit a zero shear viscosity of about 40-1000 Pa-s at 25C are most preferred.
[0030]
HA-amides can be obtained commercially from Fijia Advanced Biopolymers (Abano Terme, Italy), and are available from Danishefsky and Siskovic in the "Conversion of Commerce Across the Group Groups of Medicines." 16, pp. 199-205 (1971), of Bulpitt and Aeschlimann "New strategy for chemical modification of hyaluronic acid: Preparation of functionalized derivatives and their use in the formation of novel biocompatible hydrogels", Biomed. Mater. Res. 47, pages 152-169 (1999), or may be synthesized by other methods. WO 00/01733 (Bellini et al.), Which discloses an amide of HA and a process for its preparation, is hereby incorporated by reference. Although this reference generally discloses the use of such amides as vehicles for drug delivery, for use in viscoelastic or ophthalmic surgery, the novel compositions and methods of the present invention are disclosed. It does not disclose or suggest.
[0031]
Other transition viscoelastic materials of the present invention include modified HA, wherein a hydrophobic group is coupled to HA via a hydroxyl, N-acetamide, or carboxyl group and converted. Form hydrophobic amines ("HA-amines"), ethers ("HA-ethers"), thioethers ("HA thioethers") and alkyl ("HA-alkyl") side chains. Examples of such transition viscoelastic materials include HA alkyl ethers, HA alkyl amines, HA alkyl thioethers, HA alkyl carbamates, HA alkyl thiocarbamates, HA alkyl thioureas, and HA alkyl ureas, where the alkyl group is , Methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl Or any other alkyl group containing up to 30 carbons; and any isomer of an alkyl group, including cycloalkyl and aryl isomers. Such transition viscoelastic materials are disclosed, for example, in the method of March, Advanced Organic Chemistry-Reactions, Mechanisms, and Structure, John Wiley & Sons: New York, 4th Edition, 1992.
[0032]
Varying molecular weights of chondroitin sulfate (CS) can be modified in a manner similar to HA described above to produce the transition viscoelastics of the present invention. For example, a carboxylate group can be amidated with HA in a manner similar to that described above. Further, the hydroxyl or N-acetamide moieties of chondroitin sulfate are hydrophobic to produce the transition viscoelastic materials of the invention in the same manner as described above for HA with similar alkyl, cycloalkyl and aryl substituents. It can be converted to amines, ethers, thioethers, carbamates, thiocarbamates, ureas, and thioureas. Examples of such transition viscoelastic materials include CS alkyl ether, CS alkyl amine, CS alkyl thioether, CS alkyl carbamate, CS alkyl thiocarbamate, CS alkyl thiourea, and CS alkyl urea, wherein the alkyl group is , Methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl Or any other alkyl group containing up to 30 carbons; and any structural isomers of such groups, including cycloalkyl and aryl isomers. Such transition viscoelastic materials are disclosed in March, Advanced Organic Chemistry-Reactions, Mechanisms, and Structure, John Wiley & Sons: New York, 4th Edition, 1992.
[0033]
Examples 1 to 6 below are examples of preferred compositions of the present invention.
[0034]
(Example 1)
[0035]
[Table 1]

(Example 2)
[0036]
[Table 2]

(Example 3)
[0037]
[Table 3]

(Example 4)
[0038]
[Table 4]

(Example 5)
[0039]
[Table 5]

(Example 6)
[0040]
[Table 6]

Examples 7-18 below show the rheological properties of the compositions of the present invention.
[0041]
(Example 7)
The rheological properties of the HA-amide compositions of the present invention were compared to similar non-transition HA compositions over various concentrations. 10% substituted dodecylamide-HA formulation of Example 3 (0.2%, 0.4%, 0.6%, 0.8% and 1.0% w / v) and unmodified precursor Control compositions containing HA (0.2, 0.4, 0.6, 0.8 and 1.0%) were prepared according to the following procedure. Cap the container containing the various formulations and stir occasionally at 50 ° C., making sure that all the dodecylamide HA or HA powder is soaked in the buffer and complete dissolution has occurred. Heat for 4 hours. Each solution was then transferred to a separate 5 cc syringe, capped and centrifuged at 2500 RPM to remove bubbles. The loaded syringes were then each connected to an empty 5 cc syringe via a Dual-hub assembly. The syringe was cooled for 1 hour and mixed using 50 passes in each assembly.
[0042]
To perform the rheological analysis, the sample was aspirated through a 27 gauge needle on a Bohlin CS-10 (Constant Stress Rheometer) sample plate, the sample was placed through the 27 gauge needle, and the instrument was set in viscometry mode. The viscosity of the sample was measured against shear rate using a shear stress of 1.09 to 52.89 Pa at 16 ° C. As approaching full shear rate, possible sweeps are used to account for possible sample losses due to centripetal force at the high shear rate endpoint. For each sample, the transition behavior (viscosity versus temperature) was then characterized using a temperature range of 10 ° C to 50 ° C and a heating rate of 2.5 ° C / min. Each sample was processed using the same parameters. The summarized results are included in Table 1.
[0043]
(Table 1: Viscosity of 10% substituted dodecylamine-HA vs. control HA at 16 ° C)
[0044]
[Table 7]

As shown in Table 1, the dodecylamide-HA composition had a much higher viscosity than the unmodified HA composition. Also, an increase of about 5 orders of magnitude in low shear viscosity correlated with an increase in decylamide-HA concentration (i.e., 0.2% to 1.0% w / v).
[0045]
(Example 8)
The composition of Example 4 was evaluated rheologically. The composition was prepared in a manner similar to that disclosed in Example 6.
[0046]
This sample was analyzed for viscosity vs. shear rate using a Bohlin CS-10 controlled stress rheometer using the same procedure as described in Example 6, in a shear stress range of 0.41 to 32.58 Pa. Was treated rheologically. The results are contained in Table 2.
[0047]
(Table 2: Viscosity vs. shear stress for 32% substituted octylamide-HA at 16 ° C.)
[0048]
[Table 8]

As shown in Table 2, the 1% solution exhibited a low shear viscosity of about 1000 Pa-s.
[0049]
In a similar experiment, the viscosity of the composition was tested over a temperature range of 17 ° C to 37 ° C with a shear stress of 1.781 Pa. The results are reported in Table 3.
[0050]
Table 3: Viscosity vs. temperature for a 1% solution of octylamide-HA 32% substituted.
[0051]
[Table 9]

As shown in Table 3 and illustrated in FIG. 3, the transition viscosity loss behavior of this material correlates linearly with increasing temperature. Total viscosity loss over this temperature range was about 88%.
[0052]
(Example 9)
The storage stability of preferred compositions of the present invention was observed in the following experiments as a measure of retained viscosity. The dodecylamide-HA of Example 2 was incubated at 4 ° C. and room temperature (“RT”, ie, 21-23 ° C.) for 5.5 months. At predetermined time points, an aliquot of each composition was removed and a rheological analysis of the sample (shear stress range for this example was 0.16-52.89 Pa). The results are listed in Table 4 and illustrated in FIG.
[0053]
(Table 4: Viscosity stability of 0.8% solution of 10% substituted dodecylamide-HA)
[0054]
[Table 10]

As shown in Table 4, between the zero time (control) and the one month incubation time, in viscosity, the dodecylamide-HA composition underwent an initial shift of 16 Pa-s at low shear conditions. However, the viscosity was stable from the one month incubation to the 5.5 month incubation.
[0055]
The transition stability of the hexadecylamide-HA composition stored at 4 ° C. for 5.5 months was also tested. The results are disclosed in Table 5.
[0056]
Table 5: Viscosity versus temperature stability analysis of 8% substituted hexadecylamide-HA stored in phosphate buffered saline at 4 ° C.
[0057]
[Table 11]

As shown in Table 5 and FIG. 5, the viscosities of all compositions transitioned through a temperature change from 25 ° C. to 37 ° C. and lost 70% to 80% of their viscosities at a shear stress of 2.89 Pa. This is comparable to a loss of viscosity of only about 35% for a hyaluronic acid solution of similar starting viscosity.
[0058]
(Example 10)
The stability of the dodecylamide-HA composition of the present invention was observed using the following experiment. The 1% (w / v) dodecylamide-HA composition of Example 7 was incubated at 4 ° C, room temperature (21-23 ° C) and 37 ° C for 6 months. At appropriate time points, one aliquot of the composition was taken and the chemical stability of dodecylamide-HA was analyzed using capillary gas chromatography (GC). GC was performed on a Hewlett Packard 5890A GC system equipped with a flame ionization detector (FID) using the following parameters:
[0059]
[Table 12]

The column used was a DB5 condensed silica capillary column from J & W Scientific (Folsom, CA) (30 meters long, with an inner diameter of 0.32 mm and a film thickness of 1.0 mm).
[0060]
After a predetermined incubation time, the samples were mixed with one equivalent of a mixture of 2 parts by weight of ethyl acetate to 1 part by weight of ethanol and incubated at 50 ° C. for 1 hour. To this mixture was added a further 3 parts by weight of an ethyl acetate-ethanol mixture. This second addition resulted in the precipitation of the polysaccharide, which was centrifuged and the supernatant was analyzed by GC for the presence of the degraded hydrophobic group, dodecylamine. When 100% hydrolysis of the side chain of dodecylamine-HA occurred, complete precipitation of 10% of the substituted dodecylamine-HA resulted in 42 ppm dodecylamine in the supernatant. The test results showed that less than 1 ppm of dodecylamine was present in the supernatant of the treated composition sample over various temperatures and incubation times. These results indicated that the amide bond of the transition viscoelastic material was very stable in the buffered composition.
[0061]
(Example 11)
NMR analysis for determination of hydrophobic group substitution level of hydrophobically modified hyaluronic acid (HM-HA) compound)
In a 4 mL glass vial, 3-5 mg of HM-HA material was added. In the same vial, 0.8 mL of water was added, and the vial was then vortexed for 5-10 seconds. The sample vial was placed in an oven set at 50 ° C and heated overnight (15-20 hours) to dissolve. The next day, the hyaluronic acid lyase (600-900 units / sealed ampoule, Cat. No. H-1136, Sigma Chemical Co.) enzyme solution is clicked open the sealed ampoule and about 900 units of enzyme (1 unit / μL) Was prepared by adding 0.8 mL of water to an ampoule containing Then, 100 μL (0.1 mL) of the enzyme solution was added to the vial. The vial was capped and placed in a 37 ° C. oven overnight (15-20 hours).
[0062]
The next day, the vial was removed from the oven and 100 μL (0.1 mL) of heavy water (99.6% atom-% D, catalog number 42,345-9, Aldrich Chemical Co.) was added to the vial. After mixing, the solution was transferred to an NMR tube using a glass disposable transfer pipette. The sample was then analyzed to obtain a proton NMR spectrum on a 600 MHz Bruker NMR instrument, capable of operating in humidity suppression mode, using exact peak signal acquisition.
[0063]
Using the NMR spectrum of the enzymatically treated HM-HA sample, the level of hydrophobic substitution was determined from three signals indicating hydrophobic residues between 0.8 and 1.3 ppm versus 2.0 for the N-acetylmethyl group. The integrals for 2-4 signals at 2.1 ppm were calculated from the uptake values by adding them together.
[0064]
Three signals between 0.8 and 1.3 ppm indicate that C in the hydrophobic group (containing n carbon atoms). ₂ ~ C _n Derived from a hydrogen atom bonded to carbon. This hyaluronate lyase enzyme has no interference signal in either the hydrophobic group region or the N-acetylmethyl signal region. Since N-acetylmethyl groups are present for each repeating unit of the HA structure, the level of hydrophobic substitution can be calculated from the ratio of the integrated value of the hydrophobic group to the integrated value of the N-acetylmethyl group. Thus, a linear normal alkyl group [-(CH ₂ ) _n-1 CH ₃ ] Is calculated according to the following formula:
% Hydrophobic substitution = [integration 0.8 to 1.5 ppm / (2 (n-1) +1)] / [integration 2.0 to 2.1 ppm / 3] × 100
Can be given by
[0065]
(Example 12)
The following examples demonstrate the lower stability of the less preferred viscoelastic agents of the present invention. A composition similar to the compositions of Examples 1-6, wherein the viscoelastic is 15% dodecyl ester-HA, sodium salt (about 200 kDa) or 43% or 52% benzyl ester-HA, sodium Salt (substituted with any of the approximately 200 kDa final, modified viscoelastic materials) was prepared in a similar manner to the method disclosed in Example 7. The composition was incubated at 4 ° C., room temperature and 37 ° C. for 9.5 weeks. Dodecyl alcohol or benzyl alcohol (the degradation product of the respective hydrophobic ester side chain) was quantified using the GC method of Example 10.
[0066]
After a predetermined incubation time, the sample was mixed with 4 volumes of acetone, which resulted in the precipitation of the polysaccharide. The precipitated polysaccharide was then centrifuged and the supernatant was analyzed by GC for the presence of the appropriate alcohol.
[0067]
Complete hydrolysis of the side chains of dodecyl ester-HA or benzyl ester-HA resulted in 70 ppm dodecyl alcohol or 400 ppm benzyl alcohol in the supernatant, respectively. The results are disclosed in Table 6.
[0068]
(Table 6:% hydrolysis of stored HA-ester in phosphate buffered saline at 4 ° C.)
[0069]
[Table 13]

As indicated above, hydrolysis of comparable modified viscoelastics was greater than 1% at various time points. Since it is desirable for the viscoelastic composition to have storage stability (ie, the viscoelastic product typically requires an expiration date of 2 years), it exhibits the rate of hydrolysis described above. Viscoelastic materials are considered less useful in the compositions of the present invention.
[0070]
(Example 13)
A 3% solution of the benzyl ester of HA (about 200 kDa) with 50% carboxylic acid substitution was prepared in a phosphate buffer with sodium chloride and in a citrate / acetate buffer with a balanced salt. These solutions formed optically clear viscoelastic gels, which were easily aspirated through a 27 gauge needle. These solutions have a low shear viscoelasticity at 25 ° C. (ke, about 200 Pa-s) comparable to Viscoat® or Provisc®, and at 25 ° C., Provisc® ) Or Viscoat®. These solutions showed a significant drop in viscosity from about 200 Pa-s at surgical temperature (25 ° C.) to 20 Pa-s at body temperature (37 ° C.).
[0071]
(Example 14)
A 1% solution of dodecyl ester of HA (about 200 kDa) with 14.3% carboxylic acid substitution was prepared in citrate / acetate buffer with balanced salt to form a clear viscoelastic solution. This solution showed a rheological profile comparable to Provisc® or Viscoat®. The viscosity at 25 ° C. and shear rates below 0.085 / s was about 90 Pa-s. Shear thinning started at 0.24 / s with a viscosity of 75 Pa-s. The viscosity at 5.4 / s dropped to about 16 Pa-s. At 31 ° C., the low shear viscosity was only about 45 Pa-s. At constant shear stress at 2.89 Pa-s, the viscosity of the formulation dropped from about 100 Pa-s at 25 ° C to about 25 Pa-s at 37 ° C.
[0072]
(Example 15)
A 0.75% solution of dodecyl ester of HA (about 200 kDa) with 14.3% carboxylic acid substitution was prepared in citrate / acetate buffer with balanced salt to form a clear viscoelastic solution. The solution had a low shear viscosity of about 25 Pa-s at 25 [deg.] C and was shear thinning at 534 / s to less than 0.1 Pa-s. This formulation also exhibited a decrease in viscosity from about 25 Pa-s at 25 ° C. to about 5 Pa-s at 37 ° C. at constant shear stress (1.1 Pa).
[0073]
(Example 16)
A 2% solution of dodecyl ester of HA (about 200 kDa) with 14.3% carboxylic acid substitution was prepared in citrate / acetate buffer with balanced salt to form a clear, thick solution. The solution (about 2 cc) was autoclaved at 125 ° C. for an exposure time of about 20 minutes and cooled with slow evacuation. After cooling to room temperature, the formulation maintained a viscosity sufficient to obtain a useful viscoelastic gel.
[0074]
(Example 17)
A 5% solution of hexadecyl ether of carboxymethylcellulose (about 100 kDa, containing a hexadecyl moiety ether-linked to 5% of the repeating monosaccharide units) was prepared in phosphate buffer with sodium chloride. The solution was clear and formed a viscous gel qualitatively.
[0075]
(Example 18)
A 1.0% by weight solution of HA, sodium salt, 20% dodecylamide with 3% chondroitin sulfate was prepared in PBS by slowly dissolving at 50 ° C. for 2 days. Another sample containing only 1.0% by weight of HA, 20% dodecylamide of the sodium salt was similarly prepared in PBS by slowly dissolving at 50 ° C. for 2 days. After lysis, each of these samples was transferred into a separate 10 mL syringe and transferred through a double hub connector 100 times to another empty syringe to provide the appropriate mixture. Samples were centrifuged to remove air bubbles and aspirated through a 27 gauge needle onto a Bohlin CS-10 Constant Stress Rheometer sample plate. Rheological analysis was performed and a plot of viscosity versus shear rate at 25 ° C. was obtained for both samples. Both samples gave apparent viscosity values of about 90 Pa-s in the low shear plateau region of the plot of viscosity versus shear rate.
[0076]
(Example 19)
The following is a description of the IOP Spike Model.
[0077]
(IOP Spike Model)
The IOP Spike Model comprises (1) a perfusion device, pump and pressure transducer / recorder as schematically shown in FIG. 7; (2) a perfusion medium; (3) a dissected human eye; and (4) a test. Viscoelastic material used.
[0078]
(1. Perfusion medium)
The perfusion medium used in the IOP Spike Model was 5 mL of penicillin-streptomycin solution (10,000 units / mL penicillin (base) from penicillin G and 10,000 μg / mL streptomycin (base) from streptomycin sulfate) and 0 mL Add 85 mL of gentamicin solution (10 mg / mL) to 500 mL of cell culture medium (Dulbecco's Modified Eagle Medium, low glucose, with L-alanyl-L-glutamine and pyruvate (Life Technologies, Grand Island, NY)). Prepared. The perfusion medium is then filtered using a 500 mL sterile filter unit (0.2 μm pore size) and stored at 4 ° C. (to 37 ° C. before use).
[0079]
(2. Eye preparation)
A cadaver eye useful in the IOP Spike Model must be: i) at the time prepared for use in this model, no older than 24-36 hours post-mortem; ii) in a humidified chamber Must be preserved as an eye; iii) not HIV, hepatitis or other infections; and iv) have not undergone eye surgery, such as glaucoma filtration, scleral fold implant or IOP implant. Anterior segment 7 of the human eye (see FIG. 10) is prepared by the following dissection method:
The eyes are carefully excised from excess muscle or connective tissue using straight fine scissors (Katena No. K4-7440) and placed in a container containing povidone-iodine solution (1% free iodine) at 25 ° C. For about 2 minutes. The eye is then removed from the iodine solution, rinsed with a saline solution, and positioned so that the center of the cornea 3 is at the top (see FIG. 9a). Referring to FIGS. 9a and 9b, the sclera 5 is then evenly spaced, using a sterile ophthalmic crescent knife (Alcon No. 8065-940001), extending radially from its edge to a serrated edge Open the superior scleral vein with 24 straight cuts 9 (each cut does not exceed a depth of 50% of the scleral thickness and is about 5 mm long) And provides an exit path for the perfusion medium. Referring to FIG. 9 b, the eye is then cut into two lobes along a horizontal plane 11 approximately halfway between the equatorial plane 13 and the scleral plane 15. Separate the anterior half (upper) of the eye from the posterior half (lower), which is discarded. This anterior half is inverted so that the cornea is turned down and the remaining vitreous is then carefully removed from the anterior half using Graefee forceps (Katena No. K5-4821). The zonules are then cut using Wescott scissors (Katena No. K4-4100) and the lens is removed from the anterior segment using Graefee forceps. The iris is then removed using barley forceps (Katena No. K5-4010) and the choroid is cut circumferentially at the serrated edge using Wescott scissors. Then, from the inside of the sclera, any remaining dye is removed using oat forceps. The remaining anterior segment 7 is then rinsed twice with the perfusion medium to wash away dye, tissue remnants or other debris.
[0080]
(3. Perfusion device)
The perfusion apparatus used in the IOP spike model was the Johnson and Tschumper and the perfusion system of Clark et al. (1987); and described in Clarke et al., "Dexamethasone Induced Occurrence of Hypertension in Perfusion-Cultured Human Eyes," Invest. Ophthalmol. Vis. Sci., 36 (2): 478-489 (1995). It is. A significant modification to the previous system is a reduction in chamber volume from about 0.8-1.0 mL to about 0.5-0.6 mL and perfusion to better approximate the volume of the human anterior segment volume of the pseudolens. The inversion of the chamber during. Volume reduction is achieved by the islands formed on the platform of the chamber, which reduces the space in the dome of the front segment, and reduces the viscosity in the rear dead space (i.e., rearward relative to the trabecular meshwork). It should prevent or reduce stagnation of the elastic solution. By inverting the chamber (relative to the previous system) during perfusion, the viscoelastic material is effectively mixed by perfusing over the islets, which rise in the direction of the depression, so that the cornea Stagnation of the viscoelastic material caused by the depression is prevented.
[0081]
The perfusion device 1 is shown in FIGS. The apparatus 1 includes a base 2, a cylinder 4, an island 6, an o-ring 8, a plurality of screws 10, and a cap 12. In use, the device 1 also comprises a front segment 7.
[0082]
The base 2 has a top 22, a bottom 24 and sides 26 and is disk-shaped with channels 14 and 16 shaped and sized to receive the screw 10, a platform 18 and a thread 19. The channel 14 connects the opening 28 of the side surface 26 and the opening 20 of the island 6. Channel 16 communicates an opening 30 in side surface 26 with an opening 32 in platform 18. Channels 14 and 16 are shaped and sized to provide accurate flow (channel 14) and precise pressure measurements (channel 16) of the perfusion medium reciprocating in apparatus 1. Opening 28 is sized and shaped to receive a fitting (to connect to injection line 29), and opening 30 is also to receive a fitting (to connect to transducer line 31). 2) size and shape. The fitting is a standard connector known in the art useful for receiving tubing or other cylindrical lines. The platform 18 protrudes from the base 2, has sides 34 and is conical in shape and size to receive the front segment 7. Island 6 protrudes from the center of platform 18.
[0083]
With reference to FIGS. 8 and 10, the cylinder 4 is coaxially and permanently mounted on the upper part 22 of the base 2 and extends coplanar therefrom. Island 6 has an opening 20 and comprises a portion of channel 14 and extends from platform 18. The o-ring 8 includes a grooved nail, a concave inner end 36 and a plurality of holes 38 sized and shaped to receive the screw 10 through the o-ring 8. The end 38 is such that, when using the device 1, the compression of the o-ring 8 against the base 2 causes the periphery of the front segment 7 between the end 36 and the side 34 of the platform 18 to sandwich It is a size and a shape that forms the chamber 42. As described above, the volume of the anterior chamber 42 is designed by the present inventors to approximate the combined volume of the anterior chamber and the lens of the human eye (typically about 0.5-0.6 mL). Was.
[0084]
As shown in FIGS. 8 and 10, the cap 12 is shaped and sized to receive a portion of the cylinder 4 and form a closed space 40. The preferred perfusion device for the IOP spike model is a polysulfone base 2, a polysulfone island 6, a polysulfone o-ring 8, a nylon screw 10, a clear polysulfone cylinder 4, medical steel channels 14 and 16 and a clear steel channel. A polystyrene cap 12 is used.
[0085]
(4. Assembly and preparation of perfusion apparatus)
Prior to use, disassemble device 1 and autoclave or low temperature sterilize the individual components, then soak the layered flow chamber with a sporicidin sterile solution (50 ml / L water), Subsequently, it was rinsed overnight in sterile deionized water.
[0086]
Referring to FIGS. 7 and 10, the perfusion medium is pumped in turn connected to an injection line 29 (injecting perfusion medium into chamber 42 through channel 14); It is connected to a calibration pressure transducer and a recorder capable of recording the pressure in the chamber 42. The apparatus 1 is then reassembled by first connecting the fittings located in the openings 28 and 30 to the injection and transducer lines, respectively. The device 1 is then repositioned with the upper part 22 facing up. The anterior segment 7 is placed on the platform 18 with the corneal side up. A slight perfusion medium flow is then applied by syringe through channel 16 to properly accommodate segment 7 on platform 18. An o-ring 8 (which has an outer diameter of about 1.5 inches and an inner diameter of 0.710 to 0.736 inches) is then placed on the segment 7. It is important that the o-ring 8 accommodates the segment 7 well and avoids leakage (slightly different diameter o-rings 8 can be used to improve accommodation). The screw 10 is inserted into the thread 19 through the hole 38 and brought into close contact, ensuring that the o-ring 8 is evenly received. The o-ring 8 is brought into close contact with the periphery of the segment 7 so as to release the flow applied through the channel 16 so that excessive pressure is not applied to the containing segment 7. The screw 10 is rotated relative to the base 2 so that the periphery of the segment 7 is sandwiched tightly between the platform 18 and the o-ring 8 (not the tightness at which the segment 7 bursts). The syringe is then used to push the perfusion medium through the channel 14 while simultaneously withdrawing the perfusion medium from the channel 16 through the opening 30 and allowing any air bubbles present to flow out of the chamber 42 through the channel 16. Tilt 2 After purging the bubbles, the channels 14 and 16 are closed and the media flow is perfused. The device 1 is then turned horizontally with the upper part 22 up.
[0087]
Next, the cap 12 is placed on the cylinder 4, thereby forming the space 40. The device 1 is then inverted with the bottom 24 facing up and placed in a tissue culture incubator (Nuaire) (maintaining a humidified atmosphere at 37 ° C. (5% CO 2/95% air)). The transducer line 31 and the injection line 29 should be located against the seal of the incubator door and will not be damaged or obstructed when the door is closed. The compression converter should keep the level of the device 1. In this configuration, the device 1 can now easily be used in an IOP spike model.
[0088]
(5. Initial perfusion)
Open the perfusion line and activate the pump (setting "6" for Harvard Model # 944), allowing free flow of perfusion medium through opening 28 and channel 14. The pump is operated until the pressure increases to about 5-10 mmHg, after which the pump speed is reduced to about 2 μL / min (setting “12”). Segment 7 is perfused up to about 24 hours before injection of the viscoelastic candidate. If a stable baseline (at a pressure between 10 and 40 mm Hg) is not established within 24 hours, the flow rate can be adjusted repeatedly every 2-3 ml of perfusion volume until a stable baseline IOP is achieved. If this problem is not resolved over the next 24 hours and the subsequent flow rate adjustment and flushing steps are not processed within 48 hours, the front segment 7 is unreliable and perfusion should be terminated.
[0089]
(6. Injection and perfusion of viscoelastic substance)
Once the anterior segment 7 has generated a stable baseline IOP between 10 and 40 mmHg for at least 4 hours (perfusion rate between about 1.75 and 2.05 μL / min), the IOP spike study is ready. Typically, such points are achieved 24 hours after the first perfusion. This model is first confirmed by injection of a "positive" control. The positive control was 0.5 mL of diluted sodium hyaluronate (approximately 750 kDal Lifecore Biomedical, Inc., Chaska, MN), which contained 10% of the buffered solution at 3.5% HA in the same buffered solution. It is prepared by diluting it to 90%. Here, each 1 mL of the buffered solution contains about 0.45 mg of sodium dihydrogen phosphate hydrate, 2.00 mg of disodium monohydrogen phosphate, 4.3 mg of sodium chloride (Water For Injection, USP grade, q .S.) And has a neutral pH. Inject 0.5 mL of the positive control diluted HA (0.35%) into the same volume of tubing group attached to the multi-valve assembly 33 on the perfusion line 29 and switch the multi-valve assembly 33 to complete sample volume. Into the perfusion apparatus 1. Thus, the infusion rate is determined by the perfusion rate. Monitor and record the IOP continuously. Observe and record any IOP spikes above the baseline IOP. If the positive control produces an IOP spike between 20-80 mmHg above baseline within 24 hours of infusion, this model is considered valid and used to test candidate transition viscoelastics. obtain.
[0090]
Generally, the transition viscoelastic sample can also be injected twice in a single anterior segment at intervals of one day (the first injection is a positive control). The sample viscoelastic material should be diluted to 1/10 of the original concentration with the same buffered solution used to prepare the control sample. A stable and acceptable baseline IOP should be achieved before each new injection, as indicated by the diminution of any IOP spikes caused by previous viscoelastic material samples. If the baseline IOP does not recover within 10-40 mmHg within one day, further perfusion in a given anterior segment should be stopped.
[0091]
As noted above, the transition viscoelastic materials of the present invention (i.e., produce little or no IOP spikes) exhibit an average spike of 10 mm Hg or do not exceed baseline.
[0092]
(Example 20)
The transition viscoelastic material of the present invention (AL-12488, 43% substituted benzyl ester modified HA (about 200 kDal)) was tested in the IOP spike model described above and tested with positive control (Benchmark) and 200 kDal HA (from Fidia). Compared. The results of this study are illustrated in FIG. Arrows indicate various injections. Injections 1 and 4 were 0.35% of the positive control HA, Injection 2 was 0.35% of Fidia unmodified HA and Injection 3 was 0.35% of AL-12488. All injected samples had a volume of 0.5 ml. Asterisks indicate individual IOP spikes resulting from the injection. Only the transition viscoelastic (AL-12448) can be characterized as exhibiting little or no IOP spikes. This is because the spikes observed in the IOP spike model are above and below about 10 mmHg above the baseline IOP, and in fact are well below about 10 mmHg.
[0093]
For a particular step in a surgical procedure, the suitability of a given transition viscoelastic material may include, for example, the concentration of the viscoelastic material, average molecular weight, viscosity, pseudoplasticity, elasticity, rigidity, adhesion (coatability). One skilled in the art will understand that it depends on cohesiveness, molecular charge and solution permeability. The suitability of this viscous material further depends on the functions expected to be exerted by the viscoelastic material and the surgical technique used by the surgeon.
[0094]
A suitable buffer system (eg, sodium phosphate, sodium acetate or sodium borate) can be added to the composition to prevent pH drift under storage conditions.
[0095]
Since all or most of the transition viscoelastic materials of the present invention may be left in the eye after surgery, these viscoelastic materials are solely responsible for the dual role of viscoelastic surgical means and drug delivery devices. Fit.
[0096]
Ophthalmic drugs suitable for use in the compositions of the present invention include, but are not limited to: anti-glaucoma drugs, such as beta-blockers (timolol, betaxolol, levobetaxolol) , Carteolol, mimetics including pilocarpine, carbonic anhydrase inhibitors, prostaglandins, seratonergics, muscarinic agonists, dopaminergic agonists, adrenergic agonists including apraclonidine and brimonidine Anti-infectives (including quinolones such as ciprofloxacin and aminoglycosides such as tobramycin and gentamicin); non-steroidal and steroidal anti-inflammatory agents (eg, suprofen) Diclofenac, ketorolac, rimexolone and tetrahydrocortisol; growth factors (eg, EGF); immunosuppressants; and antiallergic agents including olopatadine) Ophthalmic drugs include pharmaceutically acceptable salts (eg, maleic acid) Timolol, brimonidine tartrate or diclofenac sodium) .The compositions of the present invention may also include combinations of ophthalmic drugs such as the following combinations (i) and (ii): (i) betaxolol Beta-blockers selected from the group consisting of: and timolol; and (ii) latanoprost; 15-ketratanoplast; fluprostenol isopropyl ester (especially lR- [lα (Z), ^* ), 3α, 5α] -7- [3,5-dihydroxy-2- [3-hydroxy-4- [3- (trifluoromethyl) -phenoxy] -1-butenyl] cyclopentyl] -5-heptenoic acid, 1 -Methylethyl ester); and isopropyl [2R (1E, 3R), 3S (4Z), 4R] -7- [tetrahydro-2- [4- (3-chlorophenoxy) -3-hydroxy-1-butenyl]- Prostaglandin selected from the group consisting of 4-hydroxy-3-furanyl] -4-heptenoic acid.
[0097]
If a pharmaceutical agent is added to the transition viscoelastic material, such agent may have limited solubility in water and therefore require a surfactant or other suitable co-solvent in the composition And Such co-solvents typically include: polyethoxylated castor oils, Polysorbates 20, 60 and 80; Pluronic® F-68, F-84 and P-103 (BASF Corp., Parsippany) NJ, USA); cyclodextrins; or other agents known to those skilled in the art. Such co-solvents are typically used at a level of about 0.01-2% by weight. To improve visualization of the viscoelastic material during surgery and / or for improved visualization of such tissue, ocular tissue, particularly a capsular bag during capsulohexis in cataract surgery, may be used. It may also be desirable to add a pharmaceutically acceptable dye to the viscoelastic material for staining. The use of such dyes in conventional viscoelastic materials is described in WO 99/58160. Preferred dyes include trypan blue, trypan red, brilliant crysyl blue and indocyanine green. The concentration of the dye in the viscoelastic solution is preferably between about 0.001% and 2% by weight, most preferably between about 0.01% and 0.1% by weight. However, it will be appreciated by those skilled in the art that any such additives (drugs, co-solvents or dyes) may be used only to the extent that they do not critically affect the viscoelastic properties of the compositions of the present invention. Understood.
[0098]
The method of the invention also involves the use of various viscoelastic agents having different adhesive or cohesive properties. One skilled in the art will recognize that the compositions of the present invention can be used by skilled surgeons in a variety of surgical procedures.
[0099]
Given the advantages of each type of viscoelastic material, a surgeon may use various viscoelastic compositions of the present invention in a single surgical procedure. Although the use of the transition viscoelastic materials of the present invention has not previously been disclosed for use in surgery, US Pat. No. 5,273,056 (McLaughlin et al.) Discloses that viscoelastic Disclosed are methods that utilize the use of compositions comprising viscoelastic materials of varying properties (the entire contents of this document are incorporated herein by reference).
[0100]
For example, for parts of a surgical procedure that include phacoemulsification and / or irrigation / aspiration (eg, cataract surgery), the use of viscoelastic drugs that have relatively high adhesive and relatively low cohesive properties may be used. Generally preferred. Such viscoelastic agents are referred to herein as "adhesive" agents. It is believed that the tackiness of a viscoelastic drug in solution depends, at least in part, on the average molecular weight of the drug. At a given concentration, the higher the molecular weight, the higher the tackiness. These parts of the surgical procedure, including manipulation of delicate tissue, are generally better served by viscoelastic drugs that have relatively high cohesive properties and relatively low adhesive properties. Such agents are referred to herein as "sticky" agents. For such sticky drugs, which are primarily used for tissue manipulation or maintenance purposes, as opposed to protective purposes, functionally desirable viscosities have been achieved by skilled surgeons who practice such drugs. Viscosity is sufficient to allow it to be used as a soft tool to manipulate or support tissue of interest during a surgical procedure.
[0101]
For other viscoelastic drugs ("adhesive" drugs) that are primarily used for protective purposes, as opposed to tissue manipulation purposes, the functionally desirable viscosity is such that the protective layer of such drugs is It is of sufficient viscosity to allow it to remain on the tissue or cells of interest while the process is being performed. Such viscosities typically range from about 3,000 cps to about 60,000 cps (shear rate 2 seconds). ^-1 , And 25 ° C.), and preferably about 40,000 cps. Such adhesive agents may provide the protective function described above, but do not cause inadvertent removal that could jeopardize the delicate tissue being protected. Unfortunately, due to this same property, aspiration of such adhesive viscoelastic material at the end of surgery (recommended for all such commercial products in cataract surgery) is a problem for surgeons, And this property may expose the coated tissue to trauma during the removal procedure. An important advantage of the transition viscoelastic materials of the present invention is that they can be pinned to the surgical site at the end of the surgical procedure, thereby avoiding unnecessary trauma to the affected soft tissue.
[0102]
Preferred methods of the invention may use a plurality of viscoelastic materials in a given surgical procedure, at least one such viscoelastic material being a transition viscoelastic material. In a most preferred embodiment of the present invention, transition viscoelasticity with better adhesive properties is used in cataract surgery, at the end of which some or all of the transition viscoelastic material remains in situ, And little or no IOP spikes.
[0103]
Although the invention has been described by reference to certain preferred embodiments, it is to be understood that it may be embodied in other specific forms or modifications thereof without departing from the spirit or essential characteristics of the invention. Should be. Therefore, the above embodiments are to be considered in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the appended claims rather than the foregoing detailed description.
[Brief description of the drawings]
FIG.
FIG. 1 is a graph showing viscosity as a function of concentration for dodecylamide HA of the present invention and control HA.
FIG. 2
FIG. 2 is a graph showing the viscosity of octylamide HA of the present invention as a function of shear rate.
FIG. 3
FIG. 3 is a graph showing the transition viscosity of octylamide HA of the present invention.
FIG. 4
FIG. 4 is a graph showing the viscosity stability of the autoclaved dodecylamide HA of the present invention.
FIG. 5
FIG. 5 is a graph showing the stability of the transition behavior of hexadecylamide HA of the present invention.
FIG. 6
FIG. 6 is a graph showing the hydrolysis rate of the esterified HA of the present invention.
FIG. 7
FIG. 7 is a schematic diagram of the IOP spike model of the present invention.
FIG. 8
FIG. 8 is an exploded elevation view of the perfusion apparatus of the present invention.
FIG. 9a
FIG. 9a is a top plan view of the eye for use in a reflux device.
FIG. 9b
FIG. 9b is a side view of the eye of FIG. 9a.
FIG. 10
FIG. 10 is a cross-sectional view of the perfusion apparatus of the present invention including the front part in FIG.
FIG. 11
FIG. 11 is a graph showing the effect of traditional viscoelastic and transition viscoelastic materials of the present invention on IOP using the IOP spike model of the present invention.

Claims (26)

A sterilized, non-inflammatory, viscoelastic composition comprising a polymeric agent in an aqueous solution, wherein the composition exhibits a zero shear viscosity at 25 ° C of at least 1 Pa-s, wherein the viscoelastic composition comprises: A composition that exhibits little or no IOP spikes when tested in a validated IOP spike model. The polymer agent is a hydrophobically modified polysaccharide or mucopolysaccharide (with or without a surfactant); a dialyzed amphoteric polyelectrolyte or a dialyzed mixture of oppositely charged polyelectrolytes; a polysaccharide or mucopolysaccharide and The composition according to claim 1, wherein the composition is selected from the group consisting of a mixture with a cationic hydrophilic polymer; a polysaccharide and a hydrophilic synthetic polymer that undergo a conformational transition depending on temperature; and a combination thereof. The composition of claim 2, wherein the solution exhibits a zero shear viscosity of about 5 to about 10,000 Pa-s at 25 ° C. and a viscosity factor of about 1000 to about 20,000. The polymeric agent is a hydrophobically modified polysaccharide selected from the group consisting of HA-amide, HA-ester, HA-amine, HA-ether, HA-thioether, HA-alkyl, and combinations thereof. The composition of claim 3. The composition of claim 4, wherein the polysaccharide is an HA-amide selected from the group consisting of octylamide HA, dodecylamide HA, and hexadecylamide HA. A method of performing an eye surgery, comprising:
(A) making a surgical incision in the eye to provide access to the interior of the eye;
(B) instilling the viscoelastic composition of claim 1 through the surgical incision into the interior of the eye; and (c) closing the surgical incision.
A method comprising: The viscoelastic composition has a zero shear viscosity at 25 ° C. of about 5 to about 10,000 Pa, and the viscosity is such that the transition viscoelastic material undergoes a temperature change from about 25 to about 37 ° C. 7. The method of claim 6, wherein said method is reduced by at least 50%. 9. The method of claim 7, wherein the surgical incision is closed without prior exogenous removal of the viscoelastic composition. A method of performing eye surgery without significant intraoperative intraocular pressure spikes, comprising:
(A) instilling a first therapeutically effective amount of a transition viscoelastic substance into the eye, wherein the transition viscoelastic substance has a zero shear viscosity at 25 ° C. of at least 5 Pa-s; A non-inflammatory aqueous solution, and wherein the transition viscoelastic material exhibits little or no IOP spikes when tested in a validated IOP spike model; and (b) a second treatment Leaving an effective amount of the transition viscoelastic material in the eye at the end of the surgical procedure;
Wherein the first and second therapeutically effective amounts of the transition viscoelastic material can be the same or different. The first therapeutically effective amount of the transition viscoelastic material comprises a tissue protective effective amount of the transition viscoelastic material, a tissue manipulation effective amount of the transition viscoelastic material, and a drug delivery effective amount of the transition viscoelastic material. And wherein the second therapeutically effective amount of the transition viscoelastic is selected from the group consisting of a tissue protective effective amount of the transition viscoelastic and a drug delivery effective amount of the transition viscoelastic. 10. The method according to 9. The method of claim 10, wherein the transition viscoelastic material comprises hydrophobically modified HA. 12. The method of claim 11, wherein the hydrophobically modified HA is HA and is selected from the group consisting of octylamide HA, dodecylamide HA, and hexadecylamide HA. 13. The method of claim 12, wherein the surgery is a cataract surgery. A method of protecting or stabilizing ocular tissue in an eye during surgery on the eye tissue, comprising dropping a protective or stabilizing effective amount of a sterile non-inflammatory viscoelastic composition onto the eye. A method wherein the viscoelastic composition exhibits little or no IOP spikes when tested in a validated IOP spike model. A sterile, non-inflammatory, transition viscoelastic composition comprising a hydrophobically modified polysaccharide in an aqueous solution, wherein the solution exhibits a zero shear viscosity at 25 ° C of at least 1 Pa-s, and A composition wherein the zero shear viscosity of the solution is reduced by at least 50% when the solution is subjected to a temperature change from about 25 ° C to about 37 ° C. 16. The composition of claim 15, wherein the solution has a zero shear viscosity of about 5 to about 10,000 Pa-s at 25 [deg.] C and exhibits a viscosity factor of about 1000 to about 20,000. 17. The hydrophobically modified polysaccharide is selected from the group consisting of HA-amide, HA-ester, HA-amine, HA-ether, HA-thioether, and HA-alkyl, and mixtures thereof. A composition according to claim 1. 18. The composition of claim 17, wherein the polysaccharide is an HA-amide selected from the group consisting of octylamide HA, dodecylamide HA, and hexadecylamide HA. A method of performing an eye surgery, comprising:
(A) making a surgical incision in the eye to provide access to the interior of the eye;
(B) instilling a transition viscoelastic substance into the interior of the eye through the surgical incision; and (c) closing the surgical incision.
A method comprising: The transition viscoelastic material has a zero shear viscosity at 25 ° C. of about 5 to about 10,000 Pa-s, and the viscosity indicates a temperature change of the transition viscoelastic material from about 25 ° C. to about 37 ° C. 20. The method of claim 19, wherein the method reduces at least 50% when receiving. 21. The method of claim 20, wherein the surgical incision is closed without prior extrinsic removal of the transition viscoelastic material. A method of performing eye surgery without significant intraoperative intraocular pressure spikes, comprising:
(A) instilling a first therapeutically effective amount of a transition viscoelastic substance into the eye, wherein the transition viscoelastic substance has a zero shear viscosity at 25 ° C. of at least 5 Pa-s; A non-inflammatory aqueous solution, and wherein the viscosity is reduced by at least 50% when the transition viscoelastic material is subjected to a temperature change from about 25 ° C. to about 37 ° C .; Leaving a therapeutically effective amount of the transition viscoelastic material in the eye at the end of the surgical procedure,
Wherein the first and second therapeutically effective amounts of the transition viscoelastic material can be the same or different. The first therapeutically effective amount of the transition viscoelastic material comprises a tissue protective effective amount of the transition viscoelastic material, a tissue manipulation effective amount of the transition viscoelastic material, and a drug delivery effective amount of the transition viscoelastic material. And wherein the second therapeutically effective amount of the transition viscoelastic is selected from the group consisting of a tissue protective effective amount of the transition viscoelastic and a drug delivery effective amount of the transition viscoelastic. Item 23. The method according to Item 22. 24. The method of claim 23, wherein the transition viscoelastic material comprises hydrophobically modified HA. 25. The method of claim 24, wherein said hydrophobically modified HA is HA and is selected from the group consisting of octylamide HA, dodecylamide HA, and hexadecylamide HA. 26. The method of claim 25, wherein the surgery is a cataract surgery.

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