WO2013020917A1

WO2013020917A1 - Ophthalmologic composition comprising an aqueous solution of at least one viscoelastic polysaccharide

Info

Publication number: WO2013020917A1
Application number: PCT/EP2012/065248
Authority: WO
Inventors: Jürgen Nachbaur; Gillian Dr. RODDEN; André Dr. WOLFSTEIN; Claude MOISSONNIER; Pascal Bernard; Gildas LOREC; Nicole BIELEFELDT; Brian Rathert; Lidia Dr. Nachbaur; Mario Gerlach
Original assignee: Carl Zeiss Meditec AG
Current assignee: Carl Zeiss Meditec AG
Priority date: 2011-08-09
Filing date: 2012-08-03
Publication date: 2013-02-14
Anticipated expiration: 2014-02-09
Also published as: GB2493568B; GB201114317D0; GB2493568A

Abstract

The invention relates to an ophthalmologic composition, comprising an aqueous solution of at least one viscoelastic polysaccharide, wherein the at least one polysaccharide is covalently bound to at least one dye. The invention also relates to a method for producing an ophthalmologic composition, in which at least one dye is covalently bound to at least one water-soluble, viscoelastic polysaccharide.

Description

Ophthalmologic composition comprising an aqueous solution of at least one viscoelastic polysaccharide

Field of the invention

The invention relates to an ophthalmologic composition, comprising an aqueous 5 solution of at least one viscoelastic polysaccharide. The invention further relates to a method for producing an ophthalmologic composition.

Prior art

Cataract is a common disease especially in elderly people, where the crystalline lens gradually becomes less transparent. This opacity of the natural lens leads to the loss of visual acuity. To restore vision, cataract surgery has to be performed. In 10 a surgical step called phacoemulsification, the natural lens is destroyed and the pieces are aspirated out of the eye. In the next step, an artificial lens is injected into the eye and visual acuity is re-established.

Immediately before phacoemulsification, the anterior chamber is usually filled with an ophthalmologic composition, comprising a transparent viscoelastic solution. The i s viscoelastic ophthalmologic composition is used as a surgical aid to protect intraocular tissues (for example the corneal endothelium during phacoemulsification), as a space maintainer (for example to maintain the anterior chamber of the eye) and to facilitate intraocular maneuvers, for example to make a controlled capsulorhexis.

Viscoelastic compositions are water based solutions containing a polysaccharide 20 like hyaluronic acid, hydroxypropylmethylcellulose, chondroitin sulfate or mixtures thereof that are routinely used in cataract surgery. The viscoelastic composition might differentiate in the molecular weight of the polysaccharide dissolved in the solution, in the concentration of the polysaccharide and in the viscosity of the solution. They are generally well tolerated following brief exposure to intraocular tissues. Most currently available ophthalmologic compositions comprising viscoelastic polysaccharides are transparent. A disadvantage of the transparency is that it is difficult to determine or control the amount and location of the ophthalmologic compositions in the eye. It is of importance that at the end of the surgery all of the ophthalmologic 5 composition is removed from the eye to prevent a trabecular meshwork obstruction and thus the elevation of intraocular pressure which may lead to glaucoma. Due to the transparency of the used polysaccharides, it is difficult to judge if residual ophthalmologic composition is still left in the eye. Furthermore, poor visibility of the viscoelastic ophthalmologic composition within the eye also prohibits exact visualiza- 10 tion of the amount injected.

EP 1 263 363 B1 suggests the use of a viscoelastic ophthalmologic composition based on aqueous solutions of hyaluronic acid and hydroxypropylmethylcellulose. To avoid the above-named problems associated with transparency the ophthalmologic solution also contains trypan blue to stain the viscoelastic solution. i s From WO 01 /66053 A1 , a further ophthalmologic composition is known, which is composed of a mixture of a viscoelastic polysaccharide with a vital dye, that is with a dye, which can be applied to living cells without killing them.

However, therein, both the trypan blue and the vital dye have to possess a substantially higher solubility in the ophthalmologic composition than in the surrounding tis- 20 sue in order not to stain the tissue. However, in particular upon longer dwell of the ophthalmologic composition in the eye, for example during surgery, it cannot be excluded that a certain proportion of the dye diffuses into the surrounding tissue and stains it. Moreover, there exist only comparatively few dyes, which can be applied to living cells without permanently damaging them.

25 It has been proposed to formulate a viscoelastic material containing fluorescein as a dye in the past (Zirm et al, British Journal of Ophthalmology 67, 1983, 259-263). These materials however did not have the desired advantages in ocular surgery. Dyes like fluorescein can diffuse out of the ophthalmologic composition, too, as a result of which they also stain the surrounding tissue. Another problem is that fluo-

30 rescein has to be irradiated with UV-light to show fluorescence and to make the viscoelastic solution visible. In order to minimize the diffusion of the dye from the ophthalmologic composition, US 4764360 A1 uses a high molecular weight polymer dye with a molecular weight preferably exceeding 30,000 Dalton (u) to maintain the dye in the ophthalmologic solution.

Detailed description of the invention

It is the object of the present invention to improve an ophthalmologic composition of the initially mentioned type such that it is simpler and safer in application. A further 5 object of the invention is to provide a method for producing such an ophthalmologic composition.

According to the invention, the objects are solved by an ophthalmologic composition having the features of claim 1 as well as by a method for producing an ophthalmologic composition according to claim 1 1 . Advantageous developments of the inven- 10 tion are specified in the respective dependent claims, wherein advantageous developments of the ophthalmologic composition are to be regarded as advantageous developments of the method and vice versa.

In an ophthalmologic composition according to the invention, comprising an aqueous solution of at least one viscoelastic polysaccharide, it is provided that the at i s least one polysaccharide is covalently bound to at least one dye. Therein, within the scope of the invention, chemical compounds are to be understood by dye, which include at least one chromophore molecule structure, which absorbs light in the wavelength range visible to the human between about 380 nm and about 800 nm and preferably does not exhibit any fluorescence or phosphorescence. By the cova-

20 lent bond of the dye to the at least one viscoelastic polysaccharide, it is reliably excluded that the dye diffuses into adjoining tissue and undesirably stains it during use of the ophthalmologic composition. Moreover, unlike fluorescent dyes such as fluorescein, rhodamine or the like, it is not required to irradiate the ophthalmologic composition with UV light to visualize it. This allows a substantially simpler handling of

25 the ophthalmologic composition. In addition, there is a priori no risk that the concerned tissue is damaged by the irradiation with high-energy UV light. Further, a user - for example a surgeon - can even recognize minor traces without additional auxiliary means such as UV lamps or the like due to the integral coloration of the ophthalmologic composition, whereby the use of the ophthalmologic composition

30 according to the invention in addition becomes substantially simpler and safer - for example within the scope of eye surgeries. In simplest configuration, the ophthalmo- logic composition is composed of an aqueous solution of a single viscoelastic polysaccharide, to which the dye is covalently bound. Alternatively, the ophthalmologic composition can include plural different viscoelastic polysaccharides and/or further additives. Independently thereof, it can also be provided that two or more different dyes are covalently bound to a viscoelastic polysaccharide.

In an advantageous development of the invention, it is provided that the polysaccharide is cellulose, a cellulose ether with methyl and/or ethyl and/or propyl groups, in particular hydroxypropyl methylcellulose, hydroxyethyl methylcellulose and/or me- thylcellulose, a glycosaminoglycan, in particular hyaluronic acid, chondroitin sul- phate, dermatan sulphate, heparin, heparan sulphate, keratan sulphate, alginic acid, polymannuronic acid, polyguluronic acid, polyglucuronic acid, amylose, amylopectin, callose, chitosan, polygalactomannan, dextran, xanthan and/or a mixture thereof. Hereby, in particular the viscoelastic properties of the ophthalmologic composition can be adapted to the respective purpose of employment and use in optimum man- ner. Therein, basically, it can also be provided that the ophthalmologic composition includes two or more polysaccharides of the same type, which only differ with regard to the molecular proportion of covalently bound dye.

In a further advantageous development of the invention, it is provided that the at least one dye is bound directly and/or via a spacer to the polysaccharide. Hereby, the dye can be particularly simply adapted to the present reactive groups of the concerned polysaccharide and be covalently bound to it. The use of a spacer is for example advantageous if the reactive group of the dye could not be bound to a corresponding reactive group of the polysaccharide or only within the scope of multistage reactions. Furthermore, the use of a spacer is advantageous if the absorption behavior of the dye would otherwise be affected in undesired manner by the cova- lent binding to the polysaccharide. Finally, by the use of a spacer the viscoelastic properties of the polysaccharide can be influenced as needed.

In a further advantageous development of the invention, it is provided that the at least one polysaccharide is obtainable by a reaction of the polysaccharide with at least one reactive dye from the group of modified and/or unmodified aminoanthra- cenedione and/or modified and/or unmodified nitrophenyldiazenylbenzenamine. The use of an aminoanthracenedione or of an aminoanthracenedione derivative and/or of a nitrophenyldiazenylbenzenamine or of a nitrophenyldiazenylbenzenamine de- rivative as a dye, which is covalently bound to the polysaccharide, therein offers the advantage that the color of the viscoelastic polysaccharide and thereby of the ophthalmologic composition is specifically adjustable nearly in the entire visible wavelength range. Furthermore, these two dyes or dye groups are characterized by a great fastness to washing and light. Thus, the ophthalmologic composition is particularly simply and safely to handle and additionally has high storage stability.

In a further advantageous development of the invention, it is provided that the at least one polysaccharide is obtainable by reaction with at least one reactive dye of the general formula (I),

wherein in the general formula (I) at least one of the substituents Ri to R₈ is an amino group, and the remaining substituents Ri to R₈, which are different from the amino group are selected from hydrogen, halogen, d-C₄-alkyl, CrC₄-alkoxy, C C₄- alkoxy-CrC₄-alkyl, CrC₄-alkyl-CrC₄-alkoxy, CrC₄-alkoxy-CrC₄-alkoxy, aryloxy, acetamide, propionamide, butyramide, isobutyramide, sulphonate, (aminophenyl)-N- alkylacetamide, (aminophenylsulphonyl)alkyl sulphate, alkylbenzenesulphonamide, tri(alkyl)benzenamine, hydroxy, (alkylsulphonyl)benzenamine, and (alkenylsul- phonyl)benzenamine, and/or wherein at least two adjacent substituents R_x, R_x+i with x=1 to 3 and/or 5 to 7 form a 3-, 4-, 5-, 6- or 7-membered homocyclic or heterocyclic radical, wherein said cyclic radical can be unsaturated or aromatic. Therein, all of the stereoisomers, racemic mixtures and position isomers are to be considered as included. With the aid of a dye of the general formula (I), the color properties of the polysaccharide covalently bound to it can be varied within wide limits, wherein combinations of different dyes of the general formula (I) can basically also be used to achieve a specific coloration. By at least one of the radicals Ri to R₈ being an amino group, the dye can additionally be coupled to a plurality of functional groups in chemically particularly simple manner. Therefore, different viscoelastic polysaccha- rides with correspondingly different functional groups can also quickly and simply be coupled to the dye of the general formula (I) without the requirement of costly multistage reactions, thereby resulting significant cost advantages. All reactive dyes of the general formula (I) exhibit a high extinction coefficient in the visible range of the light spectrum.

In a further advantageous development of the invention, it is provided that the at least one polysaccharide is obtainable through reaction with at least one reactive dye of the general formula (II),

wherein in the general formula (II) at least one of the substituents Ri to R₅ is an amino group and at least one of the substituents R₆ to R ₀ is a nitro group, and wherein the remaining radicals Ri to R ₀, which are different from the amino group and the nitro group are selected from hydrogen, halogen, d-C₄-alkyl, d-C₄-alkoxy, Ci-C₄-alkoxy-CrC₄-alkyl, CrC₄-alkyl-CrC₄-alkoxy, CrC₄-alkoxy-CrC₄-alkoxy, ary- loxy, acetamide, propionamide, butyramide, isobutyramide, sulphonate, (amino- phenyl)-N-alkylacetamide, (aminophenylsulphonyl)alkyl sulphate, alkylbenzenesul- phonamide, tri(alkyl)benzenamine, hydroxy, (alkylsulphonyl)benzenamine, and (al- kenylsulphonyl)benzenamine, and/or wherein at least two adjacent substituents R_y, R_y+i with y=1 to 4 and/or 6 to 9 form the cyclic radical

with:

R=hydrogen, halogen, amino, hydroxyl, nitro, CrC₄-alkyl, CrC₄-alkoxy, C C₄- alkoxy-CrC₄-alkyl, CrC₄-alkyl-CrC₄-alkoxy, and/or CrC₄-alkoxy-CrC₄-alkoxy. Therein, all of the stereoisomers, racemic mixtures and position isomers are to be considered as included. With the aid of a dye of the general formula (II), the color properties of the polysaccharide covalently bound to it can also be varied within wide limits, wherein combinations of different dyes of the general formula (II) can 5 basically also be used to achieve a specific coloration. By at least one of the radicals Ri to R₅ being an amino group and at least one of the radicals R₆ to R ₀ being a nitro group, a particularly high extinction coefficient in the visible range of the light spectrum results. With the aid of the at least one amino group, the dye can additionally be covalently bound to a plurality of functional groups in chemically particularly sim- 10 pie manner. Therefore, different viscoelastic polysaccharides with correspondingly different functional groups can also quickly, simply be coupled to the dye of the general formula (II) without the requirement of costly multi-stage reactions, thereby resulting significant cost advantages.

Further advantages arise by the zero-shear viscosity of the aqueous solution being i s between 20,000 and 8,000,000 mPa.s, preferably between 50,000 and 500,000 mPa.s. Hereby, the ophthalmologic composition has a particularly good flow behavior and is correspondingly well to handle in typical applications.

In a further advantageous development of the invention it is provided that the molecular weight of the colored polysaccharide is between 500,000 u and 5,000,000 u, 20 preferably between 800,000 u and 2,500,000 u. Hereby too, a particularly good flow behavior and a correspondingly good manageability of the ophthalmologic composition is achieved. In addition, plural dye molecules can be covalently coupled to a polysaccharide molecule without this resulting in substantial variations of the properties of the viscoelastic polysaccharide.

25 In a further advantageous development of the invention, it is provided that the concentration of the colored polysaccharide in the ophthalmologic composition is between 0.5% and 5% (w/w), preferably between 1 % and 3% (w/w). By a concentration between 0.5% and 5% (w/w), within the scope of the invention, in particular concentrations of 0.5 %, 0.6 %, 0.7 %, 0.8 %, 0.9 %, 1 .0 %, 1 .1 %, 1 .2 %, 1 .3 %,

30 1 .4 %, 1 .5 %, 1 .6 %, 1 .7 %, 1 .8 %, 1 .9 %, 2.0 %, 2.1 %, 2.2 %, 2.3 %, 2.4 %, 2.5 %, 2.6 %, 2.7 %, 2.8 %, 2.9 %, 3,0 %, 3,1 %, 3,2 %, 3,3 %, 3,4 %, 3,5 %, 3,6 %, 3,7 %, 3,8 %, 3,9 %, 4.0 %, 4.1 %, 4.2 %, 4.3 %, 4.4 %, 4.5 %, 4.6 %, 4.7 %, 4.8 %, 4.9 %, and 5.0 % as well as corresponding intermediate values are to be understood. Therein, within the scope of the invention, percentage information is to be understood as mass percent unless otherwise stated. By use of the polysaccharide in the indicated range of concentration, a particularly good flow behavior and a correspondingly good manageability of the ophthalmologic composition is achieved for 5 typical application cases.

In a further advantageous development of the invention, it is provided that the ophthalmologic composition is prepared for use in ophthalmology, in particular for use in a phacoemulsification method. Due to the integral, non-washable and simply adjustable coloration of the ophthalmologic composition, the viscoelastic solution can be 10 introduced into the eye in a particularly simple and controlled manner without herein being the risk of washout of the dye or of undesired coloration of the surrounding tissue. The entire ophthalmologic composition can be removed from the eye without residue in correspondingly simple and safe manner for example after a cataract surgery. i s A further aspect of the invention relates to a method for producing an ophthalmologic composition, in which at least one dye is covalently bound to at least one water-soluble, viscoelastic polysaccharide. By the covalent binding of the at least one dye to the at least one viscoelastic polysaccharide, it is reliably excluded that the dye diffuses into adjoining tissue and undesirably stains it during the use of the oph-

20 thalmologic composition. Moreover, unlike fluorescent dyes such as fluorescein, rhodamine or the like, it is not required to irradiate the ophthalmologic composition with UV light to render it visible. This allows a substantially simpler handling of the ophthalmologic composition. In addition, there is a priori no risk that the concerned tissue is damaged by the irradiation with high-energy UV light. Furthermore, a user -

25 for example a surgeon - can even recognize minor traces without additional auxiliary means such as UV lamps or the like due to the integral coloration of the ophthalmologic composition, whereby the use of the ophthalmologic composition according to the invention - for example within the scope of eye surgeries- additionally becomes substantially simpler and safer. In simplest configuration, the ophthalmo-

30 logic composition is produced with a viscoelastic polysaccharide, to which a single dye type is covalently bound. Alternatively, it can be provided that plural different viscoelastic polysaccharides and/or further additives are used to produce the ophthalmologic composition. Independently thereof, it can also be provided that two or more different dyes are covalently bound to a viscoelastic polysaccharide, whereupon the colored viscoelastic polysaccharide - optionally with further additives - is used for producing the ophthalmologic composition.

Furthermore, it can be provided that a dye with plural reactive groups is used. Hereby, the dye advantageously can be used as a cross-linker for cross-linking plural polysaccharides, whereby the viscoelastic properties of the polysaccharide can be specifically adjusted among other things. Alternatively or additionally, of course, non-colored cross-linkers such as for example divinyl sulphones or diepoxies can also be used for cross-linking for example alcohol or other functional groups of plural polysaccharides.

In a further advantageous development of the invention, it is provided that the at least one dye is used in a molar ratio between 1:10 and 1 :30 with regard to the polysaccharide and/or in a concentration of between 0.0005% and 1%, preferably between 0.01 and 0.3%, based on the weight of the ophthalmologic composition. Therein, within the scope of the invention, by a molar ratio between 1 :10 and 1 :30, in particular molar ratios of 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1 :20, 1:21, 1 :22, 1 :23, 1 :24, 1 :25, 1 :26, 1 :27, 1 :28, 1 :29, and 1 :30 as well as corresponding intermediate values are to be understood. Within the scope of the invention, by a concentration of between 0.0005% and 1%, in particular concentrations of 0.0005%, 0.001 %, 0.011 %, 0.021 %, 0.031 %, 0.041 %, 0.051 %, 0.061 %, 0.071 %, 0.081 %, 0.091 %, 0.101 %, 0.111 %, 0.121 %, 0.131 %, 0.141 %, 0.151 %, 0.161 %, 0.171 %, 0.181 %, 0.191 %, 0.201 %, 0.211 %, 0.221 %, 0.231 %, 0.241 %, 0.251 %, 0.261 %, 0.271 %, 0.281 %, 0.291 %, 0.301 %, 0.311 %, 0.321 %, 0.331 %, 0.341 %, 0.351 %, 0.361 %, 0.371 %, 0.381 %, 0.391 %, 0.401 %, 0.411 %, 0.421 %, 0.431 %, 0.441 %, 0.451 %, 0.461 %, 0.471 %, 0.481 %, 0.491 %, 0.501 %, 0.511 %, 0.521 %, 0.531 %, 0.541 %, 0.551 %, 0.561 %, 0.571 %, 0.581 %, 0.591 %, 0.601 %, 0.611 %, 0.621 %, 0.631 %, 0.641 %, 0.651 %, 0.661 %, 0.671 %, 0.681 %, 0.691 %, 0.701 %, 0.711 %, 0.721 %, 0.731 %, 0.741 %, 0.751 %, 0.761 %, 0.771 %, 0.781 %, 0.791 %, 0.801 %, 0.811 %, 0.821 %, 0.831 %, 0.841 %, 0.851 %, 0.861 %, 0.871 %, 0.881 %, 0.891 %, 0.901 %, 0.911 %, 0.921 %, 0.931 %, 0.941 %, 0.951 %, 0.961 %, 0.971 %, 0.981 %, 0.991 %, and 1.000 % as well as corresponding intermediate values are to be understood. By the use of the dye in the specified molar ratios and/or concentrations, the ophthalmologic composition has an optimum colorfulness for typical applications.

In a further advantageous development of the invention, it is provided that a dye with an amino group is used and covalently bound to the polysaccharide by way of an Ugi reaction. The Ugi reaction is a multi-component reaction involving a ketone or aldehyde, an amine, an isocyanide and a carboxylic acid. The products of the Ugi reaction are bis-amides. The Ugi reaction is an uncatalyzed reaction but is usually complete within minutes after adding the isocyanide. The main advantages of using an Ugi reaction are the inherent high atom economy as only a molecule of water is lost and the high product yields. Accordingly, the dye including the amino group can be bound quickly, simply and with high yields to polysaccharides comprising functional keto groups, aldehyde groups and/or carboxylic acid groups. An example for a suitable polysaccharide is hyaluronic acid. Hyaluronic acid is a polysaccharide with repeating disaccharide units of glucuronosyl-β-1 ,3-N-acetylglucosamine linked by β- 1 ,4-glycoside (glycosidic) bonds and has the general formula

In a further advantageous development of the invention, it is provided that for producing the ophthalmologic composition the polysaccharide coupled to the dye and/or a physiologically acceptable salt thereof is dissolved and/or dispersed in an amount of between 0.05 percent by weight and 5 percent by weight possibly together with a buffer system and/or with further agents and/or excipients in a protic solvent, in particular in water. Within the scope of the invention, by an amount of between 0.05 percent by weight and 5 percent by weight, in particular amounts of 0.05 %, 0.15 %, 0.25 %, 0.35 %, 0.45 %, 0.55 %, 0.65 %, 0.75 %, 0.85 %, 0.95 %, 1 .05 %, 1 .15 %, 1 .25 %, 1 .35 %, 1 .45 %, 1 .55 %, 1 .65 %, 1 .75 %, 1 .85 %, 1 .95 %, 2.05 %, 2.15 %, 2.25 %, 2.35 %, 2.45 %, 2.55 %, 2.65 %, 2.75 %, 2.85 %, 2.95 %, 3.05 %, 3.15 %, 3.25 %, 3.35 %, 3.45 %, 3.55 %, 3.65 %, 3.75 %, 3.85 %, 3.95 %, 4.05 %, 4.15 %, 4.25 %, 4.35 %, 4.45 %, 4.55 %, 4.65 %, 4.75 %, 4.85 %, 4.95 %, and 5.00 % as well as corresponding intermediate values are to be understood. Hereby, the property profile of the ophthalmologic composition can be adapted to different purposes of application in optimum manner.

In a further advantageous development of the invention, it is provided that in order to bond the at least one dye, the viscoelastic polysaccharide is functionalized and the at least one dye is covalently bound to the added functional group of the polysaccharide. In other words, first, a functional group is introduced into the viscoelastic polysaccharide, which is subsequently reacted with the at least one dye, in order to covalently bind the at least one dye to the polysaccharide. In this manner, the at least one dye can be simply bound to different polysaccharides with correspondingly specific functional groups largely independent of its precisely present reactive group. Alternatively or additionally, it can be provided that the at least one dye is first func- tionalized and subsequently covalently bound to the viscoelastic polysaccharide via its newly created functional group by means of a desired type of reaction.

Further features of the invention appear from the claims as well as based on the following embodiments. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the embodiments are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention.

Preferred embodiments of the invention

The present invention generally provides a colored ophthalmologic composition which can be completely removed after cataract surgery. The ophthalmologic composition comprises a viscoelastic solution based on a polysaccharide to which at least one dye is covalently bound. This means for example that a surgeon can visualize even very small traces of the viscoelastic ophthalmologic composition. By way of covalently binding the dye to the polysaccharide it is also ensured that the dye does not diffuse out of the solution and therefore does not stain the surrounding tissues. The ophthalmologic composition according to the invention can for example be used as eye drops. The viscoelastic property of the solution of the color labeled polysaccharide therein provides for a stable and long lasting tear film. Alternatively, it can be provided that the ophthalmologic composition according to the invention is used as caring solutions for contact lenses. Hereby, uncolored or colored contact lenses can be better recognized and simpler be removed from the contact lens container.

In the ophthalmic surgery, the ophthalmologic composition according to the invention can be used for filling up the vitreous body as well as for stabilizing the anterior chamber and for protection of the highly sensible endothelial cell layer of the cornea during surgery on the anterior eye portions, especially the surgery of the cataract. As the viscoelastic polysaccharide, to which the dye is covalently bound, for example hyaluronic acid is suited.

Suitable dyes that can be covalently bound to hyaluronic acid or another polysaccharide are based on aminoanthracenedione derivatives of the general formula (I):

wherein in the general formula (I) at least one of the substituents Ri to R₈ is an amino group, and the remaining substituents Ri to R₈, which are different from the amino group, are selected from: hydrogen, halogen, d-C₄-alkyl, CrC₄-alkoxy, CrC₄-alkoxy-CrC₄-alkyl, CrC₄-alkyl- CrC₄-alkoxy, CrC₄-alkoxy-CrC₄-alkoxy, aryloxy, acetamide, propionamide, bu- tyramide, isobutyramide, sulphonate, (aminophenyl)-N-alkylacetamide, (aminophen- ylsulphonyl)alkyl sulphate, alkylbenzenesulphonamide, tri(alkyl)benzenamine, hydroxy, (alkylsulphonyl)benzenamine, and (alkenylsulphonyl)benzenamine, and/or wherein at least two adjacent substituents R_x, R_x+i with x=1 to 3 and/or 5 to 7 form a 3-, 4-, 5-, 6- or 7-membered homocyclic or heterocyclic, unsaturated or aromatic radical.

Alternatively or additionally a reactive dye from the group of ((nitro- phenyl)diazenyl)benzenamine derivatives having the general formula (II)

may be covalently bound to the polysaccharide, wherein in the general formula (II) at least one of the substituents Ri to R₅ is an amino group and at least one of the substituents R₆ to R ₀ is a nitro group, and wherein the remaining radicals Ri to R ₀, which are different from the amino group and the nitro group, are selected from: hydrogen, halogen, d-C₄-alkyl, CrC₄-alkoxy, Ci-C₄-alkoxy-Ci-C₄-alkyl, CrC₄-alkyl- CrC₄-alkoxy, Ci-C₄-alkoxy-Ci-C₄-alkoxy, aryloxy, acetamide, propionamide, bu- tyramide, isobutyramide, sulphonate, (aminophenyl)-N-alkylacetamide, (aminophen- ylsulphonyl)alkyl sulphate, alkylbenzenesulphonamide, tri(alkyl)benzenamine, hydroxy, (alkylsulphonyl)benzenamine, and (alkenylsulphonyl)benzenamine, and/or wherein at least two adjacent substituents R_y, R_y+i with y=1 to 4 and/or 6 to 9 form the cyclic radical

with: R=hydrogen, halogen, amino, hydroxyl, nitro, CrC₄-alkyl, CrC₄-alkoxy, CrC₄- alkoxy-CrC₄-alkyl, Ci-C₄-alkyl-Ci-C₄-alkoxy, and/or Ci-C₄-alkoxy-Ci-C₄-alkoxy. Since both the dyes of the general formula (I) and the dyes of the general formula (II) have free amino groups, they can be bound to a polysaccharide having free keto, aldehyde and/or carboxyl groups without further derivatization or functionalization with the aid of the so-called Ugi reaction. The Ugi reaction is a 4 component con- 5 densation (U-4CC), which allows the synthesis of -aminoacylamide derivatives from aldehydes, amines, carboxylic acids and isocyanides. Therein, the Ugi reaction proceeds according to the general reaction scheme:

In the specific case, thus, the dyes of the general formulas (I) und (II) function as the 10 amino component and the hyaluronic acid functions as the carboxylic acid component of the Ugi reaction. For example, acetaldehyde can be used as the aldehyde. For example, cyclohexanenitrile is suitable as the isocyanide. Generally, low molecular alcohols have proven as the solvent in the Ugi reaction.

Preferably, the reactants are prepared in high concentrations with cooling and react i s very fast, that is within a few minutes at room temperature. Lewis acids known per se can be employed in the conversion in particular of sterically demanding educts for catalysis.

In the case of hyaluronic acid, which has the general formula

th e dyes of the general formulas (I) and (II) thus can react with the free carboxyl groups of the hyaluronic acid with the aid of their amino groups in a reaction step and hereby be covalently bound to the hyaluronic acid. The carboxylic acids employed within the scope of an Ugi reaction can advantageously be diversely varied such that other polysaccharides with free carboxyl groups can also be used without previous functionalization within the scope of an Ugi reaction. Polysaccharides without carboxyl groups can be subjected to a preceding derivatization or functionalization for later use in the Ugi reaction. Conversely, polysaccharides with free amino groups can of course also be reacted with dyes having free carboxyl groups.

An advantage of the dyes of the general formulas (I) and (II) is in their basically very high extinction coefficient in the visible range of the light spectrum (about 400 nm to about 800 nm). Furthermore, the color of the dyes of the general formulas (I) and (II) can be simply varied in a wide color range by use of corresponding substituents and/or position isomers, whereby the ophthalmologic composition can be simply adapted to different purposes of use.

In the following table 1 , various embodiments for dyes of the general formula (I) are specified.

Table 1 : Embodiments for dyes of the general formula (I)

Example 1

Name and sodium 1 -amino-4-(4-(N-methyl-acetamido)phenylamino)-9,10-

Synonyms dioxo-9,10-dihydroanthracene-2-sulfonate; Acid Blue 41 ; CAS

2666-17-3 Example 2

Name and sodium 2-(3-(4-amino-9,10-dioxo-3-sulfonato-9,10-

Synonyms dihydroanthracen-1 -ylamino)phenylsulfonyl)ethyl sulphate; Reactive Blue 19 (Remazol Brilliant Blue R); CAS 2580-78-1

Example 3

Name and N-(4-amino-3-methoxy-9,10-dioxo-9,10-dihydroanthracen-1 -yl)-4- Synonyms methylbenzenesulfonamide; Disperse Red 86; CAS 81 -68-5

Example 4

Name and 1 -amino-4-hydroxy-2-(2-methoxyethoxy)anthracene-9, 10-dione;

Synonyms Disperse Red 59; CAS 17869-10-2

Example 5

Name and sodium 1 -amino-4-(mesitylamino)-9,10-dioxo-9,10-

Synonyms dihydroanthracene-2-sulfonate; Acid Blue 129; CAS 6397-02-0

In the following table 2, various embodiments for dyes of the general formula (II) are specified.

Table 2: Embodiments for dyes of the general formula (II)

Example 1 o 3;

Example 10

Name and (E)-1 -((4-nitrophenyl)diazenyl)naphthalene-2-amine; 1 -(4'-

Synonyms Nitrophenylazo)-2-naphthylamine; Solvent Red 5; CAS 3025-77-

2

Example 1 1

Name and (E)-4-amino-3-((4-nitrophenyl)diazenyl)naphthalene-1 -sulphonic

Synonyms acid; Acid Red 74; CAS 6300-18-1

However, it is to be emphasized that besides the Ugi reaction, basically, other chemical reaction types can also be used for covalently binding the concerned dye to the concerned viscoelastic polysaccharide. For example, dyes with a free alcohol group can be bound to hyaluronic acid by an esterification reaction.

Labeling of hyaluronic acid (HA) can for example also be obtained by the reaction of CNBr-activated HA at vicinal diols and a dye comprising a reactive amine group according to the following reaction scheme:

wherein HA denotes hyaluronic acid and NH₂-R denotes the reactive dye comprising an amine group. The reaction may also involve the hydroxyl groups in two hyaluronic acid molecules.

It is also possible to use a dye comprising an isothiocyanate group (denoted by SCN-R), which targets mostly the primary hydroxyl groups of HA or other viscoelas- tic polysaccharides:

The reaction is conducted at 37 °C overnight. The resulting color labeled polysaccharide is stable for over a month.

A further type of reaction for covalently binding a dye to hyaluronic acid includes activation of a hyaluronic acid derivative with N-hydroxysuccinimide coupled di- phenylphosphoric acid. The resulting adduct is reacted with a dye comprising a reactive hydrazide group (denoted by [R]CC(NN)=0) according to the following general reaction scheme:

Another method to chemically bond a reactive dye to hyaluronic acid (HA) or other polysaccharides comprising carboxylic groups is depicted in the following reaction scheme:

The reaction employs a dye comprising a hydrazide group. The first step is to form an O-acylurea of HA by reaction of HA with 1 -ethyl-3-(3- dimethylaminopropyl)carbodiimide (EDC) having the formula

The resulting intermediate is then reacted with the reactive dye to form the color labeled HA.

Another possibility is the reaction between the carboxylic groups of HA and dyes comprising a carbodiimide group in the presence or absence of primary amines at pH 4.5 according to the general reaction scheme:

The reaction of carbodiimides proceeds rapidly at room temperature. The final group is an N-acylurea or O-acylurea. The carbodiimides are synthesized in a 2-step reaction: the reaction of a dye comprising a primary amine and isothiocyanate to form a thiourea and the reaction of said thiourea and HgO to produce the reactive dye comprising a carbodiimide group.

HA esters can also be produced by a nucleophilic reaction of a reactive dye comprising a halide with a quaternary salt of hyaluronic acid:

Another way to molecularly label the viscoelastic polysaccharide is given by the cross-linking of HA with diepoxies:

In acidic conditions, the ester of HA is formed by linking the epoxy to HA at the acidic position. In basic conditions, the ether is produced by linking the epoxy to HA at the primary alcohol position.

Another way to crosslink and therefore functionalize HA at the primary alcohol posi- tion is to use divinylsulfone as cross-linker:

Alternatively, it can be provided herein that a dye with a free hydroxy group is used and bound to the hyaluronic acid with the aid of the cross-linker.

Alternatively or additionally to hyaluronic acid, basically, other viscoelastic polysaccharides such as for example hydroxypropylmethylcellulose, chondroitin sulfate or mixtures thereof can also be used.

An ophthalmologic composition comprising an aqueous solution of a viscoelastic polysaccharide which is covalently bound to one or several dyes of the general formulas (I) and/or (II) may be used in a phacoemulsification method. During the phacoemulsification, the anterior chamber of the eye is filled with the ophthalmologic composition comprising the colored viscoelastic solution. The viscoelastic ophthalmologic composition is used as a surgical aid to protect intraocular tissues, for ex- ample the corneal endothelium, during the phacoemulsification, as a space main- tainer to maintain the anterior chamber of the eye, and to facilitate intraocular maneuvers, for example to make a controlled capsulorhexis. Because the dye is covalently bound to the polysaccharide, the dye does not diffuse out of the solution and therefore does not stain the surrounding tissues. After the capsulorhexis the colored ophthalmologic composition may be completely removed from the anterior chamber as the surgeon can visualize even very small traces of the viscoelastic ophthalmologic composition.

Claims

1 . Ophthalmologic composition, comprising an aqueous solution of at least one viscoelastic polysaccharide,

characterized in that

the at least one polysaccharide is covalently bound to at least one dye.

The ophthalmologic composition according to claim 1 ,

characterized in that

the polysaccharide is cellulose, a cellulose ether with methyl and/or ethyl and/or propyl groups, in particular hydroxypropyl methylcellulose, hydroxyethyl methylcellulose and/or methylcellulose, a glycosaminoglycan, in particular hyaluronic acid, chondroitin sulphate, dermatan sulphate, heparin, heparan sulphate, keratan sulphate, alginic acid, polymannuronic acid, polyguluronic acid, polyglucuronic acid, amylose, amylopectin, callose, chitosan, polygalac- tomannan, dextran, xanthan and/or a mixture thereof.

The ophthalmologic composition according to claim 1 or 2,

characterized in that

the at least one dye is bound to the polysaccharide directly and/or

spacer.

The ophthalmologic composition according to any one of claims 1 to 3, characterized in that

the at least one polysaccharide is obtainable by a reaction of the polysaccharide with at least one reactive dye from the group of modified and/or unmodi- tied aminoanthracenedione and/or of modified and/or unmodified nitro- phenyldiazenylbenzenamine.

The ophthalmologic composition according to claim 4,

characterized in that

the at least one polysaccharide is obtainable by reaction with at least active dye of the general formula (I),

wherein in the general formula (I) at least one of the substituents Ri to R₈ is an amino group, and the remaining substituents Ri to R_8, which are different from the amino group:

- are selected from: hydrogen, halogen, d-C₄-alkyl, CrC₄-alkoxy, C C₄-alkoxy-CrC₄-alkyl, CrC₄-alkyl-CrC₄-alkoxy, CrC₄-alkoxy-CrC₄- alkoxy, aryloxy, acetamide, propionamide, butyramide, isobutyra- mide, sulphonate, (aminophenyl)-N-alkylacetamide, (aminophenyl- sulphonyl)alkyl sulphate, alkylbenzenesulphonamide, tri(alkyl)benzenamine, hydroxy, (alkylsulphonyl)benzenamine, and (alkenylsulphonyl)benzenamine; and/or wherein at least two adjacent substituents R_x, R_x+i with x=1 to 3 and/or 5 to 7 form a 3-, 4-, 5-, 6- or 7-membered homocyclic or heterocyclic, unsaturated or aromatic radical.

6. The ophthalmologic composition according to claim 4 or 5, characterized in that the at least one polysaccharide is obtainable by reaction with at least one reactive dye of the general formula (II),

R7 fie

wherein in the general formula (II) at least one of the substituents Ri to R₅ is an amino group and at least one of the substituents R₆ to Ri₀ is a nitro group, and wherein the remaining radicals Ri to R ₀, which are different from the amino group and the nitro group:

- are selected from hydrogen, halogen, d-C₄-alkyl, CrC₄-alkoxy, C C₄-alkoxy-CrC₄-alkyl, Ci-C₄-alkyl-Ci-C₄-alkoxy, Ci-C₄-alkoxy-Ci-C₄- alkoxy, aryloxy, acetamide, propionamide, butyramide, isobutyra- mide, sulphonate, (aminophenyl)-N-alkylacetamide, (aminophenyl- sulphonyl)alkyl sulphate, alkylbenzenesulphonamide,

tri(alkyl)benzenamine, hydroxy, (alkylsulphonyl)benzenamine, and (alkenylsulphonyl)benzenamine; and/or

- wherein at least two adjacent substituents R_y, R_y+i with y=1 to 4 and/or 6 to 9 form the cyclic radical

with:

R=hydrogen, halogen, amino, hydroxyl, nitro, CrC₄-alkyl, CrC₄- alkoxy, Ci-C₄-alkoxy-Ci-C₄-alkyl, Ci-C₄-alkyl-Ci-C₄-alkoxy, and/or C C₄-alkoxy-CrC₄-alkoxy.

7. The ophthalmologic composition according to any one of claims 1 to 6, characterized in that

the zero-shear viscosity of the aqueous solution is between 20,000 and 8,000,000 mPa.s, preferably between 50,000 and 500,000 mPa.s.

The ophthalmologic composition according to any one of claims 1 to 7, characterized in that

the molecular weight of the colored polysaccharide is between 500,000 5,000,000 u, preferably between 800,000 u and 2,500,000 u.

9. The ophthalmologic composition according to any one of claims 1 to 8,

characterized in that

the concentration of the colored polysaccharide in the ophthalmologic composition is between 0.5% and 5% (w/w), preferably between 1 % and 3% (w/w).

10. The ophthalmologic composition according to any one of claims 1 to 9,

characterized in that

it is prepared for use in ophthalmology, in particular for use in a phacoemulsification method.

1 1 . A method for producing an ophthalmologic composition, in which at least one dye is covalently bound to at least one water-soluble, viscoelastic polysaccharide.

The method according to claim 1 1 ,

characterized in that

the at least one dye is used in a molar ratio between 1 :10 and 1 :30 with regard to the polysaccharide and/or in a concentration of between 0.0005% and 1 %, preferably between 0.01 and 0.3%, based on the weight of the ophthalmologic composition.

The method according to claim 1 1 or 12,

characterized in that

a dye with an amino group is used and covalently bound to the polysaccharide by way of an Ugi reaction.

The method according to any one of claims 1 1 to 13,

characterized in that

for producing the ophthalmologic composition the polysaccharide coupled to the dye and/or a physiologically acceptable salt thereof is dissolved and/or dispersed in an amount of between 0.05 percent by weight and 5 percent by weight possibly together with a buffer system and/or with further agents and/or excipients in a protic solvent, in particular in water.

The method according to any one of claims 1 1 to 14,

characterized in that

in order to bond the at least one dye, the viscoelastic polysaccharide is func- tionalized and the at least one dye is covalently bound to the added functional group of the polysaccharide.