DE3021034A1 - CLEANING AGENTS FOR CONTACT LENSES AND THEIR USE - Google Patents

Description

HOFFMANIS · IjJITLJB & PARTNER

PAT E N TAN WALT II

DR. ING. E. HOFFMANN (1930-1976) · DI PL-IN G. W. EITLE ■ D R. RER. NAT. K. H O FFMAN N · D I PL.-I N G. W. LEH N

DIPL.-ING. K. FÜCHSLE DR. RER. NAT. B. HANSEN ARABELLASTRASSE 4 [STERNHAUS) · D-8000 MD NCH EN 81 · TELEPHONE (089) 9Π087. TELEX 05-29619 (PATH E)

. S-

33 579 o / fi

POLYMER TECHNOLOGY CORPORATION Wilmington, Mass./USA

Cleaning agents for contact lenses and their application

It has long been known that contact lenses are free from Surface deposits need to be in order to maintain comfort and optimal eyesight, and to make a change of strength to avoid. Unfortunately, contact lenses tend to have surface deposits from external sources (Mascara, hairspray and the like) and from endogenous sources (slimy, oily eye secretions and the like) to accumulate. Contact lenses containing silicone are particularly susceptible of all contact lenses, annoying waxy ones Accumulate surface debris that is difficult, if not entirely, to remove from the lenses without damaging them.

In current contact lens cleaning solutions for hard and soft contact lenses, there are a variety of water-soluble detergents in addition to water-soluble hydrated polymers in sterile, homogeneous aqueous solutions have been used. Other cleaning agents

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use thixotropic synthetic water-soluble polymers and thixotropic synthetic clays with surface active agents Agents forming stiff gels for cleaning hard contact lenses.

Abrasive materials are not heretofore found in contact lens cleaning solutions has been used because it was feared that abrasives would scratch the surface of plastic contact lenses arise, and thereby a deterioration in optical clarity and also an eye irritation would have expected.

The object of the invention isc to provide a contact lens cleaning material available that substantially support material suspending consisting of a surfactant, an inorganic abrasive and one that is very suitable, causing as a cleaning agent and a superior cleaning of silicone-containing plastic contact lenses, and that also is also suitable as a cleaner and / or cleaning polisher for other contact lens materials.

Another object of the invention is to provide a method for cleaning eye contact lenses that thereby is characterized in that a cleaning solution containing an abrasive is applied to the surface of a lens, and abrades unwanted debris from the surface without altering the power of the contact lenses will.

According to the invention, there is the contact lens cleaning material consisting essentially of a surfactant, a inorganic abrasives and a backing material such as

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Water or an organic liquid. Furthermore, means are provided to the surface-active agent and to obtain the abrasive in substantially uniform suspension so that one can get a contact lens with the solution can clean without damaging the lens. Preferably the material is in liquid solution, however it can also be in the form of a paste. The cleaner can have a buffing effect if you consider the amount of abrasive elevated. Preferably, the abrasive is fine grained so that it will not scratch the lenses.

According to the method according to the invention, eye contact lenses are cleaned by placing the surface of the lenses in Presence of a cleaning solution comprising an abrasive, a surfactant, a liquid carrier and contains a suspending agent. The cleaning solution is applied to the surface of the lenses and there undesirable surface deposits, if any, are abraded away without affecting the power of the contact lenses is changed. By increasing the amount of abrasive material and by applying greater pressure during If used for a longer period of time, the material can also be used for polishing, although it is preferable to use it only as one Cleaning polisher applies.

It is a feature of the invention that a multiplication of the cleaning effect of certain surfactants is achieved when you consider the frictional force when rubbing the surface-active Increased by means of the plastic surface. This is achieved that one in the solution of the surface-active By means of a solid abrasive in particulate form, its concentration depending on the desired

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Function of the respective formulation can be selected. The particle size that is normally used is comparable to or slightly smaller than abrasives used for polishing lens surfaces during their manufacture normally used. These particles remain evenly suspended in the surfactant solution, without settling, because if they settle down, the effect as a cleaner would be different, and the particles also do not aggregate because otherwise scratches on the Lens surfaces would be caused.

Another feature of the invention is that the suspending agent for the abrasive particles is so selected becomes that the overall suspension is stable almost indefinitely. The cleaning solution can contain sterilants and buffering agents as well also contain fragrances. In certain cases it is possible to use a surfactant both for suspending the To use abrasive particles as well as for cleaning action. However, it is more common as a suspending agent to use a high concentration of water-soluble salts or organic polymers.

Although the cleaning solutions described here are used in particular for cleaning and / or cleaning and polishing hard, gas-permeable contact lenses containing siloxane are suitable, they can also be used for contact lenses, made from polymethyl methacrylate, silicone and cellulose acetate butyrate, as well as for contact lenses other materials.

The preferred formulations for the contact lens cleaners of the invention contain a surfactant

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Agents together with an abrasive for a combined chemical and mechanical cleaning effect, as well as a suspending agent for the abrasive, so that a stable suspension is formed in an aqueous solution.

Preferred surface active agents are detergents or anionic sulfate surfactants of the general formula

^C n ^H 2n ₊ 1 ^{O (CH} 2 ^CH 2 ^O) x ^SO 3 ^{R +}

XO to 10
η 8 to 20
R ⁺ Na ⁺ , K ⁺ , NH ⁺ 1 / 2Mg ⁺⁺ ,

mean.

Examples of such detergents are sodium lauryl sulfate, Sodium cetyl sulfate, sodium octyl sulfate, sodium tridecyl sulfate, Sodium oleyl sulfate, sodium tridecyl ether sulfate, triethanolamine lauryl sulfate, Ammonium lauryl ether sulfate, sodium lauryl ether sulfate and magnesium lauryl ether sulfate.

The abrasive compound or compounds are water-insoluble inorganic compounds used for their abrasion properties. The abrasive material is one hard and tough substance with many sharp protruding cutting edges and points and is usually used for grinding, Smoothing and polishing used. Such abrasives include various types of silica, aluminum trioxide, Manganese oxides, zirconium oxides and carbonates.

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It is preferred to use abrasive materials with average particle sizes of 10 µm or less. Suitable abrasives are e.g. silicon dioxide, aluminum oxide, kaolin, Calcium carbonate or zirconium oxide.

The suspending agent or agents in the composition must be a stable suspension of the abrasive in the cleaning solution result. Such a suspension can be achieved by changing the viscosity of the aqueous solution Addition of soluble salts or of hydrophilic polymers or by adding water-soluble, neutral or ionic ones Polymers that can interact with the surface of one or more of the inorganic abrasives, and that this prevents failure.

Suitable suspending agents are, for example, the following:

Alkali halides (high concentration), alkaline earth salts (moderate concentration), polyvinyl alcohol, polyacrylamide, hydrolyzed polyacrylamide, polyacrylic acid, xanthan resin, hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfate, Methyl cellulose, methyl hydroxyethyl cellulose, methylhydroxypropyl cellulose, poly-N-vinylpyrrolidone, guar gum, Carboxymethyl guargum, hydroxyethy guargum, hydrated Polyacrylonitrile starch, hydrolyzed polyacrylonitrile-2-acrylamido-2-methylpropanesulfonate starch, Clays, such as bentonite, montorillonite and hectorite, neutral, cationic and anionic detergents, partially acetylated cellulose. Gelatin. Polyethylene Glycol and Oxide and K-Carageenan.

Buffering agents can be used, preferably those usually used in a pH range of 5 to and generally between 7 and 8 apply. Such buffers

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e.g. boric acid, sodium diborate, phosphoric acid, disodium phosphate and sodium bicarbonate.

The use of salts as suspending agents generally makes the cleaning solution sterile, in cases where but which are not sterile, antibacterial compounds can be used. Such connections include chlorhexidine, benzalkonium chloride, phenyl mercuric acetate, phenyl ethyl alcohol, methyl or propyl paraben, cetyl pyridinium chloride, Thimerosal and the like, optionally together with EDTA (ethylenediaminetetraacetic acid).

Fragrances such as peppermint and the like can also be used admit.

In the simplest case, a contact lens is cleaned by placing the lens in the cleaning solution, or with it this is sprayed, and then the solution is moved, e.g. by rubbing, shaking or cleaning. Then the lens with Rinsed with water and inserted directly into the eye, or it is placed in a moisturizing and / or emollient solution prior to insertion placed.

Typical examples of the present invention are given below:

EXAMPLE ί

Composition:

Sodium tridecyl ether sulfate (30%) 80 g

Distilled water 160 g

Sodium chloride 20 g

Silicon dioxide (9 µm average 24 g

particle size)

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The surface active agent is mixed with water and then add sodium chloride and continue mixing until a thick solution is obtained. Then you add silicon dioxide powder to the solution and mix thoroughly until a smooth viscous suspension is obtained. After 8 months No settling abrasive material was observed when stored without agitation.

EXAMPLE II
Composition:

Sodium tridecyl ether sulfate (30%) 133 g

Distilled water 267 g

Sodium chloride 30 g

Silicon dioxide (9 µm average - 1 g

particle size)

Production was identical to that in Example 1.

EXAMPLE III

Composition:

Sodium tridecyl ether sulfate (30%) 133 g

Distilled water 267 g

Sodium chloride 30 g

Silicon dioxide (9 µm dia- 1 g

cut particle size)

The preparation was the same as in Example 1.

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133 G 133 G 133 G 267 G 267 G 267 G 30th G 30th G - 12th

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EXAMPLE IV

Composition: AB

Sodium tridecyl ether sulfate (30% ■)
Distilled water
Sodium chloride

Silicon dioxide (9 µm average particle size)

The cleaning solutions were prepared in the same way as described in Example 1.

High silicone contact lenses have a tendency to build up waxy surface deposits that you just get Difficult, if at all, to be removed by solvents, detergents, or polishes without affecting the surface the lenses is damaged. The best way to detect such deposits is to rinse and rinse a dry lens against a black background (a self-illuminated binocular microscope can be used for this, the is classified according to the surface and the thickness (permeability) in 1 to 4 degrees, with a rating of 4 indicates very heavy deposits). 60 pairs of lenses with approximately symmetrical surface depositions of the evaluation Two or more were subjected to the following procedure: One lens per pair was manually made using the formulation "A" cleaned. The other lenses were divided into three groups of 20 each. A group became manually with the formulation "B", the second group with the formulation "C" and the last group with different im Commercially available contact lens cleaners (solutions and gels)

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treated. It was found that the formulations "B" and "C" were equally effective, but that formulation "A" was more effective than the formulations in several ways "B" and "C". In fact, the formulations "B" and "C" were relatively ineffective at preventing debris from To remove grade 4, while the formulation "A" according to the invention achieved a high level of effectiveness in all cases. In addition, none of the commercially available contact lens cleaners were more effective than formulations "B" and "C" and many were even less effective. This example shows the suitability of suspended abrasives for improved cleaning performance over simple solutions surface-active middle L.

EXAMPLE V

The cleaning solution described in Example III was reconstituted in a number of patients at the start of wearing hard contact lenses (containing silicone) provided. Patients were instructed to keep their lenses with them cleanse this formulation every evening. 6 months later, the lenses were examined and matched with lenses Group of patients compared their lenses at night with a number of different contact lens cleaners cleaned. The lenses of the patients who used the cleaning solution according to Example 3 showed significantly less surface deposits and were usually easier to carry.

The cleaning solution prepared according to Example 3 was also given to a small group of contact lens wearers, the lenses made of polymethyl methacrylate and the blurred vision due to the development of so-called "dry"

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Spots on the front surface of their lenses complained, though They put their lenses in a number of commercially available contact lens cleaners, solvents or polishes in the evenings treated. In all cases, the evening use of the cleaning solution according to the invention made the hydrophobic ones Avoid dry surfaces and keep your vision clear while wearing the lenses during the day.

EXAMPLE VI

The surface of all hard contact lenses will scratch after a while. Common polishing agents remove small scratches and smooth the grooves that occur on deeper scratches, thereby improving the comfort and appearance of the Lenses. However, many of the scratched contact lenses also have considerable amounts of surface deposits, which are not removed by polishing. When polishing contact lens surfaces with significant deposits these are only distributed and then separate again and thus reduce the moisture content of the surfaces Additionally. The contact solution described in Example I combines the effects of a cleaner (removal of the Surface film) and a polishing agent (removal of surface scratches) and is much more effective than when used a cleaner and a polishing agent in separate processes. A cleaning polishing agent as described in Example 1 Art is particularly suitable in practice for restoring the optical properties and the wettability of hard contact lenses.

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"■■ &'

EXAMPLE VII
Composition:

Sodium tridecyl ether sulfate (30) 100 g

4% hydroxyethyl cellulose solution 200 g

Alumina (0.06 µm) 10 g

4% by weight of hydroxyethyl cellulose (Cellosize QP-40) from Union Carbide Corporation, New York, New York / USA) is dissolved in distilled water. Then add the surfactant to the solution and mix well. Eventually that will Alumina is mixed thoroughly into this solution until a smooth viscous solution is obtained. This example shows that one can use a water soluble polymer to suspend the abrasive powder.

EXAMPLE VIII
Composition:

Sodium tridecyl ether sulfate (30%) 100 g

Distilled water 200 g

Hydrite 10 (kaolin clay) 30 g

Sodium chloride 25 g

The production was carried out in the same way as in the example In this example the use of kaolin is shown, a material that has a milder abrasive effect compared to silica or alumina.

EXAMPLE IX

Composition:

Sodium tridecyl ether sulfate (30%) 100 g

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Glycerine 200 g

Silicon dioxide (9 µm average 3 g

particle size)

The surfactant was dissolved in glycerin and silica was mixed into the solution.

This example shows the use of an organic liquid in connection with a surface active agent for making a transparent cleaning solution.

EXAMPLE X

Composition: AB

Sodium tridecyl ether sulfate (30%) ammonium lauryl ether sulfate (27%)

Silicon dioxide (4 µm average particle size)

Hydrite 10 (kaolin clay) - 75 g

The abrasive powder is surfactant with the Medium mixed and with moderate shear effect a stable paste is made.

This example shows the use of the surfactant Agent as a suspending agent for the abrasive to form a cleaning paste.

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100 30th G 125 G - G - - 100 G G - 35

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EXAMPLE XI
Composition:

Triethanolamine lauryl sulfate (40%) 75 g

Distilled water 520 g

Xanthan gum 10 g

Silicon dioxide (4 um average 18g

particle size)

Xanthan gum is dissolved in distilled water. The surfactant is added to the solution with thorough mixing. Silicon dioxide is de-nn mixed into this solution until one a smooth viscous solution is obtained.

This example demonstrates the use of a water soluble polymer to suspend the abrasive powder.

While the invention has been described in a number of examples, many changes are possible. If you use the invention Cleaning solutions as cleaning agents, the surfactant is preferably in the amount of 1 to 30% by weight of the material is present, the abrasive particles make up 0.1 to 5% by weight and the backing material such as Water, 98.9 to 69.9 wt .-%, the suspending agent, based on 100 parts of the above ingredients 5 to 25 parts when using inorganic salts and 1 to 10 parts when using polymers. The same suspension center] is used when the cleaning solution is used as a cleaning-polishing agent used, but here the amount of surfactant can be in the range of 1 to 30 wt .-% and the amount of abrasive is increased to 5 to 25% by weight while adding water or other suspension vehicles up to 100%. If you wish instead of a free flowing one Liquid a paste, so can the surfactant

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15 to 40% by weight, the abrasive 20 to 50% by weight, with the remainder being water or another water-soluble solvent is. Of course, one or more surfactants, abrasives or solvents can also be used When used in a single composition, the particle size of the abrasive can vary widely, however preferably it corresponds to that used for lens polishes in the ophthalmic lens industry. For example one can use silica with a particle size averaging 9 µm with a range of 1 to 20 µm and an upper one Limit of 30 µm in the form of Syloid 63, a commercial product of Davison Chemical W.R. Grace Co., Baltimore, Maryland / USA use. Other particle size ranges are possible.

In all cases the surfactant acts together with the abrasive and gives a synergistic effect in cleaning contact lenses in the case of the present invention Procedure. While specific surfactants have been previously described, other surfactants 'can also be used. Means that combine with water to form colloidal particles known as Called mycelia are known. The structure is such that hydrophobic hydrocarbon chains are inside the solvent are, and that polar head groups on the surface of the particles are. The presence of mycelia in an aqueous solution gives them small areas that are mainly more hydrophobic Are nature. This results in the good solubility and good wettability of the materials in water.

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Claims (11)

302103A HOFFMANN · EITIJE & PARTNER I1AT E N TAN W ALT 15 DR. ING. E. HOFFMANN (1930-1976). D I PL-! N G. W. EITLF. · D R. RER. NAT. K. H O FFMAN N · D 1 PL.-1 N G. W. LEH N DIPL.-ING. K. FOCHSLE DR. RER. NAT. B. HANSEN ARABELLASTRASSE 4 (STEKi-! HAUS) · D-3000 MO NCH EN 81 · TELEPHONE (08?) 911087 · TELEX 05-29619 (PATH E) 33 579 o / fi POLYMER TECHNOLOGY CORPORATION Wilmington, Mass./USA cleaning agents for contact lenses and their application claims: 1. Cleaning agents for contact lenses, containing essentially a surfactant, an inorganic abrasive, a backing material, as well as means for the surface material and the grinding material to keep evenly suspended so that the solution for cleaning contact lenses without damaging the same suitable is. 2. Contact lens cleaning material according to claim 1, characterized in that the solution is in liquid form. 030062/0661 INSPECTED 3. Contact lens cleaning material according to claim 1, characterized in that the material is a semi-viscous paste. 4. Contact lens cleaning material according to claim 1, characterized characterized in that the surfactant is in an amount of 1 to 30 percent by weight of the abrasive are present in an amount of 0.1 to 5% by weight, and that the carrier is water in an amount up to 100%, and that the agents are selected from the suspending agent Class consisting of inorganic salts and hydrophilic polymers. 5. Contact lens cleaning material according to claim 1, characterized in that the surface-active Agents in an amount of 1 to 30% by weight, the abrasive in an amount of 5 to 25% by weight, and that the carrier is water in an amount up to 100%, the agents being suspending agents selected from the class consisting of inorganic salts and hydrophilic polymers. 6th Contact lens cleaning agent according to claim 1, characterized characterized in that the surfactant is in an amount of 15 to 40 percent by weight of the abrasive are present in an amount of 20 to 50% by weight, and that the The carrier is water in an amount up to 100% and that the agents are suspending agents selected from the group consisting of inorganic salts and hydrophilic polymers. 030062/0681 7. Contact lens cleaning material according to claim 1, characterized in that the Abrasive is selected from the group consisting of silicon dioxide, aluminum dioxide, kaolin, calcium carbonate, Zirconia and mixtures thereof. 8. Cleaning material according to claim 1, characterized in that the surface-active Means the following general formula: ^C n ^H 2 ^{n -M O (CH 2 CH} 2 ^O) x ^SO 3 ^{R +} has what
χ Ο to 10 η 8 to 20 NH R ⁺ Na ⁺ , K ⁺ , NH ⁺ 1 / 2Mg ⁺⁺ , mean. 9. A method for cleaning eye contact lenses, characterized in that a cleaning solution, containing an abrasive and a surfactant on a surface of the lenses and cleans the surface of any unwanted deposits that may be present, without affecting the power of the contact lenses to change. 10. The method according to claim 9, characterized that the cleaning solution also contains a carrier material and means to the surfactants and the abrasive are kept substantially evenly suspended so that the solution is able to clean the contact lenses without damaging them. 030062/0 6 61 11. The method according to claim 10, characterized in that the carrier material is water and that the suspending agent is an inorganic salt or a hydrophilic polymer. 030062/0681