DE3021034C3 - Use of a means for cleaning hard contact lenses - Google Patents

Description

It has long been known that contact lenses are free of Surface deposits must be to ensure comfort and to get the best eyesight, and a change to avoid the strength. Unfortunately, contact lenses tend in addition, surface deposits from external sources (Mascara, hair spray) and endogenous Sources (slimy, oily eye secretions) to accumulate. Silicone containing contact lenses are from all Contact lenses very vulnerable, disturbing waxy Accumulate surface deposits that are difficult to if at all can completely remove from the lenses, without damaging them.

In the past contact lens cleaning solutions for Hard and soft contact lenses are a variety of water-soluble cleaning agents in addition to water-soluble hydrated polymers in sterile, homogeneous aqueous solutions have been used. Other cleaning agents use thixotropic synthetic water-soluble polymers and thixotropic synthetic clays with surfactant Means to form stiff gels for cleaning hard contact lenses.

Abrasive materials are not previously in contact lens cleaning solutions been used because it was feared that through abrasive scratches on the surface of the plastic contact lenses arise, and thereby a deterioration the optical clarity and also an eye irritation would have expected. Thus, in US-PS 40 96 870 for the cleaning of soft contact lenses an aqueous Suspension of pancreatin is recommended and expressly approved by the Use of abrasives advised against. For hard contact lenses in US-PS 38 84 826 an aqueous thixotropic Composition described essentially a surfactant, a thixotropic gelling agent, contains a sterilizing agent and water. There will be too the use of abrasives expressly as unsuitable explained. Abrasive for  Polishing of optical lenses based on ceria, a thickening agent, a Surfactants and water are from the US-PS 42 22 747 known.

The object of the invention is a means for cleaning contact lenses to provide that particularly effective Contaminants removed from contact lenses. This task is by a cleaning agent according to claim 1 solved. Contrary to the previously held opinion contains the contact lens cleaning agent used in the invention inorganic abrasive, as it was previously only for abrasive materials recommended for eyeglasses made of organic materials has been.

Become with a cleaning agent used in the invention The contact lenses are cleaned by placing the lenses in the cleaning solution sets and moves there, z. B. shakes. You can also use the lens with the cleaning solution spray and then clean by rubbing. After cleaning, the contact lens is rinsed with water and then can be put back into the eye.

By the concomitant use of an inorganic abrasive becomes the cleaning effect of the surfactant elevated. The particle size of the abrasive is generally comparable or slightly smaller than that the abrasive used in polishing lens surfaces normally used during their manufacture become. These particles remain in the invention Medium evenly suspended without settling.

The cleaning solution can additionally sterilize and Buffering agents and fragrances included. In these Cases it is also possible that the surface-active Means at the same time as suspending agent for the Abrasive particles acts.

The cleaning agent used in the invention is particularly for Clean, if necessary with simultaneous polishing of hard contact lenses containing siloxane.

Preferred surfactants have the general formula

C _n H₂ _{n +} ₁O (CH₂CH₂O) _x SO₃ ^- R⁺

wherein

x 0 to 10
n 8 to 20
R⁺ Na⁺, K⁺, NH₄⁺, 1/2 Mg ⁺⁺ or HN⁺ (CH₂CH₂OH) ₃

mean.

Examples of such detergents are sodium lauryl sulfate, Sodium cetylsulfate, sodium octylsulfate, sodium tridecylsulfate, Sodium oleylsulfate, sodium tridecyl ether sulfate, triethanolamine lauryl sulfate, Ammonium lauryl ether sulfate, sodium lauryl ether sulfate and magnesium lauryl ether sulfate.

The abrasives are water-insoluble inorganic compounds, because of their abrasion properties be used. The abrasive material is one hard and tough substance with many sharp protruding Cutting edges and points and is usually crushed, Smoothing and polishing used. Such abrasives include different types of silica, aluminum trioxide, Manganese oxides, zirconium oxides and carbonates.

Preferably, abrasive materials having average particle sizes are used of 10 μm or less. On preferred abrasive is silica.

The suspending agent (s) in the composition must a stable suspension of the abrasive in the cleaning solution result. Such a suspension is characterized achieved that the viscosity of the aqueous solution by Addition of soluble salts or hydrophilic polymers or by adding water-soluble, neutral or ionic Polymers with the surface of one or more the inorganic abrasive can interact and thereby prevents a failure.

Suitable suspending agents are, for. For example:
Alkali halides (high concentration), alkaline earth salts (moderate concentration), polyvinyl alcohol, polyacrylamide, hydrolyzed polyacrylamide, polyacrylic acid, xanthan gum, hydroxyethylcellulose, carboxymethylcellulose, cellulose sulfate, methylcellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, poly-N-vinylpyrrolidone, guar gum, carboxymethylguargum, hydroxyethyl guar gum, hydrolyzed 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-carrageenan.

Buffering agents may be used, preferably the usual in a pH range of 5 to 8 and generally applies between 7 and 8. Such buffers are z. As boric acid, sodium borate, phosphoric acid, disodium phosphate and sodium bicarbonate.

The use of salts as a suspending agent in the In general, the cleaning solution sterile, in cases where but where a sterility is not awarded, you can use antibacterial compounds. Such compounds include chlorhexidine, benzalkonium chloride, phenylmercuric acetate, Phenylethyl alcohol, methyl or propylparaben, cetylpyridinium chloride and thimerosal, optionally together with EDTA (ethylenediaminetetraacetic acid).

Fragrances, such as peppermint, can also be added.  

Example 1

Composition: Sodium tridecyl ether sulfate (30%) | 80 g Distilled water 160 g sodium chloride 20 g Silica (9 μm average particle size) 24 g

The surfactant is mixed with water and then add sodium chloride and mix, until you get a thick solution. Then you give silica powder to the solution and mixed thoroughly until to obtain a smooth viscous suspension. After 8 months Storage without movement was no settled abrasive material detected.

example 2

Composition: Sodium tridecyl ether sulfate (30%) | 133 g Distilled water 267 g sodium chloride 30 g Silica (9 μm average particle size) 8 g

The preparation was identical as in Example 1.

example 3

Composition: Sodium tridecyl ether sulfate (30%) | 133 g Distilled water 267 g sodium chloride 30 g Silica (9 μm average particle size) 1 g

The preparation was the same as in Example 1.

Example 4

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

Contact lenses with a high silicone content tend to to accumulate waxy surface deposits, which only one hard, if any, by solvents, detergents or polish can remove without the surface the lenses are damaged. Such deposits can be on best by flushing a dry lens and against a black background looks (a self-illuminated Binocular microscope can be used for this, the according to the surface and the thickness (permeability) in 1 to 4 degrees, with a rating of 4 shows very strong deposits). 60 lens pairs with approximately symmetrical surface deposits of the evaluation 2 or more were subjected to the following procedure: One lens per pair was manually using the formulation "A" cleaned. The respective other lenses were divided into three groups of 20 each. A group became manually with the phrase "B", the second group with the Formulation "C" and the last group with different in the Commercially available contact lens cleaners (solutions and gels) treated. It was found that the formulations "B" and "C" were equally effective, but that the formulation "A" was more effective than the formulations in many ways "B" and "C". In fact, the formulations were "B" and "C" are relatively ineffective to remove deposits from Grade 4 to remove while using the inventive Formulation "A" achieved high efficacy in all cases. In addition, none of the commercially available contact lens cleaners more effective than the formulations "B" and "C" and many were even less effective. This example shows the suitability of suspended abrasives for a improved cleaning effect compared to simple solutions surfactant.  

example 5

The cleaning solution described in Example 3 was a Series of patients newly born at the beginning of wearing Hard contact lenses (containing silicone) provided. Patients were advised to bring their lenses with them to purify this formulation every evening. 6 months later the lenses were examined and with lenses of a same Group of patients comparing their lenses in the evening with a range of different contact lens cleaners cleaned. The lenses of the patient holding the cleaning solution used according to Example 3, showed significantly less surface deposits and were usually better to wear.

The cleaning solution prepared according to Example 3 also became given to a small group of contact lens wearers, the lenses made of polymethyl methacrylate and the over washed Point of view due to the development of so-called "dry" Stains on the front surface of their lenses lamented when They use their lenses in a row in the evening Contact lens cleaners, solvents or with polishing agents treated. In all cases settled by the evening Application of the cleaning solution according to the invention the hydrophobic or avoid dry areas and the visibility remained clear when wearing the lenses during the day.

example 6

The surface of all hard contact lenses scratched some time. Common polishes remove small scratches and smooth the grooves that occur at deeper scratches and thereby improve the comfort and appearance of the Lenses. However, many of the scratched contact lenses show also considerable amounts of surface deposits, which are not removed by polishing. When polishing of contact lens surfaces with significant deposits these are often only distributed and divorced again thereby reducing the wettability of the surfaces additionally. The contact solution described in Example 1 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 polish described in Example 1 Art is particularly suitable in practice for restoration optical properties and wettability from hard contact lenses.

example 7

Composition: Sodium tridecyl ether sulfate (30%) | 100 g 4% hydroxyethylcellulose solution in water 200 g Alumina (0.06 μm) 10 g

Dissolve 4 wt .-% hydroxyethyl cellulose in distilled water. Then you give the surface-active Means to the solution and mixed well. Finally that will be Alumina thoroughly mixed into this solution until to obtain a smooth viscous suspension. This example shows that a water-soluble polymer for suspending the Abrasive powder can use.

example 8

Composition: Sodium tridecyl ether sulfate (30%) | 100 g Distilled water 200 g kaolin clay 30 g sodium chloride 25 g

The preparation was carried out in the same manner as in Example 1. This example shows the use of kaolin a material compared to silica or alumina has a milder abrasive action.

example 9

Composition: Sodium tridecyl ether sulfate (30%) | 100 g glycerin 200 g Silica (9 μm average particle size) 3 g

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

This example shows the use of an organic liquid in the context of a surfactant for the preparation of a transparent cleaning solution.  

Example 10

The abrasive powder becomes with the surface active Mixture mixed and blended moderately becomes a stable paste produced.

In this example, the surfactant acts at the same time as a suspending agent for the abrasive forming a cleaning paste.

example 11

Composition: Triethanolamine lauryl sulfate (40%) | 75 g Distilled water 520 g xanthan gum 10 g Silica (4 μm average particle size) 18 g

Xanthan gum is dissolved in distilled water. To the solution with good mixing, add the surfactant. Silica is then mixed into this solution until one gets a smooth viscous solution.

This example demonstrates the use of a water-soluble Polymer for suspending the abrasive powder.

Although the invention is described in a number of examples many changes are possible. The surfactant is preferably in amounts of 1 to 30 wt% present, the abrasive particles make 0.1 to 5 wt .-% and the carrier material, such as Water, 98.9 to 69.9% by weight, the suspending agent, based on 100 parts of the above ingredients 5 to 25 parts is when using inorganic salts, and 1 to 10 Parts when using hydrophilic polymers. The same suspending agents used when using the cleaning solution as a cleaning polish used; here is the amount surface-active agent in the range from 1 to 30% by weight and the amount of abrasive is 5 to 25 wt .-% increased while adding water or other suspending vehicle up to 100%. If you want instead of a free-flowing Liquid a paste, so may the surfactant 15 to 40 wt .-%, the abrasive 20 to 50 wt .-%, the remainder being water or another water-soluble solvent is. Of course you can also one or more surfactants, abrasives or solvents in a single composition. The particle size of the abrasive can vary widely, but preferably, it corresponds to that used for lens polish used in the eye lens industry.

Claims (9)

1. Use of a composition containing a surface-active Agent, an inorganic abrasive and a Carrier material, and in addition suspending agent, the the surfactant and the abrasive Keep evenly suspended, for cleaning hard Contact lenses. 2. Use according to claim 1, characterized in that the agent in liquid Form is present. 3. Use according to claim 1, characterized in that the agent is semi-viscous Paste is present. 4. Use according to claim 1, characterized in that the means the surfactants in an amount of 1 to 30 Wt .-%, the abrasive in an amount of 0.1 to 5 wt .-%, as a carrier material water in an amount of 98.9 to 69.9 wt .-%, and as a suspending agent inorganic salt in an amount of 5 to 25 Parts by weight per 100 parts by weight of the aforementioned Ingredients or a hydrophilic polymer in one Amount of 1 to 10 parts by weight per 100 parts by weight of contains the aforementioned ingredients. 5. Use according to claim 1, characterized in that the means the surfactants in an amount of 1 to  30 wt .-%, the abrasive in an amount of 5 to 25 wt .-% and water as a carrier material to 100 Wt .-% and suspending agent, selected from inorganic salts and hydrophilic polymers, contains. 6. Use according to claim 1, characterized in that the means the surfactants in an amount of 15 to 40 wt .-%, the abrasive in an amount of 20 to 50 wt .-% and as a carrier water in an amount up to Contains 100 wt .-%, and the suspending agent inorganic salts or hydrophilic polymers. 7. Use according to claim 1, characterized in that the means as Abrasives silica, alumina, kaolin, Calcium carbonate, zirconium oxide and / or mixtures thereof contains. 8. Use according to claim 1, characterized in that in the composition the surface-active agent has the following general formula C _n H _{2n + 1} O (CH₂CH₂O) _x SO₃-R⁺hat wherein: x is 0 to 10,
n 8 to 20,
R⁺ Na⁺, K⁺, NH₄⁺, 1/2 Mg ⁺⁺ or HN⁺ (CH₂CH₂OH) ₃. 9. Use according to claim 8, characterized in that the abrasive Silica is.