FR2459993A1 - CLEANING METHOD FOR CONTACT LENSES AND PRODUCT FOR THE APPLICATION OF THE METHOD - Google Patents

Abstract

A.PROCEDE FOR CLEANING OPHTHALMOLOGICAL CONTACT LENSES. B. CHARACTERIZED IN THAT IT CONSISTS OF APPLYING A CLEANING SOLUTION CONTAINING AN ABRASIVE AGENT AND A SURFACE ACTIVE AGENT TO THE SURFACE OF THE LENS AND ABRASING THIS SURFACE, IN ORDER TO REMOVE THE SURFICIAL DEPOSITS PRESENT, WITHOUT CHANGING THE POWER THE CONTACT LENS. C. PRODUCT APPLICABLE TO CLEANING CONTACT LENSES WITHOUT RISK OF DEGRADATION.

Description

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  The invention relates to the cleaning of

contact lenses.

  It has been realized that contact lenses must remain free of surface deposits, in order to maintain the comfort necessary for their use, as well as optimal vision, and to reduce the risks of a change in ocular characteristics. Unfortunately, the lenses

  are likely to receive superficial deposits

  skies from external sources (mascara, hairspray, etc.) and internal deaf (phlegm, oily secretions etc.). Contact lenses containing silicones are the most vulnerable by the superficial deposition of tenance waxes, which is difficult if not impossible to remove

  totally, without damaging the lens.

  The known cleaning products for soft or rigid contact lenses have heretofore contained a variety of water-soluble cleaning agents, in addition to water-soluble moisturizing polymers, in sterile homogeneous aqueous solution. Other cleaning agents used water-soluble synthetic thixotropic polymers and synthetic thixotropic clays with detergents to give firm gels for

  cleaning hard contact lenses.

  Abrasive materials have not been used

  hitherto in the cleaning solutions of the len

  contact lenses, possibly because it was considered that these abrasive products were likely to scratch the surface of plastic contact lenses, which would result in reduced optical clarity and increased irritation

eyes.

  The object of the invention is to produce a product for cleaning contact lenses, consisting mainly of a surfactant, a mineral abrasive material and a suspending agent, this agent being very effective and allowing a thorough cleaning of contact lenses. plastic contact containing silicones, while also being usable for cleaning and / or cleaning and polishing

  other contact lens materials.

  The subject of the invention is a method for cleaning ophthalmic contact lenses.

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  method comprising applying a cleaning solution, containing an abrasive, to the surface of the lenses, and abrasion of the surface to remove surface and unwanted debris

  if there is, without altering the capacity of the contact lenses.

  In accordance with the invention, a contact lens cleaner consists essentially of a surfactant, a mineral abrasive and a suspending agent, such as water or an organic liquid. Means are provided to maintain the surfactant and abrasive in substantially uniform suspension, so that the solution can be used to clean contact lenses

without attacking them.

  The cleaning product is preferably

  as a liquid solution, but may also be in the form of cream. The cleaner can also polish when it contains an increased proportion of abrasive. Preferably the abrasive is in the form of fine particles, so as to

  do not scratch the lenses when using.

  According to the method of the invention, an ophthalmic contact lens is cleaned with a cleaning solution containing an abrasive, a surfactant, a liquid carrier and a suspending agent. The cleaning solution is applied and the surface of the lens is subjected to abrasion, in order to remove the indiserable surface deposits.

  without altering the power of the contact lens. In increase

  abrasive, and by applying substantial pressure over a prolonged period, the material can be used as "polishl" (polishing agent) although it is preferable

  to use it as a cleaning and polishing agent.

  A feature of the invention is a considerable strengthening of the cleaning efficiency of certain surfactants, by increasing the friction produced when the surfactant is rubbed onto the plastic surface. This is done by introducing, within the surfactant solution, abrasive solid particles, the size and concentration of which can be varied.

  according to the function that one wishes to confer on the formulation.

  The particle size normally used is comparable to, or smaller than, the abrasives used to polish the surface of the lenses during manufacture, as is traditionally known. The particles remain suspended uniformly in the surfactant solution, without settling, as the sediment can affect the effectiveness of the cleaner, and not agglomerate, which could cause scratches on the surface of the lenses. Another feature of the invention is that the agent for suspending the particles

  abrasive so that the suspension remains stable practically

  indefinitely. The cleaning solution may contain sterilizing agents and buffering agents, as well as perfumes. In some cases, it may be possible to use a surfactant as well to effect the susperion of the abrasive particles, as to deploy a cleaning action. Nevertheless, it is more usual to use a high concentration water-soluble salt, or a polymer

  organic, to act as suspending agent.

  Although the cleaning solutions described in this application are specifically intended for the cleaning and / or cleaning and polishing of rigid, gas-permeable, siloxane-containing contact lenses, they can also be applied to polymethyl methacrylate contact lenses, silicones and aceto-butyrate of cellulose, or of other plastics or other materials

  used for contact lenses.

  According to a recommended formulation, the contact lens cleaning solution according to the invention uses a surfactant with an abrasive, for a combined chemical and mechanical cleaning action, and a suspending agent for the abrasive allowing form a

  stable suspension, in aqueous solution.

  The preferred surfactants are detergents or surfactants such as anionic sulfates having the general formula: ## STR2 ## wherein x varies from 0 to 10 n ranges from 8 to 20 R + represents na +, K , NH + 1Mg y HN (CH CH OH)

(CH + C H, HH) CO

2 22 3

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  Examples of such detergents are sodium lauryl sulphate sodium cetyl sulphate sodium octyl sulphate tridecyl ether sodium sulphate triethanolamine lauryl sulphate lauryl ether ammonium sulfate lauryl ether sodium sulphate lauryl magnesium sulphate The abrasive compound or compounds are water-insoluble mineral compounds used for their

  abrasive characteristics. The abrasive material is a subsi-

  resistant, hard, containing many sharp, sharp edges or tips, and usually used for grinding, smoothing and polishing. These abrasives include various types of silicas, aluminas, manganese oxides, zirconium oxides and carbonates. It is recommended to use abrasives with an average particle size

10 microns or less.

  These abrasives are chosen from silicas,

  alumina, kaolin, calcium carbonation, zirconium oxide.

  The suspending agent or agents should provide a stable suspension of the abrasive in the cleaning solution. Such a suspension can be obtained by increasing the viscosity of the aqueous solution, by the addition of soluble salts or hydrophilic polymers, or by the addition of water-soluble neutral or ionic polymers, which can interact with the surface of an aqueous solution. or more abrasive mineral particles, preventing or preventing

thus their precipitation.

  Such suspending agents may consist of one or more of the following: alkali metal halides (high concentration) alkaline earth metal salts (high concentration) polyvinyl alcohol polyacrylamide polyacrylamide hydrolyzed polyacrylic acid 5.-xanthan gum hydroxyethyl cellulose carboxymethyl cellulose cellulose sulfate methyl cellulose methyl hydroxyethyl cellulose methyl hydroxypropyl cellulose poly-N-vinylpyrrolidone guar gum guar gum carboxymethyl guar hydroxyethyl polyacrylonitrile hydrolysed starch polyacrylonitrile 2-acrylamido-starch hydrolysis 2-methylpropane sulfonate hydrolysed starch clays such as bentonite, montorillonite and hectorite neutral, cationic and anionic detergents partially acetylated cellulose gelatin glycol and polyethylene oxide K-carageenan Buffering agents may be used, preferably of the standard type used for a pH of 5 to 8, and especially from 7 to 8. These buffers include boric acid, sodium borate, phosphoric acid, disodium phosphate

and sodium bicarbonate.

  The use of salts as suspending agents generally renders the cleaning solution sterile. Nevertheless, in cases where sterility is mandatory, anti-microbial compounds may be used. These compounds include chlorhexidine, benzalkonium chloride, phenyl mercury acetate, phenylethyl alcohol, methyl or propyl paraben, cetyl pyridinium chloride, thimerosal and others, if

possible in association with EDTA.

  It is possible to use perfumes

  like the "wintergreen" or the "peppermint".

  In the simplest way, the contact lens is cleaned, by immersion in the cleaning solution, or the solution is sprayed onto the lens, while ensuring agitation of the solution such as rubbing, shaking, or shaking. 'wipe the cleaning solution

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  on the surface of the lens. The lens is then rinsed with water and inserted directly into the eye, or placed in a

  quench solution and / or humidification prior to insertion.

  The invention will be better understood using the examples described below:

EXAMPLE 1

  Formulation: tridecyl ether sodium sulphate (30%) 80 g distilled water 160 g sodium chloride 20 g silica (9 microns average) 24 g The surfactant is mixed with water, then the sodium chloride is added and the mixing is continued until a thick solution is obtained. The powder

  of silica is added to the solution and vigorous mixing is

  until a smooth viscous suspension is obtained.

  No abrasive sedimentation was observed after eight months.

months of storage.

EXAMPLE II

  Formulation: tridecyl ether sodium sulphate (30%) 133 g distilled water 267 g sodium chloride 30 g silica (9 microns average) 8 g The preparation is identical to that

described in Example 1.

EXAMPLE III

  Formulation: tridecylether sodium sulphate (30%) 133 g distilled water 267 g sodium chloride 30 g silica (9 microns average) 1 g The preparation is identical to that

described in Example 1.

EXAMPLE IV

  Formulation A B C Sodium tridecyl ether sulphate (30%) 133 g 133 g 133 g distilled water 267 g 267 g 267 g

4o sodium chloride 30 g 30 g -

  silica (9 microns average) 12 g - -

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  Cleaning solutions have been prepared

as described in Example 1.

  On contact lenses having a

  high silicone content, develops in a

  a persistent waxy surface deposit which is difficult and often impossible to remove with solvents, surfactants or polishes, without damaging the surface of the lenses. To best visualize these deposits, they are studied on a washed and dried lens, in front of a black background with a self-illuminated binocular microscope, and can be quantified by gradation from 1 to 4, depending on the area and thickness (opacity), a grade of 4 indicating a serious deportation. Sixty

  pairs of lenses having roughly the same super

  Symmetric, grade 2, or more, were subjected to the following treatment: one lens of each pair was manually cleaned, using the "A" formulation. The other lenses were separated into three groups of twenty. One group was manually cleaned with formulation "B", the second group with formulation "C", and the last group, with various contact lens cleaners available

  in trade (solutions and gels).

  Formulations "B" and "C" were found to be equally effective, but formulation "A" was much more effective than "B" and "C" formulations in all

  cases. In fact, the "B" and "C" formulations have been relatively

  However, the formulation "A" according to the invention was very effective in all cases. Finally, none of the commercial contact lens cleaners were more effective than the "B" and "C" formulations and many were less effective. This example demonstrates the utility of a slurry abrasive to provide enhanced cleaning action over simple

surfactant solutions.

EXAMPLE V

  The cleaning solution described in Example III was provided to a number of patients at the beginning of the period when they began to wear newly manufactured rigid contact lenses (containing silicones). They were asked to clean their lenses with this formulation every night. After 6 months, we inspected

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  leun lenses and compared them with lenses from a similar group, where subjects had to clean their lenses every night with various commercial cleaners. The lenses of the patients using the cleaning solution of Example III were much more free of surface deposition.

  were also in general, more comfortable-to wear.

  The cleaning solution described in Example III was also given to a small group of traditional polymethyl methacrylate contact lens wearers who complained of blurred vision resulting from the formation of "dry" spots on the front surface of their lenses. , spots that regressed when nightly cleaning lenses with various commercial cleaners, solvents, or polishes. In any case, the use every evening of the solution according to the invention eliminated the hydrophobic or dry surfaces and

  the vision of the subjects remained clear during the day.

EXAMPLE VI

  The surface of any hard contact lens may possibly scratch. Traditional polishing products eliminate surface scratches and smooth adjacent edges to deeper scratches, improving lens comfort and optical quality. Nevertheless, many of these scratched contact lenses also have surficial deposits that are not removed by polishing. In fact, the polishing of contact lens surfaces with serious deposition can simply spray

  and redistribute the deposits, thus further reducing the

  lability of the surface. The cleaning solution described in Example 1 combines the functions of cleaning (to remove the surface film) and polishing (to eliminate surface scratches), and is much more effective than the separate use of a cleaning solution. and a polishing solution. A cleaning / polishing solution, such as that described in Example 1, is therefore particularly useful for the professional, in order to restore the rigid contact lenses, with regard to the properties

optical and wettability.

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EXAMPLE VII

  Formulation: sodium tridecyl ether sulphate (30%) 100 g 4% HEC solutin 200 g aluminum oxide (0.06 microns) 10 g 4% by weight hydroxyethyl cellulose is dissolved (cellosize QP -40, a product of Union Carbide Corp. of New York, New-YorR ') in distilled water. The surfactant is then added and the solution is mixed well. Aluminum oxide is then vigorously incorporated in this

  solution until a smooth viscous solution is obtained.

  This example shows the use of a water-soluble polymer for suspending the

abrasive powder.

EXAMPLE VIII

  Formulation: tridecyl ether sodium sulphate (30%) 100 g distilled water 200 g hydrate 10 (Kaolin clay) 30 g sodium chloride 25 g The preparation is identical to that

described in Example 1.

  This example shows the use of Kaolin which allows a softer abrasive action compared to that of

silica or alumina.

EXAMPLE IX

  Formulation: sodium tridecyl ether sulfate (30%) 100 g glycerine 200 g silica (9 microns average) 3 g The surfactant is dissolved in the

  glycerine and then the silica is incorporated in this solution.

  This example shows the use of an organic liquid in conjunction with the surfactant, for

  get a clear cleaning solution.

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EXAMPLE X

  Formulation: A B C tridecyl ether sodium sulphate (30%) 100 g 125 g lauryl ether ammonium sulphate (27%) - - 100 g silica (4 microns on average) 30 g - 35 g

  hydrite 10 (kaolin clay) - 75 g -

  The abrasive powder is mixed with the surfactant

  active, with moderate stirring, to form a stable paste.

  This example shows the use of

  active as suspending agent for the abrasive, in order to

form a cleaning paste.

EXAMPLE XI

  Triethanolamine lauryl sulfate formulation (40%) 75 g distilled water 520 g xanthan gum 10 g silica (average 4 microns) 18 g xanthan gum is dissolved in water

  distilled. The surfactant is added and the solution is well mixed.

  The silica is then incorporated with vigorous stirring at this point.

  solution, until a smooth viscous solution is obtained.

  This example shows the use of a water-soluble polymer to suspend the powder

abrasive.

  While specific examples of the

  have been presented and described, many variants are possible. When the cleaning solutions of the invention

  are used only for cleaning, surfactants

  The active ingredients are preferably from 1 to 30% by weight of the material, the abrasive particles from 0.1 to 5% by weight, and the carrier material such as water from 98.9 to 69.9% by weight with an agent

  suspension, based on 100 parts of the above-mentioned

  above, being from 5 to 25 parts when inorganic salts are used, and from 1 to 10 parts when polymers are used. The same suspending agents are used when the cleaning solution is used to act as a cleaner / polisher, but then the proportion of surfactant can be between 1 and 30% by weight and the amount of abrasive 4 is increased from 5 to 25% by weight, while water or

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  Another suspension support is used to supplement the

  100%. When it is desired to obtain a paste rather than a free-flowing liquid, it is possible to use 15 to 40% by weight of a surfactant, of 20 to 50% by weight of an abrasive, the balance being constituted by water or a solvent that is soluble in water. Of course, it is possible to use one or more surfactants, abrasives or solvents in the same composition, if desired. The particle sizes of the abrasives may vary widely, but in general they are

  those used for polishing lenses in the indus-

  Ophthalmologic. Silica particle sizes for example, with an average of 9 microns and a range of 1 to 20 microns with an upper limit of 30 microns, in the form of syloid 63, a trademark of Davison Chemical W.R. Grace CO. of Baltimore, Maryland, can be

  used. Other ranges of sizes are possible.

  In all cases, the surfactant, in the form of a detergent or a surfactant, acts in common with the abrasive to combine the best qualities of the two, which can lead to a synergetic action vis-à-vis -vis

  contact lenses, according to the method of the invention.

  Although surfactants have been specifically mentioned in this application, other agents

  surfactants can also be used. These agents

  socient in water to form a colloidal particle known as micelle. The structure is such that the chains

  Hydrophobic hydrocarbons are indoors far from the soil.

  and the polar groups are on the surface of the particle.

  The presence of micelles in the aqueous solutions, endows these

  ci of tiny regions, whose predominant nature is hydrophobic. This allows a high solubility in water and

  good wettability of the materials.

Claims (9)

  1. A method for cleaning ophthalmic contact lenses, characterized in that it consists in applying a cleaning solution containing an abrasive agent and a surfactant to the surface of the lens.   and to abrade this surface, in order to remove the superficial deposits.   present, without changing the power of the lens of contact.-   2. A cleaning product for contact lenses, according to the method according to claim 1, characterized in that it consists essentially of a   surfactant, a mineral abrasive, a suspen-   and an agent for maintaining the surfactant and the abrasive in substantially uniform suspension, so that this solution is suitable for cleaning contact lenses without affect them.   3. The cleaning product for contact lenses according to claim 2, characterized in that the solution is in liquid form.   4. The cleaning product for contact lenses according to claim 2, characterized in that the   material is in the form of semi-hardy paste.   5. Product according to claim 2, characterized in that the surfactant is present in a proportion of 1 to 30% by weight, the abrasive 0.1 to 5% by weight, and that the suspension support is from water, in a proportion sufficient to complete to 100%, the suspending agent belonging to the group of mineral salts and hydrophilic polymers.   6. Product according to claim 4, characterized in that the surfactant is present in a proportion of 1 to 30% by weight, the abrasive of 5 to 25% by weight,   and that the suspension support is water, in sufficient proportion   to complete 100%, the suspending agent   belonging to the group of mineral salts and hydrophilic polymers   philes. 7. Product according to claim 2,   characterized in that the surfactant is present in a   from 15 to 40% by weight, the abrasive from 20 to 50% by weight, and that the suspension support is water, in a proportion ranging from 12 to 13%, the suspending agent. belonging to the group   inorganic salts and hydrophilic polymers.   8.- Product according to claim 2, characterized in that the abrasive belongs to the group of silicas, alumina, kaolin, calcium carbonate, zirconium oxide. and their mixtures.   9. Product according to claim 4, characterized in that the surfactant has the general formula: ## STR2 ##   R + is Na +, K +, NH 1 -Mg ++, HN + (CH 2 CH 2 OH) 3.