GB1566646A - Creation of Inventions and Patents with Artificial Intelligence

GB1566646A – Contact lens preserving solution
– Google Patents

GB1566646A – Contact lens preserving solution
– Google Patents
Contact lens preserving solution

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Publication number
GB1566646A

GB1566646A
GB2467877A
GB2467877A
GB1566646A
GB 1566646 A
GB1566646 A
GB 1566646A
GB 2467877 A
GB2467877 A
GB 2467877A
GB 2467877 A
GB2467877 A
GB 2467877A
GB 1566646 A
GB1566646 A
GB 1566646A
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GB
United Kingdom
Prior art keywords
composition
compound
ene
amount
diol
Prior art date
1977-06-14
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB2467877A
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Nelson Research and Development Co

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Nelson Research and Development Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1977-06-14
Filing date
1977-06-14
Publication date
1980-05-08

1977-06-14
Application filed by Nelson Research and Development Co
filed
Critical
Nelson Research and Development Co

1977-06-14
Priority to GB2467877A
priority
Critical
patent/GB1566646A/en

1980-05-08
Publication of GB1566646A
publication
Critical
patent/GB1566646A/en

Status
Expired
legal-status
Critical
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Classifications

A—HUMAN NECESSITIES

A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE

A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES

A61L12/00—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor

A61L12/08—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor using chemical substances

A61L12/14—Organic compounds not covered by groups A61L12/10 or A61L12/12

A—HUMAN NECESSITIES

A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING

A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS

A01N35/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having two bonds to hetero atoms with at the most one bond to halogen, e.g. aldehyde radical

A01N35/06—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having two bonds to hetero atoms with at the most one bond to halogen, e.g. aldehyde radical containing keto or thioketo groups as part of a ring, e.g. cyclohexanone, quinone; Derivatives thereof, e.g. ketals

A—HUMAN NECESSITIES

A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING

A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS

A01N37/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having three bonds to hetero atoms with at the most two bonds to halogen, e.g. carboxylic acids

A01N37/36—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having three bonds to hetero atoms with at the most two bonds to halogen, e.g. carboxylic acids containing at least one carboxylic group or a thio analogue, or a derivative thereof, and a singly bound oxygen or sulfur atom attached to the same carbon skeleton, this oxygen or sulfur atom not being a member of a carboxylic group or of a thio analogue, or of a derivative thereof, e.g. hydroxy-carboxylic acids

A—HUMAN NECESSITIES

A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING

A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS

A01N43/00—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds

A01N43/02—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one or more oxygen or sulfur atoms as the only ring hetero atoms

A01N43/04—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one or more oxygen or sulfur atoms as the only ring hetero atoms with one hetero atom

A01N43/06—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one or more oxygen or sulfur atoms as the only ring hetero atoms with one hetero atom five-membered rings

A01N43/08—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one or more oxygen or sulfur atoms as the only ring hetero atoms with one hetero atom five-membered rings with oxygen as the ring hetero atom

Description

(54) CONTACT LENS PRESERVING SOLUTION
(71) We, NELSON RESEARCH & DEVELOPMENT COMPANY a
Corporation organised and existing under the laws of the State of California,
United States of America, of 19722 Jamboree Boulevard, Irvine, California, United
States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates generally to the preservation of contact lenses. More particularly, the present invention relates to a method and composition for sterilizing plastic hydrophilic or “soft” contact lenses.
Hydrophilic or partially hydrophilic plastic materials have been described for use in making so-called soft contact lenses. For example, U.S. Patent Nos.
3,503,393 and 2,976,576 describes processes for producing three-dimensional hydrophilic polymers of polyhydroxyethylmethacrylate in aqueous reaction media having a sparingly cross-linked polymeric hydrogel structure and having the appearance of elastic, soft, transparent hydrogels. Other soft contact lenses include lenses made out of silicone and other optically suitable flexible materials.
The main virtues of these lenses is their softness and optical suitability. The hydrophylic lenses are particularly useful in ophthalmology due to their remarkable ability to absorb water with a concomitant swelling to a soft mass of extremely good mechanical strength, complete transparency and the ability to retain shape and dimensions when equilibrated in a given fluid.
One of the problems connected with these soft contact lenses is the method of their sterilization and cleaning. The very property of the hydrophilic soft lenses which allows them to absorb up to 150 percent by weight of water also allows preservatives which might otherwise be used for cleaning and sterilization to be absorbed and even concentrated and later released when the soft contact lens is on the eye. The release may be much slower than the uptake, thereby allowing the preservative to build up in the lenses. This build-up eventually affects the physical characteristics of the lenses including dimension, color, etc. This can have the harmful result of damaging or staining the contact lens itself and/or harming the sensitive tissues of the conjunctivae or cornea.
Hard contact lenses do not absorb appreciable amounts of water (i.e. 0.10.4%) and thus the use of effective preservatives generally does not create a problem in the hard contact lens field. Sterilization of hydrophilic soft contact lenses is carried out by procedures described in U.S. Patent No. 3,689,673 or 3,888,782 or more generally by boiling the lenses in normal saline. Forthermore, users of soft contact lenses are warned that under no crcumstances should solutions designed for hard contact lenses be used, for the reason that the preservatives in such solutions will be absorbed and even concentrated by the soft lens and may seriously damage the soft lens and/or the eye of the user. In this connection, United States Patent No.
3,689,673 further discloses that a number of commonly used antimicrobial agents are concentrated in the soft lens and suggests that these materials may cause corneal damage and that similar in vitro and in vivo tests have shown the undesirability of such antimicrobial agents when used with hydrophilic lenses.
It is also known that the relatively rapid oxidation of an ene-diol compound effects substantially a complete kill of microorganisms which are in contact with it.
Ordinarily, the oxidation of an ene-diol compound occurs too slowly to be effective as a microbicide. However, some metal ions, notably copper ions, catalyze the reaction so that it takes place rapidly and thereby is effective as a microbicide, e.g., see U.S. Patent No. 3,065,139.
Commercial utility of the rapid oxidation of an ene-diol compound to obtain the benefit of its microbicidal effect is difficult because the reaction takes place so quickly when the necessary ingredients are in contact with each other that commercially packaged products do not have useful shelf life. United States Patent
No. 3,681,492 deals with compositions in which the rate of oxidation of ene-diol is inhibited or retarded so that the microbicidal effect is sustained for a longer period.
However, even the retarded compositions generally are not useful as commercial products because the reaction can only be retarded for a relatively short time, for example, a matter of days, which is not long enough to provide a suitable shelf life for a commercial product. In addition, a highly retarded reaction does not produce as intense an antimicrobial effect as a mildly retarded reaction or one which is not retarded.
It has now been discovered that contact lenses generally and especially plastic hydrophilic (soft) contact lenses may be effectively sterilized and used without deleterious effect to the lenses or the eyes of the user by the present invention. The sterilizing solution of this invention will not be absorbed by the lenses in significant quantities. In addition, to the extent, if any, that the sterilizing solution of this invention is absorbed by the lenses, it will not harm the lenses or the eyes of the wearer. This invention also solves the shelf life problem discussed above.
The present invention relates to a method for sterilizing contact lenses comprising contacting a contact lens for a period of time sufficient to sterilize the lens with a substantially isotonic, aqueous composition comprising a microbicidally effective amount of an ene-diol compound and a minor, catalytic amount of a catalytic metal compound.
The invention also relates to a method for sterilizing plastic hydrophilic soft contact lenses comprising forming a substantially isotonic microbicidal solution by combining a microbicidal amount of an ene-diol in a dissolvable or dispersible solid, unit dosage form with an aqueous diluent containing a minor catalytic amount of copper ions and contacting a plastic hydrophilic soft contact lens with said microbicidal solution for a period of time sufficient to sterilize the lens.
According to the present invention there is also provided a composition comprising a substantially isotonic, aqueous composition including a microbicidally effective amount of an ene-diol compound selected from a dihydroxymaleic acid compound, a dihydroxyfumaric acid compound, a reductic acid compound, a squaric acid compound, the dipotassium salt of a dihydroxymaleic acid compound, the disodium salt of a dihydroxymaleic acid compound, the dilithium salt of a dihydroxymaleic acid compound, and mixtures thereof, and a minor, catalytic amount of a catalytic metal compound.
One of the essential ingredients of this invention is an ene-diol compound.
Typical ene-diol compounds are ascorbic acid compounds, reductic acid compounds, squaric acid compounds, dihydroxymaleic acid compounds and dihydroxyfumaric acid compounds. Typical examples of the foregoing ene-diol compounds are ascorbic acid itself, salts of ascorbic acid such as sodium ascorbate, ascorbic acid esters such as ascorbyl palmitate and any other ascorbic acid derivatives that retain the ene-diol molecular structure. The comparable acid, salt and ester forms of the other ene-diols described herein may also be used in this invention. Mixtures of ene-diols may also be used. The preferred ene-diol is dihydroxymaleic acid and its salts, e.g. potassium. The total amount of ene-diol which is generally used in the present invention varies from 0.001 to 10% by weight of the total composition and preferably 0.1 to 10% by weight of the total composition. Higher concentrations may be used, but are not necessary in order to obtain the benefits of the invention.
Although all of the ene-diols disclosed herein are useful, some of the ene-diols are preferred for the reason that Applicants have discovered that the ene-diol, dihydroxymaleic acid and its esters and salts are unique in that aqueous solutions of this ene-diol are colorless. That is, other ene-diols, notably ascorbic acid, tend to form yellow-brown solutions in water which are undesirable from a commercial point of view and which may tend to adversely affect the soft lenses over a long period of time.
Another of the essential ingredients of this invention is the catalytic metal compound. The catalytic metal compound may be an ionizable compound of copper, iron, cobalt, nickel, manganese, or titanium. These catalytic metal compounds are described in United States Patent No. 3,065,139. The preferred catalytic metal is copper, particularly cupric compounds; and the particularly preferred catalytic metal compound is cupric chloride because it is an excellent catalyst, highly soluble in water, relatively neutral, and readily available. The anhydrous or hydrate, e.g. monohydrate, or dihydrate forms of cupric chloride may be used but the anhydrous form is preferred. The catalyst may also be used in the form of ss weakly complexed metal compound. Water-insoluble copper compounds, e.g., cupric acetylacetonate and cupric oleate, may also be used provided cupric ions become available in the final composition.
One preferred embodiment of the invention is a mixture of dry granules of at least two types. One type of granule is a granule containing one or more ene-diol compounds. The other type of granule is a granule containing a minor amount of the catalytic metal compound and a major amount of a water soluble bulk material capable of being formed as granules. The term “dry” is used herein in the sense that is a composition containing no water in the sense of water that is capable of making something moist or capable of freezing. The dry compositions of this iven ion may include materials containing water of crystallization or other forms of water that are not available to dissolve materials or to react with materials in the composition.
Since the catalyst in the preferred embodiments described above is present in very small amounts compared to the other ingredients of the mixture, it represents a minor amount of the granule in which it is maintained. It is preferred that the catalytic material be present in small quantities, less than 5 Ó by weight of the total granule in which it is contained because only a small amount of catalyst is required to effect the oxidation of the ene-diol compound and because it is included in a granule of bulk material for the purpose of maintaining it out of contact with the ene-diol compound. The concentration of the metal containing compound in the total mixture of ene-diol containing and metal catalyst containing granules is abdut .1 to about 1 x 10-6 percent.
Accordingly, the granules containing catalytic metals should include a major amount, and preferably at least 90%, of a bulk material that can be mixed homogeneously with the catalytic material and then compacted to form an intact granule. The bulk material may be entirely neutral or it may participate in the usefulness of the composition of this invention. The bulk material must be one that does not react with or otherwise adversely influence either the catalytic metal compound or the ene-diol compound in that it will be in intimate contact with both.
The bulk material may be neutral material such as a sugar, but it preferably is a participating material such as a mixture of sodium bicarbonate and an organic acid such as tartaric acid or malic acid which, when dissolved in water, will effervesce and thereby provide a mechanical action to blend the other ingredients of the composition homogeneously throughout the water in which they are being dissolved. The bulk material should be water soluble or at least water dispersible so that upon introducing the composition into the water, the catalytic metal compound will be quickly dissolved so that it may catalyze the oxidation of the enediol compound and thereby quickly produce the microbicidal effect that is desired.
The granules are prepared by useful pharmaceutical granulation methods such as heat granulation or wet granulation. When heat granulation is used, heating must
not decompose any of the ingredients, particularly the ene-diol compound. When wet granulation is used, the solvents must be anhydrous, e.g. anhydrous ethanol or
anhydrous isopropyl alcohol. The granules may also be compressed into tablet forms. If the latter, conventional lubricants such as stearic acid, talc, calcium stearate, etc, may be incorporated into the granules.
The granules employed in compositions of this invention may be of any size.
The ene-diol compound may be in granules as small as an impalpable powder and it
may be prepared simply by comminution or otherwise subdividing the ene-diol compound. The granules that include the catalytic metal compound, however,
must be prepared by mixing subdivided particles of the catalytic metal compound
and the bulk material and then forming granules from the mixture. As long as the granules are prepared in that manner, only a small amount of catalytic material will
be at the surface of the granule, and the oxidation of ene-diol compound by contact with the catalyst will be avoided. The granules thus prepared may be of any size.
The granules containing ene-diol compound or the granules containing catalytic
metal compound may be coated with a water soluble material to even further effect
separation of these materials during storage. This may be done, for example, by
preparing granules of a mixture of catalytic metal compound and bulk material and
then rolling those granules in additional bulk material to provide an outer coating that is devoid of catalytic metal compound. Conventional techniques for coating or microencapsulating may also be used.
The composition of this invention may include other ingredients which, although not essential to the effectiveness, may be desirable for providing their own properties to the mixture. If a sustained microbicidal effect is desired, an aminecontaining inhibitor can be included in the composition to retard the rate of reaction to the degree desired. The preferred amine-containing inhibitor is ammonium chloride, although any of the amines disclosed in United States Patent
No. 3,681,492 may be employed. The inhibitor may be included either in the granules containing ene-diol compounds, in the granules containing the catalytic metal compound, or in a third type of granule containing neither of the above. If the inhibitors are included in the granules containing catalytic metal compound, they will have the additional function of adding to the amount of bulk material which shields the catalytic material from contact with ene-diol compounds.
Ingredients which aid in dispersing the various ingredients throughout a body of water into which they are introduced may also be useful in the compositions of this invention. The above-mentioned sodium bicarbonate and organic acid mixtures are useful as such dispersants. For different bulk materials it may be desirable to employ conventional disintegrators such as “Veegum HV” (Registered
Trade Mark), methylcellulose, starch, sugar, etc., within the granules to aid in the speed and effectiveness of dissolving or dispersing them throughout the water into which the composition is introduced. For purposes of this disclosure, the word “dissolving” is used functionally to mean dissolving or dispersing.
Since oxidation of the ene-diol compound is the reaction that produces the microbicidal effect and since the catalyst simply accelerates the rate of that reaction, the catalyst may be present in much smaller quantities than the ene-diol compound. In the total composition, the catalyst may be present only in the amount of one part of catalyst per thousand parts of ene-diol compound, on a weight basis, to be effective. It is preferred that the catalyst not be present in an amount more than one part of catalyst per one hundred parts of ene-diol compound, thereby avoiding any potentially toxic amounts of metal compound in the ultimate aqueous solution that is made and also avoiding waste of catalytic metal. If an amine-containing inhibitor is employed, it may be present in any amount to provide the degree of retardation of the reaction rate that is desired.
Generally amounts of up to 1.5% by weight of the composition are sufficient to inhibit the reaction rate for any period desired, and usually much smaller amounts will be employed.
In a second preferred embodiment, the metal catalyst and amine-containing inhibitor can be formulated in a conventional tablet and the ene-diol may be micronized to a fine powder. Prior to use, the tablet is dissolved in a measured amount of water, a portion of which thereafter is used to dissolve a premeasured amount of ene-diol to form the microbicidal solution for sterilizing contact lenses.
In a third preferred embodiment, a non-aqueous liquid concentrate containing suitable amount of the desired ene-diol compound and the desired metal catalyst may be prepared by dissolving the ene-diol and metal catalyst in a non-aqueous solvent such as an organic alcohol, e.g., ethanol or other non-aqueous solvents which are non-deleterious to contact lenses, e.g. propylene glycol, cyclohexane, cyclohexanol, ethylene glycol, glycerol, m-heptane, m-hexane, isopropyl alcohol, m-pentane, dimethyl sulfoxide and dimethyl formamide.
The composition is then used to sterilize the contact lenses by adding a suitable quantity of the liquid concentrate to a measured amount of water and contacting the lenses for the required time with the microbicidal solution formed in the mixture.
In a fourth embodiment, the granules may be formed into tablets by conventional tableting means, though additional water soluble coatings may be required to be made on the granules to prevent premature reaction.
In a fifth embodiment, ene-diol can be formulated in a conventional tablet and the metal catalyst may be dissolved in an accompanying aqueous diluent. Prior to use, the tablet is dissolved in the diluent to form the microbicidal solution for sterilizing contact lenses.
A typical composition of the present invention may contain in addition to the active ingredients described earlier, buffers, stabilizers and isotonic agents which
aid in making the ophthalmic composition more comfortable to the user. These additional materials must not distort the soft lens. In this regard, we have found the
Polysorbate 80 and Brij 58 act to stablize the aqueous formation in amounts ranging from 0.05 to 0.6 and preferably about 0,2us (w/v). The word “Brij” is a Registered
Trade Mark.
Suitable buffers include sodium or potassium citrate, citric acid, boric acid, various mixed phosphate buffers including combinations of Na2HPO4, NaH2PO4, K2HPO4and KHCO3. Generally, buffers may be used in amounts ranging from 0.05 to 2.5 and preferably 0.1 to 2.0 ,ó (w/v). The potassium salts of buffers are preferred when using dihydroxymaleic or dihydroxyfumaric acid as the ene-diol in the composition. Potassium salts of these acids were found to be water soluble to a much greater extent than the corresponding sodium salts.
The treating solution for soft contact lenses should be maintained at an osmotic pressure similar to that of physiologic saline, i.e.. substantially isotonic, or approximately 0-9 Ó saline, or with suitable agents alone or in combination to render the solution substantially isotonic. Hypotonic solution, e.g., tap water, will cause the lens to adhere tightly to the cornea while hypertonic solutions (excess saline) will result in stinging, lacrimation and a red eye.
If solid dosage forms are used, the formulation may include conventional lubricants, binders, and excipients which include glycerol, sorbitol, boric acid, propylene glycol, polyethylene glycols, dextran and methylcellulose. These materials are used in amounts varying between 0.01 and 10 and preferably between about 0.1 and 5 weight percent.
The method of use of the sterilizing and cleaning solution is the following. The lenses are first rinsed with a few drops of the subject solution of saline to remove contaminants such as mucus, eye makeup, etc., and then placed in a suitable container with sufficient amount of the subject solution to cover the lenses. The lenses are allowed to soak for at least about 10-30 minutes and up to 8 hours to achieve substantial kill of spores, fungi and yeasts. This soaking has been shown to effectively sterilize the lenses. The foregoing method is carried out at ambient temperature or elevated temperatures, i.e. about 40–100″C.
The word “sterilize” is used in the present invention to mean the rendering non-viable of substantially all pathogenic microbes, including Gram negative and
Gram positive bacteria as well as fungi.
The term “microbicide” is used in the present invention to mean a composition which renders non-viable all microorganisms including, but not limited to, bacteria, fungi, yeasts and viruses.
To illustrate the manner in which the invention may be carried out, the following examples are given. It is understood however, that the examples are for the purposes of illustration and the invention is not to be regarded as limited to any of the specific materials or conditions set forth therein. Unless otherwise stated, *Ó means weight per unit volume expressed as a percent “(w/v)”. Moreover, the compositions utilized are all substantially isotonic.
Example I.
A number of different types of granules were made by homogeneously blending impalpable powders of the various ingredients and compressing these powders to form granules. The granules were of irregular shape and were about a maximum of one millimeter in major dimension. The granules identified as type I were ene-diolcontaining granules. The granules identified as type 2 were the catalytic metal compound-containing granules. The following table sets forth the compositions of the various granules.
TABLE I
% Weight
Ingredients 1 2
Ascorbic acid 20.35
Sodium ascorbate 43.72
Ammonium chloride 2.14
Sodium bicarbonate 12.85 33.52
Malic acid 2.00 14.74
Mannitol 6.21
Sorbitol 2.73
Cupric chloride dihydrate 1.74
Sodium chloride 10.00 50.00
A mixture was prepared of eight parts of granule type 1 and two parts of granule type 2. The two types of granules were uniformly mixed with each other and placed in a hermetically sealed container. The container was stored for three months after which it was opened and the granules discharged. Visual observation and chemical analysis revealed that there had been no change in the chemical composition of the granules. When tested against microorganisms, the composition was found to be effective as a microbicide in the presence of water (2% w/v).
Example II.
Example I was repeated, except the compositions were not first granulated.
The result was that the compositions of type I and 2 granules were homogeneously mixed as powders. On storage, the mixed powder turned yellow-brown, indicating that a reaction had taken place. When tested against microorganisms, the composition was found to be ineffective as a microbicide.
Example III.
Example I was repeated, except the compositions were not first granulated and the two mixtures were placed separately in hermetically sealed containers in proper amounts such that when combined a four to one ratio of type I to type 2 compositions resulted. When tested against microorganisms, the composition was found to be effective as a microbicide.
Example IV.
Example I was repeated four times except ascorbic acid and sodium ascorbate were replaced in the first instance with equal moles of dihydroxymaleic acid, in the second instance with dihydroxyfumaric acid, in the third instance with reductic acid, and in the fourth instance with squaric acid (3,4-di-hydroxy-3-cyclobutene 1,2-dione) and in each instance potassium carbonate was used in place of sodium carbonate. Results comparable to the results of Example I were obtained in all four instances.
Example V.
Example I was repeated, except the type I granules did not contain ammonium chloride and the sodium bicarbonate and the malic acid were increased proportionally. Similar results were obtained.
Example VI.
A number of different compositions were made by blending various ingredients to form clear diluents to which an ene-diol compound was added to produce the sterilizing solution. The following table sets forth the composition of various sterilizing solutions.
TABLE 2
Ingredient “, Weight
Part A 1 2 3 4 5
Ammonium Chloride 0.025 0.025 0.025 0.025 0.025
Cupric chloride dihydrate 0.005 0.005 0.005 0.005 0.005
Potassium Phosphate monobasic 0.530 0.530 0.530 0.530 0.530
Potassium phosphate dibasic 1.060 1.060 1.060 1.060 1.060
Potassium chloride 0.300 0.300 0.300 0.300 0.300
Water 97.880 97.880 97.820 97.842 97.820
Part B
Dihydroxymaleic acid 0.200
Dihydroxyfumaric acid 0.200
Reductic acid 0.260
Ascorbic acid 0.238
Squaric acid 0.260
When tested against microorganisms, these compositions were found to be
effective as a microbicide.
Example VII.
Example Vl was repeated, except various salts of dihydroxymaleic acid were
combined in separate instances with the diluent to produce the sterlizing solution.
The following table sets forth the composition of typical sterlizing solutions.
TABLE 3
Ingredients Oo Weight
Part A 1 2 3
Ammonium chloride 0.025 0.025 0.025
Cupric chloride dihydrate 0.005 0.005 0.005
Potassium phosphate, monobasic 0.530 0.530 0.530
Potassium phosphate, dibasic 1.060 1.060 1.060
Potassium chloride 0.100 0.100 0.100
Water 97.975 98.018 98.060
Part B
Dihydroxymaleate dipotassium salt 0.305
Dihydroxymaleate disodium salt 0.262
Dihydroxymaleate dilithium salt 0.220
When tested against microorganisms, these compositions were found to be effective as a microbicide.
Example VIII.
The effectiveness of composition 1 in Table 2 of Example VI as a microbicide for contact lens sterilization was determined. Contact lenses were dipped in bacterial cultures of 108 organisms per milliliter of either staphylococcus or pseudomonas. Upon removal it was shown that 107 organisms per milliliter remained in contact with the lenses and the test lenses were then soaked in said composition and control lenses in sterile saline solution. At specific time intervals, bacterial counts were made on the lenses removed from the soaking solutions and rinsed with sterile saline. The results of the study are shown in Table 4.
TABLE 4
Bacterial count
at time of removal
Lens Bacterial Culture t = 10 mins t = 20 mins t = 30 mins Staphylococcus < 105 2 Pseudomonas < 105 3 Staphylococcus < 103 4 Pseudomonas < 103 5 Staphylococcus < 102 6 Pseudomonas < 102 7 Control > 107 8 Control > 107 9 Control > 107 The results show that said composition is effective as a microbicide when sterilizing contact lenses.
Example IX.
Example VI was repeated, except the ene-diol compounds were contained in water-soluble gelatin capsules. Comparable results wer obtained.
Example X
Example VI was repeated, except the ene-diol compounds were contained in effervescent granules. Comparable results were obtained.
Example XI.
Example VI was repeated, except the ene-diol compounds were contained in anhydrous organic solutions in high concentrations such that only small volumes were required to be added to the diluent. Comparable results were obtained.
Example XII.
Example VI was repeated, except the water was not added to Part A. The
result was that the compositions of part A and part E were added as powders to the
water to obtain the sterilizing solutions. When tested against microorganisms. the
compositions were found to be effective as microbicides.
Example XIII.
Example XII was repeated, except the individual parts A and B werc pressed into tablet form. The result was that one tablet of part A and one tablet of part B were added to the water to obtain the sterilizing solutions. Comparable results were obtained.
Example XIV.
Example Xli was repeated, except the individual parts A and B were contained in water-soluble gelatin capsules. The result was that one capsule of part A and one capsule of part B were added to the water to obtain the sterilizing solutions.
Comparable results were obtained.
Example XV.
Example XII was repeated, except part A was pressed into tablet form. The result was that one tablet and part B powder were added to the water to obtain the sterilizing solutions. Comparable results were obtained.
Example XVI.
Example XII was repeated, except part B was pressed into tablet form. The result was that one solution in high concentrations. The result was that only a small volume of the concentrated solution was required to be added to the water to obtain the sterilizing solutions. Comparable results were obtained.
WHAT WE CLAIM IS:
1. A method for sterilizing contact lenses comprising contacting a contact lens for a period of time sufficient to sterilize the lens with a substantially isotonic, aqueous composition comprising a microbicidally effective amount of an ene-diol compound and a minor, catalytic amount of a catalytic metal compound.
2. A method as claimed in claim I, wherein said ene-diol compound is selected from an ascorbic acid compound, a reductic acid compound, a squaric acid compound, a dihydroxymaleic acid compound, a dihydroxyfumaric acid compound, salts of these acids and mixtures thereof.
3. A method as claimed in claim 1 or 2 wherein said catalytic metal compound
is a copper compound.
4. A method as claimed in claim 3, wherein said copper compound is cupric chloride.
5. A method as claimed in any preceding claim, wherein the contact lenses are plastic hydrophilic soft contact lenses.
6. A method for sterilizing contact lenses as claimed in any preceding claim, substantially as hereinbefore described and exemplified.
7. Contact lenses whenever sterilized by a method as claimed in any one of

Claims (1)

claims I to 6.
8. A method for sterilizing plastic hydrophilic soft contact lenses comprising forming a substantially isotonic microbicidal solution by combining a microbicidal amount of an ene-diol in a dissolvable or dispersible solid, unit dosage form with an aqueous diluent containing a minor catalytic amount of copper ions and contacting a plastic hydrophilic soft contact lens with said microbicidal solution for a period of time sufficient to sterilize the lens.
9. A method as claimed in claim 8 wherein said dosage form is an effervescent granule.
10. A method as claimed in claim 8 wherein said dosage form is a tablet.
11. A method for sterilizing plastic hydrophilic soft contact lenses as claimed in claims 8, 9 or 10, substantially as hereinbefore described and exemplified.
12. Plastic hydrophilic soft contact lenses whenever sterilized by a method as claimed in any one of claims 8 to 11.
13. A composition comprising a substantially isotonic, aqueous composition including a microbicidally effective amount of an ene-diol compound selected from a dihydroxymaleic acid compound, a dihydroxyfumaric acid compound, a reductic acid compound, a squaric acid compound, the dipotassium salt of a dihydroxymaleic acid compound, the disodium salt of a dihydroxymaleic acid compound, the dilithium salt of a dihydroxymaleic acid compound, and mixtures thereof, and a minor, catalytic amount of a catalytic metal compound.
14. A composition as claimed in claim 13 wherein the ene-diol compound is present in an amount of from 0.01 to 10% by weight of the total composition.
15. A composition as claimed in claim 13 or 14 wherein the catalytic metal compound is an ionizable compound of copper, iron, cobalt, nickel, manganese or titanium.
16. A composition as claimed in claim 15, wherein the catalytic metal compound is cupric chloride.
17. A composition as claimed in any one of claims 13 to 16, comprising a mixture of two types of dry granules, one type being a granule containing one or more ene-diol compounds and the other type of granule being a granule containing a minor amount of the catalytic metal compound and a major amount of a water soluble bulk material capable of being formed as granules.
18. A composition as claimed in claim 17 wherein the catalytic metal compound is present in an amount of less than 5% by weight of the total granule in which it is contained.
19. A composition as claimed in any one of claims 13 to 18, additionally
including an amine-containing inhibitor.
20. A composition as claimed in any one of claims 13 to 19 additionally including one or more buffers, stabilizers and/or isotonic agents.
21. A composition as claimed in any one of claims 13 to 20, substantially as hereinbefore described and exemplified.

GB2467877A
1977-06-14
1977-06-14
Contact lens preserving solution

Expired

GB1566646A
(en)

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GB2467877A

GB1566646A
(en)

1977-06-14
1977-06-14
Contact lens preserving solution

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Priority Date
Filing Date
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GB2467877A

GB1566646A
(en)

1977-06-14
1977-06-14
Contact lens preserving solution

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GB1566646A
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GB1566646A
(en)

1980-05-08

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GB2467877A
Expired

GB1566646A
(en)

1977-06-14
1977-06-14
Contact lens preserving solution

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GB1566646A
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Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

GB2252421A
(en)

1990-12-31
1992-08-05
Tchelva Ramanathan
Cleaning soft contact lenses

1977

1977-06-14
GB
GB2467877A
patent/GB1566646A/en
not_active
Expired

Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

GB2252421A
(en)

1990-12-31
1992-08-05
Tchelva Ramanathan
Cleaning soft contact lenses

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