U.S. patent application number 10/226851 was filed with the patent office on 2003-01-16 for multi-purpose contact lens care compositions.
This patent application is currently assigned to Allergan. Invention is credited to Graham, Richard, Vehige, Joseph G..
Application Number | 20030013624 10/226851 |
Document ID | / |
Family ID | 25527303 |
Filed Date | 2003-01-16 |
United States Patent
Application |
20030013624 |
Kind Code |
A1 |
Graham, Richard ; et
al. |
January 16, 2003 |
Multi-purpose contact lens care compositions
Abstract
Multi-purpose solutions for contact lens care provide
substantial lens wearer/user comfort and/or acceptability. Such
solutions include an aqueous liquid medium; an antimicrobial
component, preferably a biguanide polymer present in an amount of
less than about 5 ppm; a surfactant component, preferably a
poly(oxyethylene)-poly(oxypropylene) block copolymer surfactant, in
an effective amount; a phosphate buffer component in an effective
amount; a viscosity inducing component, preferably selected from
cellulosic derivatives, in an effective amount; and a tonicity
component in an effective amount. Such solutions have substantial
performance, comfort and acceptability benefits, which, ultimately,
lead to ocular health advantages and avoidance of problems caused
by contact lens wear.
Inventors: |
Graham, Richard; (Irvine,
CA) ; Vehige, Joseph G.; (Laguna Niguel, CA) |
Correspondence
Address: |
STOUT, UXA, BUYAN & MULLINS LLP
4 VENTURE, SUITE 300
IRVINE
CA
92618
US
|
Assignee: |
Allergan
Irvine
CA
|
Family ID: |
25527303 |
Appl. No.: |
10/226851 |
Filed: |
August 23, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10226851 |
Aug 23, 2002 |
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09968253 |
Oct 1, 2001 |
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09968253 |
Oct 1, 2001 |
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09417526 |
Oct 13, 1999 |
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6319883 |
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09417526 |
Oct 13, 1999 |
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08980033 |
Nov 26, 1997 |
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6063745 |
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Current U.S.
Class: |
510/112 ;
510/421 |
Current CPC
Class: |
A61L 12/141 20130101;
A61L 12/142 20130101 |
Class at
Publication: |
510/112 ;
510/421 |
International
Class: |
C11D 017/08 |
Claims
What is claimed is:
1. A multi-purpose solution for contact lens care comprising: an
aqueous liquid medium; an antimicrobial component in an amount
effective to disinfect a contact lens contacted with said solution,
said non-oxidative antimicrobial component being selected from the
group consisting of biguanides, biguanide polymers, salts thereof
and mixtures thereof, and being present in an amount in a range of
about 0.1 ppm to about 3 ppm; a
poly(oxyethylene)-poly(oxypropylene) block copolymer surfactant in
an amount effective in cleaning a contact lens contacted with said
solution; a phosphate buffer component in an amount effective in
maintaining the pH of said solution within a physiologically
acceptable range; a viscosity inducing component selected from the
group consisting of cellulosic derivatives and mixtures thereof in
an effective amount in a range of about 0.05% to about 0.5% (w/v);
a chelating component in an effective amount of less than
0.05%(w/v); and a tonicity component in an amount effective in
providing the desired tonicity to said solution.
2. The multi-purpose solution of claim 1 wherein said antimicrobial
component is selected from the group consisting of
polyhexamethylene biguanide, salts thereof and mixtures
thereof.
3. The multi-purpose solution of claim 1 wherein said surfactant is
present in an amount in the range of about 0.01% to about
0.8%(w/v).
4. The multi-purpose solution of claim 1 wherein said phosphate
buffer component includes a combination of sodium hydrogen
phosphate and sodium dihydrogen phosphate.
5. The multi-purpose solution of claim 1 wherein said phosphate
buffer component is present in an amount in a range of about 0.01%
to about 0.5%(w/v).
6. The multi-purpose solution of claim 1 wherein said viscosity
inducing component is hydroxypropylmethyl cellulose.
7. The multi-purpose solution of claim 1 wherein said tonicity
component includes a combination of sodium chloride and potassium
chloride and is present in a range of about 0.4% to about
1.5%(w/v).
8. The multi-purpose solution of claim 1 wherein said chelating
component is EDTA.
9. A multi-purpose solution for contact lens care comprising: an
aqueous liquid medium; an antimicrobial component selected from the
group consisting of biguanides, biguanide polymers, salts thereof
and mixtures thereof, and being present in an amount in a range of
about 0.1 ppm to less than 5 ppm; a surfactant component in an
amount effective in cleaning a contact lens contacted with said
solution; a phosphate buffer component in an amount effective in
maintaining the pH of said solution within a physiologically
acceptable range; a viscosity inducing component in an amount
effective in increasing the viscosity of said solution; and a
tonicity component in an amount effective in providing the desired
tonicity to said solution.
10. The multi-purpose solution of claim 9 wherein said
antimicrobial component is selected from the group consisting of
polyhexamethylene biguanide, salts thereof and mixtures
thereof.
11. The multi-purpose solution of claim 9 wherein said viscosity
inducing component is hydroxypropylmethyl cellulose.
12. The multi-purpose solution of claim 9 wherein said surfactant
is selected from the group consisting of
poly(oxyethylene)-poly(oxypropylene- ) block copolymers and
mixtures thereof, and is present in an amount in a range of about
0.01% to about 0.8%(w/v).
13. The multi-purpose solution of claim 9 wherein said tonicity
component includes a combination of sodium chloride and potassium
chloride and is present in a range of about 0.4% to about
1.5%(w/v).
14. The multi-purpose solution of claim 9 which further comprises
an effective amount of EDTA in a range of less than 0.05%(w/v).
15. A multi-purpose solution for contact lens care comprising: an
aqueous liquid medium; an antimicrobial component in an amount
effective to disinfect a contact lens contacted with said solution;
a surfactant component in an amount effective in cleaning a contact
lens contacted with said solution; a phosphate buffer component in
an amount effective in maintaining the pH of said solution within a
physiologically acceptable range; a viscosity inducing component
selected from the group consisting of cellulosic derivatives and
mixtures thereof and being present in an effective amount in a
range of about 0.05% to about 0.5%(w/v); a chelating component in
an effective amount of less than 0.05%(w/v); and a tonicity
component in an amount effective in providing the desired tonicity
to said solution.
16. The multi-purpose solution of claim 15 wherein said viscosity
inducing component is hydroxypropylmethyl cellulose.
17. The multi-purpose solution of claim 15 wherein said chelating
agent is EDTA.
18. The multi-purpose solution of claim 15 wherein said
antimicrobial component is selected from the group consisting of
biguanides, biguanide polymers, salts thereof and mixtures thereof,
and is present in an amount in a range of about 0.1 ppm to less
than 5 ppm.
19. The multi-purpose solution of claim 18 wherein said
antimicrobial component is selected from the group consisting of
polyhexamethylene biguanide, salts thereof and mixtures
thereof.
20. The multi-purpose solution of claim 15 wherein said surfactant
is present in an amount in a range of about 0.01% to about
0.8%(w/v).
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to compositions for treating,
for example, disinfecting, cleaning, soaking, conditioning and
wetting contact lenses. More particularly, the invention relates to
multi-purpose solutions useful in treating contact lenses, for
example, for disinfecting contact lenses, for removing deposit
material from contact lenses, for soaking, conditioning and/or
wetting contact lenses and the like, which provide substantial
comfort and acceptability benefits to the users of such
solutions.
[0002] Contact lenses need to be periodically treated, for example,
disinfected, cleaned, soaked and the like, on a regular basis
because of the tendency for a variety of ocular and environmental
contaminants, microbes and other materials to accumulate on the
lenses and/or the need to provide the lenses in suitable condition
for safe and comfortable wear. User compliance, that is users
treating contact lenses on a regular and consistent basis, is
important in order to promote ocular health and to avoid problems
associated with contact lens wear. User compliance is enhanced when
the treatment solution employed provides high degrees of lens
wearer/user comfort and acceptability. Therefore, it would be
advantageous to provide compositions for treating contact lenses
which provide such comfort and/or are accepted by contact lens
wearers/users of such compositions.
[0003] Fu U.S. Pat. No. 4,323,467 discloses an aqueous composition
combining a poly(oxyethylene)-poly(oxypropylene) substituted
ethylenediamine surfactant, a germicidal agent, a viscosity
builder, a tonicity agent, a sequestering agent and water for
treating rigid contact lenses. This patent discloses a germicide,
such as thimerosal and/or benzalkonium chloride, in a concentration
of 0.0005-0.05%. The Fu patent does not disclose the use of any
specific buffer. Although the compositions of the Fu patent have
multiple utilities, there is a potential for eye discomfort and/or
irritation, for example, because of the relatively high
concentrations of germicide and the apparent lack of pH
control.
[0004] British Patent 1,432,345 discloses a contact lens
disinfecting composition including an ophthalmically acceptable
biguanide in a total amount of from 0.0005% to 0.05% by weight.
This British patent discloses that the solution preferably has a pH
of from 5 to 8 and employs a phosphate buffer. The patent also
discloses employing additional bactericides, thickening agents and
non-ionic surfactants, as well as disodium EDTA in concentrations
of at least 0.1%. Although these compositions are effective as
contact lens disinfectants, they do pose a risk of eye discomfort
and/or irritation, for example, because of the relatively high
concentrations of biguanide and EDTA employed.
[0005] Ogunbiyi et al U.S. Pat. No. 4,758,595 discloses an aqueous
solution of a biguanide in an amount of 0.000001 to 0.0003% weight
percent in combination with a borate buffer system, EDTA, and one
or more surfactants. This U.S. patent additionally states that
conventional buffers, other than the borate buffer, can be used but
only in conjunction with increased amounts of biguanide. Thus, the
general conclusion of this U.S. patent is that if reduced amounts
of biguanide are to be used, a borate buffer is essential. Although
such compositions are useful, the potential for ocular discomfort
and irritation in a relatively large percentage of the total
population still exists, for example, because of the requirement
that a borate buffer be employed.
[0006] There continues to be a need to provide new contact lens
treatment systems, for example, multi-purpose solutions, that
effect the desired treatment or treatments of the lens and, at the
same time, provide substantial, preferably enhanced, lens
wearer/user comfort and acceptability.
SUMMARY OF THE INVENTION
[0007] New compositions for treating contact lenses have been
discovered. The present compositions, that is multi-purpose aqueous
solutions, include antimicrobial components, preferably reduced
concentrations of antimicrobial components, in combination with
phosphate buffers and viscosity inducing components to provide the
desired antimicrobial activity and performance effectiveness and,
importantly, substantial, preferably enhanced, lens wearer/user
comfort and acceptability benefits. These compositions are
surprising and unexpected in view of the above-noted prior art
which employs relatively large concentrations of antimicrobial
components and/or buffering systems other than phosphate buffering
systems and/or does not employ viscosity inducing components. In
addition, the inclusion of one or more other components in the
present compositions is effective in providing additional
beneficial properties to the compositions, and preferably provide
further lens wearer/user comfort and acceptability benefits. The
present compositions have a multitude of applications, for example,
as disinfecting, cleaning, soaking, wetting and conditioning
compositions, for contact lens care, while providing substantial
lens wearer/user comfort and acceptability. The present
compositions preferably increase user compliance, that is promote
regular and consistent contact lens care, and, ultimately, lead to
or facilitate better ocular health.
[0008] In one embodiment of the present invention, multi-purpose
solutions for contact lens care are provided. Such solutions
comprise an aqueous liquid medium; an antimicrobial component in an
amount effective to disinfect a contact lens contacted with the
solution; a surfactant in an amount effective in cleaning a contact
lens contacted with the solution; a phosphate buffer component in
an amount effective in maintaining the pH of the solution within a
physiologically acceptable range; a viscosity inducing component
present in an effective amount; and a tonicity component in an
amount effective in providing the desired tonicity to the
solution.
[0009] The antimicrobial component may be any suitable, preferably
ophthalmically acceptable, material effective to disinfect a
contact lens contacted with the present solutions. Preferably, the
antimicrobial component is selected from biguanides, biguanides
polymers, salts thereof and mixtures thereof, and is present in an
amount in the range of about 0.1 ppm to about 3 ppm or less than 5
ppm (w/v). The preferred relatively reduced concentration of the
antimicrobial component has been found to be very effective, in the
present compositions, in disinfecting contact lenses contacted with
the compositions, while at the same time promoting lens wearer/user
comfort and acceptability.
[0010] Any suitable, preferably ophthalmically acceptable,
surfactant component which is effective in cleaning contact lenses
may be employed. The surfactant component preferably is non-ionic
and, more preferably, is selected from
poly(oxyethylene)-poly(oxypropylene) block copolymers and mixtures
thereof.
[0011] Any suitable, preferably ophthalmically acceptable,
viscosity inducing or thickening agent may be included in the
present compositions. The viscosity inducing component preferably
is selected from cellulosic derivatives and mixtures thereof and is
present in an amount in the range of about 0.05% to about 0.5%
(w/v). Without wishing to limit the invention to any particular
theory of operation, it is believed that the presence of a
viscosity inducing component at least assists in providing the lens
wearer/user comfort and acceptability benefits of the present
invention, which promote regular and consistent contact lens care
and ultimately lead to or facilitate better ocular health. The
present combinations of components, for example, including such
viscosity inducing components, are effective in providing the
degree of lens wearer/user comfort and acceptability benefits
described herein.
[0012] Although any suitable, preferably ophthalmically acceptable,
tonicity component may be employed, a very useful tonicity
component is a combination of sodium chloride and potassium
chloride.
[0013] The present compositions preferably include an effective
amount of a chelating component. Any suitable, preferably
ophthalmically acceptable, chelating component may be included in
the present compositions, although ethylenediaminetetraacetic acid
(EDTA), salts thereof and mixtures thereof are particularly
effective. More preferably, the present compositions include
chelating components in effective amounts less than about 0.05%
(w/v) and still more preferably 0.02% (w/v) or less. Such reduced
amounts of chelating component in the present compositions remain
effective in providing the desired chelating and/or sequestering
functions while, at the same time, are better tolerated in the eye,
thereby reducing the risk of user discomfort and/or ocular
irritation.
[0014] Various combinations of two or more of the above-noted
components may be used in providing at least one of the benefits
described herein. Therefore, each and every such combination is
included within the scope of the present invention.
[0015] These and other aspects of the present invention are
apparent in the following detailed description, examples and
claims.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention is directed to multi-purpose solutions
useful for treating, for example, disinfecting, cleaning, soaking,
rinsing, wetting, conditioning and the like, contact lenses. Any
contact lenses, for example, conventional hard contact lenses,
rigid gas permeable contact lenses and soft, hydrophilic or
hydrogel, contact lenses, can be treated in accordance with the
present invention.
[0017] In one embodiment, the present compositions comprise a
liquid aqueous medium; an antimicrobial component in the liquid
aqueous medium in an amount effective to disinfect a contact lens
contacted with the composition; a surfactant, preferably a
non-ionic surfactant, component in an amount effective in cleaning
a contact lens contacted with the composition; a phosphate buffer
component in an amount effective in maintaining the pH of the
composition within a physiologically acceptable range; an effective
amount of a viscosity inducing component; and an effective amount
of a tonicity component. The present compositions preferably
include an effective amount of a chelating or sequestering
component, more preferably in a range of less than 0.05% (w/v).
Each of the components, in the concentration employed, included in
the solutions and the formulated solutions of the present invention
preferably are ophthalmically acceptable. In addition, each of the
components, in the concentration employed, included in the present
solutions preferably is soluble in the liquid aqueous medium.
[0018] A solution or component thereof is "ophthalmically
acceptable" when it is compatible with ocular tissue, that is, it
does not cause significant or undue detrimental effects when
brought into contact with ocular tissue. Preferably, each component
of the present compositions is also compatible with the other
components of the present compositions. The present compositions
are more preferably substantially ophthalmically optimized. An
ophthalmically optimized composition is one which, within the
constraints of component chemistry, minimizes ocular response, or
conversely delivers ophthalmic benefit to the lens wearing eye.
[0019] The presently useful antimicrobial components include
chemicals which derive their antimicrobial activity through a
chemical or physiochemical interaction with microbes or
microorganisms, such as those contaminating a contact lens.
Suitable antimicrobial components are those generally employed in
ophthalmic applications and include, but are not limited to,
quaternary ammonium salts used in ophthalmic applications such as
poly[dimethylimino-2-butene-1,4-diyl] chloride,
alpha-[4-tris(2-hydroxyethyl) ammonium]-dichloride (chemical
registry number 75345-27-6, available under the trademark
Polyquaternium 1.RTM. from Onyx Corporation), benzalkonium halides,
and biguanides, such as salts of alexidine, alexidine-free base,
salts of chlorhexidine, hexamethylene biguanides and their
polymers, and salts thereof, antimicrobial polypeptides, chlorine
dioxide precursors, and the like and mixtures thereof. Generally,
the hexamethylene biguanide polymers (PHMB), also referred to as
polyaminopropyl biguanide (PAPB), have molecular weights of up to
about 100,000. Such compounds are known and are disclosed in
Ogunbiyi et al U.S. Pat. No. 4,758,595, the disclosure of which is
hereby incorporated in its entirety by reference herein.
[0020] The antimicrobial components useful in the present invention
preferably are present in the liquid aqueous medium in
concentrations in the range of about 0.00001% to about 2%
(w/v).
[0021] More preferably, the antimicrobial component is present in
the liquid aqueous medium at an ophthalmically acceptable or safe
concentration such that the user can remove the disinfected lens
from the liquid aqueous medium and thereafter directly place the
lens in the eye of safe and comfortable wear.
[0022] The antimicrobial components suitable for inclusion in the
present invention include chlorine dioxide precursors. Specific
examples of chlorine dioxide precursors include stabilized chlorine
dioxide (SCD), metal chlorites, such as alkali metal and alkaline
earth metal chlorites, and the like and mixtures thereof. Technical
grade sodium chlorite is a very useful chlorine dioxide precursor.
Chlorine dioxide-containing complexes such as complexes of chlorine
dioxide with carbonate, chlorine dioxide with bicarbonate and
mixtures thereof are also included as chlorine dioxide precursors.
The exact chemical composition of many chlorine dioxide precursors,
for example, SCD and the chlorine dioxide complexes, is not
completely understood. The manufacture or production of certain
chlorine dioxide precursors is described in McNicholas U.S. Pat.
No. 3,278,447, which is incorporated in its entirety herein by
reference. Specific examples of useful SCD products include that
sold under the trademark Dura Klor by Rio Linda Chemical Company,
Inc., and that sold under the trademark Anthium Dioxide by
International Dioxide, Inc.
[0023] If a chlorine dioxide precursor in included in the present
compositions, it preferably is present in an effective contact lens
disinfecting amount. Such effective disinfecting concentrations
preferably are in the range of about 0.002 to about 0.06% (w/v) of
the present compositions. Such chlorine dioxide precursors may be
used in combination with other antimicrobial components, such as
biguanides, biguanide polymers, salts thereof and mixtures
thereof.
[0024] In the event that chlorine dioxide precursors are employed
as antimicrobial components, the compositions preferably have an
osmolality of at least about 200 mOsmol/kg and are buffered to
maintain the pH within an acceptable physiological range, for
example, a range of about 6 to about 10.
[0025] In one embodiment, the antimicrobial component is
non-oxidative. It has been found that reduced amounts of
non-oxidative antimicrobial components, for example, in a range of
about 0.1 ppm to about 3 ppm or less than 5 ppm (w/v), in the
present compositions are effective in disinfecting contact lenses
and reduce the risk of such antimicrobial components causing ocular
discomfort and/or irritation. Such reduced concentration of
antimicrobial component is very useful when the antimicrobial
component employed is selected from biguanides, biguanide polymers,
salts thereof and mixtures thereof.
[0026] When a contact lens is desired to be disinfected by the
present compositions, an amount of the antimicrobial component
effective to disinfect the lens is used. Preferably, such an
effective amount of the antimicrobial component reduces the
microbial burden or load on the contact lens by one log order in
three hours. More preferably, an effective amount of the
disinfectant reduces the microbial load by one log order in one
hour.
[0027] The phosphate buffer component is present in an amount
effective to maintain the pH of the composition or solution in the
desired range, for example, in a physiologically acceptable range
of about 4 or about 5 or about 6 to about 8 or about 9 or about 10.
In particular, the solution preferably has a pH in the range of
about 6 to about 8. The phosphate buffer component preferably
includes one or more phosphate buffers, for example, combinations
of monobasic phosphates, dibasic phosphates and the like.
Particularly useful phosphate buffers are those selected from
phosphate salts of alkali and/or alkaline earth metals. Examples of
suitable phosphate buffers include one or more of sodium dibasic
phosphate (Na.sub.2HPO.sub.4), sodium monobasic phosphate
(NaH.sub.2PO.sub.4) and potassium monobasic phosphate
(KH.sub.2PO.sub.4). The present buffer components frequently are
used in amounts in a range of about 0.01% or about 0.02% to about
0.5% (w/v), calculated as phosphate ion.
[0028] The present compositions preferably further comprise
effective amounts of one or more additional components, such as a
detergent or surfactant component; a viscosity inducing or
thickening component; a chelating or sequestering component; a
tonicity component; and the like and mixtures thereof. The
additional component or components may be selected from materials
which are known to be useful in contact lens care compositions and
are included in amounts effective to provide the desired effect or
benefit. When an additional component is included, it is preferably
compatible under typical use and storage conditions with the other
components of the composition. For instance, the aforesaid
additional component or components preferably are substantially
stable in the presence of the antimicrobial and buffer components
described herein.
[0029] A surfactant component preferably is present in an amount
effective in cleaning, that is to at least facilitate removing, and
preferably effective to remove, debris or deposit material from, a
contact lens contacted with the surfactant-containing solution.
Exemplary surfactant components include, but are not limited to,
nonionic surfactants, for example, polysorbates (such as
polysorbate 20-Trademark Tween 20), 4-(1, 1, 3, 3-tetramethylbutyl)
phenol/poly(oxyethylene) polymers (such as the polymer sold under
the trademark Tyloxapol), poly(oxyethylene)-poly(oxypr- opylene)
block copolymers, glycolic esters of fatty acids and the like, and
mixtures thereof.
[0030] The surfactant component preferably is nonionic, and more
preferably is selected from poly(oxyethylene)-poly(oxypropylene)
block copolymers and mixtures thereof. Such surfactant components
can be obtained commercially from the BASF Corporation under the
trademark Pluronic.RTM.. Such block copolymers can be generally
described as polyoxyethylene/polyoxypropylene condensation polymers
terminated in primary hydroxyl groups. They may be synthesized by
first creating a hydrophobe of desired molecular weight by the
controlled addition of propylene oxide to the two hydroxyl groups
of propylene glycol. In the second step of the synthesis, ethylene
oxide is added to sandwich this hydrophobe between hydrophile
groups.
[0031] In accordance with a more preferred embodiment of the
invention, such block copolymers having molecular weights in the
range of about 2500 to 13,000 daltons are suitable, with a
molecular weight range of about 6000 to about 12,000 daltons being
still more preferred. Specific examples of surfactants which are
satisfactory include: poloxamer 108, poloxamer 188, poloxamer 237,
poloxamer 238, poloxamer 288 and poloxamer 407. Particularly good
results are obtained poloxamer 237.
[0032] The amount of surfactant component, if any, present varies
over a wide range depending on a number of factors, for example,
the specific surfactant or surfactants being used, the other
components in the composition and the like. Often the amount of
surfactant is in the range of about 0.005% or about 0.01% to about
0.1% or about 0.5% or about 0.8% (w/v).
[0033] The viscosity inducing components employed in the present
solutions preferably are effective at low or reduced
concentrations, are compatible with the other components of the
present solutions and are nonionic. Such viscosity inducing
components are effective to enhance and/or prolong the cleaning and
wetting activity of the surfactant component and/or condition the
lens surface rendering it more hydrophilic (less lipophilic) and/or
to act as a demulcent on the eye. Increasing the solution viscosity
provides a film on the lens which may facilitate comfortable
wearing of the treated contact lens. The viscosity inducing
component may also act to cushion the impact on the eye surface
during insertion and serves also to alleviate eye irritation.
[0034] Suitable viscosity inducing components include, but are not
limited to, water soluble natural gums, cellulose-derived polymers
and the like. Useful natural gums include guar gum, gum tragacanth
and the like. Useful cellulose-derived viscosity inducing
components include cellulose-derived polymers, such as
hydroxypropyl cellulose, hydroxypropylmethyl cellulose,
carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose
and the like. More preferably, the viscosity inducing agent is
selected from cellulose derivatives (polymers) and mixtures
thereof.
[0035] A very useful viscosity inducing component is
hydroxypropylmethyl cellulose (HPMC).
[0036] The viscosity inducing component is used in an amount
effective to increase the viscosity of the solution, preferably to
a viscosity in the range of about 1.5 to about 30, or even as high
as about 750, cps at 25.degree. C., preferably as determined by USP
test method No. 911 (USP 23, 1995). To achieve this range of
viscosity increase, an amount of viscosity inducing component of
about 0.01% to about 5% (w/v) preferably is employed, with amounts
of about 0.05% to about 0.5% being more preferred.
[0037] A chelating or sequestering component preferably is included
in an amount effective to enhance the effectiveness of the
antimicrobial component and/or to complex with metal ions to
provide more effective cleaning of the contact lens.
[0038] A wide range of organic acids, amines or compounds which
include an acid group and an amine function are capable of acting
as chelating components in the present compositions. For example,
nitrilotriacetic acid, diethylenetriaminepentacetic acid,
hydroxyethylethylenediaminetriac- etic acid, 1,2-diaminocyclohexane
tetraacetic acid, hydroxyethylaminodiacetic acid,
ethylenediaminetetraacetic acid and its salts, polyphosphates,
citric acid and its salts, tartaric acid and its salts, and the
like and mixtures thereof, are useful as chelating components.
Ethylenediaminetetraacetic acid (EDTA) and its alkali metal salts,
are preferred, with disodium salt of EDTA, also known as disodium
edetate, being particularly preferred.
[0039] The chelating component preferably is present in an
effective amount, for example, in a range of about 0.01% and about
1% (w/v) of the solution.
[0040] In a very useful embodiment, particularly when the chelating
component is EDTA, salts thereof and mixtures thereof, a reduced
amount is employed, for example, in the range of less than about
0.05% (w/v) or even about 0.02% (w/v) or less. Such reduced amounts
of chelating component have been found to be effective in the
present compositions while, at the same time, providing for reduced
discomfort and/or ocular irritation.
[0041] The liquid aqueous medium used is selected to have no
substantial deleterious effect on the lens being treated, or on the
wearer of the treated lens. The liquid medium is constituted to
permit, and even facilitate, the lens treatment or treatments by
the present compositions. The liquid aqueous medium advantageously
has an osmolality in the range of at least about 200-mOsmol/kg for
example, about 300 or about 350 to about 400 mOsmol/kg. The liquid
aqueous medium more preferably is substantially isotonic or
hypertonic (for example, slightly hypertonic) and/or is
ophthalmically acceptable.
[0042] The liquid aqueous medium preferably includes an effective
amount of a tonicity component to provide the liquid medium with
the desired tonicity. Such tonicity components may be present in
the liquid aqueous medium and/or may be introduced into the liquid
aqueous medium. Among the suitable tonicity adjusting components
that may be employed are those conventionally used in contact lens
care products, such as various inorganic salts. Sodium chloride
and/or potassium chloride and the like are very useful tonicity
components. The amount of tonicity component included is effective
to provide the desired degree of tonicity to the solution. Such
amount may, for example, be in the range of about 0.4% to about
1.5% (w/v). If a combination of sodium chloride and potassium
chloride is employed, it is preferred that the weight ratio of
sodium chloride to potassium chloride be in the range of about 3 to
about 6 or about 8.
[0043] Methods for treating a contact lens using the herein
described compositions are included within the scope of the
invention. Such methods comprise contacting a contact lens with
such a composition at conditions effective to provide the desired
treatment to the contact lens.
[0044] The contacting temperature is preferred to be in the range
of about 0.degree. C. to about 100.degree. C., and more preferably
in the range of about 10.degree. C. to about 60.degree. C. and
still more preferably in the range of about 15.degree. C. to about
30.degree. C. Contacting at or about ambient temperature is very
convenient and useful. The contacting preferably occurs at or about
atmospheric pressure. The contacting preferably occurs for a time
in the range of about 5 minutes or about 1 hour to about 12 hours
or more.
[0045] The contact lens can be contacted with the liquid aqueous
medium by immersing the lens in the medium. During at least a
portion of the contacting, the liquid medium containing the contact
lens can be agitated, for example, by shaking the container
containing the liquid aqueous medium and contact lens, to at least
facilitate removal of deposit material from the lens. After such
contacting step, the contact lens may be manually rubbed to remove
further deposit material from the lens. The cleaning method can
also include rinsing the lens substantially free of the liquid
aqueous medium prior to returning the lens to a wearer's eye.
[0046] The following non-limiting examples illustrate certain
aspects of the present invention.
EXAMPLE 1
[0047] A solution is prepared by blending together the following
components:
1 PHMB 1 ppm (w/v) (polyhexamethylene biguanide) Disodium EDTA
0.02% (w/v) Poloxamer 237 0.05% (w/v) (poly(oxyethylene)-poly
(oxypropylene) block copolymer) Sodium Phosphate 0.12% (w/v)
Dibasic (heptahydrate) Sodium Phosphate 0.01% (w/v) Monobasic
(monohydrate) HPMC (Hydroxypropylmethyl 0.15% (w/v) Cellulose)
Sodium Chloride 0.79% (w/v) Potassium Chloride 0.14% (w/v) Water
(USP) Q.S. 100%
[0048] Approximately three (3) ml of this solution is introduced
into a lens vial containing a lipid, oily deposit laden,
hydrophilic or soft contact lens. The contact lens is maintained in
this solution at room temperature for at least about four (4)
hours. This treatment is effective to disinfect the contact lens.
In addition, it is found that a substantial portion of the deposits
previously present on the lens has been removed. This demonstrates
that this solution has substantial passive contact lens cleaning
ability. Passive cleaning refers to the cleaning which occurs
during soaking of a contact lens, without mechanical or enzymatic
enhancement.
[0049] After this time, the lens is removed from the solution and
is placed in the lens wearer's eye for safe and comfortable wear.
Alternately, after the lens is removed from the solution, it is
rinsed with another quantity of this solution and the rinsed lens
is then placed in the lens wearer's eye for safe and comfortable
wear.
EXAMPLE 2
[0050] Example 1 is repeated except that the lens is rubbed and
rinsed with a different quantity of the solution prior to being
placed in the lens vial. After at least about four (4) hours, the
lens is removed from the solution. The lens is then placed in the
lens wearer's eye for safe and comfortable wear.
EXAMPLE 3
[0051] The solution of Example 1 is used as a long-term soaking
medium for a hydrophilic contact lens. Thus, approximately three
(3) ml of this solution is placed in a vial and a contact lens is
maintained in the solution at room temperature for about sixty (60)
hours. After this soaking period, the lens is removed from the
solution and placed in the lens wearer's eye for safe and
comfortable wear. Alternately, after the lens is removed from the
solution, it is rinsed with another quantity of this solution and
the rinsed lens is then placed in the lens wearer's eye for safe
and comfortable wear.
EXAMPLE 4
[0052] A hydrophilic contact lens is ready for wear. In order to
facilitate such wearing, one or two drops of the solution of
Example 1 is placed on the lens immediately prior to placing the
lens in the lens wearer's eye. The wearing of this lens is
comfortable and safe.
EXAMPLE 5
[0053] A lens wearer wearing a contact lens applies one or two
drops of the solution of Example 1 in the eye wearing the lens.
This effects a re-wetting of the lens and provides for comfortable
and safe lens wear.
EXAMPLE 6
[0054] A series of tests are conducted to evaluate the comfort,
safety and acceptability of the solution prepared in accordance
with Example 1 compared to two other solutions.
[0055] The first of these other solutions, referred to hereinafter
as Composition A, is sold under the trademark ReNu.RTM. by Bausch
& Lomb and includes 0.5 ppm PHMB, a
poly(oxyethylene)-poly(oxypropylene) substituted ethylenediamine
surfactant, a borate buffer system, 0.1% disodium EDTA, and sodium
chloride as a tonicity agent.
[0056] The second of these other solutions, referred to hereinafter
as Composition B, is similar to the composition of Example 1 except
that Composition B included 0.6% (w/v) tromethamine, and neither of
the phosphates.
[0057] Each of these compositions is tested to evaluate its
comfort, safety and acceptability for the care of hydrogel
(hydrophilic) contact lenses worn on a daily basis among subjects
previously adapted to at least one commercially available
multi-purpose solution.
[0058] The study is a randomized, double-masked, three-way cross
over study. The study is broken down into a series of three (3) one
(1) month treatment periods. Each of the compositions is used on a
daily basis for cleaning, rinsing after cleaning, disinfection, and
rinsing prior to lens application, as needed. Because each
treatment period is only one (1) month in duration, no enzymatic
cleaner is used in this study.
[0059] The subjects are evaluated at day zero (baseline), day seven
(7) and day thirty (30) for each of the three (3) treatment
periods. The primary comfort and acceptability variables are lens
wearing comfort and end of study product preference. The primary
safety variable is slit lamp examination findings.
[0060] 123 subjects are enrolled. 116 (94.3%) complete Preference
Questionnaires for Treatment Period 2. 118 (95.9%) complete
Preference Questionnaires for Treatment Period 3.
[0061] The results of this study are summarized as follows. The
slit lamp examinations indicate that each of the compositions
tested is acceptably safe. The comfort and acceptability results
included in this summary are based on subjective answers to
selected questions (at the end of Treatment Periods 2 and 3).
[0062] Further tabulations are made based on subjective answers to
the selected questions noted above, as well as to other questions
included in the Preference Questionnaires. These tabulations are
made using answers from the Preference Questionnaires for Treatment
Period 3.
[0063] Results of these further tabulations are as follows:
2 Respondents Preferring Composition A No Pre- P Preference
Question % ference Value Respondents Preferring Example 1
Composition % Overall preference 65 28 7 0.02 In-the-hand
preference 56 27 17 0.02 In-the-eye preference 63 27 11 0.02
Comfort in-the-eye 60 25 15 0.02 Amount of time for 47 21 32 0.02
lenses to settle in the eye Keeping lenses moist 55 28 17 0.02 in
eyes Keeping lenses 57 28 15 0.02 lubricated in eyes Soothing in
eyes 57 27 16 0.02 Respondents Preferring Composition B Composition
% Overall preference 55 40 5 0.18 In-the-hand preference 51 31 18
0.08 In-the-eye preference 60 34 6 0.02 Comfort in-the-eye 36 34 10
0.06 Amount of time for lenses to settle in 44 31 25 0.26 the eye
Keeping lenses moist 47 34 19 0.26 in eyes Keeping lenses 47 32 21
0.18 lubricated in eyes Soothing in eyes 57 32 10 0.02 *BASED ON A
P-VALUE OF 0.02, THESE RESULTS ARE SIGNIFICANT AT A 95% LEVEL OF
CONFIDENCE
[0064] These results indicate a clear preference of the composition
of Example 1 over Composition A; and an overall preference of the
composition of Example 1 over Composition B.
[0065] These results are indeed surprising since Composition A is a
commercially available multi-purpose solution. Possible reasons for
the preference of the Example 1 composition relative to Composition
A include one or more of the presence of HPMC, the presence of a
poly(oxyethylene)-poly(oxypropylene) block copolymer surfactant,
the presence of the phosphate buffer, and/or the presence of a
reduced amount of EDTA.
[0066] The present compositions provide a very beneficial and
advantageous combination of performance efficacy and lens
wearer/user comfort and acceptability. In the context of contact
lens care solutions, lens wearer/user comfort and acceptability are
very important, for example, to promote regular and effective
treating of contact lenses. Such treating of contact lenses
ultimately promotes ocular health and reduces the frequency of
problems caused by wearing contact lenses. Thus, lens wearer/user
comfort and acceptability are of substantial importance and benefit
in a contact lens care product, in particular in the present
compositions which exhibit substantial, even enhanced, lens
wearer/user comfort and acceptability.
[0067] While this invention has been described with respect to
various specific examples and embodiments, it is to be understood
that the invention is not limited thereto and that it can be
variously practiced within the scope of the following claims.
* * * * *