U.S. patent number RE36,657 [Application Number 09/195,458] was granted by the patent office on 2000-04-11 for denture adhesive composition.
This patent grant is currently assigned to Block Drug Company, Inc.. Invention is credited to Hal C. Clarke, Robert C. Gasman, Alfred J. Smetana, Joseph Synodis, Eddie Wong.
United States Patent |
RE36,657 |
Synodis , et al. |
April 11, 2000 |
Denture adhesive composition
Abstract
A denture adhesive composition contains a denture adhesive and a
pharmacologically acceptable carrier in which the denture adhesive
is a salt of a copolymer of maleic acid or anhydride and a 1 to 5
carbon atom alkyl vinyl ether having a specific viscosity of at
least 4.0. The denture adhesive composition is used to adhere a
denture to the oral mucosa.
Inventors: |
Synodis; Joseph (Summit,
NJ), Smetana; Alfred J. (Wayne, NJ), Gasman; Robert
C. (Montville, NJ), Wong; Eddie (New Providence, NJ),
Clarke; Hal C. (Elmont, NY) |
Assignee: |
Block Drug Company, Inc.
(Jersey City, NJ)
|
Family
ID: |
23107759 |
Appl.
No.: |
09/195,458 |
Filed: |
November 18, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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288587 |
Aug 10, 1994 |
|
|
|
Reissue of: |
635782 |
Apr 22, 1996 |
05830933 |
Nov 3, 1998 |
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Current U.S.
Class: |
524/37; 523/105;
525/368; 525/367; 524/549; 524/558; 524/559; 525/328.9; 525/327.8;
524/45; 523/120 |
Current CPC
Class: |
C09J
135/08 (20130101); A61K 6/35 (20200101); C08L
35/08 (20130101); C09J 135/08 (20130101); C08L
2666/26 (20130101); A61K 6/35 (20200101); C08L
35/08 (20130101); C08L 1/28 (20130101); C08L
2666/26 (20130101) |
Current International
Class: |
A61K
6/00 (20060101); C08F 008/42 () |
Field of
Search: |
;524/37,45,549,558,559
;523/105,120 ;525/327.8,328.9,367,368 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Morris; Terrel
Assistant Examiner: Guarriello; John J.
Parent Case Text
This is a continuation of application Ser. No. 08/288,587 filed on
Aug. 10, 1994 now abandoned.
Claims
What is claimed is:
1. A denture adhesive composition comprising a pharmacologically
acceptable carrier and an effective adhesion amount of a salt of a
copolymer of maleic acid or anhydride and a 1 to 5 carbon atom
alkyl vinyl ether, wherein said .[.salt.]. .Iadd.copolymer
.Iaddend.has a specific viscosity of at least about 4.0.
2. The denture adhesive of claim 1, in which the specific viscosity
is at least about 4.5.
3. The denture adhesive composition of claim 2, in which the
carboxylic acid groups of said copolymer are not completely
neutralized.
4. The denture adhesive composition of claim 3, in which the alkyl
moiety is methyl.
5. The denture adhesive composition of claim 4, in which the salt
cation comprises a metal selected from Groups IA, IIA and IIB of
the Periodic Table.
6. The denture adhesive composition of claim 4, in which the salt
cation is selected from the group consisting of sodium, potassium,
calcium, zinc, magnesium or mixtures thereof.
7. The denture adhesive composition of claim 6, in the form of a
cream.
8. The denture adhesive composition of claim 7, in which the
denture adhesive is a mixed sodium/calcium salt of the copolymer of
maleic anhydride and methyl vinyl ether and the amount thereof is
from about 15% to about 55%.
9. The denture adhesive composition of claim 6, in the form of a
powder.
10. The denture adhesive composition of claim 9 in which the
denture adhesive is a mixed salt of the copolymer of maleic
anhydride and methyl vinyl ether and the amount thereof is from
about 15% to about 55%.
11. The denture adhesive composition of claim 1 in which the
carboxylic acid groups of said copolymer are not completely
neutralized.
12. The denture adhesive composition of claim 1 in which the alkyl
moiety is methyl.
13. The denture adhesive composition of claim 1 in which the salt
cation comprises an alkali metal.
14. The denture adhesive composition of claim 1 in which the salt
cation is selected from the group consisting of sodium, potassium,
calcium, zinc, magnesium or mixtures thereof.
15. The denture adhesive composition of claim 1 in which the amount
of denture adhesive is from about 17% to about 48%.
16. The denture adhesive composition of claim 1 in the form of a
cream.
17. The denture adhesive composition of claim 16 in which the
amount of denture adhesive is about 30%.
18. The denture adhesive composition of claim 1 in the form of a
powder.
19. The denture adhesive composition of claim 18 in which the
amount of denture adhesive is about 50%.
20. The denture adhesive composition of claim 1 containing from
about 10% to about 30% of a carboxymethyl cellulose gum.
21. The denture adhesive composition of claim 20 wherein the gum is
sodium carboxymethyl cellulose and the amount thereof is about
15-53%.
22. A method of adhering a denture to the oval mucosa by employing
a denture adhesive composition utilizing the denture adhesive
composition of claim 1.
23. A method of adhering a denture to the oval mucosa by employing
a denture adhesive composition utilizing the denture adhesive
composition of claim 2.
24. A method of adhering a denture to the oval mucosa by employing
a denture adhesive composition utilizing the denture adhesive
composition of claim 3.
25. A method of adhering a denture to the oval mucosa by employing
a denture adhesive composition utilizing the denture adhesive
composition of claim 8.
26. A method of adhering a denture to the oval mucosa by employing
a denture adhesive composition utilizing the denture adhesive
composition of claim 10.
27. A method of adhering a denture to the oval mucosa by employing
a denture adhesive composition utilizing the denture adhesive
composition of claim 20.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to adhesives, especially denture
adhesives, and to methods of making and using such adhesives.
2. Description of Related Art
Dentures are usually secured in the mouth using creams or powders
that have adhesive properties. These denture adhesive compositions
serve both to adhere the dentures to the gums and also to provide a
cushion and sealant between the gums and the dentures to thereby
permit a comfortable fit. The denture adhesives are also required
to have acceptable organoleptic qualities. They further need to be
sufficiently strong so that a single application of the adhesive is
sufficient for a full day's use while not preventing or hindering
removal of the dentures at the end of the day for cleaning and the
like. The latter requirement has taken on more prominence in recent
years since the number of hours of continuous wear which is
considered to constitute a "full day" has been increasing.
The technical literature discloses a wide variety of denture
adhesive materials. However, most presently available commercial
denture adhesives are based on all vinyl ether/maleic acid or
anhydride copolymers. This class of adhesives was set forth as a
potential denture adhesive in Germann et al., U.S. Pat. No.
3,003,988, which issued more than 30 years ago. That patent
describes synthetic, water sensitized but water insoluble,
materials comprising mixed partial salts of lower alkyl vinyl
ether-maleic anhydride copolymers for stabilizing dentures. The
salts mentioned in the patent are a mixture of (a) calcium and (b)
alkalies including sodium, potassium and quaternary ammonium
compounds in a 1:1 to 5:1 molar ratio. The calcium and alkali
materials are added to the copolymer to form a mixed salt. The use
of this class of materials has been described in a variety of other
patents. Examples include U.S. Pat. No. 4,989,391, 5,037,924,
5,093,387, 4,980,391 and 4,373,036, European Published Patent
Application No. 406,643 and WO 92/10988.
These polymers and their salts have not proven to be as fully
effective as desired for securing the denture, particularly when
the denture wearer consumes hot liquids. Additionally, they have
been found susceptible to "washout", a term which refers to the
erosion of the adhesive from under the denture during use. As a
result, the formulations have provided less than the 12 hours of
holding power that denture wearers have begun to demand.
In order to provide additional adhesive and cohesive properties,
one approach which has been taken is to manipulate the salt form of
the copolymer. Examples can be found in WO 92/22280, WO 92/10988,
WO 92/10987 and U.S. Pat. No. 4,758,630 and 5,073,604. Another
approach has been to employ an adhesion adjuvant in the formulation
or converting the copolymer into a terpolymer, and examples of
these approaches can be found in U.S. Pat. No. 3,736,274, 5,037,924
and 5,093,387.
Despite the efforts that have been put into improving the
properties of maleic anhydride/alkyl vinyl ether type polymers and
their salts, these formulations do not provide the full desired
measure of adhesion, cohesion and resistance to washout from
beneath the denture.
The copolymer can be made in a variety of molecular weights and an
appropriate value is selected depending on the use to which it is
going to be put. It is generally recognized that the copolymer of
the alkyl vinyl ether and maleic anhydride must have a suitably
high molecular weight in order to be suitable for use as a denture
adhesive. The minimum molecular weight is frequently indicated as
corresponding to a specific viscosity of about 1.2 when measured in
a 1% weight/volume solution in methyl ethyl ketone at 25.degree.
C.
How high the molecular weight can be in excess of that value is
rarely mentioned or considered to be important and the description
in WO 92/10988 is a good example of this fact. U.S. Pat. No.
4,373,036 is a rare exception in that it indicates the specific
viscosity can be about 1.5-3.5.
The dearth of consideration of molecular weight is understandable
both on a theoretical and experimental basis. As molecular weight
increases, the solubility of the polymer decreases. The polymer
develops its adhesive strength when it is hydrated by the moisture
in an individual's saliva and decreased solubility would make the
polymer harder to hydrate. Accordingly, the expectation is that as
the molecular weight increases, the solubility would decrease to
the point where the polymer would no longer function suitably as an
adhesive.
On an experimental basis, it has been observed that a copolymer
having a specific viscosity of about 3.5 does not have any
statistically significant adhesive properties compared to those of
a copolymer having a specific viscosity of about 2.6. Since it is
more difficult to produce the higher molecular weight polymer,
there is no reason to do so. In view of these considerations, it is
not surprising that attempts to improve denture adhesive
compositions have ignored the molecular weight the polymer.
Surprisingly, it has now been found that when the molecular weight
is sufficiently high, a superior denture adhesive is achieved.
It is the object of this invention to provide an improved denture
adhesive composition having both strong adhesive properties and
good washout resistance to provide long holding properties. This
and other objects of the invention will become apparent to those of
ordinary skill in this art from the following detailed
description.
SUMMARY OF THE INVENTION
The invention relates to an improved denture adhesive composition
comprising of a denture adhesive and a carrier therefor. More
particularly, the improved composition employs a denture adhesive
which is a salt of copolymer of maleic anhydride and an alkyl vinyl
ether having a specific viscosity of at least about 4. The
improvement in a method of adhering a denture to the oral mucosa
resulting from the use of the new composition is also a part of
this invention.
DESCRIPTION OF THE INVENTION
The denture adhesive composition of the present invention contains
a denture adhesive effective amount of a denture adhesive and a
pharmacologically acceptable carrier therefor. The denture adhesive
usually comprises from about 15% to about 55% by weight of the
denture adhesive composition. Preferably it is from about 17% to
about 48% by weight and most preferably about 30% in a cream
formula and about 50% in a powder formula. The denture adhesive
employed in the composition is a salt of a copolymer of maleic acid
or maleic anhydride and an alkyl vinyl ether in which the alkyl
group has 1 to about 5 carbon atoms. The preferred copolymer is a
copolymer of maleic anhydride and methyl vinyl ether. The polymer
can be produced by any of the methods which are described in the
technical literature or it can be purchased commercially. However,
in accordance with the present invention, the copolymer has a
molecular weight, as represented by the specific viscosity measured
as a 1% weight/volume solution of methyl ethyl ketone at 25.degree.
C., of at least about 4. More preferably, the specific viscosity is
at least about 4.5.
The copolymer is employed in the form of a metal salt. Those salts
where only a portion of the acid groups have been reacted i.e.
which are partially neutralized, are preferred. The preferred
alkaline cations include sodium, zinc, potassium, calcium and
magnesium. Preferably the salts are mixed salts of calcium/sodium
or calcium/potassium, and most preferably they are partial
zinc/magnesium salts and sodium/zinc/magnesium salts. Examples of
these magnesium salts are found in U.S. patent application Ser. No.
08/288,586, now U.S. Pat. No. 5,525,652 filed concurrently
herewith. That application is entitled "Denture Adhesive" and lists
Clarke, Ahn, Wong, Gasman, Smetana and Synodis as inventors. The
disclosure of that application is hereby incorporated by reference.
Even though the salts of that application are preferred, this
invention is not limited to salts disclosed that application.
When the salt is prepared, the metal compounds used react with the
carboxylic acid groups on the copolymer and neutralize them.
Preferably less than 100% of the carboxylic acid groups on the
copolymer chain are neutralized. More preferably, the metal
compounds neutralize from about 50% to about 90% of the carboxylic
acid groups of the copolymer and most preferably from about 65% to
about 75% of the carboxylic acid groups.
One of the particular advantages of this invention is that the use
of the copolymer having a specific viscosity of at least about 4
permits one to employ a lower degree of neutralization in order to
achieve a given level of denture adhesive performance. This means
that the necessary minimum cohesion strength for good denture
adhesive performance can be achieved by neutralizing less of the
acid groups when the molecular weight of the copolymer is such that
the specific viscosity of the copolymer is high. The use of a lower
degree of neutralization has its own advantages. As a result of the
lower concentration of metal cation, the fully hydrated polymer
salt is a softer (lower glass transition temperature) adhesive and,
in addition, there is a higher concentration of unreacted carboxyl
groups. Polymers containing non-neutralized, free carboxyl groups
are expected to adhere better through hydrogen bonding to the
functional carbonyl groups present in the acrylic plastic of the
denture and to the oral mucosa than carboxylate anions present in
an alkaline adhesive containing more metal cations. Still further,
the higher molecular weight and reduced degree of neutralization
also reduce the tendency toward adhesive washout from between the
denture and the oral mucous. The copolymer salt of this invention
is made by dissolving the copolymer in a suitable solvent such as
water. An elevated temperature can be used to expedite the
dissolution of the polymer in the solvent as long as the
temperature is not so high as to deleteriously affect the polymer.
Separately, a dispersion of the metal compound in water may be
prepared. Preferably the metal compound solution also includes a
catalyst, such as a Lewis acid or base, to facilitate the partial
reaction of the metal compound with the carboxyl hydrogen in the
copolymer.
In choosing the alkaline, inorganic metal compound used to
neutralize the carboxylic acid groups, the anion portion of the
compound is not restricted, although it is preferably an oxide,
hydroxide, carbonate or halide. Of the halides, chlorides are most
preferred. In general, the oxides or hydroxides are preferred
because of their ease of handling, availability and the generally
innocuous nature of the by-products formed in their reaction with
carboxylic acids.
After the polymer solution has cooled sufficiently (when heated),
the solution or dispersion of metal compound and the polymer
solution are combined and allowed to react. The product salt formed
is dried, preferably milled to less than about 100 mesh and then
dispersed in a pharmacologically acceptable carrier to form the
denture adhesive of this invention using techniques well known in
the art.
In addition to the denture adhesive, the composition contains a
pharmacologically acceptably carrier. The pharmacologically
acceptable carrier contains conventional materials and if desired,
can contain any adhesive adjuvants which have heretofore been used.
For instance, the carrier may contain a carboxymethyl cellulose gum
which is used for sensitizing the adhesive to moisture and
enhancing the cohesive properties of the formulation and improving
gel strength.
Carboxyethyl cellulose and carboxypropyl cellulose materials may
also be used. When present, the cellulose gum preferably comprises
from about 10% to about 30% by weight of the denture adhesive
composition, more preferably from about 15% to about 25% and most
preferably from about 20% to about 22% of the composition for a
cream formula. In a powder formula, the cellulose gum preferably
comprises from about 45% to about 55% of the composition. The
cellulose may be present in the form of a full or partial salt,
preferably a sodium salt.
Non-active ingredients that may be present in the carrier portion
of the denture adhesive composition include thickening agents such
as petrolatum, waxes, mineral oil and other oils; flavors such as
synthetic flavor oils and/or oils derived from plants and fruits;
colors suitable for food, drug and cosmetic use and known as
FD&C colors; preservatives such as the parabens, benzoic acid
and benzoates and the like; viscosity modifiers; and non-toxic
anti-caking agents such as silica, magnesium stearate and talc.
In a cream formulation, the mineral oil or the like preferably
comprises from about 10% to about 35%, preferably from about 12% to
about 17% by weight of the composition, and petrolatum and the like
preferably comprise from about 20% to about 50%, preferably from
about 25% to about 45% by weight of the composition.
In order to further illustrate the present invention, various
examples are set forth below. In these, as throughout the so
specification and claims, all parts and percentages are by weight
and all temperature in degree centigrade unless otherwise
indicated.
EXAMPLE 1
A series of partially neutralized mixed salts of methyl vinyl
ether/maleic anhydride copolymer are prepared as follows. 3.25
Kilograms of distilled water are heated in a stirred reaction
vessel to about 90.degree. C., 253 grams of methyl vinyl
ether/maleic anhydride copolymer are added slowly and mixing
continued until a clear solution is obtained. The solution is then
cooled to 65.degree.-75.degree. C.
Separately, 84 grams of calcium hydroxide and 13 grams of sodium
hydroxide dispersion in 500 grams of water is prepared. When the
temperature of the copolymer solution has reached
65.degree.-75.degree. C., the dispersion is added while mixing at
high speed to prevent a localized reaction. Mixing is continued for
15 minutes after addition of the metal-containing dispersion is
complete and the reaction mixture is then transferred to a series
of shallow steel drying trays which are placed in a hot air
convection oven at about 75.degree. C. for 18-20 hours. The dry
partial salt is then milled and screened through a 100 mesh
screen.
EXAMPLE 2
3.25 Kilograms of distilled water are heated in a stirred reaction
vessel to about 90.degree. C. 257 Grams of methyl vinyl
ether/maleic anhydride copolymer are added slowly and mixing
continued until a clear solution is obtained. The solution is then
cooled to 65.degree.-75.degree. C.
Separately, 79.4 grams of calcium hydroxide and 13.2 grams of
sodium hydroxide dispersion in 500 grams of water is prepared. When
the temperature of the copolymer solution has reached
65.degree.-75.degree. C., the dispersion is added while mixing at
high speed to prevent a localized reaction mixing is continued for
15 minutes after addition of the metal-containing dispersion is
complete and the reaction mixture is then transferred to a series
of shallow steel drying trays which are placed in a hot air
convection oven at about 75.degree. C. for 18-20 hours. The dry
partial salt is then milled and screened through a 100 mesh
screen.
EXAMPLE 3
3.25 Kilograms of distilled water are heated in a stirred reaction
vessel to about 90.degree. C. 262 Grams of methyl vinyl
ether/maleic anhydride copolymer are added slowly and mixing
continued until a clear solution is obtained. The solution is then
cooled to 65.degree.-75.degree. C. Separately, 74.6 grams of
calcium hydroxide and 13.4 grams of sodium hydroxide dispersion in
500 grams of water is prepared. When the temperature of the
copolymer solution has reached 65.degree.-75.degree. C., the
dispersion is added while mixing at high speed to prevent a
localized reaction. Mixing is continued for 15 minutes after
addition of the metal-containing dispersion is complete and the
reaction mixture is then transferred to a series of shallow steel
drying trays which are placed in a hot air convection oven at about
75.degree. C. for 18-20 hours. The dry partial salt is then milled
and screened through a 100 mesh screen.
EXAMPLE 4
3.25 Kilograms of distilled water are heated in a stirred reaction
vessel to about 90.degree. C. 266.7 Grams of methyl vinyl
ether/maleic anhydride copolymer are added slowly and mixing
continued until a clear solution is obtained. The solution is then
cooled to 65.degree.-75.degree. C.
Separately, 69.6 grams of calcium hydroxide and 13.7 grams of
sodium hydroxide dispersion in 500 grams of water is prepared. When
the temperature of the copolymer solution has reached
65.degree.-75.degree. C., the dispersion is added while mixing at
high speed to prevent a localized reaction. Mixing is continued for
15 minutes after addition of the metal-containing dispersion is
complete and the reaction mixture is then transferred to a series
of shallow steel drying trays which are placed in a hot air
convection oven at about 75.degree. C. for 18-20 hours. The dry
partial salt is then milled and screened through a 100 mesh
screen.
The table set forth below indicates the metal hydroxide used to
form the dispersion and the percent of the carboxylic acid groups
neutralized in the polymer produced.
______________________________________ Example Metal Compound %
Neutralized ______________________________________ 1 Sodium
hydroxide/calcium hydroxide 45 2 Sodium hydroxide/calcium hydroxide
30 3 Sodium hydroxide/calcium hydroxide 60 4 Sodium
hydroxide/calcium hydroxide 80
______________________________________
EXAMPLES 5-8
A series of denture adhesive creams are prepared using the salts of
Example 1. The respective salts are blended with the other
ingredients in the following manner.
Mineral oil (about 17 parts) is heated to a temperature of about
75.degree. C. Petrolatum (about 28 parts) is heated to the same
temperature and is added to the mineral oil and blended until a
uniform consistency is reached. Sodium carboxymethyl cellulose
(about 24 parts), colorant (0.05 part), anti-caking agent,
preservative (0.05 part) and flavor (0.4 part) are added while the
mixture is slowly cooled to about 50.degree. C. The partial mixed
salt of the copolymer is then added at about 50.degree. C. and the
resulting denture adhesive cream is cooled to room temperature.
EXAMPLES 9-11
Adhesive shear strength was measured employing three homogeneously
mixed samples of adhesive formulations of Examples 5-8 and water in
weight ratios of 1:1, 1:0.75 and 1:0.5. Each combination was spread
on an about 2.54 cm square area of a transparent acrylic slide and
then a second slide having a 1.9 cm diameter hole in one end was
placed over the first slide. The resulting sandwich was held under
about 20 lb (9 kg) pressure for 5 seconds and then set aside for
about 5 minutes to allow hydration to occur. Pressure (about 20
lb-9 kg) was again applied for 5 seconds and then the shear
strength was measured using an Instron Model 1122 machine. The
results of the measurements were averaged. It was noted that a 75%
sodium/calcium partial mixed salt of methyl vinyl ether/maleic
anhydride copolymer (specific viscosity 4.7) had a better shear
strength than a 75% sodium/calcium mixed partial salt of the
copolymer having a specific viscosity of either 3.5 or 2.6.
EXAMPLES 12-15
Denture adhesive paste formulations containing a 75% sodium/calcium
partial salt of a methyl vinyl ether/maleic anhydride copolymer
using the following ingredients: sodium carboxymethyl cellulose
(about 24 parts), petrolatum (about 28 parts), mineral oil (about
17 parts), colorant (about 0.05 parts) and preservative (about 0.05
parts).
Pastes in which the copolymer (before salt formation) had a
specific viscosity of either 2.6, 3.5 or 4.7 were evaluated by a
panel of denture users. The pastes where the copolymer had a
specific viscosity of 2.6 or 3.5 were perceived to be equivalent
while the paste in which the specific viscosity was 4.7 was noted
to exhibit a longer and stronger hold.
EXAMPLES 16-18
Denture adhesive powders were prepared using sodium/calcium partial
salts produced in example 4. The respective salts were dry blended
with an equal weight of sodium carboxymethyl cellulose. The powders
were then evaluated by a panel of denture wearers.
No statistically significant differences were noted in this testing
between the partial salts when the methyl vinyl ether/maleic
anhydride copolymer had a specific viscosity of either 2.6 or 3.5.
However, when the copolymer partial salt had been made from the
copolymer having a specific viscosity of 4.7, a statistically
significant improvement adhesive performance was noted. The high
molecular weight salt was noted to have a longer hold and a
stronger hold than the lower molecular weight products.
The various embodiments which have been described in this
application were set forth for the purpose of further illustrating
the invention and were not intended to limit it. Various changes
and modifications can be made from those embodiments without
departing from the spirit and scope of the invention.
* * * * *