U.S. patent application number 09/754438 was filed with the patent office on 2001-12-06 for hydrogels containing substances.
This patent application is currently assigned to The B.F. Goodrich Company. Invention is credited to Chiarelli, Joseph A., Frate, Dean M., Ma, Yong.
Application Number | 20010049417 09/754438 |
Document ID | / |
Family ID | 26804562 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010049417 |
Kind Code |
A1 |
Frate, Dean M. ; et
al. |
December 6, 2001 |
Hydrogels containing substances
Abstract
A blend of one or more crosslinked polymers or copolymers
prepared from an olefinically unsaturated polymerizable carboxylic
or anhydride monomer and at least one high molecular weight
essentially linear polymer prepared from an olefinically
unsaturated polymerizable carboxylic acid monomer. The blend is
neutralized to typically a low pH, and generally contains a
noncovalent, e.g. ionic, crosslinking agent, and a cure rate
modifier. The hydrogel blend is capable of containing a large
amount of water, has good tack, good adhesion, and can be utilized
as an application vehicle having a backing thereon as well as
containing various substances such as personal care compounds,
pharmaceuticals, active ingredients, and the like.
Inventors: |
Frate, Dean M.; (Cleveland,
OH) ; Chiarelli, Joseph A.; (Broadview Heights,
OH) ; Ma, Yong; (Beverly Hills, CA) |
Correspondence
Address: |
Brian Kolkowski, Esq.
Patent Law Department
THE B.F.GOODRICH COMPANY
9921 Brecksville Road
Brecksville
OH
44141-3289
US
|
Assignee: |
The B.F. Goodrich Company
|
Family ID: |
26804562 |
Appl. No.: |
09/754438 |
Filed: |
January 4, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09754438 |
Jan 4, 2001 |
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09430044 |
Oct 29, 1999 |
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6211296 |
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60107237 |
Nov 5, 1998 |
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Current U.S.
Class: |
525/221 ;
524/522 |
Current CPC
Class: |
A61K 9/7023 20130101;
Y10S 524/916 20130101 |
Class at
Publication: |
525/221 ;
524/522 |
International
Class: |
C08L 033/00; C08J
003/00 |
Claims
What is claimed is:
1. An aqueous polymeric composition, comprising: a blend of at
least one crosslinked polymer, derived from at least one
olefinically unsaturated carboxylic or anhydride monomer, and at
least one high molecular weight substantially linear polymer
derived from at least one olefinically unsaturated carboxylic acid
monomer.
2. An aqueous polymeric composition according to claim 1, wherein
said crosslinked polymer is a homopolymer, or a copolymer, or an
interpolymer, or combinations thereof, wherein said homopolymer is
derived from said olefinically unsatured carboxylic or anhydride
monomer having a total of from 3 to about 34 carbon atoms, wherein
said copolymer is derived from said olefinically unsaturated
carboxylic or anhydride monomer having a total of from 3 to about
34 carbon atoms with monomers of acrylic esters, acrylamides,
olefins, vinyl esters, vinyl ethers, vinyl amides, amines, styrenic
monomers, or unsaturated anhydride monomers, or combinations
thereof having a total of from 3 to about 40 carbon atoms; and
wherein said interpolymer is derived from one or more of said
olefinically unsaturated carboxylic monomers or anhydrides in an
amount of more than 15 percent by weight based upon the weight of
said interpolymer and a steric stabilizer surfactant having at
least one hydrophilic moiety and at least one hydrophobic moiety in
a linear block or a random comb configuration.
3. An aqueous polymeric composition according to claim 2, wherein
said high molecular weight substantially linear polymer has 5 side
chains or less per 100 repeat units, and wherein the weight average
molecular weight of said substantially linear polymer is at least
50,000.
4. An aqueous polymeric composition according to claim 3, wherein
said at least one olefinically unsaturated carboxylic acid monomer
utilized to form said high molecular weight substantially linear
polymer has a total of from 3 to 30 carbon atoms, wherein said high
molecular weight substantially linear polymer has 3 side chains or
less per 100 repeat units, and wherein said high molecular weight
substantially linear polymer has a weight average molecular weight
of from about 50,000 to about 2,000,000.
5. An aqueous polymeric composition according to claim 4, wherein
said at least one monomer utilized to form said at least one
crosslinked polymer has an olefinic double bond either in the alpha
or beta position with respect to said carboxyl group, and wherein
the amount of said crosslinked polymer is from about 5 parts to
about 30 parts by weight per 100 parts by weight of water.
6. An aqueous polymeric composition according to claim 5, wherein
said interpolymer is formed from an aqueous solution containing a
low surface tension surface active agent which is a hydrocarbon, a
fluorocarbon, or a silicone surface active agent.
7. An aqueous polymeric composition according to claim 5, wherein
said crosslinked polymer is derived from a monomer comprising
acrylic acid, methacrylic acid, maleic acid, or maleic anhydride
monomer, or combinations thereof, and wherein said high molecular
weight substantially linear polymer is derived from a monomer
comprising acrylic acid, methacrylic acid, or combinations
thereof.
8. An aqueous polymeric composition according to claim 7, wherein
said crosslinking agent forming said at least one crosslinked
polymer is allyl pentaerythritol, trimethylolpropane dialylether,
allyl sucrose, or combinations thereof, and wherein said high
molecular weight substantially linear polymer has a molecular
weight of from about 200,000 to about 1,000,000.
9. An aqueous polymeric composition according to claim 1, including
a non-covalent crosslinking agent.
10. An aqueous polymeric composition according to claim 7,
including an ionic crosslinking agent.
11. A hydrogel, comprising: a blend of at least one crosslinked
polymer derived from an olefinically unsaturated carboxylic or
anhydride monomer, and at least one high molecular weight
substantially linear polymer derived from at least one olefinically
unsaturated carboxylic acid monomer, water, a non-covalent
crosslinking agent, and wherein the pH of said hydrogel is from
about 3.5 to about 14.0.
12. A hydrogel according to claim 11, including an effective amount
of a neutralizing agent to yield said pH of from about 3.5 to about
14.0.
13. A hydrogel according to claim 12, wherein the amount of said
crosslinked polymer is from about 5 to about 30 parts by weight per
100 parts by weight of said water, wherein the amount of said high
molecular weight substantially linear polymer is from about 5 to
about 40 parts by weight per 100 parts by weight of said water, and
including a cure rate modifier.
14. A hydrogei according to claim 12, wherein crosslinked polymer
is a homopolymer, a copolymer or an interpolymer, wherein said
homopolymer is derived from said olefinically unsaturated
carboxylic or anhydride monomer having a total of from 3 to about
34 carbon atoms, wherein said copolymer is derived from said
olefinically unsaturated carboxylic or anhydride monomer having a
total of from 3 to about 34 carbon atoms with monomers of acrylic
esters, acrylamides, olefins, vinyl esters, vinyl ethers, vinyl
amides, amines, styrenic monomers, or unsaturated anhydride
monomers, or combinations thereof having a total of from 3 to about
40 carbon atoms; and wherein said interpolymer is derived from one
or more of said olefinically unsaturated carboxylic monomers or
anhydrides in an amount of more than 15 percent by weight based
upon the weight of said interpolymer and a steric stabilizer
surfactant having at least one hydrophilic moiety and at least one
hydrophobic moiety in a linear block or a random comb
configuration, wherein said high molecular weight substantially
linear polymer has 5 side chains or less per 100 repeat units, and
wherein the weight average molecular weight of said polymer is at
least 50,000.
15. A hydrogel according to claim 14, wherein the amount of swell
of said hydrogel is from about 2 to about 10 times the original
non-swell dimension thereof, and including a cure rate modifier,
and wherein said pH is from about 3.5 to about 10.
16. A hydrogel according to claim 15, wherein said at least one
olefinically unsaturated carboxylic acid monomer utilized to form
said high molecular weight substantially linear polymer has a total
of from 3 to 30 carbon atoms, wherein said high molecular weight
substantially linear polymer has 3 side chains or less per 100
repeat units, and wherein said high molecular weight substantially
linear polymer has a weight average molecular weight of from about
50,000 to about 2,000,000.
17. A hydrogel according to claim 16, wherein said non-covalent
crosslinking agent is an ionic crosslinking agent, wherein said at
least one monomer utilized to form said at least one crosslinked
polymer has an olefinic double bond either in the alpha or beta
position with respect to said carboxyl group, and wherein the
amount of said crosslinked polymer is from about 5 parts to about
30 parts by weight per 100 parts by weight of water, and wherein
said cure rate modifier is a monoalcohol, a diol, a polyol, or
combinations thereof.
18. A hydrogel according to claim 17, wherein the said pH of said
hydrogel is from about 3.5 to about 10.0, and wherein the amount of
said swell of said hydrogel is from about 3 to about 5 times its
original dimension.
19. A hydrogel according to claim 18, wherein said crosslinked
polymer is derived from a monomer comprising acrylic acid,
methacrylic acid, maleic acid, or maleic anhydride, or combinations
thereof, and wherein said high molecular weight substantially
linear polymer is derived from monomers comprising acrylic acid,
methacrylic acid, or combinations thereof.
20. A hydrogel according to claim 11, including at least one
substance, said substance located substantially within said
hydrogel.
21. A hydrogel according to claim 13, including at least one
substance, said substance located substantially within said
hydrogel.
22. A hydrogel according to claim 14, including at least one
substance located substantially within said hydrogel, wherein said
substance includes a pharmaceutical, a biologically active
compound, an absorptive material, a personal care compound, an
active ingredient, a therapeutic aid, or combinations thereof.
23. A hydrogel according to claim 17, including at least one
substance located substantially within said hydrogel, wherein said
substance includes a pharmaceutical, a biologically active
compound, an absorptive material, a personal care compound, an
active ingredient, a therapeutic aid, or combinations thereof.
24. A hydrogel according to claim 19, including a substance located
substantially within said hydrogel, wherein said substance includes
a pharmaceutical, a biologically active compound, an absorptive
material, a personal care compound, an active ingredient, a
therapeutic aid, or combinations thereof.
25. A patch comprising; a backing, a hydrogel located on said
backing, said hydrogel containing at least one substance and
optionally a release layer thereon.
26. A patch according to claim 25, wherein said hydrogel comprises:
a blend of at least one crosslinked polymer derived from an
olefinically unsaturated carboxylic or anhydride monomer, and at
least one high molecular weight substantially linear polymer
derived from at least one olefinically unsaturated carboxylic acid
monomer, water, wherein the amount of said crosslinked polymer is
from about 5 to about 30 parts by weight per 100 parts by weight of
said water, wherein the amount of said high molecular weight
substantially linear polymer is from about 5 to about 40 parts by
weight per 100 parts by weight of said water, a non-covalent
crosslinking agent.
27. A patch according to claim 26, wherein crosslinking polymer is
a homopolymer, a copolymer or an interpolymer, wherein said
homopolymer is derived from said olefinically unsaturated
carboxylic or anhydride monomer having a total of from 3 to about
34 carbon atoms, wherein said copolymer is derived from said
olefinically unsaturated carboxylic or anhydride monomer having a
total of from 3 to about 34 carbon atoms with monomers of acrylic
esters, acrylamides, olefins, vinyl esters, vinyl ethers, vinyl
amides, amines, styrenic monomers, or unsaturated anhydride
monomers, or combinations thereof having a total of from 3 to about
40 carbon atoms; wherein said interpolymer is derived from one or
more of said olefinically unsaturated carboxylic monomers or
anhydrides in an amount of more than 15 percent by weight based
upon the weight of said interpolymer and a steric stabilizer
surfactant having at least one hydrophilic moiety and at least one
hydrophobic moiety in a linear block or a random comb
configuration, and wherein said high molecular weight substantially
linear polymer has 5 side chains or less per 100 repeat units, and
wherein the weight average molecular weight of said polymer is at
least 50,000.
28. A patch according to claim 27, wherein said pH of said hydrogel
is from about 3.5 to about 14, and wherein said hydrogel includes a
cure rate modifier.
29. A patch according to claim 26, wherein the amount of swell of
said hydrogel is from about 2 to about 10 times the original
non-swell dimension thereof, and wherein said substance includes
includes a pharmaceutical, a biologically active compound, an
absorptive material, a personal care compound, an active
ingredient, a therapeutic aid, or combinations thereof.
30. A patch according to claim 28, wherein said at least one
olefinically unsaturated carboxylic acid monomer utilize to form
said high molecular weight substantially linear polymer has a total
of from 3 to 30 carbon atoms, wherein said high molecular weight
substantially linear polymer has 3 side chains or less per 100
repeat units, and wherein said high molecular weight substantially
linear polymer has a weight average molecular weight of from about
200,000 to about 2,000,000.
31. A patch according to claim 30, wherein said pH of said hydrogel
is from about 3.5 to about 10.0, wherein said crosslinked polymer
is derived from a monomer comprising acrylic acid, methacrylic
acid, maleic acid, or maleic anhydride, or combinations thereof,
and wherein said high molecular weight substantially linear polymer
is derived from monomers comprising acrylic acid, or methacrylic
acid, or combinations thereof.
32. A patch according to claim 31, wherein the amount of swell of
said hydrogel is from about 2 to about 10 times the original
non-swell dimension thereof, and wherein said substance is includes
a pharmaceutical, a biologically active compound, an absorptive
material, a personal care compound, an active ingredient, a
therapeutic aid, or combinations thereof.
33. A patch according to claim 29, including said release
layer.
34. A patch according to claim 32, including said release layer.
Description
CROSS REFERENCE
[0001] This patent application is based upon U.S. Provisional
Application Ser. No. 60/107,237, filed Nov. 5, 1998.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to articles created using
blends of polymers and other ingredients, and to a process for
preparing the same. The articles serve as a hydrogel for applying
various substances to a substrate. The substance can be a personal
care compound, a biologically active compound, an active
ingredient, an absorptive material, etc. The substrates can be
living organisms, or inanimate objects.
[0004] 2. Background Art
[0005] The earliest cataplasms were probably called poultices. A
poultice is a medicated mass (often clay, herbal component, and a
carrier such as water) spread on cloth and applied to the skin,
often for sores or other lesions. Later, various gels and viscosity
modifiers were added to cataplasms. Typically and preferably, a
cataplasm has direct contact with skin or the substrate to be
treated. As prepared commercially in a multiple cataplasm package,
a cataplasm often has a backing on one side, which provides
physical strength and a durable exposed surface during use on the
substrate, and a release layer on the other side, which is removed
before application to the substrate.
[0006] Transdermal delivery systems have been developed for various
pharmaceutical applications. They generally transfer a medicine
through the skin rather than to the skin. The active ingredients in
commercial transdermal delivery systems are usually limited to a
single chemical compound or a family of compounds. These systems
are typically more expensive than oral medication and comprise an
impermeable backing layer, a reservoir, a metering layer, and an
adhesive layer. The system is usually protected by a release
layer.
SUMMARY OF INVENTION
[0007] Hydrogels containing various substances or compounds such as
personal care compounds, pharmaceuticals, etc., are described. The
hydrogel contains significant amounts of water therein and is a
blend of a crosslinked polymer and a high molecular weight
essentially linear polymer. Noncovalent crosslinks, such as ionic
crosslinks in the presence of cure rate modifiers, permit the
hydrogel to be formed into a suitable end product before being
cured.
DETAILED DESCRIPTION OF THE INVENTION
[0008] From a compositional aspect, the hydrogel is a blend of at
least two polymers one of which is a crosslinked polymer derived
from one or more olefinically unsaturated polymerizable carboxylic
monomers and optionally one or more comonomers. The other polymer
is a high molecular weight substantially linear polymer derived
from one or more olefinically unsaturated polymerizable carboxylic
acid monomers. The hydrogel also contains a neutralizing agent;
desirably a noncovalent crosslinking agent; and a cure rate
modifier; and is generally located on a backing with a release
compound or liner covering the hydrogel. The hydrogel is typically
applied to a substrate such as human skin and contains therein a
substance such as a personal care compound, a pharmaceutical, an
active ingredient, or the like; The hydrogel is typically located
on a substrate.
[0009] In some embodiments, the hydrogel removes a compound from
the substrate by binding an absorptive substance to the substrate.
That is, the hydrogel and its active ingredient act as absorbents
of an impurity or irritants. An example of this would be the
removal of undesired oil or other components from the skin. The
hydrogel offers a new way to deliver or remove some compounds
(those not before applied with cataplasms) to/from various
substrates with improved performance attributes.
[0010] The hydrogel comprises any natural or synthetic polymer that
is highly swollen by water. In the cataplasm application the
hydrogel and its backing desirably remain a coherent mass, i.e. it
doesn't fracture during application, removal, or use and can be
discarded as a single unit of waste. It is generally desired that
none of the hydrogel, other than the delivered substance, remain on
the substrate after use. The backing can be any material convenient
to the particular application. It is generally only present for
ease of handling and integrity purposes, although it can facilitate
application and solvent retention. Wovens, nonwovens, and films
such as plastic can be used as backings. Natural or synthetic
products can also be used. The release liner can be any suitable
material known to the art or to the literature and generally is a
plastic which optionally contains a release agent thereon such as a
silicone.
[0011] Desirably the hydrogel is crosslinked or otherwise linked
together as an integral material (e.g. a polymer and/or a
noncontinuous hydrogel can be connected together via
interentanglement of the chains, crystalline crosslinks, ionic
crosslinks, hydrogen bonds, etc). For the purposes of this
specification, integral will mean some connection, either temporary
or permanent, that allows the hydrogel to function as a solid at
typical storage and use temperatures of the particular substance.
Function will imply that the hydrogel does not unduly flow,
fracture, or fragment during use, but understandably does not imply
tremendous physical integrity, which is not generally required. The
preferred polymers forming the hydrogel will be gel-like particles
that have the capacity to increase their volume by swelling in
water by a factor from about 10 to about 1000 or 10,000.
Preferably, they swell from about 10, 20, 30, or 40 times to about
500 or 1000 times their original volume.
[0012] Polyurethanes may also be used in the hydrogel. These may be
thermoplastic or elastomeric polyurethanes. They may be
hydrophobic, hydrophilic or amphiphilic depending on the active
ingredients or other additives to be incorporated into the
hydrogel. Polyurethanes and their precursors are well known to the
art. It is preferred that the polyurethanes only be an additive to
the hydrogel and that they be appropriately functionalized or
processed to be uniformly dispersed in the hydrogel.
[0013] According to the present invention, an olefinically
unsaturated polymerizable carboxylic monomer is utilized. Such
monomers are described in detail and set forth in U.S. Pat. No.
5,468,797, as well as prior U.S. Pat. Nos. 5,373,044, and 5,288,814
thereof, which are hereby fully incorporated by reference with
regard to all aspects thereof. As set forth in the '797 patent, the
monomer contains at least one activated C.dbd.C group as well as a
carboxyl or anhyride group. Such polymers can be homopolymers of an
unsaturated, polymerizable carboxylic monomer containing from 3 to
34 carbon atoms, and preferably from 3 to 6 carbon atoms such as an
acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic
anhydride, and the like. The carboxyl containing polymers, before
crosslinking, have molecular weights greater than about 500 to as
high as several million, usually greater than about 10,000 to
900,000 or more.
[0014] Copolymers of the polymerizable carboxylic monomers can be
made utilizing monomers having a total of from 3 to about 40 and
desirably from 3 to about 34 carbon atoms such as acrylate esters,
acrylamides, olefins, vinyl esters, vinyl ethers, vinyl amides,
amines or styrenics. The amount of repeat units derived from such
comonomers is generally from about 0.001 to about 30 percent and
desirably from about 0.01 to about 20 percent by weight of the
copolymer.
[0015] Typical materials are those described in U.S. Pat. No.
2,798,053. Copolymers, for example, include copolymers of acrylic
acid with small amounts of polyalkenyl polyether cross-linkers that
are gel-like polymers, which, especially in the form of their
salts, absorb large quantities of water or solvents with subsequent
substantial increase in volume. Other useful carboxyl containing
polymers are described in U.S. Pat. No. 3,940,351, directed to
polymers of unsaturated carboxylic acid and at least one alkyl
acrylic or methacrylic ester where the alkyl group contains 10 to
30 carbon atoms, and U.S. Pat. No. 5,034,486; 5,034,487; and
5,034,488; which are directed to maleic anhydride copolymers with
vinyl ethers. Other types of such copolymers are described in U.S.
Pat. No. 4,062,817 wherein the polymers described in U.S. Pat. No.
3,940,351 contain additionally another alkyl acrylic or methacrylic
ester and the alkyl groups contain 1 to 8 carbon atoms. Carboxylic
polymers and copolymers such as those of acrylic acid and
methacrylic acid also may be crosslinked with polyfunctional
materials as divinyl benzene, unsaturated diesters and the like, as
is disclosed in U.S. Pat. Nos. 2,340,110; 2,340,111; and 2,533,635.
The disclosures of all of these U.S. patents are hereby
incorporated herein by reference.
[0016] The carboxylic monomers are the olefinically-unsaturated
carboxylic acids containing at least one activated carbon-to-carbon
olefinic double bond, and at least one carboxyl group; that is, an
acid or function readily converted to an acid containing an
olefinic double bond which readily functions in polymerization
because of its presence in the monomer molecule, either in the
alpha or beta position with respect to a carboxyl group,
--C.dbd.C--COOH; or as part of a terminal methylene grouping,
CH2.dbd.C<. Olefinically-unsaturated acids of this class include
such materials as the acrylic acids typified by acrylic acid
itself, methacrylic acid, alpha-cyano acrylic acid, beta
methylacrylic acid (crotonic acid), alpha-phenyl acrylic acid,
beta-acryloxy propionic acid, cinnamic acid, p-chloro cinnamic
acid, 5-phenyl-2,4-pentadienoic acid, itaconic acid, citraconic
acid, mesaconic acid, glutaconic acid, aconitic acid, maleic acid,
fumaric acid, and tricarboxy ethylene. As used herein, the term
"carboxylic acid" includes the polycarboxylic acids and those acid
anhydrides, such as maleic anhydride, wherein the anhydride group
is formed by the elimination of one molecule of water from two
carboxyl groups located on the same carboxylic acid molecule.
Maleic anhydride and other acid anhydrides useful herein have the
general structure 1
[0017] wherein R and R' are selected from the group consisting of
hydrogen, halogen and cyanogen (--C.ident.N) groups and alkyl,
aryl, alkaryl, aralkyl, and cycloalkyl groups such as methyl,
ethyl, propyl, octyl, decyl, phenyl, tolyi, xylyl, benzyl,
cyclohexyl, and the like.
[0018] The preferred carboxylic monomers are the monoolefinic
acrylic acids having the general structure 2
[0019] wherein R.sup.2 is a substituent of hydrogen, halogen, and
the cyanogen (--C.ident.N) groups, monovalent alkyl radicals,
monovalent aryl radicals, monovalent aralkyl radicals, monovalent
alkaryl radicals, and monovalent cycloaliphatic radicals. Of this
class, acrylic and methacrylic acid are most preferred. Other
useful carboxylic monomers are maleic acid and its anhydride.
[0020] The above noted polymers can be crosslinked with any
polyene, e.g. decadiene or trivinyl cyclohexane; acrylamides, such
as methylene bis acrylamide; polyfunctional acrylates, such as
trimethylol propane triacrylate; or polyfunctional vinylidene
monomer containing at least 2 terminal CH.sub.2< groups,
including for example, butadiene, isoprene, divnyl benzene, divinyl
naphthalene, allyl acrylates and the like. Particularly useful
crosslinking monomers for use in preparing the copolymers are
polyalkenyl polyethers having more than one alkenyl ether grouping
per molecule. The most useful possess alkenyl groups in which an
olefinic double bond is present attached to a terminal methylene
grouping, CH.sub.2.dbd.C<. They are made by the etherification
of a polyhydric alcohol containing at least 2 carbon atoms and at
least 2 hydroxyl groups. It is preferred to utilize polyethers
containing an average of two or more alkenyl ether groupings per
molecule. Other crosslinking monomers include for example, diallyl
esters, dimethallyl ethers, allyl or methallyl acrylates and
acrylamides, tetraallyl tin, tetravinyl silane, polyalkenyl
methanes, diacrylates, and dimethacryiates, divinyl compounds such
as divinyl benzene, polyallyl phosphate, diallyloxy compounds and
phosphite esters and the like. Also, polyallyl esters of
poly(methacrylic acid) can be utilized. Typical agents are allyl
pentaerythritol, allyl sucrose, trimethylolpropane triacrylate,
1,6-hexanediol diacrylate, trimethylolpropane diallyl ether,
pentaerythritol triacrylate. tetramethylene dimethacrylate,
ethylene diacrylate, ethylene dimethacrylate, triethylene glycol
dimethacrylate, and the like. When the crosslinking agent is
present, the polymeric mixtures usually contain up to about 5% or
more by weight of crosslinking monomer based on the total of
carboxylic acid monomer, plus other monomers, if present, and more
preferably from about 0.01 to 3.0 weight percent by weight.
[0021] Preferred crosslinking agents include allyl pentaerythritol,
trimethylolpropane diallylether, and allyl sucrose.
[0022] In addition to the above described polymers and copolymers,
an interpolymer of the same, can also be utilized. Such
interpolymers are made by preparation of the above polymers or
copolymers in the presence of a steric stabilizer surfactant. The
steric stabilizer surfactant has at least one hydrophilic moiety
and at least one hydrophobic moiety in a linear block or a random
comb configuration, or mixtures thereof. The interpolymer can be
mixed with a wetting additive such as a low surface tension
surfactant, a glycol, a polyhydric alcohol, or mixtures
thereof.
[0023] A detailed description of the preparation of the
interpolymers, the steric stabilizer surfactants, the wetting
additive, and the like is described in detail in U.S. Pat. No.
5,468,797 and accordingly is fully incorporated by reference. When
the steric stabilizer is a linear block copolymer steric
stabilizer, it is defined by the following formula:
C.sub.w--(B--A--B.sub.y--)--.sub.xD.sub.z,
[0024] where
[0025] A is a hydrophilic moiety, having a solubility in water at
25.degree. C. of 1% or greater, a molecular weight of from about
200 to about 50,000, and selected to be covalently bonded to the B
blocks;
[0026] B is a hydrophobic moiety, having a molecular weight of from
about 300 to about 60,000, a solubility of less than 1% in water at
25.degree. C., capable of being covalently bonded to the A
blocks;
[0027] C and D are terminating groups which can be A or B; can be
the same or different groups, and will depend upon the
manufacturing process, since they are present to control the
polymer length, to add other functionality;
[0028] w is 0 or 1;
[0029] x is an integer of 1 or more;
[0030] y is 0 or 1; and
[0031] z is 0 or 1.
[0032] Examples of hydrophilic groups are polyethylene oxide,
poly(1,3-dioxolane), copolymers of polyethylene oxide or
poly(1,3-dioxolane), poly(2-methyl-2-oxazoline polyglycidyl
trimethyl ammonium chloride, polymethylene oxide, and the like,
with polyethylene oxide being preferred. Examples of hydrophobic
groups are polyesters, such as those derived from 2-hydroxybutyric
acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid,
2-hydroxycaproic acid, 10-hydroxydecanoic acid,
12-hydroxydodecanoic acid, 16-hydroxyhexadecanoic acid,
2-hydroxyisobutyric acid, 2-(4-hydroxyphenoxy) propionic acid,
4-hydroxyphenylpyruvic acid, 12-hydroxystearic acid,
2-hydroxyvaleric acid, polylactones such as caprolactone or
butyrolactone, polylactams such as those derived from caprolactam,
polyurethanes, or polyisobutylene, where the hydrophobe should
provide a steric barrier of greater than 50 Angstroms, preferably
greater than 75 Angstroms, with greater than 100 Angstroms being
also preferred, and the like, with polyhydroxy fatty acids, such as
poly(12-hydroxystearic acid) being preferred. The steric barrier is
the length of the hydrophobe in its fully extended condition. Such
steric stabilizers are commercially available under the brand name
Hypermer.RTM. from Imperial Chemicals Industries, Inc.
[0033] Steric stabilizer molecules comprise both hydrophilic and
hydrophobic units. Hydrophobic polymer units or hydrophobic blocks
may be prepared by a number of well known methods. These methods
include condensation reactions of hydroxy acids, condensation of
polyols (preferably diols) with polycarboxylic acids (preferably
diacids). Other useful methods include polymerization of lactones
and lactams, and the reactions of polyols with polyisocyanates.
Polyisobutylenes can be prepared by acidic condensation of
isobutene. Hydrophobic blocks or polymer units can be reacted with
hydrophilic units by such reactions as are known to those skilled
in the art. These reactions include condensation reactions and
coupling reactions, for example. Subsequent to the steric
stabilizer preparation, the stabilizers may be further reacted with
modifying agents to enhance their utility. U.S. Pat. No. 4,203,877
to Alan S. Baker teaches making such steric stabilizers, and the
entire disclosure thereof is incorporated herein by reference.
[0034] When the steric stabilizer is a random copolymeric comb
steric stabilizer, it is defined by the following formula:
[0035] where
[0036] R.sub.1 and R.sub.2 are terminating groups and may be the
same or different and will be different from Z and Q.
[0037] Z is a hydrophobic moiety having a solubility of less than
1% in water at 25.degree. C.,
[0038] Q is a hydrophilic moiety, having a solubility of more than
1% in water at 25.degree. C.,
[0039] m and n are integers of 1 or more, and are selected such
that the molecular weight of the polymer is from about 100 to about
250,000.
[0040] Examples of the hydrophobic monomer unit or moiety are
dimethyl siloxane, diphenyl siloxane, methylphenyl siloxane, alkyl
acrylate, alkyl methacrylate, and the like, with dimethyl siloxane
being preferred.
[0041] Examples of the hydrophilic monomer unit or moiety are
methyl-3-polyethoxypropyl siloxane-.OMEGA.-phosphate or sulfate,
and the alkali metal or ammonium salts derived therefrom: units
derived from polyethoxy (meth)acrylate containing from 1 to 40
moles of ethylene oxide; acrylic acid; acrylamide; methacrylic
acid, maleic anhydride; dimethyl amino ethyl (meth)acrylate; or its
reaction product with methyl chloride or dimethyl sulfate; dimethyl
amino propyl(meth)acrylamide and its reaction product with methyl
chloride or dimethyl sulfate, and the like, with
methyl-3-polyethoxypropyl siloxane-.OMEGA.-phosphate being
preferred.
[0042] Examples of terminating agents are monohalo silanes,
mercaptans, haloalkanes, alkyl aromatics, alcohols, and the like,
which will produce terminating groups such as trialkyl silyl:
alkyl, aryl alkyl, alcoholate, and the like, with preferred
terminating groups being trimethyl silyl.
[0043] The wetting additive is preferably a low surface tension
surfactant (or wetting agent) and can be a fluorine containing,
silicone containing or hydrocarbon surfactant, as long as it has an
ability to reduce the surface tension of water (which is 72 dynes
per centimeter at 25.degree. C.), preferably to less than 40
dynes/cm at 25.degree. C., with less than 30 dynes/cm being further
preferred. By the term hydrocarbon surfactant we mean any
surfactant which contains carbon, hydrogen, and oxygen and does not
contain fluorine or silicon atoms. The amount of low surface
tension surfactant will usually be less than 10% by weight based
upon the weight of the acrylic acid interpolymer (10 phr), although
0.001 phr to 5.0 phr is preferred. The exact amount will depend
upon the surfactant which is selected and its ability to reduce the
surface tension of water. Those surfactants which can be used at
the least dosage, such as a fluorine containing surfactant are
preferred. Further, it was unexpectedly discovered that some of the
surfactants are quite effective at very low dosages, such that the
surfactant has no or little effect on the properties of the
interpolymer in its use as a thickener, emulsifier, or thickening
aid. Although not fully understood, it is believed that some of the
surfactants when used in greater doses will result in increased
wetting times because the additional surfactant will provide an
additional coating on the polymer particles and slow the wetting
process.
[0044] Table I shows a list of low surface tension surfactants
which can be used in accordance with the present invention. The
surface tension values represent the ability of a 1% by weight
dosage of these surfactant to reduce the surface tension of water
at 25.degree. C. As can be appreciated, this list is considered
representative and other low surface tension surfactants could be
employed.
[0045] The surfactant employed can be anionic, cationic, or
nonionic with nonionic surfactants being preferred. When the
surfactants is added prepolymerization, the cationic and anionic
nature of the surfactant can play a part in or influence the
polymerization, while the nonionic surfactants remain relatively
inactive.
1 SURFACE TENSION SURFAC- (Dynes/cm) TANT(*) 1% Dose @ (Trade Name)
SUPPLIER COMPOSITION 25.degree. C. Fluowet Hoechst Fluoroaliphatic
ethoxylate 18.09 OTN (F/N) Celanese Forafac Atochem Polyfluoralkyl
betaine 18.44 1157N (F/N) Fluorad 3M Fluorinated alkyl 19.95
FC-170C (F/N) polyoxyethylene ethanols Florafac Atochem Anionic
fluorinated 20.84 1033 (F/N) surfactant Fluorad 3M Fluorinated
alkyl alkoxlate 20.84 FC-171 (F/N) Silwet L-77 Union
Polyalkylenoxide-modified 21.35 (S/N) Carbide heptamethyl
trisiloxane Flourad 3M Ammonium perfluoroalkyl 21.17 FC-120 (F/A)
sullonate Zonyl FSP DuPont Ammoniated phosphate 23.04 (F/A)
fluorochemical Zonyl FSN DuPont Hydroxy terminated 22.18 (F/N)
fluorochemical Silwet L-7600 Union Polyalkyleneoxide-modified 24.88
(S/N) Carbide polydimethyl siloxane Silwet L-7602 Union
Polyalkyleneoxide-modified 25.15 (S/N) Carbide polydimethyl
siloxane Silwet L-7604 Union Polyalkyleneoxide-modified 24.30 (S/N)
Carbide polydimethyl siloxane Dow Corning Dow Silicone glycol
copolymer 28.93 193 (S/N) Corning Neodol 25-7 Shell
C.sub.12-C.sub.15 linear primary 28.84 (H/N) alcohol ethoxylate
Glucopon Henkel C.sub.8-C.sub.10 alkyl poly- 29.11 225CS (H/N)
saccharide ether Pecosil Phoenix Dimethicone copolyol 27.65 DIP 100
(H/N) Chemical phosphate Pecosil Phoenix Dimethicone copolyol 30.35
PS-100 (H/N) Chemical phosphate Pecosil Phoenix Dimethicone
copolyol 30.54 PS-100-OP Chemical phosphate (H/N) Adogen 432
Ashland Trialkyl (C.sub.8-C.sub.10) 30.21 (H/C) Chemical ammonium
chloride Triton X-100 Union Polyoxyethylene ether 31.32 (H/N)
Carbide Alpha-Step Stepan .alpha. sulfomethyl ester 33.54 MC-48
(H/A) Company (*)F = Fluorine containing; S = Silicone Containing;
H = Hydrocarbon; A = Anionic; C = Cationic; N = Nonionic
[0046] The wetting additive can be added to the monomers in
polymerizing the polycarboxylic acid interpolymer or after
polymerization, or in the case of the low surface tension
surfactants, it also can be added to the water into which the
interpolymer is to be dispersed. It is preferred that the wetting
additive be admixed after or post-polymerization. It is theorized
that, when the surfactant is added during polymerization, it
remains with the polymer as an admixture, but a portion of the
surfactant is trapped in the interstices of the interpolymer, so
the same amount added pre-polymerization will not be as effective
as that amount added post-polymerization of the interpolymer.
Further, there is nothing critical in the method of addition. For
example, the surfactant can be added as a liquid to the
interpolymer while it is still in the polymerization solvent and
before drying or it can be sprayed on the dry polymer powder which
can then be subject to further drying.
[0047] The glycol and polyhydric alcohol are most preferredly
admixed after polymerization, and provide little or no benefit when
added to water into which the interpolymer is to be dispersed. It
is reasoned that the presence of the alcohol functionality will
interfere or interact with the acid functionality of the acid
polymer being formed. When added to the polymer
post-polymerization, it is possible to control the conditions, such
as excessive heat when drying, which could lead to interference or
interaction.
[0048] The polyhydric alcohols are organic hygroscopic
compositions, usually alcohols, which facilitate the wetting of the
interpolymer particles in water. For the purpose of this
disclosure, we mean the term "polyhydric alcohols" is to include
all hygroscopic alcohol compositions including glycols, such as
polyethylene glycol. The use of either a low surface tension
surfactant or a polyhydric alcohol benefits the wetting of the
polymer particles by aiding the wetting of the water by lowering
the surface tension of the water and allowing it to penetrate the
polymer particle or by drawing the particle to the water (or the
water to the particle) via the hygroscopic mechanisms. As will be
seen either benefits the wetting of the polymer without detriment
to the use of the polymer as, e.g., a thickener.
[0049] The preferred polyhydric alcohols are glycerine (or
glycerol). The preferred glycol is low molecular weight
polyethylene glycol. Other polyhydric alcohols (or polyols) or
glycols can be employed.
[0050] Examples of preferred linear block copolymeric steric
stabilizers and random copolymeric comb steric stabilizers include
fluorinated alkyl polyoxyethylene ethanols such as Fluorad FC-170C,
fluorinated alkyl alkoxylate such as Fluorad FC-171, and ammonium
perfluoralkyl sulfonate such as Fluorad FC-120, all made by 3M.
[0051] The relative proportions of the steric stabilizer based upon
the total weight of the olefinically unsaturated polymerizable
carboxylic monomers and optional comonomers is generally from about
0.001 to about 20 percent, desirably from about 0.01 to about 10
percent, and preferably to about 0.2 to about 6.0 percent by
weight.
[0052] The above crosslinked polymers, copolymers and interpolymers
made from one or more olefinically unsaturated polymerizable
carboxylic monomers are commercially available as Carbopol.RTM. 980
NF from BFGoodrich. Generally, other such crosslinked polymers,
copolymers, etc., are available as various CARBOPOL.RTM. polymers
from BFGoodrich, as various PEMULEN.RTM. polymers from BFGoodrich,
as various NOVEON.RTM. polymers from BFGoodrich, as various HIVIS
WAKO.RTM. polymers from Wako Junyaku Kogyo, and as various
SYNTHALEN.RTM. polymers from 3 V Sigma.
[0053] It has been found that hydrogels capable of absorbing large
amounts of water having unexpectedly low initial viscosities, and
yet good tack and adhesion, as well as strong cohesion forces,
which result in a rigid gel, are formed by blending the above
crosslinked polymers, derived from olefinically unsaturated
polymerizable carboxylic or anhydride monomers, with a high
molecular weight substantially linear polymer derived from an
olefinically unsaturated polymerizable carboxylic acid monomer.
Such olefinic unsaturated acid monomers generally contain a
carboxyl group and a total of from 3 to about 20 or 30 carbon atoms
and preferably from 3 to about 7 carbon atoms. Specific examples
include acrylic acid, methacrylic acid, maleic acid, itaconic acid,
crotonic acid, citraconic acid, aconitic acid, fumaric acid, and
the like. Preferred acids include acrylic and methacrylic, with
acrylic acid being highly preferred. By the term "substantially
linear" polymers which are derived from the olefinically
unsaturated polymerizable carboxylic acids, it is meant that the
polymer generally has 5 or less, desirably 3 or 2 or less, and
preferably 1 or less side chains for every 100 repeat units of the
polymer. Such polymers have a weight average molecular weight OT
generally from about 50,000 to about 2,000,000, desirably from
about 200,000 to 1,000,000, and preferably from about 400,000 to
about 600,000. Examples of suitable long chain high molecular
weight polycarboxylic acids include CARBOPOL.RTM. 907,
GOODRITE.RTM. K-702 and K-709 from BFGoodrich.
[0054] The polymeric blend is generally formed by dispersing a
crosslinked polymer derived from olefinically unsaturated
polymerizable carboxylic monomers into water. The amount of the
polymer is generally from about 5 parts to about 30 parts by weight
and desirably from about 10 parts to about 15 parts by weight for
every 100 parts by weight of water. Similarly, the high molecular
weight, linear polymer is dissolved in water in an amount of from
about 5 to about 40 parts by weight and desirably from about 10 to
about 20 parts by weight for every 100 parts by weight of water.
The high molecular weight, linear polymer and the crosslinked
polymer are then blended together. Optionally, additional water or
other solvent such as alcohols, polyols, or polyalkoxides can be
added. Such additional water or solvent is dependent upon the
desired final qualities and physical constraints of individual
formulations.
[0055] It has been found that the degree of neutralization of the
hydrogel polymer blend has a direct impact on the ability of the
blend to be non-covalently crosslinked; e.g., ionicly crosslinked
or crosslinked by hydrogen bonding. Accordingly, the crosslinked
polymer or copolymer and high molecular weight linear polyacid is
partially neutralized from an initial pH of from about 2.5 to about
3.5 to a pH of from about 3.5 to about 14, or about 10, or about
6.0, and desirably from about 4.2 to about 5.2. Neutralization can
be carried out with any convenient neutralizing agent or compound
such as ammonium hydroxide, sodium hydroxide, other alkali
hydroxides, borates, phosphates, pyrophosphates or polyphosphates;
AMP-95 (2-Amino-2-Methyl-1-Propanol) a product of Angus Chemical,
cocamine, oleamine, diisopropanolamine, diisopropylamine,
dodecylamine, Peg-15 cocoamine, morpholine,
tetrakis(hydroxypropyl)ethyle- nediamine, triamylamine,
triethanolamine, triethylamine, or tromethamine (2-Amino
2-Hydroxymethyl-1,3-propanedioi). Preferred neutralizing agents
include NaOH, tetrakis(hydroxypropyl)ethylenediamine,
triethanolamine.
[0056] A viable non-covalent crosslinking system for the blend of a
crosslinked polymer derived from olefinically unsaturated
polymerizable carboxylic monomers and the high molecular weight
linear polymer includes ionic crosslinkers such as polyvalent metal
ions such as aluminum and zinc. The plus-3 oxidation state for
aluminum is preferred and the plus-2 oxidation state for zinc is
preferred. Desired compounds generally include halogen salts such
as AlCl.sub.3, ZnCl.sub.2, MgCl.sub.2, CaCl.sub.2, BCl.sub.3,
BF.sub.3, and the like. Sufficient amounts of the polyvalent metals
are required to achieve crosslinking. Below a critical amount, the
resulting hydrogel is too fluid. Above a critical amount, the metal
ions are absorbed into the carboxyl forming an overly rigid,
non-adhesive hydroael The use of chemical crosslinks or the use of
polymers already including chemical crosslinks in the form of
microparticles or microgels can minimize the amount of ionic
crosslinkers that are needed. This is desirable as the ionic
crosslinkers may undesirably interact with many of the substances
such as an active ingredient, decreasing the efficiency of delivery
and sometimes preventing delivery. Reduction of the amount of ionic
crosslinkers typically reduces any deleterious effect of the ionic
crosslinkers. The amount of such ionic crosslinkers is dependent on
the desired physical characteristics of the hydrogel and
interactions with its various substances.
[0057] Other non-covalent crosslinking compounds include various
crystallite crosslinked polymers such as polyvinyl alcohol, and the
like.
[0058] Still other types of non-covalent crosslinking compounds
include various hydrogen bonded compounds such as various complexes
of polyacrylic acid with at least the following compounds:
polyfunctional Lewis bases such as polyvinyl alcohol, polyvinyl
pyrrollidone, polyethylene imine, polyethylene oxide, polypropylene
oxide, glycosylated proteins, macromolecular polyols,
polyacrylamide, and polysaccharides.
[0059] In order to prevent overly quick curing of the polymer blend
and the formation of a rubber-like hydrogel, various cure rate
modifiers are utilized such as monoalcohols, diols, and/or polyols
such as glycerol. Examples of monoalcohols include methanol,
ethanol, propanol, isopropanol, butanol, isobutanol, and t-butanol
and monoethers of ethylene glycol, propylene glycol, polyethylene
glycol, polypropylene glycol, and mixed ethylene oxide/propylene
oxide glycols. Examples of diols include ethylene glycol, propylene
glycol, butylene glycol, neopentyl glycol, ethoxy diglycol and
hexylene glycol. Other suitable curing rate modifier agents include
sugar solutions (xylitol, sorbitol), PEG (POE, polyoxyethylene,
polyethylene glycol), PPG (polypropylene glycol), PEG/PPG
(copolymers or blockpolymers), and the like. The amount of the
alcohol utilized is generally from about 1 to about 80, desirably
from about 10 to about 50, and preferably from about 20 to about 30
parts by weight for every part by weight of the ionic crosslinking
agent.
[0060] The utilization of a cure rate modifier is to allow the
hydrogel to be suitably shaped before cure occurs. For example, the
hydrogel can be applied as a film to a backing such as nonwoven
material, etc., as described herein above.
[0061] The hydrogel blends of the present invention are generally
only partially swollen with respect to the full amount of water
they can absorb. Such deficient amounts of water generally include
from about 2 to about 10 and desirably from about 3 to about 5
times their original linear dimension. Otherwise, too much water
results in too weak of a hydrogel, such that the adhesive force is
stronger or greater than the cohesive force of the gel.
[0062] The hydrogel of the present invention can be utilized in
various forms. One desired form is a so-called patch wherein the
hydrogel containing the curing agent and the cure rate modifier,
etc., is spread on a suitable backing. A release liner is then
applied to the top of the hydrogel. The hydrogel is then allowed to
cure. Another suitable form is a hydrogel in the form of a sheet or
layer which contains a release layer on either side thereof or on
both sides thereof. The hydrogel containing a substance therein be
it a personal care compound, a pharmaceutical compound, an active
ingredient, a biological active compound, an absorptive material,
etc., can be wrapped in a suitable container such as an impervious
plastic wrap, foil pouch, etc., and stored until needed. Then it
can be applied to a desired substrate as noted herein below.
[0063] The applied substance can be any material known, purported,
or thought to have beneficial effect on the chosen substrate such
as the substances listed in the preceding paragraph. While
water-soluble active ingredients are most easily incorporated, the
use of nonwater carriers, emulsifiers, dispersed organic
(hydrocarbon) phases, etc. can allow the delivery of nonpolar
compounds (e.g. hydrocarbon materials such as aliphatic and
aromatic compounds).
[0064] One class of substances are the therapeutic aids which
include, but are not limited to, moisturizers (or things that help
the substrate (skin) retain water); oils (or things that help the
skin retain oil); antimicrobial agents; antibacterial agents;
fungicide; anti-inflammatory/analgesic agents (e.g. things that
reduce irritation); softening agents; toughening agents; agents
that enhance elasticity of the substrate (e.g. skin); agents that
enhance abrasion resistance of the substrate (e.g. skin, fabric,
apparel), that provide some slipperiness to skin or fabric, or
prevent pilling of fabric by other mechanisms; agents that
otherwise change the texture of the substrate; agents that promote
growth or cell reproduction; agents that retard growth or cell
reproduction; stimulants for the cells or nerves; antihistamines;
local anesthetics; etc.
[0065] The substance may remove unwanted components from the
substrate such as removing oil, greases, irritants, nail polish,
etc.; removing blemishes, defects, unusual texture, scars, growths
(e.g. warts); removing hair; etc.
[0066] The hydrogel may apply an active ingredient with one or more
of the following advantageous properties: sustained delivery,
consistency in dosage, enhanced delivery, dosage control,
efficiency, and bioavailability for: wound healing, burn healing,
scar reducing, etc.; skin or keratin color changes (lightening,
darkening, coloring), applying decorative images, highlighting;
enhancing penetration of another active ingredient or medicine
through the skin or other substrate; altering the fragrance or
aroma of the substrate; reducing or enhancing fat, e.g. cellulite
reduction; applying a hormone, steroid, or pheromone-, etc.
[0067] The active ingredient of the hydrogel may be of any polarity
from low to high including fragrances, coloring, pigments,
ointments, etc. Where desired, water solubility may be enhanced by
the addition of other carriers, additives, etc. In many
embodiments, a mixture of two or more active ingredients which act
independently or in conjunction with each other will be used. The
active ingredient can be any of the following: a moisturizer; an
anti-aging agent (removing aging effect or repairing aging
effects); an astringent; an acid (e.g. glycolic, citric, and
vitamins); a skin stimulator (e.g. menthol, camphor, and cayenne
pepper extract); a firming agent; a slimming agent; a radical
scavenger; solubilizers; an antihistamine (e.g. diphenhydramine or
chlorpheniramine maleate); methyl salicylate; glycol salicylate; an
aromatherapeutic; a humectant; an emollient; a phytochemical
(natural extract such as herbal and botanical e/.g. bamboo, tea
tree oil, etc.); an antioxidant; a skin whitening agent (e.g.
hydroquinone, peroxide, and kojic acid); a self tanning agent or
agent for adding skin colorant (e.g. dihydroxy acetone); a skin
protecting agent (e.g. moisturizers, waxes, sunblocks (organic or
inorganic)); a spot remover (substrate may be people, clothing,
animals, plants, hard surface, or fabric); keratin; retinol;
vitamins; vitamin complexes; precursors of active ingredients such
as precursors of retinol; salicylic acid and derivatives of
salicylic acid; peptide; oligomeric and polymeric peptide; an
enzyme; a coenzyme; proteins and their precursors; amino acid (e.g.
dimers, cyclic and aliphatic amino acid); glycosamineoglycans;
saccharides; derivatives of saccharides; polysaccharides,
oligomeric saccharides; cyclic oligomeric saccharides;
carbohydrates; fatty acid triglycerides, essential fatty acids;
lipids; lecithin; phospholipids; conditioning agents; milk
derivatives, carotenes; cyclodextrins; tocopherols; phytosterols;
cationic agents; oil (natural such as animal and vegetable,
synthetic including primrose oil, jojoba oil, mineral oil, castor
oil, palm oil, coconut oil, corn oil, silicones, and derivatized
forms thereof); gelatins, natural starch, modified starches,
cellulosics and chemically modified cellulosics, sodium alginate,
acacia, corn starch, casein, natural gums, and/or modified natural
gums; waxes (natural such as plant and synthetic); quaternized
compounds; silicone and/or silicone derivatives; protein
hydrolyzates or derivatized proteins; chitin; denatured chitin;
chitosan; marine derived compounds or marine origin materials (e.g.
anything from the sea including things such as kelp, coral,
seaweed, marine moisturizing factor, algae, sea plants,
phytoplankton, kelp, and their extracts); hydrolyzed animal and/or
vegetable protein; astringent (e.g. zinc oxide, tannic acid, alum,
aluminum sulfate, vitamin, di-.alpha.-tocopherol); a wetting agent;
a water repellent; an antimicrobial; a deodorant; a fungicide; a
fruit acid; nut extracts/oils; a fragrance; flower acids;
ceramides; a flavinoid; biologically derived materials
(biotechnology); sodium hyaluronate; hyaluronic acid; etc.
[0068] It is also anticipated that the active ingredients can be
added to the hydrogel after being blended with, contained within,
and/or bound to another medium (liquid/solid or other). Examples
include encapsulated ingredients, nanospheres, actives in zeolites,
actives in oil, actives in liposomes, actives in glycospheres,
etc.
[0069] The above substance added to the hydrogel be it a personal
care compound, a pharmaceutical, an active ingredient, or the like,
is generally added over a broad range of amounts depending upon the
particular type of substance and the desired end result. The
substance can be added to the blend of polymers prior to
neutralization, or after neutralization but prior to ionic
crosslinking or hydrogen bonding crosslinking. Alternatively, the
substance can be added after the addition of the crosslinking
agents but prior to the same curing. The crosslinking time will
vary depending upon the amount of the various cure rate modifiers
utilized and also upon the type of polymers utilized. As a rough
rule of thumb, the desired cure time is approximately several hours
to several days.
[0070] Substrates for application of the hydrogel compound include
the skin, hair, and fingernails. The hair and fingernails can be
grouped in the class of keratinous substrates. While personal use
by humans is a preferred embodiment, uses on animals, plants, etc
is not excluded. Hair substrates can be temporarily or permanently
changed in color (including decorative images), texture (including
adding or removing curls in hair), and for prevention of microbial,
bacterial, and fungal activity on the substrate surface.
[0071] Substrates also include apparel, fabrics, hard surfaces, and
vehicles including automobiles. For these substrates the
improvements include but are not limited to sustained delivery
(e.g. volatile components trapped in the hydrogel do not evaporate
as quickly as when applied directly to the substrate and are
available to the substrate over the entire treatment period),
consistency in dosage, enhanced delivery, controlled dosage amount,
efficiency, etc. A preferred embodiment for these substrates is
those applications or active ingredients, which are adversely
affected by atmospheric oxygen. The exposure of the substrate
surface to atmospheric oxygen is restricted during the time the
cataplasm is in place and this allows more effective use of oxygen
sensitive compounds. Depending on the particular substrate and
cataplasms for these substrates, the stability at various storage
and use temperatures can vary widely.
[0072] The physical integrity of the hydrogel is desirably such
that fracture and/or fragmentation of the hydrogel does not occur
during storage and use. If the hydrogel is adhesive or has an
adhesive layer attached thereto to better secure its relative
location on the substrate during delivery or removal of the active
ingredient(s), then the hydrogel desirably has a cohesive strength
in excess of the adhesion value to the substrate.
[0073] The hydrogel, in addition to the substance, can contain
various conventional additives in any desired amount. Such
additives include clay, herb and herbal extracts, chemical
compounds and materials which absorb undesirable components from
skin or other substrates, adsorption enhancers, desorption
enhancers, absorption enhancers, humectants (e.g. glycerin,
propylene glycol, sorbitol), water miscible or immiscible organic
solvents (or other active carriers or active reservoirs), adhesive
and/or a polymer that imparts adhesivity to the hydrogel (e.g.
polyvinyl alcohol)--may be important to adhere cataplasm to backing
or adhere cataplasm to substrate--, gel support media or polymer to
interconnect hydrogel particles, modulus modifier, tensile strength
modifier, elongation to break modifier--these conform the hydrogel
and cataplasm physical properties to the application
requirements--, gelation rate regulator (e.g. EDTA, citric acid,
lactic acid, tartaric acid, and polyacrylic acid, also called
chelating agents), additives to reduce negative interaction by
hydrogel to substrate (irritation, inflammation or corrosion)--may
be as simple as pH adjuster, oil, wax, etc--, etc.
[0074] A preferred form of application of the hydrogel is in the
form of a patch wherein the hydrogel is located on a backing and
the hydrogel optionally has a release liner thereon. The backing
can be made of any suitable natural or synthetic fiber or fabric,
and can be woven or nonwoven. Examples of fibers or natural fabrics
include cotton, wool and the like. Examples of synthetic fibers or
fabrics include polyester such as polyethyleneterephthalate,
polyethylene, polypropylene, nylon, acetate and the like. The
backing can also be in the form of an impermeable or permeable foam
made from natural materials or from synthetic materials such as
polyolefin, polyester, polyurethane, and the like. Thickness of the
backing can vary widely as from 1, 3 or 5 to about 10, 20, 30, 40,
and even 50 mils. The release liner can be a plastic such as a
polyolefin, for example polyethylene or polypropylene, or it can be
polyvinylchloride, nylon, and the like. Optionally, it can contain
a release liner thereon such as a thin layer of silicone. The patch
can be applied to a substrate such as human skin simply by removing
the release liner and applying the hydrogel, containing the backing
thereon, thereto.
[0075] The present invention will be better understood by reference
to the following examples which serve to illustrate, but not to
limit the present invention.
2 Formulations Oil/Water Hydrogel Formulation % Phase Ingredient
(w/w) Function A Carbopol .RTM. 980 NF (11.25% aq) 40.00
crosslinked polymer Carbopol .RTM. 907 (20.00% aq) 17.50 linear
polymer DI Water 10.36 dilluent/solvent Methyl Salicylate 11.00
substance: active ingredient B Menthol 7.70 substance: active
ingredient Camphor 3.30 substance: active ingredient C NaOH(18% aq)
4.00 Neutralizer D AlCl.sub.3.6H.sub.2O 0.14 ionic crosslinker
Glycerin 5.00 cure rate modifier DI Water 1.00 dilluent/solvent
[0076] Procedure:
[0077] 1. Phase A was combined in a Hobart mixer and blended at low
speed until smooth (.about.10 min).
[0078] 2. Phase B was combined and mixed in a sealed vessel until
the menthol and camphor were dissolved.
[0079] 3. Phase B was added to Phase A and blended at low speed in
the Hobart mixer until homogeneous (.about.15 min).
[0080] 4. Phase C is added to Phases A+B and mixed at medium speed
in the Hobart mixer until a smooth emulsion/suspension was observed
(.about.15 min).
[0081] 5. Phase D was combined with mixing until all of the
AlCl.sub.3o6H.sub.2O was solubilized.
[0082] 6. Phase D was added to Phases A+B+C and mixed at medium
speed in the Hobart mixer until homogeneous (.about.15 min).
[0083] 7. A portion of the finished formulation was drawn onto a
fabric backing and topped with a release liner to form a
"patch".
[0084] These formualtions relate to a range of properties:
3 Formula- Carbopol .RTM. Carbopol .RTM. DI tion 980 NF 907 Water
Glycerin AlCl3 1 3.00 2.00 87.42 5.00 0.08 2 3.00 3.00 80.84 10.00
0.16 3 3.00 4.00 81.88 7.50 0.12 4 4.00 2.00 80.88 10.00 0.12 5
4.00 3.00 81.92 7.50 0.08 6 4.00 4.00 82.84 5.00 0.16 7 5.00 2.00
81.84 7.50 0.16 8 5.00 3.00 82.88 5.00 0.12 NaOH Formulation (18%)
Peak Force of Adhesion Energy of Adhesion 1 2.50 8.70 14.29 2 3.00
9.80 11.90 3 3.50 13.00 67.69 4 3.00 9.80 19.72 5 3.50 11.40 59.18
6 4.00 16.40 17.44 7 3.50 9.10 7.68 8 4.00 12.00 17.91
[0085] As apparent from the above tables, the formulations of the
present invention utilizing the blend of at least one crosslinked
polymer derived from at least one olefinically unsaturated
carboxylic monomer and at least one high molecular weight linear
polymer derived from at least one olefinically unsaturated
carboxylic acid monomer form suitable hydrogels exhibiting a
controllable range of physical attributes as noted by the peak
force of adhesion as well as the energy of adhesion values.
[0086] While in accordance with the Patent Statutes the best mode
and preferred embodiment have been set forth, the scope of the
invention is not limited thereto but rather by the scope of the
claims.
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