U.S. patent application number 12/766505 was filed with the patent office on 2010-10-28 for water-soluble pressure sensitive adhesives.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to Steven S. Kantner.
Application Number | 20100272784 12/766505 |
Document ID | / |
Family ID | 42992354 |
Filed Date | 2010-10-28 |
United States Patent
Application |
20100272784 |
Kind Code |
A1 |
Kantner; Steven S. |
October 28, 2010 |
WATER-SOLUBLE PRESSURE SENSITIVE ADHESIVES
Abstract
A water-soluble pressure sensitive adhesive comprises a
homogeneous blend comprising (a) a polymer selected from the group
consisting of N-vinyl caprolactam homopolymers, N-vinyl pyrrolidone
copolymers, and mixtures thereof and (b) a non-volatile plasticizer
comprising a monohydric or polyhydric alcohol having
hydrophilic-lipophilic balance of about 2 to about 10. The N-vinyl
pyrrolidone copolymers comprise about 60% or less by weight N-vinyl
pyrrolidone.
Inventors: |
Kantner; Steven S.; (St.
Paul, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
42992354 |
Appl. No.: |
12/766505 |
Filed: |
April 23, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61173307 |
Apr 28, 2009 |
|
|
|
Current U.S.
Class: |
424/448 ;
524/310; 524/317; 524/376; 524/379; 524/386; 602/54;
604/385.05 |
Current CPC
Class: |
C09J 139/06 20130101;
A61F 2013/00646 20130101; C09J 133/14 20130101; A61F 2013/00868
20130101; A61F 13/023 20130101; C08F 220/34 20130101; A61F
2013/00642 20130101; A61L 15/585 20130101; A61L 15/585 20130101;
A61F 2013/00659 20130101; C08L 39/06 20130101; C09J 177/00
20130101 |
Class at
Publication: |
424/448 ;
524/379; 524/386; 524/376; 524/310; 524/317; 602/54;
604/385.05 |
International
Class: |
A61F 13/00 20060101
A61F013/00; C09J 139/04 20060101 C09J139/04; C09J 139/06 20060101
C09J139/06; A61F 13/02 20060101 A61F013/02; A61F 13/15 20060101
A61F013/15 |
Claims
1. A pressure sensitive adhesive comprising a homogeneous blend
comprising: (a) a polymer selected from the group consisting of
N-vinyl caprolactam homopolymers, N-vinyl pyrrolidone copolymers,
and mixtures thereof, the N-vinylpyrrolidone copolymers comprising
about 60% or less by weight N-vinyl pyrrolidone; and (b) a
non-volatile plasticizer comprising a monohydric or polyhydric
alcohol having hydrophilic-lipophilic balance of about 2 to about
10; wherein the pressure sensitive adhesive is water-soluble.
2. The pressure sensitive adhesive of claim 1 wherein the polymer
comprises from about 35% to about 75% by weight of the pressure
sensitive adhesive.
3. The pressure sensitive adhesive of claim 1 wherein the
plasticizer comprises from about 10% to about 80% by weight of the
pressure sensitive adhesive.
4. The pressure sensitive adhesive of claim 1 wherein the polymer
is an N-vinyl caprolactam homopolymer
5. The pressure sensitive adhesive of claim 1 wherein the polymer
is an N-vinyl pyrrolidone copolymer.
6. The pressure sensitive adhesive of claim 5 wherein the polymer
is selected from the group consisting of N-vinyl
caprolactam/N-vinyl pyrrolidone copolymers and vinyl
acetate/N-vinyl pyrrolidone copolymers, the vinyl acetate/N-vinyl
pyrrolidone copolymers comprising from about 20% to about 60% by
weight N-vinyl pyrrolidone.
7. The pressure sensitive adhesive of claim 6 wherein the polymer
is a copolymer of N-vinyl pyrrolidone and vinyl acetate comprising
from about 30% to about 50% by weight N-vinyl pyrrolidone.
8. The pressure sensitive adhesive of claim 1 wherein the
N-vinylpyrrolidone copolymers comprise about 30% or less by weight
N-vinyl pyrrolidone.
9. The pressure sensitive adhesive of claim 1 wherein the polymer
has an overall number average molecular weight from about 10,000
daltons to about 100,000 daltons.
10. The pressure sensitive adhesive of claim 1 wherein the polymer
further comprises a comonomer in an amount up to about 10% by
weight, the comonomer having no carboxylic acid functionality or
tetraalkyl ammonium functionality.
11. The pressure sensitive adhesive of claim 1 wherein the
plasticizer has a vapor pressure below about 0.1 mm Hg at
20.degree. C.
12. The pressure sensitive adhesive of claim 1 wherein the
plasticizer has a water solubility of less than about 5 g/100
g.
13. The pressure sensitive adhesive of claim 1 wherein the
plasticizer is selected from the group consisting of polyether
glycols having a carbon to oxygen mole ratio greater than about
2.5:1, polyester polyols, C5-C10 alkyl diols, C4-C10 carboxylate
monoesters of propylene glycol, C4-C10 carboxylate mono- and
diesters of glycerin, C4-C10 alkyl monoethers of propylene glycol,
C4-C10 alkyl mono- and diethers of glycerin, C4-C10 alkyl esters of
lactic acid, C2-C4 triesters of citric acid, and mixtures
thereof.
14. The pressure sensitive adhesive of claim 13 wherein the
plasticizer is a polyether polyol.
15. The pressure sensitive adhesive of claim 14 wherein the
plasticizer is a polypropylene glycol.
16. The pressure sensitive adhesive of claim 1 wherein the pressure
sensitive adhesive increases in weight less than about 15% after
two days at 75% relative humidity and 40.degree. C.
17. The pressure sensitive adhesive of claim 16 wherein the
pressure sensitive adhesive increases in weight less than about 10%
after two days at 75% relative humidity and 40.degree. C.
18. A device for skin contacting applications comprising a flexible
backing and the pressure sensitive adhesive of claim 1 on at least
a portion of one side of the flexible backing.
19. The device of claim 18 wherein the backing has a moisture vapor
transmission rate of at least about 500 g/m.sup.2/24 hours.
20. The device of claim 18 wherein the backing comprises a
plurality of opening or holes.
21. The device of claim 18 wherein the backing is
water-soluble.
22. The device of claim 18 further comprising an absorbent pad.
23. The device of claim 22 wherein the absorbent pad is
water-soluble.
24. The device of claim 18 further comprising a support layer
releasably adhered to the backing, the pressure sensitive adhesive,
or both.
25. The device of claim 18 wherein the device is a tape, bandage,
wound dressing, or patch.
26. The device of claim 18 wherein the device is a patch designed
to deliver one or more active agents to a body surface, the patch
comprising one or more active ingredients in association with the
backing, the pressure sensitive adhesive, or both.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 61/173,307, filed Apr. 28, 2010, the
disclosure of which is incorporated by reference herein in its
entirety.
FIELD
[0002] This invention relates to water-soluble pressure sensitive
adhesives that are useful, for example in medical tape, bandage,
wound dressing, and patch constructions.
BACKGROUND
[0003] Removing a bandage adhered to the skin can be very painful.
In addition, people with fragile or delicate skin or with chronic
wounds that require repeated applications of dressings are often
concerned about skin stripping and other damage.
[0004] The conflicting requirements of high adhesion to skin so
that a bandage stays secure and gentle removal so that skin is not
stripped, hair is not pulled, and residue is not left behind has
been approached in various ways. These approaches include, for
example, increasing the breathability of the adhesive to maintain
good skin integrity for lower removal trauma (see, for example,
U.S. Pat. No. 5,614,310), "stretch release" technology (see, for
example, U.S. Pat. No. 7,078,582), reinforcing the skin with a film
forming polymer prior to applying the bandage (see, for example,
U.S. Pat. No. 4,324,595), and migrating a debonding agent like body
lotion or hexamethyl disiloxane through a porous backing to the
skin/adhesive interface (see, for example, U.S. Pat. No.
6,136,866). Many of these approaches compromise in-use adhesion,
however, and others require an extra step.
[0005] Because of theses drawbacks, there has been interest in
using water-soluble pressure sensitive adhesives (PSAs) to make
hurt-free bandages that readily dissolve off in water.
Unfortunately, most water-soluble PSAs pick up moisture, which
reduces their cohesive strength. Water-soluble patches comprising a
water-soluble adhesive and water-soluble backing for delivery of an
active ingredient are described in U.S. Patent Application Pub. No.
2002/0187181. These patches, for example, need to be manufactured
under low humidity conditions and packaged individually in foil
packaging to prevent excess uptake of moisture in humid
environments.
SUMMARY
[0006] In view of the foregoing, we recognize that there is a need
in the art for adhesives for use in bandages that eliminate
concerns around the removal of the bandages (for example, pain,
skin stripping, and residue) by providing removal by dissolution.
We further recognize that it would be advantageous for such
adhesives to be less hygroscopic than currently available
water-soluble adhesives so that the bandages can be compatible with
conventional packaging and be more suitable for long term wear.
[0007] Briefly, in one aspect, the present invention provides a
water-soluble pressure sensitive adhesive (PSA). The PSA comprises
a homogeneous blend comprising (a) a polymer selected from the
group consisting of N-vinyl caprolactam homopolymers, N-vinyl
pyrrolidone copolymers, and mixtures thereof and (b) a non-volatile
plasticizer comprising a monohydric or polyhydric alcohol having
hydrophilic-lipophilic balance of about 2 to about 10. The N-vinyl
pyrrolidone copolymers comprise about 60% or less by weight N-vinyl
pyrrolidone.
[0008] As used herein, "water-soluble" means that a material so
described can be dissolved in a 10-fold excess of water within
about 2 minutes with only gentle agitation required; "pressure
sensitive adhesive" or "PSA" means a normally tacky adhesive that
adheres with gentle pressure (for example, finger pressure);
"homogenous" means that the PSA has a substantially homogeneous
appearance to the naked eye (that is, the liquid phase is
compatible with the polymer and essentially no phase separation can
be observed with the naked eye; and "non-volatile" means having
vapor pressures below about 1.0 mm Hg at 20.degree. C. (preferably,
below about 0.5 mm Hg at 20.degree. C.; more preferably, below
about 0.3 mm Hg at 20.degree. C.; most preferably, below about 0.1
mm Hg at 20.degree. C.).
[0009] The PSAs of the invention are readily water-soluble and they
surprisingly also have low hygroscopicity. For example, the PSAs of
the invention increase in weight less than about 15% after two days
at 75% relative humidity and 40.degree. C. (preferably, less than
about 10% after two days at 75% relative humidity and 40.degree.
C.) without compromising cohesive strength.
[0010] In another aspect, the present invention provides devices
for skin contacting applications (for example, tapes, bandages,
wound dressings, or patches) comprising a flexible backing and a
water-soluble PSA of the invention. In some embodiments, the
devices of the invention further comprise a water-soluble backing
and optionally a water-soluble pad. Thus, the entire device can be
easily dissolved off the skin with water.
DETAILED DESCRIPTION
[0011] The present invention comprises a homogenous blend of a
polymer with a plasticizer which when applied to a backing provides
a PSA film thereon which is water-soluble.
Polymer
[0012] The PSAs of the invention comprise a polymer selected from
the group consisting of N-vinyl caprolactam (NVC) homopolymers,
N-vinyl pyrrolidone (NVP) copolymers, and mixtures thereof. The NVP
copolymers comprise about 60% or less by weight NVP (preferably,
about 50% or less; more preferably, about 40% or less; most
preferably, about 30% or less).
[0013] Examples of useful NVP copolymers include NVC/NVP copolymers
and vinyl acetate (VOAc)/NVP copolymers. The VOAc/NVP copolymers
typically contain about 20% by weight or more NVP. NVC homopolymers
and such NVP copolymers provide water solubility and adhesive
properties without having excessive hygroscopicity.
[0014] A preferred polymer is a copolymer of N-vinyl pyrrolidone
and vinyl acetate comprising from about 30% to about 50% by weight
N-vinyl pyrrolidone.
[0015] Optionally, low levels of comonomers may be present in
amounts of up to about 10% by weight provided that they do not
contain carboxylic acid functionality or tetraalkyl ammonium
functionality.
[0016] Polymers suitable for use in the PSAs of the invention may
be an uncrosslinked polymer or mixture of polymers with an overall
number average molecular weight between about 10,000 and about
100,000 daltons. Such polymers provide a good balance of cohesive
strength and water solubility.
[0017] Useful commercially available copolymers and homopolymers
are marketed by ISP Corp. (Wayne, N.J., United States) under the
trade names Gaffix.TM. VC-713, Advantage.TM. HC-37, Advantage.TM.
LC-A, Aquaflex.TM. SF-40, and PVP/VA E-335, I-335, E-535, I-535,
E-635, W-635, and by BASF of Germany under the trade names
Luviskol.TM. VA 37 E, 37 I, 55 I, 64 W, 64 P, and Luviskol.TM.
Plus. The NVC/NVP copolymers in these commercial products contain
small amounts of tertiary amine comonomers as disclosed in U.S.
Pat. Nos. 5,637,296 and 4,521,404.
[0018] Typically the total polymer content will range from about
35% to about 75% by weight of the PSA formulation. Adhesive
compositions containing this level of polymeric matrix have a
desirable balance of tack, softness, adhesiveness, and cohesive
strength.
Plasticizers
[0019] The PSAs of the invention also comprise a non-volatile
plasticizer. Suitable plasticizers include, but are not limited to,
monohydric alcohols and polyhydric alcohols with a hydrophilicity
expressed by having a calculated hydrophilic-lipophilic balance
(HLB) in the range of about 2 to about 10 (preferably in the range
of about 3 to about 9.5; most preferably in the range of about 4 to
about 9). Such materials are weak hydrophiles and in many cases
have low water solubility. The HLB system was originally developed
as a means of classifying surface active agents, particularly
non-ionic surfactants. It has broader application in characterizing
compounds that have hydrophilic and hydrophobic parts that are too
small to spontaneously aggregate into micelles, such as
hydrotropes. As used herein, the utility of a given plasticizer is
based on the HLB calculated for it using the group contribution
method developed by Davies.
[0020] The non-volatile plasticizers have vapor pressures below
about 1.0 mm Hg at 20.degree. C. (preferably, below about 0.5 mm Hg
at 20.degree. C.; more preferably, below about 0.3 mm Hg at
20.degree. C.; most preferably, below about 0.1 mm Hg at 20.degree.
C.).
[0021] In some embodiments, the water solubility of the plasticizer
may be less than about 10 g/100 g (preferably, less than about 5
g/100 g). Plasticizers that are completely miscible with water in
all proportions are also useful.
[0022] Classes of materials useful as plasticizers in the PSA
include polyether polyols where the carbon to oxygen mole ratio is
greater than about 2.5 to 1, polyester polyols, C5-C10 alkyl diols,
C4-C10 carboxylate monoesters of propylene glycol, C4 to C10
carboxylate mono- and diesters of glycerin, C4-C10 alkyl monoethers
of propylene glycol, C4 to C10 alkyl mono- and diethers of
glycerin, C4-C10 alkyl esters of lactic acid, C2-C4 triesters of
citric acid, and the like, and mixtures thereof.
[0023] Examples of useful polyether polyols include the
poly(alkylene oxide) glycols wherein the alkylene unit has 2 to 6
carbon atoms, such as poly(1,2-propylene oxide) glycol,
poly(1,3-propylene oxide) glycol, poly(tetramethylene oxide)
glycol, poly(pentamethylene oxide) glycol, poly(hexamethylene
oxide) glycol and poly(1,2-butylene oxide) glycol; random or block
copolymers of ethylene oxide and 1,2-propylene oxide (used in
proportions such that the carbon to oxygen mole ratio in the glycol
exceeds about 2.5:1) and poly-formals prepared by reacting
formaldehyde with glycols such as pentamethylene glycol, or
mixtures of glycols, such as a mixture of tetramethylene and
pentamethylene glycols. Mono or dialkyl ethers and esters of such
polyols are also useful as are branched polyols.
[0024] Both liquid and solid non-volatile plasticizers can be used
in the PSAs of the present invention.
[0025] Typically, the plasticizer will comprise from about 10% to
about 75% by weight of the PSA.
Optional Components
[0026] The water-soluble PSAs of the invention can optionally
comprise additives including one or more active agents as detailed
below, or low levels of compatible anionic, cationic, nonionic or
amphoteric surfactant(s). The use of such surfactants can improve
the adhesion of the PSA to oily surfaces by providing the PSA
lipophilic properties as reported, for example, in U.S. Pat. No.
6,121,508. The compatibility between the PSA and the oily surface
is improved by incorporating the surfactants into the PSA. The
surfactant also may serve to make hydrophobic active ingredients
more compatible with the PSA. Addition of tackifiers, antioxidants,
fillers, and the like to the PSA is also within the scope of the
present invention.
Devices for Skin Contacting Applications
[0027] PSAs that stick to skin are widely used in medical and
athletic skin contacting applications, offering the best, if not
the only, means for short term secural of various devices to the
human body. As detailed in Chapter 25, Hospital and First Aid
Products, by Donatas Satas and A. Maria Satas, in Handbook of
Pressure Sensitive Adhesive Technology, Second Edition, D. Satas,
Ed., 1989, PSAs are used for immobilization and dressing or
intravenous (IV) line secural, to adhere surgical drapes and
protective padding, and in devices which deliver drugs
transdermally or sense electrocardiograms. The role of these PSAs
may be solely adhesion, such as in tapes and bandages, or it may
also provide a benefit beyond adhesion, such as serving as a
reservoir for active ingredients delivered to or through the skin.
The water-soluble PSAs of the present invention are particularly
suited for use in tapes, bandages, and patches for delivery of
active ingredients.
[0028] Devices of the invention can be removed gently and
substantially without pain by dissolving (for example, soaking) the
water-soluble PSA in cold or warm water. In addition, the PSA is
not very hygroscopic making the devices suitable for long term
wear. They are also more compatible with conventional packing (that
is, they don't require individual foil packaging).
Backing
[0029] When provided as a tape, dressing, bandage, or patch, the
PSA is typically provided on a thin, flexible backing using methods
known in the art. Useful backings include nonwoven fibrous webs,
woven fibrous webs, knits, foams, films and the like. It is also
preferred, but not required, that the backing be at least partially
permeable to moisture vapor released through a patient's skin. For
example, it can be preferable that the backing has a moisture vapor
transmission rate of about 500 g/m.sup.2/24 hours. In some
instances, permeability can be obtained and/or increased by
providing a number of openings in the backing. Such openings also
provide access for aqueous solutions to dissolve the water-soluble
PSA, making the removal of, for instance, a bandage quicker and
more uniform than when aqueous penetration occurs only from the
edge. Openings are inherent in woven, knit, and non-woven backings
and may be provided in film backings by generating apertures or
perforations using mechanical or thermal means.
[0030] Other examples of useful backings include water-soluble
films and fabrics. These backings can be generated from any of the
known natural or synthetic water-soluble or water-dispersible
film-forming polymers and oligomers. In certain embodiments, the
backing is selected to be cold water-soluble. Suitable polymers and
oligomers include, but are not limited to, vegetable natural
polymers such as alginic acid and alginic acid derivatized
polymers, arabinogalactan, cellulose derivatives including but not
limited to hydroxyethyl and hydroxypropyl cellulose, starch and
starch derivatives; microorganism-derived natural polymers such as
polysaccharides, polymers derived from animals including gelatin,
collagen, mucopolysaccharides and the like; polyoxyalkylenes;
polymers and copolymers derived from ethenically unsaturated
monomers including, but not limited to, vinylic monomers, acrylates
and methacrylates, acrylamides and methacrylamides, and the like;
polyethyleneimines; and mixtures including one or more of the
foregoing. Polymers of polyvinyl alcohols, polyvinyl pyrrolidone,
proteins such as gelatin and collagen and derivatives thereof, or
carbohydrates such as arabinogalactan have been recognized as
having particular utility. Water-soluble polyvinyl alcohol films
are commercially available from Aicello Chemical Company,
Toyohashi, Japan under the tradename Solublon and from Monosol LLC
in Merrillville, Ind.
[0031] Polymers of polyvinyl alcohols may be prepared from
polyvinyl acetate and can be commercially obtained in a variety of
molecular weights and hydrolysis levels. The hydrolysis level
determines, in part, whether the polymer is cold water-soluble or
warm water-soluble, with hydrolysis greater than about 87%
resulting in more crystalline polymers, thereby requiring higher
temperatures to dissolve the polymer. The speed at which the
polymer dissolves is determined, in part, by the molecular weight
of the polymer and the presence of additional additives such as
plasticizers or crosslinkers. Certain plasticized polyvinyl alcohol
resins are thermoplastic and may be melt extruded or cast into
films.
[0032] Plasticizers can be used to reduce the brittleness of the
water-soluble backing, thereby making it tougher, more conformable
and generally improving its handling properties. Using water alone
as the plasticizer yields a backing that is prone to rapid loss of
moisture and a concomitant change into a glassy or brittle material
when exposed to ambient conditions. Hence suitable plasticizers
generally include alcohols, mixtures of alcohols, and mixtures of
water and alcohols. Suitable plasticizers for use in the present
invention include, but are not limited to, polyhydric alcohols such
as glycerin, polyglycerol, alkyl polyglycosides, diethylene glycol,
triethylene glycol, polyethylene glycol, random copolymers of
ethylene oxide and propylene oxide, ethylene oxide/propylene oxide
block copolymers such as those available from BASF under the
Pluronic tradename, propylene glycol, sorbitol, sorbitol esters,
butanediol, and their alkoxylated derivatives; monohydric alcohols
such as 3-methoxy-3-methyl-1-butanol, alkyl ether ethoxylates,
alkyl ester ethoxylates, aryl ether ethoxylates, aryl ester
ethoxylates, aralkyl ether ethoxylates or aralkyl ester
ethoxylates; urea, pyrrolidone carboxylic acids, pyrrolidone
carboxylate salts, triethanol amine, ethanol acetamide, water,
certain active agents such as vitamin E (.alpha.-tocopherol) and
many common emollients; or any mixture including one or more of the
foregoing. Non-polar active agents may be suspended or emulsified
in the backing by including a nonionic surfactant having a
hydrophilic-lipophilic balance ("HLB") value of at least about 8 as
part or all of the plasticizer. Nonionic surfactants having an HLB
value of at least about 12 have been shown to have particular
general utility. The HLB value indicates the extent to which a
given surfactant will behave as an oil-soluble versus a
water-soluble type of emulsifier as described in "The Chemistry and
Manufacture of Cosmetics," Volume I, Third Edition, Mitchell L.
Schlossman, Editor, Allured Publishing Corp., Carol Stream, Ill.,
2000. Representative non-ionic surfactants include, without
limitation, C8 to C22 alkyl ether ethoxylates, C8 to C22 alkyl
ester ethoxylates, sorbitol C8-C22 alkyl esters, sorbitol C8 to C22
alkyl ester ethoxylates, and mixtures including one or more of the
foregoing.
[0033] The amount of plasticizer present in the backing may vary
depending upon, among other things, the polymer used to form the
backing and the particular active agent or agents that also may
compose the backing. Some backings may be at least about 5%
plasticizer, by weight, although some backings may be at least
about 3% or at least about 1% plasticizer, by weight. Some backings
may be as much as 30% plasticizer, by weight, although other
backings may be as much as about 40% or as much as about 50%
plasticizer, by weight. Certain backings may include plasticizers
in the range of about 5% to about 30% by weight. Such backings
generally provide good flexibility without compromising
strength.
[0034] Water-soluble backings may be prepared by dissolving at
least one polymer and at least one plasticizer in water or other
appropriate solvent. The solution thus prepared may be cast into a
film, then dried. Water-soluble materials such as vitamin C,
hydroquinone, and salicylic acid may be dissolved directly into the
polymer solution. Water-insoluble materials such as vitamin E,
benzoyl peroxide and silicone fluid may be emulsified into the
polymer solution with an added surfactant. Alternatively, the
active agent may be applied to the backing after it is cast and
dried. In this case, the active agent is coated on the surface of
the film. If certain characteristics are desired in the final
product, additional additives may be combined with the polymer
solution in order to impart the desired characteristics to the
backing. For example, addition of low levels of silicone fluid or
silicone copolyols provides backings with a lubricious feel,
addition of a biocide prevents mold or bacterial growth on the
backing during storage, and addition of particulate materials, such
as the flattening agents used in the paint industry, provides a
non-glossy matte finish to the dried backing.
[0035] Fabrics useful as backings may be constructed by any known
technique for making woven, nonwoven, knitted, or other types of
fabrics including open and closed cell foams. Nonwoven techniques
include spun bonding, melt blowing, wet laying, hydroentangling
(such as with cold water, relatively high salt concentration, or
both), thermal bonding, or any combination of the foregoing.
Polymeric fibers useful for the manufacture of the fabric are
commercially available.
[0036] Alternatively, the films or fabrics can be melt processed
with the appropriate polymer composition using known techniques.
For example, certain plasticized polyvinyl alcohols may be melt
processed. Heat-stable active agents may be added directly to the
polymer melt. Alternatively, active agents may be coated onto or
absorbed into a water-soluble or water-dispersible film or fiber
using techniques such as those reported in U.S. Pat. No. 5,688,523.
Water-insoluble thermoplastic polymers may be included in the melt
to alter the solubility, flexibility, strength, barrier, or other
properties of the resulting carrier.
[0037] The particular form of the backing and the materials used to
prepare the backing may be selected to provide the backing with
desired characteristics. For example, a thin, transparent film
backing may be desired for applications requiring that the device
be substantially unnoticeable in use. A woven or nonwoven fabric
backing may be desired for applications in which high porosity is
required. A film or higher basis weight nonwoven may be desirable
for applications in which a more substantial device is desired.
Pad
[0038] Devices for skin contacting applications such as medical
adhesive bandages typically include a backing, an absorbent pad,
and a PSA to maintain the medical adhesive bandage in place. The
devices are typically used to cover cuts, scrapes and other skin
conditions but may also be used to cushion and protect an area. The
pad is typically absorbent, and can be manufactured from a number
of materials including but not limited to, woven or nonwoven
cotton, rayon, nonwovens, hydrocolloids, foams, and combinations
thereof.
[0039] Devices utilizing the water-soluble PSA of the current
invention may include a water-soluble non-woven pad such as the
polyvinyl alcohol non-woven available from Sheng Hung Industrial
Co., Taipei, Taiwan under the E-Tex tradename. The pad may also
contain a number of substances, including antimicrobial agents,
anesthetics, anti-itch agents, drugs for transdermal drug delivery,
chemical indicators to monitor hormones or other substances in a
patient, combinations thereof and the like.
Support Layer
[0040] A device utilizing the PSA of the present invention may
include one or more support layers releasably adhered to the
backing, the PSA, or both. The support layer is typically removed
from the backing and the PSA at about the time a treatment is
initiated. Because the backing and the adhesive of the device may
be thin, flexible and conformable, a support layer may be used to
provide structural support to the device, thereby making the device
easier to handle. A support layer also may cover the PSA until the
user is prepared to apply the device to a localized body surface
for treatment. In this way, a support layer may protect the PSA
layer from contact with surfaces other than the body surface
selected for the desired treatment. This improves handling of the
device prior to treatment and reduces mess. A second support layer
may be adhered to the backing to provide rigidity to the device
after removal of the first support layer from the adhesive. This
prevents the device from wrinkling or curling up on itself,
allowing for smooth, easy placement onto skin. Once the device has
been applied to the desired body surface, the second support layer
may be removed. One method of producing such a supported device is
reported in U.S. Pat. No. 6,169,224.
[0041] The material used for the support layer is not limited.
Suitable materials for use in the support layer include, but are
not limited to, paper, foils, and polymeric films as well as
multilayered laminates thereof. The support layer should be easily
releasable from the backing or adhesive so that the device may be
applied to the body surface receiving treatment. The material for
the support layer also may be coated with one or more materials
designed to make the support layer easily releasable.
Active Agents
[0042] The device of the present invention may be, for example, a
patch or other device designed to deliver one or more active agents
to a specific, limited body surface. For certain embodiments, a
delivered active agent may remain localized at the site of
delivery. For other embodiments, an active agent may enter the
bloodstream in order to provide a systemic treatment.
[0043] A single device of the invention may deliver any number of
active agents. More than one active agent may be mixed together so
long as each active agent is compatible with each of the other
active agents being co-delivered by the same device. Alternatively,
an active agent that reacts with a second active agent may be used,
configured within the device to be separated from the second active
agent by the backing, the adhesive, or both and allowed to react
only when the device is activated by moistening. This may be
particularly useful for in situ mixing of, for example, baking soda
and hydrogen peroxide for oral care.
[0044] One or more active agents may be delivered by the device of
the present invention by being in association with the backing, the
adhesive, or both as the device is applied to the desired body
surface. The association between an active agent and the backing or
adhesive may include, but is not limited to, as a coating,
suspension, emulsion, or solution.
[0045] The device of the present invention may be useful for any of
a large number and wide variety of treatments, some of which are
described below. It should be understood that the description of
possible treatments according to the present invention is intended
to be exemplary in nature and is not intended to unduly limit the
scope of the invention in any way. One skilled in the art will be
able to design a device as disclosed herein with properties
suitable for use in the described or any other treatments.
[0046] The device of the present invention may be used to deliver a
broad assortment of active agents to the skin. The claimed device
may be flexible and conformable, thereby providing comfortable
treatment by the device to various skin contours. For skin
treatments, it may be desirable that the device is able to adhere
to dry skin, although application to wet or pre-moistened skin is
also within the scope of the claimed invention. Adhesion of the
device to dry skin allows the device to be used for various
applications in which prolonged treatment may be desirable. For
example, the device may be used to apply an active agent for an
overnight skin treatment. In one embodiment, the device is applied
to dry skin, provides prolonged treatment, and then is washed away
easily and quickly after treatment is completed. Active agents that
may be delivered to the skin in this manner include, but are not
limited to, emollients, humectants, conditioners, moisturizers,
vitamins, herbal extracts, antioxidants, steroids or other
anti-inflammatory agents, vasodilators, exfoliants such as
alpha-hydroxy acids or beta-hydroxy acids, growth factors, enzymes,
bleaching or coloring agents, antifungal or antimicrobial agents
(including antibiotics and antiseptics such as povidone-iodine,
chlorhexidine gluconate, triclosan, p-chloro-m-xyenol, fatty acid
monoesters of glycerin and propylene glycol, benzoyl peroxide,
hydrogen peroxide, silver and silver salts including, but not
limited to, silver chloride, silver oxide and silver sulfadiazine,
phenols, miconazole, clotrimazole, ketoconazole, econazole,
undecylenic acid and the like), emulsifiers, artificial tanning
agents, tanning accelerants, skin soothing agents, skin tightening
agents, anti-wrinkle agents, skin repair agents, sebum inhibiting
agents, sebum stimulators, protease inhibitors, anti-itch
ingredients, agents for inhibiting hair growth, agents for
accelerating hair growth, skin sensates, anti-acne treatments,
depilating agents, astringents, hair removers, or corn, callus or
wart removers. Ornamental or decorative designs, colorants, tattoos
or glitters also may be applied to skin in this manner. For
example, the claimed device may be used to fashion water-removable
masks for decorating at least a portion of the skin, including the
face.
[0047] Alternatively, active agents may be delivered to the skin by
at least partially activating the surface area of the device with
water or other moisture. In this way, at least some of the
adhesive, carrier, or both are dissolved or dispersed. For some
treatments, it may be desirable to completely dissolve or disperse
the adhesive and backing, thereby providing immediate and complete
delivery the active agent. Alternatively, for some treatments it
may be desirable to dissolve or disperse only a portion of the
backing, adhesive, or both. The remaining backing or adhesive can
be rubbed into the skin along with the active agent, thereby
serving as a binder providing some degree of substantivity and
persistence for the active agent. Active agents that may be
delivered to the skin in this manner include, but are not limited
to, glitters, fragrances including aromatherapy agents, perfumes,
sunscreen agents, insect repellants, deodorants and
antiperspirants.
[0048] The device also may be used to provide treatment to
fingernails or toenails. Decorative colorings or appliques may be
delivered to nails with the claimed device in a manner similar to
that described above for the similar treatments to skin and hair.
Antifungal agents, antimicrobial agents, or other medicinal agents
also may be delivered to the nails with the device.
[0049] The devices of the invention also may have utility as a
wound dressing, first aid bandage, or athletic tape wrap. These
medical articles may include active agents such as, without
limitation, antimicrobial agents, antibiotics, external analgesics
or wound healing agents. These wound dressings may further include
water-soluble absorbents.
[0050] The device of the present invention also may be used to
deliver an active agent that provides a systemic treatment.
Delivery of systemic active agents may be through the skin or
mucosal tissue. For such a treatment, a device of the present
invention carrying the systemically active agent is applied to a
localized body surface. The application of the device may be for a
prolonged period or, alternatively, the device and active agent may
be rubbed into the skin or mucosal tissue to which the device is
applied. The active agent is absorbed into the skin or mucosal
tissue and passes into the bloodstream. The bloodstream carries the
active agent throughout the body, thereby allowing the active agent
to provide systemic treatment. Active agents that may be delivered
in this manner to provide systemic treatments include, but are not
limited to, hormones, vitamins, drugs such as those reported in
U.S. Pat. No. 6,019,997, and combinations thereof.
[0051] For all treatments, the active agents should be compatible
with the backing, adhesive and support layer. The active agents,
adhesive and backing should also preferably be selected so that
each will remain stable during storage.
EXAMPLES
[0052] Objects and advantages of this invention are further
illustrated by the following examples, but the particular materials
and amounts thereof recited in these examples, as well as other
conditions and details, should not be construed to unduly limit
this invention.
Test Methods
HLB
[0053] The hydrophile-lipophile balance (HLB) was calculated using
Davies' HLB method (Proc. 2nd Inter. Congress of Surface Activity,
1426 (1957)).
Tack
[0054] Finger tack was assessed and given a rating of 0=tack free,
1=very low tack, 2=low tack, 3=medium tack, 4=good tack,
5=excellent tack.
Water Solubility
[0055] A 3/4 by 2 inch (1.9 by 5.1 cm) strip was cut along the edge
of the coated polyester film. The strip contained both coated film
and uncoated film. Holding the uncoated end, the adhesive coated
portion was immersed and withdrawn from room temperature water in a
beaker 20 times over the course of 20 seconds. The wet film was
laid onto a glass slide, adhesive side up, and a finger was gently
run down its length. An adhesive which was not readily water
soluble produced a cohesive film or a gummy, high viscosity feel.
The absence of a cohesive film or a slimy, low viscosity feel was
deemed to be from adhesive coatings which are readily water
soluble.
% Moisture Uptake
[0056] The moisture uptake and cohesiveness of the
polymer/plasticizer blend was assessed by spreading a portion of
the solution (containing 0.3-0.6 g solids) across the bottom of a
pre-weighed (A=empty weight) 6 cm diameter circular aluminum tin.
After drying overnight in a forced air oven at 80.degree. C., the
tin was reweighed (B=tin plus dry adhesive), then placed in a
chamber at 75% RH and 40.degree. C. for 2 days. Shortly after being
removed, the tin was weighed a final time (C=tin plus hydrated
adhesive) and then tack was assessed for the hydrated adhesive. Any
cohesive failure (adhesive transfer to the finger) was noted and %
moisture uptake was calculated using the formula
100.times.(C-B)/(B-A).
Sample Preparation
[0057] Examples were prepared by combining the polymer solution as
received with a similar amount of plasticizer based on solids.
Polymers which were provided as 100% solid powders were first
dissolved in ethanol to 25% solids, and then combined 4:1 with the
plasticizer to yield the 1:1 blend based on solids. After mixing to
homogeneity, a portion was coated at 1 mil (0.001 inch, 25 micron)
dry coating thickness onto 1.2 mil (30 micron) polyester film. The
film was dried for 8 minutes at 80.degree. C. then cooled to room
temperature prior to testing. The polymers and plasticizers
utilized in the adhesive compositions are shown in Tables 1 and 2,
respectively. Test results are shown in Table 3.
TABLE-US-00001 TABLE 1 Code Polymer INCI[a] Name Manufacturer PO-1
Advantage .TM. HC-37 Vinyl caprolactam/vinylpyrrolidone/ ISP
corporation, dimethylaminoethyl methacrylate Wayne, NJ copolymer
PO-2 Advantage .TM. LC-A Vinyl caprolactam/vinylpyrrolidone/ ISP
corporation, dimethylaminoethyl methacrylate Wayne, NJ copolymer
PO-3 Advantage .TM. S Vinyl caprolactam/vinylpyrrolidone/ ISP
corporation, dimethylaminoethyl methacrylate Wayne, NJ copolymer
PO-4 Aquaflex .TM. SF-40 Vinylpyrrolidone/vinyl caprolactam/ ISP
corporation, DMAPA acrylates copolymer Wayne, NJ PO-5 PVA/VA E335
30/70 N-vinyl pyrrolidone/vinyl ISP corporation, acetate copolymer
Wayne, NJ PO-6 Gaffix .TM. VC 713 Vinyl
Caprolactam/vinylpyrrolidone/ ISP corporation, dimethylaminoethyl
methacrylate Wayne, NJ copolymer PO-7 Luviskol .RTM. Plus
Polyvinylcaprolactam BASF corporation, Ludwigshafen, Germany PO-8
PVA/VA I535 50/50 N-vinyl pyrrolidone/vinyl ISP corporation,
acetate copolymer in isopropanol Wayne, NJ PO-9 PVA/VA E535 50/50
N-vinyl pyrrolidone/vinyl ISP corporation, acetate copolymer in
ethanol Wayne, NJ PO-10 Luviskol .RTM. K30 Polyvinylpyrrolidone
BASF corporation, Ludwigshafen, Germany [a]International
Nomenclature of Cosmetic Ingredients
TABLE-US-00002 TABLE 2 Code Plasticizer INCI[a] Name Manufacturer
PL-1 Polyglycol P425 PPG-12 Dow Chemical Midland, MI PL-2 Polymeg
650 Polytetramethylene Glycol LyondellBasell Industries, the
Netherlands PL-3 Brij L-4 Laureth 4 (2-dodecoxyethanol) Croda,
Edison, NJ PL-4 Sensiva .RTM. SC50 Ethylhexylglycerin Schulke and
Myer, Norderstedt, Germany PL-5 Capmul .RTM. PG-8 Propylene glycol
monocaprylate Abitec, Janesville, WI PL-6 Symdiol .RTM. 68
1,2-hexanediol and 1,2-octanediol Symrise, Holzminden, Germany PL-7
CAPA 2054 Polycaprolactone Perstop Polyols, Toledo, OH PL-8 TBC NF
Tributyl citrate Morflex Inc. Greensboro, NC PL-9 Lexgard .RTM.
GMCY Glyceryl Caprylate Inolex, Philadelphia, PA PL-10 Glycerin
Glycerin EM Industries, Gibstown, NJ PL-11 Carbowax .RTM. PEG 400
PEG-8 Dow Chemical, Midland, MI PL-12 Century .RTM. 1107 Isostearic
acid Arizona Chemical, Jacksonville, FL [a]International
Nomenclature of Cosmetic Ingredients
TABLE-US-00003 TABLE 3 Water % Moisture Example Polymer Plasticizer
HLB Tack Soluble Uptake 1 PO-1 100 phr PL-1 8.6 4.5 Yes 12.9 2 PO-1
100 phr PL-2 4.2 3 Yes 10.2 3 PO-2 100 phr PL-1 8.6 4 Yes 14.6 4
PO-2 100 phr PL-2 4.2 4.5 Yes 13.2 5 PO-3 90 phr PL-1 8.6 3 Yes
11.0 6 PO-3 100 phr PL-1 8.6 4 Yes 10.9 7 PO-3 110 phr PL-1 8.6 4
Yes 10.2 8 PO-3 80 phr PL-1/30 phr PL-3 7.5 4.5 Yes 7.0 9 PO-3 100
phr PL-2 4.2 2.5 Yes 6.6 10 PO-4 100 phr PL-1 8.6 5 Yes 12.6 11
PO-4 100 phr PL-2 4.2 4 Yes 8.0 12 PO-5 70 phr PL-1 8.6 4.5 Yes 6.7
13 PO-5 66 phr PL-2 4.2 1 Yes 7.2 14 PO-6 100 phr PL-1 8.6 4.5 Yes
12.5 15 PO-6 100 phr PL-2 4.2 3.5 Yes 10.0 16 PO-7 100 phr PL-1 8.6
4 Yes 11.1 17 PO-7 100 phr PL-2 4.2 3 Yes 7.1 18 PO-8 80 phr PL-4
6.9 5 Yes --[a] 19 PO-8 50 phr PL-5 6.6 3.5 Yes -- 20 PO-5 60 phr
PL-5 6.6 5 Yes -- 21 PO-8 50 phr PL-6 7.5 4 Yes -- 22 PO-5 65 phr
PL-6 7.5 4 Yes -- 23 PO-9 100 phr PL-7 10.0 4.5 Yes -- 24 PO-9 66
phr PL-8 9.5 2.5 Yes -- 25 PO-9 100 phr PL-8 9.5 5 Yes -- 26 PO-5
100 phr PL-8 9.5 5 Yes -- 27 PO-9 66 phr PL-9 6.3 8.5 Yes -- Comp.
1 [b] PO-10 40 phr PL-10 11.3 1.5 Yes 20.0 - honey like Comp. 2 [c]
PO-10 50 phr PL-11 12.5 3 Yes 23.5 - honey like Comp. 3 [d] PO-8
100 phr PL-12 1.0 4.5 No 5.0 Comp. 4 [d] PO-5 100 phr PL-12 1.0 5
No 3.1 [a] -- = Not Tested [b] Reproduction of Example 1 from WO
95/05416 [c] Reproduction of Example 17 from U.S. Patent
Application Pub. No. 2002/0187181 [d] Reproduction of Example 3
from U.S. Pat. No. 4,331,576 - monomer ratio of VP/VOAc copolymer
not specified
[0058] The complete disclosures of the publications cited herein
are incorporated by reference in their entirety as if each were
individually incorporated. Various modifications and alterations to
this invention will become apparent to those skilled in the art
without departing from the scope and spirit of this invention. It
should be understood that this invention is not intended to be
unduly limited by the illustrative embodiments and examples set
forth herein and that such examples and embodiments are presented
by way of example only with the scope of the invention intended to
be limited only by the claims set forth herein as follows.
* * * * *