CA2104046C

CA2104046C - Adhesive compositions, wound dressings and methods

Info

Publication number: CA2104046C
Application number: CA002104046A
Authority: CA
Inventors: Yen-Lane Chen
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1992-10-05
Filing date: 1993-08-13
Publication date: 1998-09-15
Anticipated expiration: 2013-08-13
Also published as: US5622711A; DK0591898T3; JP3574159B2; EP0591898A1; EP0591898B1; DE69325066D1; JPH06200231A; DE69325066T2; US5633010A; CA2104046A1

Abstract

Hydrocolloid adhesive compositions are disclosed comprising a hydrophobic unsaturated aliphatic homopolymer, a compatible tackifier, and at least one hydrocolloid absorbent. The compositions have enhanced resistance to breakdown by body fluids, adjustable absorbency, improved adhesive and cohesive properties, as well as a reduced tendency to leave an adhesive residue after application. Also disclosed are wound dressings, ostomy or prosthesis adhesives, methods of using wound dressings, and methods for forming the hydrocolloid adhesive compositions.

Description

4r~SY~

21 ~ 40 4 6 AD~I~lVk; COMPOSmONS. WOUND
DRESSINGS AND METHODS

Field of the Invention This invention relates to hydrocolloid adhesive co",posilions having a variety of medical uses, particularly in the field of wound dressings, ostomy care, and prosthesis application. In addition, this invention also relates 10 to wound dressings, a method of using such wound dre~s~ine~, ostomy and/or prosthesis adhesives, and to methods of forming a hydlocolloid adhesive composition.

Backglound of the Invention Hydrocolloid adhesive compositions, as well as wound d,~ssings and ostomy products formed from these adhesive compositions, have been known for many years. Typically, these co".~itions comprise a blend of a polymer matrix, such as a rubbery elastomer like polyisobutylene, in combination with one or more water-soluble or water-swellable hy~ilocolloids, such as a dry powdered llliAlUl~ of pectin, gelatin and carbo-Aymethylcellulose.When included in a wound dressing or ostomy seal, the adhesive co",~silion is usually coated on at least one surface of a water-insoluble film. See e.~., U.S.Patents Nos. 3,980,084, 3,877,431, 3,532,679, and 3,339,546, and Eulupean Patent Application No. 0343807. A commercially available example of a composition of this type is STOMADHESIVE~*(E. R. Squibb & Sons Inc., Princeton, NJ), which is used as a skin barrier around stomas to prevent skin breakdown by the corrosive fluids dischalged by the stoma.
A major problem with many conventional hydlocolloid adhesive compositions is their susceptibility to breakdown upon ~A~iUle to wûund eAudate and body fluids (i.e. their lack of structural inleg~ily after being hydrated). When the composilions are used as skin barriers, e.g., around stomas, some absorption of fluid is desirable, but excessive swelling causes thecomposition to lose its moisture seal with the skin. Leakage occurs and the barrier must be replaced more often than is desirable.
Funhermore, when the adhesive co"-posilions are used as wound dressings, the co"lposilions tend to dissolve upon eA~ule to wound e-Audate and form a gel on the surface of the wound. When the dressing is removed, a *Trade-mark A

, 21040~6 - _ 2 residue ~c",ains on the wound lalukillg removal, typically by irrigq~iion. When this breakdown occurs the dressings may also lift off the wound and allow leakage of wound exudate onto clothing and beid~ling Accordingly, a llul..b~. of allclll~ have been made to illlpl'~VC
5 the int~lity of hydlucolloid adhesive co---po~ l;ons and the resllltir~ wound dressings and ostomy products.
U.S. Patent No. 4,496,357 d~libes the incG,~ n of fumed silica into hydroc411Oi~ co---l oS;l;Qns to control swelling.
U.S. Patent No. 4,551,490 des~;,ibes a hyd~wllo;i~ adhesive 10 co~pos;liion of a homogenous blend of minçr.ql oil, one or more polyisobutylenes alone or in co..~bin~ )n with an el~t~JIl-~ such as butyl rubber, styrene radial or block copolymers, water-soluble hyd~ocolloid gums, water-swellable cohesive ~t~ gll,enil g agents, and a t~~~ifier. Both the elastomer and water-swellable agents are said to add cohejive strength to the 15 composition, while the styrene radi l or block copolymers are said to provideeYtçn~ibility and recovery from modulqr strains qcsoc ~tPd with hydration. ~Q
~, U.S. Patents Nos. 4,204,540, 4,192,785, and 4,166,051.
U.S. Patent No. 4,952,618 ~icr,losPs a hydlùcolloid adhesive co"-position formed from a lubb~l~ elast~m~ic base having hydrocolloid 20 particles, at least some of which are polycqtinni~, dispersed therein. The co",posilion is said to eAhibit i""~rûved illteglily aU,i~ulable to the polycqtionic particles c4n~.ned in the co",~silions, particularly when c4...hin~ with anionic hydr~colloid particles, either alone, or further miAed with neutral hydrocolloid particles.
In a dirît;lent approach, U.S. Patent Nos. 4,538,603 and 4,728,442 disclose a granular wound ps~~~ing that is covered with a ~ e occlusive dressing. In general, the occlusive dressing co...pon~nt can include avariety of hydlocolloid mqt~r~qlc in co .~hin~lion with one or more ~l~s~.lle sensitive adhesive ela~.n~r~, such as polyisobulrlene, and one or more 30 thermoplastic elastomers, such as butyl rubber and styrene copoly--,~
Another ",anner of addl~ss~,g lack of structural integlily is to provide hydlocolloid adhesive co",lrûs;l;ons where one or more of the polymeric co",ponenl~ are cl-emic~lly or physically cross-linked. For eY~mplc, U.S. Patent No. 4,768,503 provides a adhesive co..lpo~ilion of one or more 35 c1~Pn~ir~lly cross-linked hydluphilic polymers in cû.,,binalion with a support matrix of a high molecular weight hydr~phobic polymer.

210~046 U.S. Patents Nos. 4,477,325 and 4,738,257 describe incGl~laling into a hydrocolloid co~ )os;l;on a ~ ule of a copolymer resin of ethylene and vinyl acetate (EVA). After mixing and moltlin~, the Co~ n is subjected to ioni7ing r~ tiQn to form cross-linked polymer netwol~ of the 5 EVA or EVA with another cross-linkable resin. The cross-linked matrix is s_id to provide controlled swelling.
In a similar vein, U.S. Patent No. 4,231,369 and Eur~pean Patent Publication No. 0272149 ~ se various h~dl~c4ll-)id mqteriqlc dispersed within a physically cross-linked gel-like phase. In genlor.ql, the 10 gel-like phase is comrri~l of el~clolllr~ ;c mqt~riql~ such as A-B-A block copolymers, as well as certain ethylene/propylene c4polymers, that are said to be physically cross-linked due to phase separation and ~eîu,malion of the mqteriql~ after melt pr~xe~c;llg.
In general, the efforts to date at providing a high integlily 15 hydrocolloid adhesive co~llpos;l;ons~ and q-csoc;~d wound dressings and ostomy barriers, have not proven to be very effective. Furt~ nore, even when such m~teriql~ demonstrate improved integlily, such an improvement has typically been at the ~-l~n~e of a number of other desirable propellies, such asabsorption, good edge adhesion, shear hol~ing power, cohesive strength, lack 20 of adhesive residue, reduced adhesive cold-flow, increased c4nformability and elasticity, and decreased skin sensitivity.

Sulllln~ of the Invention In contldsl to e~i~ting mqtPriql~, the hydrocolloid adhesive 25 c4mpositions and qc~ciqted wound dressings of the present invention exhibit c4n~i~tently high wet integlily, and thus provide d~ssings that ~ q-intAin theirform and impart a minimum amount of hydrocolloid residue, if any, to a wound and the surrounding skin. In q~ition, the adhesive CC,lllpo~;l;o~ can be formulated to provide a wide range of absoll~n~;~, in~ ing high abs~ll~ncy 30 for wound drec~ingc, and low absoll,enc~ for ostomy and prosth~.sis adhesives, and still ~ in~in optimal wet integ~ . Furthel."~,le, these adhesive co...l~;l;Qn~ and dressings provide a ,lulllh-~r of other adv~nt~es, inclu~ling good edge adhesion, high shear hol~ing power, lack of adhesive residue, reduced adhesive cold-flow, good ~1hP~inn to skin, and good cohesive strength.

2 t ~ 4 ~ 4 In partlcular the present lnventlon provides a pressure sensltlve adheslve composltlon comprlslng 20-50 welght % of a hydrophoblc unsaturated allphatlc homopolymer cross-llnked by a dose of radlatlon, 20-60 welght % of a compatlble tacklfler, and 5-60 welght % of at least one hydrocollold absorbent. Preferably, the pressure sensltlve adheslve composltlon exhlblts a wet lntegrlty of at least about elghty percent.
The present lnventlon also provldes a wound dresslng comprlslng the above-descrlbed pressure sensltlve adheslve composltlon coated on at least a portlon of one ma~or surface of a molsture vapor permeable backlng. Furthermore, the present lnventlon provldes a method of treatlng a wound comprlslng applylng to the wound the above-descrlbed pressure sensltlve adheslve composltlon.
In another aspect, the present lnventlon provldes an ostomy or prosthesls adheslve comprlslng the above-descrlbed pressure sensltlve adheslve composltlon havlng an absorbency value of less than about flfty percent at twenty-four hours. In addltlon, the ostomy or prosthesls adheslvealso preferably exhlblts a shear hold value of at least about 500 mlnutes/500 g.

In yet another aspect, the present lnventlon provldes a method of formlng a pressure sensltive adheslve composltlon comprislng compoundlng a mlxture of 20-50 welght %
of a hydrophoblc unsaturated allphatlc homopolymer, 20-60 welght % of a compatlble tacklfler, and 5-60 welght % of at ~ 60557-4502 L~

~ ~ ~ 4 0 4 4a least one hydrocolloid absorbent to form a hydrocolloid adhesive mass, and irradlatlng the hydrocolloid adheslve mass wlth a dose of radlatlon of from about 5 kGy (0.5 Mrad) to about 200 kGy (20 Mrad).
These and varlous other advantages and features of novelty whlch characterlze the lnventlon are polnted out wlth partlcularlty ln the clalms annexed hereto and formlng a part hereof. However, for a better understandlng of the lnventlon, lts advantages, and ob~ects obtained by its use, reference should be had to the accompanying drawlngs and descrlptive matter, in whlch there is lllustrated and descrlbed preferred embodlments of the lnventlon.
Brlef Descrlption of the Drawlnqs The lnventlon may be further lllustrated by reference to the accompanylng Drawlngs wherein:
FIG. 1 is a top view of a wound dressing incorporating the hydrocolloid adhesive composition of the present invention;
FIG. 2 is an exploded side view of the dresslng of FIG. l;

21~4046 FIG. 3 is a top view of an qltp~rnqtive embo~limpnt of a wound dressing inccl~c,dting the hydrocolloid adhesive cc.,.~;l;on of the present invention; and FIG. 4 is an eYpl~P~ side view of the dressing of FIG. 3.

Detailed De3cli~lion of Embodin~e lt~ of the Invention Adhesive Cc~ ilions The hydl~colloi~ adhesive col.-l os;~i~n~ of the present invention 10 comprise a blend of at least three basic ingre liPnt~, viz., the hydrophobic un~lulaled aliphatic homopolymer, a cc...palible t~~lrjfi~pr~ and at least one hydrocolloid absoll ent. This IlliAIU~ of ingredients is ~ d to a dose of ionizing radiation which çhPmirqlly cross-links the hydr~phobic u~ u..~
aliphatic homopolymer colllponenl, thereby yielding the high inteE,lily adhesive15 cCIllpGsitions of the present invention. While it is preferable to irr~iqtç the ingredients after mixing and formation into a desired shape (e.g. an adhesive sheet), it is possible to irradiate the ingredients prior to mixing and/or formation. However, in such an in~tqnc~ the complete mixing of the ingredients may be imreded, and the res-llting IllLl~lure may still need to 20 eAl)osed to a further dose of radiation to deliver the high h~leglily adhesive compositions of the present invention.
The hydrophobic w~sdlu-~led qlirhqtic homopolymer can comprise either a straight-chain unsatul~d qlirh~ir homopolymer, a brq-nrh~d unsaturated aliphatic homopolymer, or a combination thereof. In ~~dition~ the 25 hydrophobic unsaturated aliphatic homopolymer can be s~stiluled along its polymer chain with another moiety, such as c-hlorine, flllorine, or a lower alkyl, and still be considered to fall within the scope of the present invention.
However, s~sl;l~;on of other monomers within the polymer chain of the holllopolymer (e.g., random, block, and sc~lucnlial copolymers) is not 30 c~idered to be within the present invention.
As used herein, a "hydr~hobic ul~satulated ylirhqtir homopolymer" refers to organic homopolymers, typically olefin holllopolymers, that are s~t~ ;qlly water insoluble, and which exhibit a cignifirqnt degree of u~satu~ted double bonds in the homopolymer chain and/or b.~nch~d side 35 chains. While polenlially any degree of un~~ m may serve to form the adhesive co---po~;t;ons of the present invention, the hydrol)hobic l.n~ ted aliphatic homopolymer p,~relably exhibits at least about fifty mole percent 2~ Q4~46 (50%) u.lsdluld~ion, and more prefe,dbly at least about ninety mole percent (90%) unsaturation. In an e-s~ci~lly plefe.led embo~lim~nt the hydrophobic unsdluldled aliphatic homopolymer e~hibits virtually one lundred mole percent (100%) u,lsdtulalion, i.e. ~sse~lt;~lly 100% ul,sdlulaled double bonds per 5 monomer unit of the homopolymer.
Pl~;f~lably, the hydl~hobic un~lulated aliphatic homopolymer comrri~Ps an elastomeric homopolymer. Nonli...i~ g e~llp'es of suitable elastomeric homopolymers include polyisoprene, polybut~ lienP~ and colllbillations thereof, with polyisoplene being particularly l"ere.led.
10 Polyisoprene is commercially available from a number of sources, including Goodyear Chemical Co., Akron, Ohio, under the NATSYN trademark, including Natsyn resin Nos. 2200, 2205,and 2210.
The hydrophobic un~a~u-dted aliphatic homopolymer preferably comprises from about 20 percent to about 50 percent by weight of the 15 hydrocolloid adhesive colnpositions of the present invention. For wound dressing applications, it is desirable to limit the amount of hydrophobic unsaturated aliphatic homopolymer present, in order to maximize the level of hydrocolloid, thereby achieving maximum fluid absoll,ency. Thus, when forming wound dressings, from about 25 weight percent to about 35 weight 20 percent of the hydrophobic unsaturated aliphatic homopolymer is employed.
Conversely, when formulating an adhesive composition for an ostomy skin barrier and/or application of prostheses, maximum hold and minim,ll absGIbency in desired. Thus, adhesive co,llposition of the present invention that are formulated for ostomy and/or prosthecic ~tt~hmçnt ~ relably comprise 25 from about 35 weight percent to about 45 weight percent of hydrophobic unsaturated aliphatic homopolymer.
The colllpatible ~~kifiPr can comprise either an elastomeric tackifier, such as polyisobutylene, or a non elaslG-nelic tackifier, including synthetic polyterpene tnrlfifiers, such as WINGTACK brand tackifiers (e.g., 30 Wingtack 10, Wingtack 86, Wingtack 95, Wingtack Plus, and Wingtack Extra) available from Goodyear Chemic~l Co., Akron, Ohio, or a combinalion of elastomeric and non-elastomeric t ~kifip~rs. As used herein, a "colllpdtible tackifier" refers to a t~c~ifiPr that is miscible with the hydrophobic ullSalulated aliphatic homopolymer, such that when the these collll)onenls are mixed they 35 form a homogeneous phase.

*Trade-mark .

_7_ ~ 4 ~ ~ ~
Preferably, the compatible t ~L-ifier comprises low molecular weight polyisobutylene (viscosity average molecular weight of from about 20,000 to 70,000, preferably from about 40,000 to about 65,000). Suitable low molecular weight polyisobutylene t~r~ifiers are available from Exxon Chemical 5 Company under the trade-marks Vistanex LM and Vistanex L-100, respectively, and include Vistanex LM-MS (viscosity average molecular weight = 44,000), Vistanex LM-MH (viscosity average molecular weight = 53,000), and Vistanex LM-H (viscosity average molecular weight = 63,000).
The cG,-,patible tackifier p~ldbly comprises from about 20 10 weight percent to about 60 weight percent, and more preferably from about 30 weight percent to about 50 weight percent of the hydrocolloid adhesive con~sitions of the present invention.
The hydrocolloid absorbent can comprise a natural hydrocolloid, such as pectin, gelatin, or c~l,o~ymethylcellulose (CMC) (Aqualon Corp., 15 Wilmington, DE), a semi-synthetic hydrocolloid, such as cross-linked carboxymethylcellulose (X-link CMC) (e.g. Ac-Di-Sol; FMC Corp., Ph~ çlphia~ PA), a synthetic hydrocolloid, such as cross-linked polyacrylic acid (PAA) (e.g., CARBOPOL No. 974P; B.F. Goodrich, Brecksville, Ohio), or a combination thereof. Preferably, the hydrocolloid absorbent co",~onent 20 comprises from about 5 percent to about 60 percent by weight of the adhesive co"~position. When preparing an adhesive co",posilion for use in a wound dressing the hydrocolloid absorbent plefel~bly comprises from about 20 percent to about 40 percent by weight of the col"posilion, while for an ostomy or prosthesis adhesive the hydrocolloid absoll,ent p~reldbly compri~es from about 25 5 percent to about 20 percent by weight of the total adhesive composition.
The particular s~lçction of the hydrocolloid absorbents to be used in any one adhesive formulation will depend upon the intende~ use for that formulation. For example, in ~ ~ing an adhesive coln~s;lion for use with a wound dressing, maximum absoll~ncy without a loss of wet integlily is ~ 30 desired. Thus, a major portion of the hydlocolloid abso,l,ent should comprise natural hydlocolloids that are water soluble, and provide maximum abs~ll~ncy.
In addition, cross-linked semi-synthetic and synthetic hydrocolloids, which are water swellable, but water insoluble, may also be included in the compos;lion to serve as a filler, and/or to help regulate the swelling of adhesive 35 composition. Conversely, when forrnulating ostomy and/or prosthesis * T rade-mark adhesives, minimal, if any abso,l~ncy, is desired. In such an instance, the cross-linked semi-synthetic and synthetic hydr~colloids would comprise the majority, if not all, of the hydlocolloid ab~ll~nt in the adhesive cc"~,ilion.
Thus, the abs~ ncy of the hydrocolloid adhesive cc..,l~csitions 5 of the present invention can be adjuit~d based on the particular need. In general, for ostomy and/or pros~hPsi~ adhesives the co.nl)osition will plef~bly exhibit an abso,l,ency value of less than about 50 percent, and more ~l~;f~bly less than about 20 percent after twenty-four hours of eApo~Jre to aqueous fluids. On the other hand, when formulating an adhesive co..~s;lic)n for use in a wound dl~ssing the cc",position will p,~f~bly exhibit an absoll en~ of at least 50 percent, and more l,lc;feldbly an absolbency of from about 100 percent to about 500 percent after twenty-four hours of exposure to aqueous fluids.
The use of cross-linked polyacrylic acid (PAA) as a hydrocolloid absoll,ent may provide additional advantages to adhesive co"~ ions according to the present invention. Specifically, the acidic nature of PAA
lowers the overall acidity of the adhesive co",positions of the present invention from a pH of about 7 to a pH of about 5. When such a composition is employed in a wound dressing, the pH of the wound exudate will likewise be lowered. This in turn may lead to promotion of more rapid healing of the wound. See e g., K. Tsukada et al., "The pH Changes of Pless.lle Ulcers Related to the Healing Process of Wounds", 4, WOUNDS: A Compendium of Clinical Research and Practice, 16 aan.-Feb., 1992). In addition, the use of PAA has also been observed to reduce the cold-flow of the adhesive layer of wound dressings formed from the adhesive co,npositions of the present invention The adhesive co--,positions of the present invention may also optionally contain a plasticizer cor-ponent at from about 0.5 percent to about 10 percent by weight of the total adhesive con~position. Plefe~dbly, the plasticizer comprises mineral oil (Specllull, COIP., Gardena, CA).
Co---l~osilions of the present invention may also contain minor amounts of other ingredients such as antioxidants, deodorants, ~lrumes, antimicrobials and other pharmacologically active agents as is well known in theart. Furthermore, additional elast"..ers, including polypr~lene-polyethylene copolymers such as EPSYN resins available from Copolymer Rubber and 35 Chemical Corp., Baton Rouge, LA, can also be included in the col--posilions of the present invention.

*Trade-mark . 60557-4502 Co...l~s;lions of the invention are made by col"~unding the hydl~phobic un~lul~led qlirhqtic hol"opolymer and col"patible t~~l~ifip-r with aheavy duty mixer until a hGIllog~ o~ls blend is obtained. Small portions of a dry-blended premi~ of one or more hydlocolloid absoll c~ls are added and 5 milling oQntinl~P~ until a homogeneous dispersion of the abs~ll~"t~ in the adhesive phase is obt~in~d. The blended adhesive mass is then molded into sheets for further conversion into wound dressings or formed into shapes such as strips, rings, etc., by any r,ulll~l of means collllllonly used for converting plastics and elaslu",~.~ into shapes such as col"~lession or injection molding.
10 In ~ition, the blended adhesive mass can also be fed into a heated single- ordual-screw extruder and coated from a standard extrusion die to form adhesive sheets capable of being converted into appr~)~lialely shaped mqtPriql~
After formation, the adhesive comrositions of the present invention are irradiated with a dose of joni7ing radiation at from about 5 kGy (0.5 Mrad) to about 200 kGy (20 Mrad), more plcr~ldbly at a dose of from about 25 kGy (2.5 Mrad) to about 50 kGy (5 Mrad). Both E-be. m and gamma irradiation can serve as the ionizing ra~i-q-tioll source used to irradiate the adhesive colllposilions of the present invention, and thereby chPn~irqlly cross-link the hydrophobic unsalul~ted aliphatic homopolymer col.,ponenl of the 20 adhesive colposilion. It is this cross-linking of the hydrophobic unsalulaledaliphatic homopolymer co"lponent that results in the conci~t~pntly high wet inleglily displayed by the adhesive cGI~lpo~itions of the present invention. In addition, the appli~qtion of ionizing r liqtion can also be used to sterili7~ the adhesive cGIllposilions and/or wound dressings of the present invention.
The degree of cross-linking in the adhesive cGIllpos;l;on~ of the present invention can be gauged by me-q~ riT~ the percent gel content of the hydrophobic unsalul~led ,qliphqtit ho",opolymer co",ponel l after being ~ d to a pre-delel"nned dose of ioni7ing r liqti~ n. Spe~ifir-qlly~ the irr~q,tliqte~d hydrophobic unsatulated qlirhqtic homopolymer is placed in a nonpolar organic solvent, such as hPYqne, hept-qnP, or tQlu~P-nP~ that is normally capable of dissolving the homopolymer. Any cross-linked homopolymer will form a gel in the solvent, while non-cross-linked hol,lopolyma will dissolve. The ,e-~
gelled homopolymer is removed from the solvent, washed, dried, weighed, and eAJJI~sed as a percent by weight of the originql irr~iqtPd mqtPriql. This gel percent mea~ulc.,lent can then be used to gauge the amount of cross-linking, and thereby the sperifir dose of r~iqtion l~quilcd to yield the high wet integrity compositions of the present invention. Accordingly, the hydn~phobic 21040~6 un~lwdled aliphatic homopolymer cGI~lponell~ of the compositions of the present invention should plcfe~ably exhibit at least 50 percent gel contP-nt, and more preferably at least 70 percent gel cor t~nt The specific dosage of r~di~tion required to reach this level of gel content will depend upon the S particular hydlophobic ullsdlul~ted ~liph~tie hol,lopolymer chosen for ine~ ion in the co...l~s;l;ons of the present invention.

Wound Dres~in~
RefPrring now to FIGS. 1 and 2, wound dressing 10 comprises 10 an oval-shaped sheet 12 of the hydrocolloid adhesive c~...~s;~;on of the present invention. ~ ~min~t~ to the top side (side facing away from the skin when the dressing is in use) is a slightly larger oval-shaped t~n~rent film b~ ing 14.
An int4....~ layer 16 of a conventional pl~,s~ e-sensi~ e skin adhesive is used to f~ilit~te l~...;nAI;Qn. The p~ )hc.~l portion of the film b~ ing 14 and 15 adhesive layer 16 extends beyond the hydlocolloid sheet 12 to assist in ~lhP,ring the hydrocolloid sheet 12 to the skin. A conventional release liner 18 is used to protect the exposed surface of the hydç~colloi1 sheet 12 and the CAlJ03~d portion of the adhesive layer 16 prior to use. Delivery sheet 20 is ~ ed to the top side of film backing 14 to prevent wrinkling and curling of the edges of20 bacLin~ 14 and adhesive layer 16 after removal of release liner 18. Delivery sheet 20 is divided into two s~tion~ of ap~n,Ai",alcly equal size and heat-sealed to the top side of film b~c~ing 14. Both sections have a non-heat-sealed edge 22 at the center of the dressing to form h~n-ilçs which fac,ilit~tç grasping and removal of the delivery sheet. Delivery sheet 20 suppolls the cA~sed 25 periphery of b~ ing 14 and adhesive layer 16 during application of the dressing to the patient. Once the dressing is in place on the skin, delivery sheet 20 is removed.
Separation of the release liner 18 from the hydroc,olloi-l sheet 12 and adhesive layer 16 of the dressing 10 is farilit~t~P~ by two tabs 24 and 26.
30 Tab 24 comprisP,s aligned rectangularly-shaped e~tP-n~ion~ of each of the delivery sheet 20, film bac~ing 14 and adhesive la~a 16, and further comprises a stiffening ",-; "bP~r 28 adhered to the adhesive layer 16 to f~ilitat~e separation of the tab Illelllb~ from each other. The second tab 26 is aligned with tab 24 and comprises a rectangularly-shaped e~ten~ion of release liner 18. A
35 pcl~oldlion line 30 s~ es tab 24 from the main oval section of the dressing.
Tab 24 provides an area for the person applying the dressing to hold onto without touching or otherwise conl~",;l-~t;ng the adhesive 14 and hydluc~llo ~ ~ ~ 4 ~ 4 sheet 12 in the main oval portion of the dressing. After the dressing is in place on the patient, tab 24 can be se~aldted from the main oval portion of the dressing along pe,rul~lion line 30. In a particularly plc:f~led em~limpnt the dressing 10 comprises a second opposing tab (not shown) on the op~osile side S of the dressing 10 from tab 24 to further facilitate the ho'~in~ and application of the dressing 10 without con~ n of the hydlucolloid sheet 12 or wound site.
The dressing illustrated in FIGS. 1 and 2 is the presently ~lc;fell~d embodiment of the invention. The oval shape reduces dlessing size and n~inimi7Ps edge lift.
The film backing 14 is preferably a highly moisture vapor permeable film of, for example, porous polyethylene such as that disclosed in U.S. Patent No. 4,539,256 or polyurelhane such as that described in U.S.
Patent Nos. 3,645,535 or 4,598,004. Moisture vapor permeable films of this type allow the wound exudate to evaporate through the dressing and reduce the pooling of exudate under the dressing. The moisture vapor tr~nsmi~sion rate of the backing is preferably at least 500 grams/square meter/24 hours when measured at 40~C and 80 percent humidity dirfele,-tial. Film backing 14 is preferably about 0.026 mm (1 mil) thick.
In a prerelled aspect, the film b~ in~ 14 further comprises a release surface (not shown), such as a low adhesion b~ i7e~ coated on the surface of the backing 14 opposite from the hydrocolloid sheet 12 and adhesive layer 16. A commercially available example of a suitable bac~ing with a low adhesion b~ i7P coating for use with the present invention is TEGADERM ~
No. 1620 dressing (3M Company, St. Paul, MN). By using a film backing 14 containing a release surface, the wound dressing 10 can have other tapes applied over the dressing after its application to a patient. This ability to tape-over the wound dressing allows the dressing to serve as an ~tt, ~hmPnt siteor platform for other medical devices. After a period of time, these tapes can be easily removed without disturbing or otherwise having to also remove the wound dressing 10, and thereby expose the wound to further cont~min~tion.
Adhesive layer 16 is also plefelably moisture vapor permeable so as not to detract si~nificq-ltly from the moisture vapor pern,eability of the film b~c~in~ 14. Suitable medicai adhesives of this type, such as the copolymer acrylate adhesive and polyvinyl etha adhesive desc~;l)ed in U.S. Patent Nos.
4,598,004 and 3,645,535, ~ ely, are well known. The adhesive is preferably about 0.026-0.075 mm (1-3 mils) thick.
* Trade-ma rk .

- 2104~6 Delivery sheet 22 is preferably a polyester-film with a polyethylene-ethylvinyl acetate heat seal coating available cG.I~Illerc;ally from 3M, under the tr~em~rk Scotchp?~~ 1220.
Hydroco11Oi~ sheet 12 pl~f~ably has the colllposilion of FY~mpl~ 28 below and has a thi~ lrn~c ~lw~n 1.0-1.75 mm (40-70 mils).
The dressing of FIGS. 3 and 4 l~pr~nts an ~lt~rnqtive emho~lim~ont of a wound dressing 32 which incol~lat~s the hydr~colloid adhesive co."l~;L;Qn of the present invention. Dressing 32 co...p.;~s a square sheet 34 of the hydroco1loid adhesive co.--l?osiLion. A square film b~ ing 36 10 of the same ~imen~it n~ as the hydlocolloid sheet is l~;n~ted to the top surface (facing away from the skin) of the hydr~colloid sheet by adhesive layer 38.
Release liner 40 covers the exposed surface of hydlucolloid sheet 34 and extends outwardly from the hydr~colloid sheet on all sides to f~-~ilit~te grasping of the liner 40 and removal thereof prior to application of the dressing to the wound. The m~tPri~l~ which can be used to form film b~ ing 34 and adhesive layer 38 are essenl;~lly the same as those ~ cus~d above in co~n~l;on with the embodiment of FIGS. 1 and 2. The dressing of FIG. 3 is cheapel to manufacture than the dressing of FIG. 1 and is also easier to cut to the dim~n~ions of the wound.
The hydrocolloid adhesive co---~s;lion~ and dressings of the present invention exhibit increased h~teglity over other co,-----cr~ially available co---posilions. In Z~ iti~ the col--~..ilions and dr~ ings of the invention alsoexhibit adjustable absorbency, high shear hol~ing power, good ~hesion to skin, good cohesive strength, good edge adhesion, reduced adhesive cold-flow, and 25 reduced adhesive residues. The integflly, absoll,ency, 90~ peel adhesion, skin adhesion, edge lift, skin adhesive residue, and shear hold force of the co---pos;l;on~ of the present invention were d~tcl---ined accor~ing to the following test procedures.

I~ltl.~J;~y Test Preweighed (W~ test s~--ples of a dressing (each a S cm disc) are placed in an 6 oz (180 ml) bottle con~ining 30 ml of phGsphate burr~d saline solution (pH 7.2) (Sigma Ch~mi~1 Co-npany, St. Louis, Mo). The bottles are capped and Z~it~tJ~d on a shaker (Eberbach Co., Ann Arbor, MI) at low speed for a period of 24 hours. ~.n~inillg test salllpl - are removed, transferred to a metal pan, and dried in a forced-air oven ~ ir~in~ at 65~C until dry (typically overnight; i.e. 12-16 hours) and weighed (Wf).

21040~S

The Inte~,lity Value of the sample is cq~ ul-ted using the following equadon:

Wf Int~g~ Value = x 100 W;
Co",po~ of this invention exhibit an Int~lity Value of at least about 80 percent and prefe,~bly at least about 90 percent. .Spe~ific in~,ily values are ~ olt~d in Tables 2, 4, and 7 below.
Absorpdon Test Preweighed(W;) test samples (each a 5 cm disc) of a dressing are placed in an 6 oz (180 ml) bottle con~ ;n~ 30 ml of pho~ph~le bl~rr~l~d saline soludon (pH 7.2) (Sigma Chemi~-ql Co-"pal y). The bottles are capped and 15 allowed to st nd without agitadon. Sqmples are removed int~.,.,it~,nlly at fixed intervals, blotted dry, and weighed, inclu-1ine a final removal after 24 hours of CA~SS~Ile, and a final weighing (W,). The Abso,l~n.;y Value is calculated using the following formula:
W, - Wj Absoll,ellcy V lue = x 100 Wj Absorbency data is lepol~d for the dressing cG",l~s;l;ons listed 25 in Tables 2, 4 and 7 below. The absoll~ncy of the co",~s;l;~n~ of the presentinvention can be adjusted depen~ling upon the int~nd~ use (e.g., ostomy vs.
wound dressings). When a wound dressing is desired, the collll~s;l;nn~ of the present invention exhibit a twenty-four hour absoll~ncy value of at least about fifty percent (50%), and preferably from about one hund~od percent (100%) to 30 about five hundred percent (500%). When n ostomy or prosth~si~ adhesive co".po~ilion is desired, the absoll~"c~ of the co,--~3.lion should be as low as possible, preferably below about fifty percent (50%), and even more plcr~l~bly below about twenty percent (20%) after 24 hours of e.~ to aqueous fluids.

90 D~pree Peel Adhesion Peel adhesion for wound dressings formed from the adhesive co",posilions of the present invention was measured using a 90~ rotary peel ~1he~ion test on an Instron testing ",~ hinç (Model No. 1122; Instron Corp., Canton, MA). A 2.5 cm wide polyester adhesive tape (No. 1280 circuit plating tape; 3M Co,l,pany) was adhered to a rotatable metal wheel which was mounted on the lower jaw of the Instron n~.achine The sample wound dressings were die cut into 1 cm x 6 cm strips, each of which was placed on the tape covered wheel with the bacl~ing facing the o~falor. The strip was then pressed and S adhered to the polyester tape ~slldle with a 2 kg rubber roller. Prior to testing, one end of the sample strip was lifted away from the subst~e to form a tab, which was clqmped onto the upper jaw of the Instron ~ ;irhine. The strip was then slowly peeled off the polyester tape s~ale at a 90~ angle and a cr~sl.r-q-~ speed of 10 mm/min. The peel force was l~cof~ed in grams per cm 10 on a chart recorder.

Skin Adhesion Adhesion to skin was de~l",ined on human volu.-l~-~ utili7ing wound dressings formed from the adhesive colllpo~;l;onc of the present 15 invention. The lqlin~le dressings were cut into 2.5 cm x 7.6 cm strips which were applied to the backs (left side=dry; right side=wet) of a s~l~t~d numb~r of volun~l~ (i.e. an equal number of randomly st~l~t~d men and women).
During application and removal of the test strips, the vol-~n~. ~ were lying on procedure tables in prone positions with arms at their sides and heads turned toone side. For each individual, two or three strips of the test mqt~ri~q,l were applied on each of the sides of the spinal column and position~d such that the length of each strip was at a right angle to the spinal co1umn. The strips were applied without tension or pulling of the skin and there was at least 0.3 cm to 1 cm space between each strip. After all strips were in place, a 2 kg rubber roller according to the specifications found in the 7th Edition of the Ples~ule-Sensitive Tape Council l~r~chu"_ (1976), was rolled along the length of each strip, once in each direction, at a travel speed of about 7.6 cm per second, to assure even pfeSSuft; applir~qtiC!n of each strip. When rolling the strip, no manual p[eS~ e was applied to the roller.
To delcl",ine the adhesive value, each strip was removed using a conventional adhesion tester having a 11.4 kg test line and a 2.5 cm clip ~tt~~hed to the test line. The clip was ~ ~h~A to the edge of the strip which isfarthest from the spinal cord, the clip being ~tt~t~h~ by m~nllqlly lifting about 1 cm of that edge of the strip and ~ c1lin~ the clip thereto. This o. ;~ n p~ l",illed the strip to be removed towards the spine so that pull was with the direction of fine hair growth on the back. This was f~cilit~t~ by positioning the ~lhesion tester opposile the side of the individual's back from which the 210~0~6 strip was to be removed. The adhesion tester was aligned with, and was at the same height as, the strip to be removed. An example of a suitable, ~hPc;~n tester for use in this test compri~Ps a conv~ ;onql motor driven screw with moving c-rri~e and a tr-qn~duc~r. ConnPction to the trqn~ducPr was a load cell 5 accessol~. Removal force placed on the t~n~duc.~P,r resulted in a signal change which was passed ll~ough a readout meter to a strip chart l~CO

F~e Lift and Skin Adhesive Residue The amount of adhesive residue ~-..~in;ng on the skin of 10 volunleels after a defined ~mo~lnt of time was ~ sured after removal of the wound dressing sample strips in the skin a~ ps;on test ~esrrihed above. In addition, prior to the removal of the sample strips the amount to which the edgeor edges of the sample strips had lifted off the skin was qllqntifiPA. Both edgelift and adhesive residue was subjectively ~ ed by an expert fqmili-r with 15 adhesive tape pe.ro~mal ce, including edge lift and residue evqlu?tion. The evaluator judged the percent of area of the edge(s) of the sample strips that had lifted away from the skin, as well as the percent area of underlying skin covered by any adhesive residue. Both of these de~P~ ,..inA~ions were graded on a scale of 0-5 as, 0 = no lift or residue (i.e. 0%); 1 = edge lift; 2 = 1% to 20 25% residue/lift; 3 = 26% to 50% residue/lift; 4 = 51% to 75% residue/lift;
and 5 = 76% to 100% residue/lift.

Shear Hold The test is a mo lific~tion of ASTM D3654. 2.5 cm x 15.2 cm 25 test strips are adhered using light finger pl~s~urP to 7.6 x 7.6 cm panels ofbright ~nne~l~ st~inless steel which have been prewashed once with ~ C~tone alcohol and thrice with heptane. A 5.1 cm x 14 cm ~ ry panel is placed flush with the testing edge of the test panel. The test strip is covered with a 2.54 cm x 15.2 cm strip of polyethylene lC~ t~ film and rolled twice in 30 each direction with a 2 kg roller at a rate of 30.5 cm per minute. The film was removed, then the auxiliary panel is carefully removed from the end of ~e tape. The tape end (about 7.6 cm) is folded back S~ 1Y over the center of an adapter hook, with the doubled portion being at least 2.5 cm long. The ~1hering length of the test strip is cut to exactly 2.5 cm in length. The test 35 panel is placed in a stand holding both it and the adapter hook in a vertical 21~4046 position. A 500 g weight is hung on the adapter hook at a time ~e~iEnqtP~ as zero, and the time until the weight and test strip fall is measured. The shear hol-linE power is CA~1CSSed as units of time per 500 g.
The invention will be further illllctr~qted by reference to the 5 following non-limiting Examples. All parts and pc~n~ages are ~,A~less~d as parts by weight unless otherwise indicqted~

EA~ P1eS 1-13 and Colll~ali~/e Examples 14-26 Wound dfessings inco,~,d~ E the hyd~ llo:d adhesive 10 co-..pos;tions of the invention, as idPntifiPd in Tables 1, 5 and 7 below, were made according to the same general procedure.
The adhesive phase of the dressing was p,cp~d by co,..~u. ding a ...ixlu,c of a co---bination of dry solids con~i~ting of a cross-linked polyacrylic acid (PAA) (CARBAPOL 974P; B.F. Goodrich, 15 Brecksville, OH), sodium c~l,u~-yn-elhylcellulose (CMC) (Aqualon Corp., Wilmington, DE) and cross-linked sodium c~l,o,~y---clllylcellulose (X-link CMC) (Ac-Di-Sol; FMC Co~,dlion, Philq~elphia, PA) with a rubber blend of low molecular weight polyisobutylene (PIB) (LM-MH; Exxon Corp., Baton Rouge, LA) and polyisoprene (Natsyn 2210; Goodye r Chpmir-ql Co., Akron, 20 OH). In addition, in some of the s~--ples, mineral oil (Specl,u--- Corp., Gardena, CA) was also blended into the co---~unded ...i~lu,e. The co...pounding was pc,Ço,---ed on a conventionql two-roll rubber mill (Ferrel-Birminghqm Co., ~n~oniq, CT), with the dry solids being gradually inco~,dled into the rubber blend as the ,.~lu~ was passed re~eA~PAly through 25 the cold-water-chilled rollers during the milling process (typically 7-10 ~inules). I3ntld~ped air was removed from the compounded mi~lu~c by applying a vacuum of 762 mm of mercury. The blended hydl~colloid adhesive mass was then removed from the rubber mill and formed into flat adhesive sheets of about 10 cm by 10 cm and 0.64 mm thick, by co,--prc~ng the mass 30 in a Carver Ldboldlol~ Press (Fred S. Carver Inc., Menomonie, WI) ...~in~inPd at approximately 65 C and 110 Mega Pascals (l~Pa) ~cl~cen two sheets of silicone release paper (Daubert Coated Products, Dipon, IL). The release paper was lG--w~Gd from one side of the adhesive sheet, and the adhesive sheet was l~.~,in~t~ to a polyu,Gll.ane bac~ing film coated with an 35 acrylate adhesive copolymer (e.g., TEGADERM transparent dressing;

3M Co",pal~y, St. Paul, MN). The res -ltin~ l~...inqle structures were then die cut into the desired dressing shapes, and were then cross-linked and st~rili7 with gamma radiation at a dose of appro~Yimqfely 30-50 kGy (3-5 Mrads).
The dressings for Co~ e FY~qm~ es 14-26 were made using 5 the same forrnulations and procedures of PYqmp'~s 1-13, except that the final d~ssings were not irradiated by a dose of gamma r~iqtinn prior to testing.
The dressings were clear enough to read through with standard type on 8.5 by 11 inch paper (21.6 cm by 27.9 cm). The spe~-ifie cc""~os;l;on~
of each of the Example and Co...~ e FY , 'c wound dressings is shown in 10 Table 1. Absoll~ncy, wet int~~ , dr,v cohesive strength, and ninety degree peel adhesion for each of the F.l~mple and Co"lp~ e Example wound dressings is shown in Table 2.

Table 1 Specific c . - of E~cample wound d.~ 13 and C , _ ~_ E~ample wound d.~, ~ 14-26 (PIB = poly: ~b~ CMC = _ bUA,~ k~ll '- , PAA = polJ ~lic acid, X-link CMC = cross-linked C~b~JA~ lr~.ll ' , and Min. Oil = mineral oil).

LM-MH CARBOPOL X-link Min.
Ex./CEx. (PIB) Polyi~~ - CMC (PAA) CMC Oil ltl4 57.5 20 10 5 7.5 0 2/15 45 27.5 12.5 7 6 2 25 3/16 42.5 30 10 12.5 5 0 4/17 37.5 20 20 12.5 10 0 5/18 47.5 20 10 15 5 2.5 6/19 30 37.5 10 12.5 7.5 2.5 7/20 39 21.5 14.5 13 9 3 30 8/21 32.5 20 20 15 10 2.5 9/22 42.5 20 10 15 7.5 5 10/23 30 32.5 10 14.5 8.5 4.5 12/25 45 30 10 5 7.5 2.5 21040~6 Table 2 Abs~ ~, wet integriq7 dry cohesive strength, ~nd ninety-degree peel adhesion for E~arnple wound d.~i ~ e 1-13 ~nd Cc "r ~_ E~uunple wound d,., ~ 1~26.

Wet Dry C ~ 90~ Peel E~.No./Comp. Absorb. Integriq Strength E~.No (%)~ (%) (~ F-l) (~/cm) 10 1/14 22/370 98/0 Pas6/~ail 327/*
2/15 90/280 95/0 Pas6/Pas6 254/193 3/16 49/210 99/99 Pas6/Fail 158/*

4/17 240/660 98/0 Pas6/Fail 263/*

5/18 221/410 95/91 Pas6/Fail 388/*
15 6/19 16/210 100/100 Pass/Fail 064/*
7/20 274/520 94/0 Pass/Fail 250/*
8/21 372/740 80/20 Pass/Fail 300/*
9/22 282/450 93/93 Pas6/Fail 270/*
10/23 14/340 98/0 Pas6/Fail 260/*
20 11/24 42/130 96/0 Pass/Fail 122/*
12/25 13/130 100/96 Pass/Fail 229/*
13/26 63/540 93/0 Pass/Fail 250/*
~a~ ~ ~ values for C "r ~, E~ample dl~ ~ Nos. 14-26 were d~'- ~ ~' after 21 hours verw6 the 27 hours for E~tample d.. ~ ~ 1-13 *irldicates cohesive failure of the tested dres6irlg The data of Tables 1 and 2 show that the F.~ wound dressings 1-13 all exhibit a wet int~.ily value above 80%, and display varying 30 abeoll,ency values which can be adjusted based upon the in~nde~ use. Further,the Fyqmrle wound dressings all ...qin~in dry cohesive strength (i.e. Pass) as shown by the ninety-degree peel q~hP,eioll values obtained for these E~.l~le mqtP iqle A sample mqtPriql is considered to have sllffi~ient dry cohesive strength to "Pass" the ~ui~n~enls of the co-~-~e;l;ons of the present invention 35 when the tested sample fails adhesively during p_el ~hfei- n testing, i.e. the sarnple dressing pulls away from the ~ale s~S1 ~nl;ally intact. In cont~et, a sample m~te i~l nPailsH to have s~ffi- iPnt dry cohesive sl~ngll- when the -adhesive layer breaks apart and/or d~lq...;n~es from the b~~~ine during peel adhesion testing, leaving a cienifit~Ant portion of the adhesive cG.~pOs l;on adhered to the testing s~stlate.
In cG---p~-;son to FYAmrle dressings 1-13, non-irr~ iiA~d S Co--,p~t;~e FsAmr1e wound dressings 14-26 either display un~ec~ ble wet in~;lily and/or fail to ..lri~ cohesive strength when tested for peel 1~hesjon. For example, while the wound d,~ssing of Co-.-pr--A~;ve FYA -1~
No. 15 is able to ...rint~.n cohesive str~n~;lh, and thereby register a peel r~hec;on value of 193 g/cm, it has ~ro wet int~glil~ u~ o.~ the wound 10 dressings of CCS.~PA~ ;Ve Fx~ s 16, 20 and 23"~inl; in wet in~lil~, but fail cohesively when subjected to a peel ~~h~sion test. Thus, these co..-~ ~';vemqt~riAl~ would t3i~;ntegldte or fail to remain adhered when applied to an exuding wound and/or would leave excessive adhesive residue both within the wound and on the ~ullounding skin when removed.
Examples 27-29 The adhesive phase of Example dressings 27-29 was formed as follows. A combination of dry solids concictin~ of sodium carbo~yl..clhylcellulose (CMC) (Aqualon Corp.) and cross-linked sodium 20 carbo~ylll~lhylcellulose (X-link CMC)(Ac-Di-Sol; FMC Co,~ldlion) was combined with low molecular weight polyisobutylene (PIB) (LM-MH; Exxon Corp.) and polyisoprene (Natsyn 2210; Good~ear Ch~rnicql Co.) in a conventional knpA~l~r-extruder (Ross-AMK Corp.; Hauppauge, NY) to form a hydrocolloid adhesive mass. The mass, a ho...ogç~ s nli,.lule of powder and 25 rubber, was passed through a single-screw extruder (Clo",l)lon & Knowles, Co., Pdwcdtuck, CT) while ~rA~luAlly increasing the extrusion ~ I..tc along the length of the extruder from about 73 C to about 121-138-C, and ",~jnl .ining a pre.~ of about 19.3 Mega Pascals (MPa). Th~c~t~r, the heated mass was passed through an extrusion die onto a web con~;nii~e a 30 silicone rele. se liner (Daubert Coated Products), and was coated at a t!~ nn~-cs of about 0.4 mm and a width of about 20 cm. The dl~ss,ngs were p.~l)a~ by 1q.nin~t;n~ die cut rectqnglPs or squares of the adhesive coated release liner onto a polyur~l,ane br~~ing (Est. ne resin; 0.04 mm; B.F. Goodrit~).
Alternatively, the dressings were p~ d by first lq....nq~;ne the adhesive to 35 the same bq~c-king de-scribed above coated with an a~l~lal~ copol~."cr adhesive (isooctyl acrylate/ethyl acrylate/acrylic acid; 70:15:15 with 0.5% of an polyethylene oxide (PEOX) catalyst). Th~î~r, the adhesive coated br~l~in~c -20- 2~4~46 were converted to dressings on a conventional roller-convertor a~>p~dlus, and were then die cut and packaged in low moisture vapor tr~n~mi~ive (MVT) film of polyethylene/saran/polyethylene t~rephtl.~l~te (Phoeni~ Health Care Products,Milwaukee, WI). The packaged and u--pacL~ed dressings were then 5 cross-linked and sterilized with a dose of gamma radiation at from about 30 kGy (3 Mrad) to about 50 kGy (50 Mrad). The dressings were clear enough to read through on using standard type on 8l/2 by 11 inch (21.6 cm by 27.9 cm) paper. The specific co,--po~ilion of the Example wound d.~sings is shown in Table 3.

Table 3 Specific cc .~ ition of E~ample wound d., ~ ~ 27-29.

LM-MH X-linlt E~. No.(PIB) ~lyisu~"~.. c CMC CMC

28 37.5 30 20 12.5 29 37.5 27.5 20 15 In order to evaluate the adhesive characteristics of the hydrocolloid dressings of the invention, the three dressings of FY~mpl~s 27-29 were evaluated in cGI~pa ison with several commercially available products, 25 including DUODERM EXTRA-THIN wound dressing (a product of Convatec;
Squibb and Sons, Inc., Princeton, NJ; believed to be a KRATON-based composition under U.S. Patent No. 4,551,490), TEGASORl~Y-Ivound dressing (a product of 3M Company, St. Paul, MN; a polyisobutylene-based co.n~iilion - under U.S. Patent No. 4,952,618), RESTORE~wound dressing (a product of 30 Hollister, Inc., Libertyville, IL; believed to be an ethylene vinyl acetate (EVA)-based co...position under U.S. Patent Nos. 4,477,325 and 4,738,257), and COMFEEL wound dl~ssing (a product of Coloplast Int~,..ational, Espergaerde, Dem..~k; believed to be a KRATON-based co--.~silion under U.S. Patent No. 4,231,369).
The sample compositions, percent absorbency, percent wet integrity, sample edge lift, skin adhesion (wet and dry), skin residue (wet and dry), and total number of sal-lples rem~ining on the backs of volunteers at the * Trade-mark r 60557-4502 210~04~
-end of the test period for F.~mple dressings 27-29 and the above-identifi~
col,lp~dti-~e products is shown in Table 4. In p~lrolllling the skin ~heQion~
skin residue, edge lift, and Q~mpl~s r~ h-in~ tests, both the TEGASORB and RESTORE products were tested on 8 volv~ (4 men and 4 women) using 3 S replicates of each ~llple, and only on dry backs. For all other s- , 'es tested, lO vol~ (5 men and 5 women) were used. Two replir~tçs of each sample were applied to these vol~ , with the left side of the back being used as the dry side, and right side, after being mt iQ~nçd with water, being used as the wet side for test pul~oses.

Table 4 Sample . - ti percent a ' A ~, percent wet integrity, sample edge lift, skin adhesion (wet and dry), skin residue (wet and dry), and the total number of test samples ~c - ~ ~ on the backs of ~ ' ~ at the end of the study (1;, = time initia1; TF = time final) for E~smple wound d~ , 27-29, and TEGASORB, RESTORE, DUODERM EXTRA-THIN, and COMFEEL wound d-~ :l.6~.
Samplc AboOl~ .~ Wd Samplc Skin Adhesion Skin Residue Test C~ . 0 Integrity Edge Samples (%) (%) Li~ Dry Dry Wet Wet Dry Dry Wet Wet n TF TO TF TO TF TO TF TO TP at Tp E~ample 27 270 85 1.2 61 53 44 72 0 1.5 0 1.4 37 of 40 E~ample 28 301 87 1.2 49 41 42 64 0.0 1.3 0.1 1.3 38 of 40 E~ampb 29 299 84 1.2 52 48 38 70 0 1.4 0 1.3 39 of 40 TEGASORB 421 57 1.1 169 80 -- -- 0.8 2.7 -- -- 24 of 24 RESTORE 313 0 2.1 64 67 -- -- 1.4 3.7 -- -- 20 of 24 DUODERM 185 68 1.4 177 56 83 67 2.2 2.5 1.9 2.1 37 of 40 EXTRA-THIN ~
COMFEEL 84 82 1.7 48 60 -- 27 0.1 1.2 -- 1.4 26 of 40 - o TF for F ~'-- 27-29, COMFEEL, and DUODERM EXTRA-THIN ~id at 72 hours, and for TEGASORB, and RESTORE at 96 hours.
~ ~1 A , for F- "? ~ 27-29, TEGASORB, and COMFEEL _d at 27 hours, for DUODERM EXTRA-THIN at 23.5 hour~, and for RESTORE at 25 hourcO.
~ 1 t~pe fell-off, 2 t~pe~O failed ~ 4 4 ~ 4 ~

With the exception of the COMFEEL dlessing, none of the other commercially available products displays the wet integrity of the dr~ssillgs of the present invention. Thus, these products may undergo si~nifi~nt deterioration and/or leave excessive hydl~colloid residue when e,.~osod to 5 exudative wounds. In particular, the RESTORE product displays a complete loss of integrity after 24 hours of e,-~s--lG in a shaker jar.
The COMFEEL product displays a nu,l~ber of other disadvantages, including very low ab~ll~ncy for a wound dressing, a problem with edge lift, and a lack of adhesive hold, as de."onstltlted by the fact that 10 only 26 of the 40 samples applied to the backs of volunt~,~ rr~ n~ at the end of the test period. Furthermore, the RESTORE, TEGASORB, and DUODERM EXTRA-THIN products display significant skin residue problems after a prolonged period of application. Only the wound dressings of the present invention provide the combined advantages of high absorbency and wet 15 integlity with good skin adhesion both wet and dry, minim~l edge lift, and low to no skin residue.

Examples 30-32. and C~lllp~ati~re Example 33 Three adhesive co"lposilions of the present invention were tested 20 for potential use as ostomy and/or prosthesis adhesives by ",eds.l~ing their shear holding power in minutes/500 g. The specific co".~ositions of the adhesives of Examples 30-32 are shown in Table 5. All of these co"-~osilions were formed by the same procedures as used in Examples 1-13. In addition, the same non-irradiated co-,.position as that of Example 30 (Comparative Example 33~
25 was tested. Furthermore, two commercially available ostomy adhesives were also tested: DUROADHESIVL (a product of Convatec; Squibb and Sons, Inc., Princeton, NJ; believed to be a KRATON-based composition under U.S. Patent No. 4,551,490), and Hollister's Ostomy Skin Barrier Adhesive (a product of Hollister, Inc., Libertyville, IL; believed to be an EVA-based com~sition 30 under U.S. Patents Nos. 4,477,325 and 4,738,257). The shear holding power in minutes/500 grams for the adhesive co-,lpositions of Examples 30-32, Con.p~ti~e Example 33, DUROADHESIVE, and the Hollister Ostomy Skin Barrier Adhesive are shown in Table 6.
-* T rade - ma rk f~

~104046 Table 5 Specific . , of E~unple ~ ~ 30-32.

E~.LM-MH X-linlc CARBOPOL Min.
No.(PIB) ~ol~ CMC CMC (PAA) Oil 12.5 10 7.5 31 37.5 40 10 5 6.25 1.25 Table 6 Shear holding power (minutes/500 g) for the adhesive ~ of F . ' 30-32, C. dtiVC; Example 33, DUROADHESIVETM, and the Hollister Ostomy Skin Barrier Adhesive.

Shear Holding Power Sample Composition ( ~/500~) Example 30 8700+
E~ample 31 1276 Example 32 1012 C~ vc; E~cample 33 56 Hollister Adhesive 52 The data of Table 6 show that the adhesive co...l~or l;nnc of the present invention exhibit superior shear hol~in~ power, a nP~s~.y p~ for an effective ostomy and/or prosthPcicr adhesive, in co...l z. ;~n to non-ihl~ialed co",~s;l;onc, as well as cull~nlly available products. In ? ~llition~ these 35 co~ )osilions are form~ tPd with low relative ab~ll,cncy. Thus, the CG...l o~;l;on of Example 31 exhibits an abs~ cy of 12% after 24 hours of CA~Su~c to aqueous fluids.

210~0~6 F~ 34-35 Two adhesive colll~sil;nn~ accolding to the present invention were formed from the same m~tPri~ls and according to the same pç~lul~ s as F~annp'es 1-13, except that WINGTACK 95 (Go~lyear chPmir~l Co., Akron, 5 OH), a commercially available synthetic pol~l~le t~~lrjfiPr was added as an 3~1itil~n~1 co---l~onent. These co,.")Q~ nC were formed into wound dles~gs accolding to the same plocedules as for F~- , 'es 1-13, and were tested for percent absorbency and percent wet ~ y accolding to the ploc~lul~s previously described. The srecifi~ co.nl oi;l;on, percent abs~ll~nc~, and 10 percent wet integrity for the wound dr~i,;,ings of Examples 34-35 are shown in Table 7. The data of Table 7 show that even with the inclll~ion of non-elastic P~ifiPrs~ the adhesive compositions of the present invention ~ int~;n their advantages of high absoll,el cy col--bin~d with high wet integlily.

T~ble 7 Specific c~ q~ n percent ~ , and percent wet integrity for the wound dl~ of F "' 34-35.

Wet LM-MH X-linkWing-tackAbsorb.Integ.
E~(PIB) Polyi~ e CMC CMC 95 (%) (9~) 35 20 40 20 15 7.5 157 89 Various modifications and ~ltp~r~tions of the present invention will be a~pa~el.~ to those skilled in the art without departing from the scope and 30 spirit of the present invention.
Consequently, for an und~ n1;ng of the scope of the present invention, reference is made to the following claims.

Claims

1. A pressure sensitive adhesive composition comprising (a) 20-50 weight % of a hydrophobic unsaturated aliphatic homopolymer cross-linked by a dose of radiation;
(b) 20-60 weight % of a compatible tackifier; and (c) 5-60 weight % of at least one hydrocolloid absorbent.

2. An adhesive composition according to claim 1, wherein the hydrophobic unsaturated aliphatic homopolymer exhibits at least about ninety mole percent unsaturation.

3. An adhesive composition according to claim 1, wherein the hydrophobic unsaturated aliphatic homopolymer cross-linked by a dose of radiation exhibits at least about 70 percent gel content.

4. An adhesive composition according to claim 1, wherein the compatible tackifier comprises an elastomeric tackifier having a viscosity average molecular weight of from about 20,000 to about 70,000.

5. An adhesive composition according to claim 1, wherein the hydrophilic absorbent is selected from the group consisting of a natural hydrocolloid, a semi-synthetic hydrocolloid, a synthetic hydrocolloid, and combinations thereof.

6. An adhesive composition according to claim 1, further comprising a plasticizer component.

7. A wound dressing comprising the adhesive composition of claim 1 coated on at least a portion of one major surface of a moisture vapor permeable backing.

8. The wound dressing according to claim 7, wherein the adhesive exhibits a shear hold value of at least about 500 minutes/500 g.

9. A method of forming a pressure sensitive adhesive composition comprising:
(a) compounding a mixture of 20-50 weight % of a hydrophobic unsaturated aliphatic homopolymer, 20-60 weight %
of a compatible tackifier, and 5-60 weight % of at least one hydrocolloid absorbent to form a hydrocolloid adhesive mass;
and (b) irradiating the hydrocolloid adhesive mass with a dose of radiation of from about 5 kGy (0.5 Mrad) to about 200 kGy (20 Mrad).