CA2098488A1 - Denture stabilizing compositions - Google Patents

Abstract

Disclosed are adhesives and stabilizer compositions comprising a lower alkyl vinyl ether-maleic acid copolymer and their salts, said copolymer having a specific viscosity larger than 1.2, the sepcific viscosity being determined in methyl ethyl ketone at 25 ·C
and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.

Description

WO 92/109~8 2 ~ $ ~ PCT/US91/09467 DENTURE STABILIZING COMPOSI

- TECHNICAL FIELD
This invention relates to improvements in adhesives, in par-ticular improved denture adhesives.
BACKGROUND OF THE INVENTI~ON~
o Ordinary remoYable dentures,:dental plates, and the like, com-prise.teeth msunted in a suitable plate or base~ Dentures function as a substitute for missing teeth and serve as a replacement for all or a portion of the teeth ordinarily found in the oral :cavity. Although dentures generally are skillfully prepared, often they do not fit perfectly. Moreover, no matter how satisfactory at first, after a period of time the fit of the denture becomes~lovse and i~perfect due to natural shrinkage and changes in the gums, mucous tissues, and the like. Loose and imperfectly fittPd dentures usually are corrected and stabilized by the use of a denture stabilizer. Denture stabilizers are used to fill the interstices between the dentures and the gums or tissues. Prior to placement of the denture in the oral cavity, a denture stabilizer is:applied to the denture-plate surface which, for ` a~~perfect fitj should-uniformly contact~the' gums a~d-mucous t;ssues.
The denture stabilizer is formulated not only for its adherent proper-25.~-ties; but:also~to provide.~a.cushion or gasket.between the denture and - . .. .the:gums.or tissues, .thereby positioning the denture`securely in the . oral cavity.~
; ' Requirements'i and icharacteristics .~for ~a satisfactory denture stabil king composition~are~many,and are dictated.by~numerous factors.
Desirably, one daily~application of~such~a composition should fùnction al)as an effectiYe means for.~.insulating" cu'shioning,!and `securely posi-~ tioning ithe :denture.nn The~composition:should-lretain.its. characteris-'` t ks.~and 'properties~ in.~the.~typical.npowder c.and.. crea~ nforms during .
' ,`; o~o~storage~under~Ya~ious climaticiconditions,~such.as~h'igh..temperature and 35lohumidity;7be~readily~.and.easily~capable~0f,~application to'..the dênture `surface'; not be'irritating.or~unco~fortable'~to the user; be:safe and nontoxi'c';?lhave: no~'disagreeable odor or: color;.have.no~.ùnpalatable ; . ?~n~:taste;`-.optiona11y~ provide antisPptic andigermicidal properties for : ` :
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preventing or inhibiting the growth of organisms ordinari1y found in the mouth; and function as an agent for prevention of putrefaction or malodorous decomposition of foods or secretions lodging beneath or adjacent to the denture. The stabilizing material must be capable of imbibing water and saliva and swell;ng, so as to fill the interstices between the denture and the gum or mucous tissues. ~he stabilizer should not attack or damage the denture, as by caus;ng a crazing of the denture-plate material. Additionally, the stabil ker should be stable to bacteria, molds and enzyme systems found in the oral cavity, o and ~ave a pH that is nonirritat1ng to the oral mucosa, generally 5-8.5, preferably a pH around neutrality. The mechanical strength of the stabilizing mass, be it gel or colloid, formed by imbibition of water should be great enough to securely maintain the position of the denture.under normal use, and not so great as to make denture removal l5 difficult when desired, or as to damage or inaure the gums, tissues or denture upon removal.
. There has been a considerable effort made over many years to develop improved denture adhesives. Both synthetic and natural polymers and gums have been used singly, in combination, and in 20 combination with various additives.
,. ,., European Patent 64,672 to ~habhar and Schmidt, published November ,- ,; 17, 1982, relates .to a hydrophilic. denture. adhesive containing an adhesive"polymeric~..fraction comprising'~carboxymethylcellulose (CMC) ~; and polyethylene oxide in a hydrophilic vehicle.
- 25 ~,j ,European Patent.Application 140,486 to A.J. Desmaris, filed.July: -t,31,- 19841relates to denture adhesive.compositions containing a hydro~
phobically modified water-solubl'e polymer, alone,or admixed with an ` .L~ `n alkal.i,,metal salt,'.of.:,CMC.- nHydrophobically:-~modified hydroxyalkyl `. CJ~ cel,l~loses,~land,~:cupolymers of,~ethylenet,oxide~.and :long chain epoxy-;~.,s30~ alkanes are preferred.for~ use in the compositions.~
~e~U.S:~Patent~4l280,936..to Dhabhar', Heyd ;? and Schm~dt jGi ssued July ~ J~ 28j~1981,,relatesitonimproved,denture.adhesives contain~ng a specifiedo~ o ~.~atio of~,!CMC~and polyethylene oxide,iin,a mineral,~oil base. .~
, . .
~,r~ n U.S.~ Patento4,474,902',.to:lDhabhar. and;Schmidt,.:issued.October 2, 35, -1984jtrelates ~o,~mproved denture~.adhesives~;containing,.karaya~gum:in a ~ .,hydrophilic,,vehicle'.',i;S~e also U.S."~.Patentt4,514,528, issued,April 30, , : sl'~l985irland :U.S.:.Patent 4,518,72lj,?issued~May 21,,,~,1985~to~these same -- inventors, relating,~; respectively, .to improved~identure adhesives .

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`: . . , w o 92/~09~8 2 ~ 9 ~ ~ ~ 8 PCT/VS91/09467 f: -3-c~ntaining adhesive polymeric fractions consisting of admixtures of partial salts of lower alkylvinyl ether maleic anhydride-type copolymers with CMC or polyethylene oxide, as well as denture ad-hesives containing CMC and polyethylene oxide. See also U.S. Patent 4,522,956, issued June 11, 1985 to Dhabhar and Schmidt relating to improved denture adhesives containing polyethylene oxide as the snle adhesive component in a hydrophilic vehicle comprising certain poly-ethylene glycols.
Other denture adhesives are described in ~.S. Patents 4,530,942, issued July 23, 1989; ~,542,168, issued September 17, 1985; and 4,569,955, issued February 11, 1986.
U.SO Patent 4,529,748 to H.G.P. Wienecke, issued July 16, 1985, relates to dental prosthesis adhesives formed from f;lm-forming substances such as various cellulose derivatives, acrylate polymers, methacrylate polymers, and other film-providing substances.
U.S. Patent 4,138,477 to Gaffar, issued February 6, 197g dis-closes oral compositions to control mouth odor containing zinc-polymer combinations formed from zinc reacted with an anionic polymer contain-ing carboxylic, sulfonic and/or phosphonic acid radicals.
U.S. Patent 3,003,988, to D.P. Germann et al., issued October 10, 1961, describes certain water-sensitized, but water-insoluble, materi-als for stabil king dent~res which are synthetic, hydrophilic, col-loidal materials comprising mixed~partial salts and esters~ of lower alkyl (1 to 4 carbons) vinyl ether-:maleic anhydride-type copolymers~
: 25 said mixed partial salts.and esters containing both divalent calcium . and monovalent alka7i (i.e., sodium, potassium and ammonium) cations.
U.S.~ Patent -4,758,630- to Shah et r al., issued:July. l9, 1988 relates to zinc and strontium partial.salts of lower alkyl (Cl to C~) vinyl ether-maleic.acid.!copolymèrs,- wherein said zinc and strontium 30 cations are "unmixed"~with any other cations or ester functions in the copolymeric`salt, thelremaining initlal carboxyl groups being unreact-ed. These iower alkyl vinyl ether-maleic acid copolymers are referred r ~ iaj~,7 to3here~nafter,by~the abbreviated ,term:"AVE/MA copolymer" and the i)i~ o methyl - vinyl..~ether-maleic-~i~acid ioopolyill3eri:1-as-~~."M71E/MA ~;copolymer".
~r, ~ n35 e~Fur`ther~t EuropeanrPatent~Application 396~411~rto Holevat3and Gounaris :J r i~published`November 7~?1990~ discloses~mixed partlal MVE/MA:copolymer ?~ ~s a l t s . ~ 6" ~ r ~ . ' ., , , , ~ `: 1 ;``

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WO 92/10988 ~ ~ PCI/US91/09467 It is known~ therefore, that combinations of mixed and unmixed partial salts of lower alkyl vinyl ether-maleic anhydride-type co-polymers are useful as denture adhesive compositions.
Yet, the search continues for denture stabilizers that will 5 provide the above-described characteristics and, importantly, will maintain the secure fit of the denture over prolonged periods (10-14 hours) without the need for reapplication.
In accordance with the present invention, improved adhesive and other characteristics are obtained in a denture stabilizing composi-tion by using specific acids and partial salt(s) of a lower alkyl ~ vinyl ether-maleic acid copolymer with a speci~ied bulk density and specific surface area.
It is an object of the present invention to provide improved denture stabilizers which are easy to manufacture and thtt will be stable over prolonged periods in the oral cavity, yet will allow easy removal of the denture on demand.
It is a further object to provide such stabilizers using toxico-logically-acceptable, palatable materials.
It is another object herein to provide stab;lizers that perform well in the presence of moisture, particularly in the presence of body fluids such as saliva, perspiration an~ blood.
: These.and..other objects are secured by .the present invention, in , the manner-disclosed hereinafter.~
~ . SUMMARY OF THE INVENTION ..
; 25 ~. -; The .present .invent;on encompasses adhesives and stabili~er . -.. ~ compositions .!;comprising: a lower. alkyl vinyl ether-maleic acid .- copolymer.cons;sting essentially of the repeated struc~ural unit:
j " ~ ; c~ ..~ . OR ~ ...
t r~ t~ ~:3!1" ~ ~ CH~ -CH---ICH-.~-CH :r : ` .
3i0 2r~ ? ~ i' S ' .~ J ~ O~I.c3~lC=O ;

- ' ~ rc ~ ;i i ~ ? ., .' ~ n wherein,R represents.a C, .to.C4 alkyl radical, n .is.ian-integer greater .I 3t~ rOnithan~one irepresenting.c!jthe :.numberiof...repeated occurrences of said 5~l structural unit,.in:~a~molecule..of,said~copolymer:.and n :is.:large enough ".e!l.ito`~1characterize said copolymer as.having a~specific~.viscosity larger than 1.2, the specific viscosity being determined in~methyl ethyl ketone at 25'C and wherein said copolymer has a bulk density o~ ~rom .

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W O 92/10988 ~ ~ 9 ~ PCT/US91/09467 -5~
about 0.3 to about 1.2 grams per cubic centimQter and a specific surface area of from about 0.5 to about 2.5 square meters pen ~ram.
Preferably these copoly~ers are part;al salts (mixed or unmixed, preferably mixed), said partial salts containing from about 10% to about 40% free acid, and as the cationic salt function, from about 0.1% to about 85% of the total initial carboxyl groups reacted with one or more of a cationic salt function selected from the group consisting of z;nc cations, strontium cat;ons, sodium cations, calcium cations, magnesium cations, potassium cations and a~monium cations and o mixtures thereof and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a spec;fic surface area o~ from about 0.5 to about 2.5 square meters per gram.
Also d;sclosed are denture stabilizing compos;tions compr;s;ng a safe and adhesively effective amount of two or more denture adhesive components wherein one of said denture adhesive components is either the copolymer or the mixed partial salt(s) of~the present invention.
Bulk densities are measured according to ASTM method B-52 (02.05).
- Preferably these copolymers or mixed partial salts are used along w;th a water-sens;tized polymeric mater;al selected from the group consisting of natural gums, synthet;c polymers, saccharide der;va-tivesj cellulose derivatives, and mixtures thereof.
All percentages and ratios used here;n relating to the neutral;-'" `zation of'the` salts of ! the''present'''invention are based`upon thestoichio~etric percent of the catior1ls' present in the salt. All percentages and ratiosi used herein are `by weight, unlessi otherwise ~ specified.. ~ - ' ' ' '`
';DETAILED'DESCRIPTION OF THE_INVENTION ~
The 'present invention~ encompasses ~~stabilizer~compositions com-' i prising: 'a~lowèrJalkyl'vinyl;ether-maleic'iacid copolymer consisting ~30 essentially of`the 'repeated structural unit~ ?
l ~ Ji~ OR~ ` ;
" r;.", ";; , : ,; ; ----CH2~ `ci~ CH---CH - -'; :'C~ ;J? ~ ;. : t,, .~. j ~ ,'.?;~ O=cii` C~O ~ (I) 2~ t~ , ~ ''r HO- '~OH'~ ; ~
35 ~ ~ J~li`r 9~Si~ n -~ ?: . . .
'?~ 1 wherein R represents a:C1'to C4 alkyl radical,-n is an integer greater~ than'one representing' the nu~ber'''`of 'repeated 'occurrences~ of said `i ~; 'structural unit in a moleculé of said copolymer and n is large enough . ' .`

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WO 92/10988 ~ PCI/US91/09467 tD characterize said copolymer as having a specific viscosity larger than 1.2, the specific viscosity being determined in methyl ethyl ketone at 25 C and wherein said copo1ymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific 5 surface area of from about 0.5 to about 2.5 square meters per gram.
Preferably these copolymers are partial salts, said partial salts containing from about 10% to about 40% free acid, and as the cationic salt function from about O.lYo to about 85% of the total initial carboxyl groups reacted with one or more of a cationic salt function selected fro~ the ~roup consisting of zinc cakions, strontium cations, sodiurn cations, calcium cations, magnesium cations, potassium cations and ammonium cations and mixtures thereof and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.
Preferably the partial salts ~preferably mixed) comprise from about 0.1% to about 85% of one or more of the above mentiDned cations in the following levels: from about 0.1% to about 65%, more pre-ferably from about 2% to about 45%, and most preferably from about 2.5% to about 30% zinc or strontium cations (preferably zinc), and from about 10% -to about 75%, more preferably from about 20% to about .65%, and most preferably from about 40% to~about 65% calcium cations, - from about 0.1%:to about 25%, andimore preferably from about-0.1% to about 20% sodiu~ cations and from about 10% to about 40%, most pre-25 ~ferably.from about 20% to about 35~ free acid.
The subject polymeric salts are advantageously prepared by theinteraction.of the AVE/MA copolymer (I) with the optional cationic lca kium,"~sodium~ ,ammonium ,and ~eitheri.zinc .or1strontium compounds , - .^:lhaving~,a.,functional-group:.typical,of reactants~ of carboxylic acid, such as, for example, tthej hydroxide,,t~acetate,, carbonate, halide, lactate, etc.~ in an aqueous medium. In a preferred embodiment, the oxide of z~nc and the hydroxide~of~.calctum and sodium are utilized.
Since ~inc hydroxidej is not commercially available, its use as a reàctant is readily and more economically accomplished by employing an : 35 aqueous slurry of particul~te zinc oxide which, although practically insoluble in Iwater, provides ~hydration ?to~.zinc hydroxide~ on the ~par~iculate .surface.3.Calcium and sodium~jhydroxides as well,,as stron-: :tium hydroxide, on the other hand,-are available in either crystalline , . .
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WO 92/10988 PCr/lJS91/09467 ~ 209~8~ _7_ or powder form and are soluble in about 50 parts water. Aqueous solutions of strontium oxide, however, which form the hydroxide when treated with water ~caution: heat evolution), may also be used.
Strontium oarbonate may also be used.
Anions that form tox;c, ;rritating or contamlnating by-products should be avo;ded, or special precautions and trPat~ent provided to assure the removal and absence of such by-products from the polymeric salt end-product. The part;cular compound used should be substantial-ly pure to assure obtaining a substantially pure, substantially off-white polymeric salt end-product.
The lower alkyl vinyl ether maleic acid (AVE/MA) copolymers (I) are readily obtained by copolymerizing a lower alkyl vinyl ether monomer, such as methyl vinyl ether, ethyl vinyl ether, divinyl ether, propyl vinyl either and'isobutyl vinyl ether, with maleic anhydride to yield. the corresponding lower alkyl vinyl ether-maleic anhydride ; copolymer which is readily hydrolyzable to the acid copolymer (I).
Both anhydride and acid forms are also available from commercial suppliers. For example, the GAF Corporation, Wayne, New Jersey, provides both the polymeric free ac1d form (I) and the corresponding anhydride form under its "GANTREZ" trademark as the "GANTKEZ S Series"
and "GANTREZ AN Series", respectively. In the former acid series, the 6ANTRE2 S 97 (M.W.~50,000) ..is particularly suitable, and, in the .latter anhydride series, the GANTREZ'AN-149 (M.W.350,000), the GANTREZ :~
AN-169 (M.W.=67,000)~and the GANTREZ AN-179 (M.W.=80,000) copolymers are particularly suitable.-. Said acid ~nd anhydride forms of AVE/MA
opolymers, having an average:molecular weight of from about 50,000 to ; ';about 80,000 (as measured by membrane osmometry in 2-butanone 1-10 grams~1000 ml solution), are also characterized by having~the previ-ously.described~:specific..viscosity.parameter.of,more than 1.2. When 30r~the-anhydrlde~.copolymer,dissol~es:in water,.the anhydride linkage is q cleaved.so that:~th~ highlyi;polar,;polymeric free,~acid ,-(I).:is formed.
`. ..Accordingly,.ithe~ anhydride;form',~ which ;is~relatively~less.iexpensive ';than the.~a'cid.~orm,~,imay''be used as a~convenient and.cheaper.precursor for.'the~acid.~-Elevateditemperatures;may.'be~iadvantageously employed to ,'d.s~35 ~ enhan^ce the.rate o'f.anhydr.ide-to-acid hydrolysis. .) on~ w~
In g'eneral, the'.lower alkyl~vinyl ether-malei'c:.acid"copolymer ~or its corresponding anhydride,` is'added to water.-preheated to .~ about 70-80-C with vigorous stirring to 'form a homcgeneous mixture.
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If the anhydride precursor is utilized, it is reoommended that the aqueous mixture be further heated to abuut 90-C with stirring to ensure comp1ete hydrolysis of the anhydride to the acid form. Heating is then discontinued although mixing is continued until the batch turns clear with a simultaneous decrease in viscosity (about 65-75C).
In a preferred embodiment, an aqueous solution of the ca~ionic zinc or strontium salt . forming compound, or, for example9 an aqueous dispersion of particulate zinc oxide is combined with ca kium hy-droxide in the form of a slurry, in an amount sufficienit to provide o the desired zinc and calcium oationic conten$ desired in the ~ end-product, is separately prepared at ambient temperature and slowly added to the hot polymeric acid solution with continuous vigorous mixing so as to prevent localized precipitation of the cationic polymeric salt. After the calcium and zinc have reacted, an aqueous solution of sodium hydroxide is added slowly, in the amount sufficient to provide the cation sodium content desired in the end-produot.
;. After addition is complete, mixing is continued to ensure that all the salt forming compounds are reacted with the copolymer.
Alternatively for this preferred embodiment, an aqueous solution containing the zinc and calcium source is preheated to 70-80-C with : vigorous stirring.to form a homogeneous slurry. The lower alkyl vinyl ether-maleic acid copolymer:~I) or its corresponding'anhydride is then added:,to the slurry while:'further heating to 90-C,:and stirring to . - ensure complete hydrolysis. : Alternatively, `the AYE/MA copolymer, :25 calciu~, and strontium zinc oxide powders are slurried-in water at 25-'.m :~.and subsequently heated .to sn-c - 9o C for reaction to occur. Upon completion of this: reaction step an aqueous solution of~sodium hy-~ 'droxide.is slowly,added.. ~ . ,tis ,;.~
il'3i.,~ The~.zinc ~or.~.strontium),;:,calciumi~ and'rsodium oations in the~i ~30.,~,resultant.mixed partial salt~of~AVE/MAicopolymer~should.belsuf~icient ,r,r.~ to'give,:a..neutr'al kation~ranging.from.about:lO~O to about.75%; prefera-bly....from`about'20%.to about 65%,}and:most..preferably.from.about 40% to lo~$!Jo~ about:65%~calcium,~,and~rom~about 0.1%.lto.,about~65%,~jtpreferably from !~J ~3~a,~.about.2%;.to-about345%il~and most~preferably~'fromrabout-~.2.-5% to about 35 30% zinc or.strontiumj! and;from ~aboutrØ1~ to~-about ~25%,i~preferably ' .-.i^n~ ;n~afrom;0.1% fto about 20% sodium, resulting in a:salt .containing frees~ acid in.the range~of from ~about 10%~to ~.about 40~, preferably from :;' !'^~`;~ about 20% to about 35Z. ~

WO 9~/10988 PCr/US9t/09467 f ~ 2098~8 9 The reaction batch is then dried using drum dryers maintalned at 80-100 PSIG with hot steam to evaporate the water con~ent and recover the polymeric salt with a high specific surface area, in the flake form.
5The resulting flakes are subjected to milling and screening to yield the desired physical properties to provide satisfactory denture stabilizing properties while maintaining the desired high specific surface areas. These surface areas can be obtained by any appropriate micronizing technique, preferably air jet milling or pin/disk or 0 hammer milling as described in Remi.nqton's Pharmaceu~ical _Sciences (16th edition) pp. 1535-1539, incorporated by references herein.
Said salts are friable so that appropriate particle size and bulk density can be obtained. For best results, drum dried particles should be milled to a preferred bulk density of about 0.3 to about 1.2 15more preferably about 0.6 to about 1.2 and most preferably about O . 7 to about 1.2 grams per cubic centimeter while maintaining a specific surface area of about d.5 to about 2.57 more preferably about 0.6 to about 2.5, and most preferably about 0.7 to about 2.0 square meters per gram. 2round particles should be capable oF passage through a 20140- to 200-mesh sieve (U.S.B.S. series) and preferably are less than 0.3 millimeters in their largest dimension.
: The subject acid copolymers and their respective salts have exceptional adhesive qualities when contacted with water or saliva such that they,are extremely useful as denture adhesive materials in denture stabilizing.icompositions. For such use the salt in particu-: late.~orm is preferably characterized by a particle size of at least - .. minus 14~-mesh U.S.B.S. sieve; a bulk density greater than 0.3 gram..''~7 .~ per cubic,centimeter `and preferably higher. then 0.6: gram~per cubic n.~ o ~ centimeter; and~a pH between 3 and::8 and preferably~between~5 and 7.5, ..30...;the: pH being -determined. on a..one percent by ~weight :dispersion in w~ter., .~lF!r~ 7i ~ .' .,!;'U.! !,~7 .i .~
,Each of the,subject::copolymer:salts ~ay be utilized,in effective '"5'.'- adhesive-~:amounts, preferably ~at .least 25çipercent~.by weight, as the ...e .^, ,sole-adhesive~component;or as a co-adhesive in joint.usàge with other Jr.,. 35:.sactive:;adhesive components~in denture~stabilizing~cbmpositions.~`:
:~;j..i , i~, ..;It ~is,preferred ~that-~said .copolymern.salt be .used.~along with a :co-adhesive: in~:`denture :stabilizing~,oompositions.77.-~Preferably, the 'G~-~ - co-adhesive:-is a polymeric material selected ~rom the group cons;sting .

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~39~48~ -lo- f of natural gums, synthetic polymers, saccharide derivatives, cellulose derivatives, and mixtures thereof. In general, from about 15 to about 70 percent, based on the total weight of the composition, of said mixed calcium/sodium/zinc or strontium salt is present.
Preferred co-adhesives include a water-soluble hydrophil;o colloid or polymer having the particular property of swelling upon exposure to moisture to form a mucilaginous mass. Such adhesive materials include both natura1 gums and synthetic polymeric yums and, among those commonly employed in denture stabilizing compositions and lo whic~ are also suitable herein co-adhesive action with the subject mixea AVE/MA copolymer salts, there may be mentioned, for example, karaya gum, gelatin, algin, sodium alginate, tragacanth, methylcPllu-lose, acrylamide polymers~ ethylene oxide polymers, polyvinylpyrroli-done, cationic polyarylamide polymers and, as the most preferred, sodium carboxymethylcellulose and mixed partial salts of poly(vinyl methylether-maleic acid) copolymer.
Accordingly, a preferred aspect of the.subject invention provides adhesives and denture stabilizing compositions having as a stabilizing component an effectiYe adhesive amount of a lower alkyl vinyl 20 ether-maleic acid copolymer consisting essentially of the repeated structural unit:
. . .. . , ~. . OR
'~r ''!' i` .1' '' '~'- ''' "''''~'''~ '~ CH~ H---CH---CH -~
. - . .. O=C C=O ~ (I
25 .... .- :. :.. :.HO~ OH

3; .) ~ .~ . n .. wherein.R represents a Cl to C~- alkyl radical, n is an integer greater ar ,~ Jw~ than? one representing ~the .number~of repeated :occurrences o~ said ; i; ~.n~ structural unit~in a;molecule of said.copolymer.and n is ~large enough 3o~1to!characterize said copolymer as having::a:.specif:ic viscosity larger than 1.2, the specific viscosity being determined in imethyl ethyl .:,i~ .. `'~ ketone at.25'C and wherein.. said .copolymer. has a bulk density of from n~ about 0.3ito about: 1.2.-.grams.per cubic centimeter ,and .a specific ':;'it~ 1!.. ;surface.area of from:.about 0.5 to about 2.5~square-meters~per gram.
35.~ )r:~ ~Preferably.these.~.copolymers are-;partial salts,hsaid.partial:salts I.J"" ?ncontaining from,about~10%~.to:about:40% free?~acid, and as the cationic 1 ... ~salt function fromaabout -Ø1% to about 85% of~;the ;total initial - : - . carboxyl groups reacted w~th~:one or more of a cationic salt function .

` , . . ~ ' ~, ' ' ' , WO ~2/10988 PCT/US91/09467 2~9~8~
selected from the group consisting of zinc cations, strontium cations, sodium cations, calcium cations, magnesium cations, potassium cations and ammonium cations and mixtures thereof and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface ar~a of from about 0.5 to aboùt 2.5 square meters per gram.
Another preferred aspect of this invention provides a denture stabilizing composition comprising a safe and adhesively effective amount of at least two denture adhesive components, wherein one of said denture adhesive components is the acid or partial salt of a lower alkyl vinyl ether-maleic acid copolymer described above.
Preferably the co-adhesive is as described above.
The compositions of the present invention can optionally include from about 0.01% to about 5% of one or more components which provide the user with sensory, including flavor, benefits. Suitable compo-nents include menthol, menthyl lactate, peppermint oil, spearmint oil, peppermint oil, leaf alcohol, as well as those paramenthane carboxy-amides flavoring agents available from ~ilkinson-Sword (such as WS-3) which are described in U.S. Patent 4,136,163 to Watson et al., issued January 23, 1979 which is incorporated by reference herein.
The compositions of the present invention are manufaetured in an art-recogni~ed manner known to those skilled in the art, such as in a powder,!cream,~ointment, liquid, paste, water or ~fil~. The compo-~ ; sitions of the present invention are preferably manufactured with drum25 ~dried AYE/MA;copolymers or their salts that are milled using appro-~- priate micronization techniques such as fluid energy or air jet or : hammer milling of drum driedimixed partial salts of AVE/MA copolymer.
.;~s ~/oSuitable examples of such,formulations are~disclosed in U.S. Patent ;,;-~;4,518,7~ ;issued Mayi21,j1985 and U.S. Patent 4,514,528, issued April ~30 , 30,~1985,~both to Dhabhar et~al;.and both of~which are hereby incor-porated by reference herein. ." n~
~ ;c Preferably,.these~compositions contain !from~about 10% to about .eliSJ~ 70%;of. one~or.imore ointment^bases. ~Prefèràbly,Othis-baselis mineral ,S~oil or petrolatum, howeYer polyethylene glycol,;paraffin,~;glycerin and mixtures thereof~are ~alsoliluseful;~lMost~lpreferred:is~a~mixture of mineral oil and petrolatum.
It is to be recognized that the adhesive salts of the present invention can be used for a wide variety of general adhesive uses ~- , - .. . . . :
.. . . . . .
..... , . . ~ .. . ... .
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w o 92J10988 ~ PCT/~Ssl/09467 ~3~ -12- ~
including, but not limited to, pharmaceutical uses (e.g., oral drug delivery and topical bandages); and aqueous adhesives ~e.g., where adhesiveness in the presence of water is required~.
The following non-limiting examples illustrate embodiments of the subject invention wherein both essential and optional ingredients are combined. It is to be understood that these examples are for illus-trative purposes only and are not to be construed as limiting the scope of the invention thereto.
f ExamPle I
o Intu a reaction vessel equipped with a high speed stirrer and ~ containing 94 parts (4.7 kg) of purified water heated to 85~C, is slowly added 6 parts (390 grams~ methyl vinyl ether-maleic anhydride copolymer to the reaction vessel over a 15 minute periodO Temperature and mixing remain constant for 60 minutes after 15 minutes, the resulting adhesive polymeric dispersion is characterized by an in-crease in viscosity, and a decrease and stabilization of reaction pH
which is a dispersion of'said material in water, said.material con-sisting of acid form of methyl vinyl ether~maleic acid copolymer.
The resultant solution of the methyl vinyl ether-maleic acid ~MVE/MA) copolymer is then dried using a drum dryer maintained at 80-100 PSIG with hot steam to evaporate the water content and recover the polymeric salt with a high specific surface~area,.in flake form.
The thus~.obtained dried~.acid form of the~MVE/MAIcopolymer is then ~..ground using an air jet or hammer mill to a.bulk density of about 0.7 to about 1.1 grams per. cubic.centimeter.while.maintaining a.specific ~ . surface area~afiabout 0.7.to about 1.5.square.meters per gram. This ; .. copolymer is then screened through a 140-mesh sieve an~ then.ithrough a ,,J "j..! .200 mesh:sieve..~U.S.B.S.~:sieveiseries). The~powder~has'!a pH..~of about .2.5 for:a.one percent solution in water.~ ' This part kular copolymer 30 ~.will1be~referred'to hereinafter:iby~the abbreviatedlterm,:racid form of MVE~MA copolymer". ..I~ ?n '~ lS;:-'.3' ',U :.'~ '' 1;`!
.".`The,product,.when:iused..iin conjunction:~with conventional denture .'..;:~ni~l adhesivesr.and. appl.ied-i~to wet-~dentures~with~;;normal~.usage,;.provides :~s ;ii n;.denture~stabilizing 'characterist-ics superior."to.those~obtained by the .~ .35.~. ~particular..conventlonal ~denture:-.adhesive itself..
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wo 92/lrig88 PCI/US91/09467 !'` 2~98~ 13-Example II
Into a reaction vessel equipped with a high speed stirrer and cDntaining 92.1 parts (1.842 kg) of purified water heated to 85C, is slowly added calcium hydroxide 1.9 parts (37.9 grams), and sodium hydroxide 0.3 parts (5.8 grams). After addition is complete, the temperature of the slurry is kept constant with high speed mixing.
While keeping heat and mixing constailt add 5.71 parts (114 grams) of methyl vinyl ether-maleic anhydride copolymer to the reaction vessel containing the alkali dispersion over a 15 minute period. Temperature and mixing remain constant for 60 minutes. A~ter 15 minutes the resulting adhesive polymeric dispersion is characterized by an in-crease in viscosity, and a decrease and stabilizatinn of the reaction pH which is a dispersion of said material in water, said material consisting of mixed partial calcium sodium salt of methyl vinyl ether-maleic acid copolymer.
The resultant solution of the calcium sodlum salt of methyl vinyl ether-maleic acid (MVE/MA) copolymer is then dried using a drum dryer maintained at 80-100 PSIG with hot steam to evaporate the water content and recover the polymeric salt with a high specific sur~ace area, in flake form. The thus obtained dried calcium sodium MVE/MA
copolymer salt is then ground using an air jet or hammer mill to a bulk density of about 0.7 to about 1.1 grams per cubic centimeter ' while maintainlng' a specific surface area of?labout 0.7 to~about 1.5 square meters per-gram. This copolymer is then screened through a -25 140-mesh sieve and then through a 200 mesh sieve (U.S.B.S. sieve : series). The powder has a pH of about 6.5 for a one percent solution in water. Analysis of the salt 1indicates about 70.0 percent neutrali-zation~with~icalcium,~-10.0 'percent 'neutralized-withrsodium with 20%
n remaining`'carbo'xyl groups.~ This''~particular :salt will ~be re~erred to ~30i~hereinafte`r~by;the abbreviated `term',~ n70% Ca/10% Na partial;;salt of MVE/MA copolymer".
''S"~ OThe ! product,~wheniused~iniconjunctionlwith conventional denture ~i~adhesives '~and~applied tou wet dentures'with unormal -usage,o-provides t ~! denturé~stabilizing ! characteristics superior 7to those obtaiiriéd by the ~^ 35 particular conve'nt~ioiial~dent'ure~adhesiYe'itself.!7~ t~
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WO 9,./10988 PCr/US91/09467 l4-ExamPle ~I~
Into a reaction vessel equipped with a high speed stirrer and containing 92.4 parts (4.6 kg) of purified water heated to 85-C, is slowly added 0.53 parts ~26.3 grams) of zinc oxide and calcium hy-5droxide 1.30 parts (64.6 grams). After ~ddition is complete, the temperature of the slurry is kept constant with high speed mixing.
While keeping heat and mixing constant add 5.76 parts (288 grams) of methyl vinyl ether-maleic anhydride copolymer to the reaction vessel containing the alkali dispersion over a 15 minute period. Temperature o and mixing remain constant for 60 minutes.~ After-15 minutes the resulting adhesive polymeric dispersion is characterized by an in-crease in viscosity, and a decrease and stabilization of the reaction pH ~hich is a dispersion of said material in water, said material consisting of mixed partial calcium zinc salt of methyl vinyl ether-maleic acid copolymer.
The resultant solution of the calcium zinc salt of methyl vinyl ; ,ether-maleic acid (MVE/MA) copolymer is then dried using a drum dryer maintained at 80-100 PSIG with hot steam to evaporate the water content and recover the polymeric salt with a high specific surface area, in flake form. The thus obtained dried calcium zinc MVE/MA
copolymer salt is then ground using an air jet or hammer mill to a ,bulk density ,of about,0.7 to about 1.1 grams per cubic centimeter ,while ~aintaining` a speci~ic~surface area of:about 0.7" to' about 1.5 , square ~meters per gram. This copolymer is then screened ,through a 140-mesh sieve and then through a 200 mesh sieve (U.S.B.S. sieve , ~,series)., The powder,has a pH of about 5.4 for,a one percent solution in water,.~ Analysis,of ~he salt indicates about 47.5 percent neutrali-;zation,jwith calciumj1~17.5 percentineutral,ized .iwith.i zinc,,with 35%
0~ remainingicarboxyl groups.~,This,particular sal,t will be;referred to ~r~3 30;~hereinafter, by lthe abbreviated term, ,"47.5% ,Ca/17.5%JZnipartial saltof MVE/MA copolymer". .' "~3:';',''`::~ 1:a ~
Thelproduct,,,when used,dn conjunction with conventional denture o,;~ "adhesives :and~applied ~to,wet dentures:,~with,~normal Ausagetihprovides ,denture,,stabilizing characteristics,~super~ior~,~o those obtained by the pa'rticular conventional~,denture adheslve,jitself `~0! ~

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Into a react1On vessel equipped with a high speed stirrer and containing 84.7 parts (7.6 kg) of purified water heated to 85~'C, is slowly added. 0.2 parts (1~3 grams) of zinc oxide and calcium hy-droxide 0.92 parts (82.7 grams). After addition is complete, the temperature of the slurry is kept constant with high speed mixing.
While keeping heat and mixing constant add 3.9 parts (348 grams~ of methyl vinyl ether-maleic anhydride copolymer to the reaction vessel containing the alkali dispersion over a 15 minute period. At about 15 minutes the resulting adhesive polymeric dispersion is characterized by an increase in viscosity, and a decrease and stabilization of the reaction pH which is a dispersion of said material in water, said material consisting of mixed partial ealcium zinc salt of methyl vinyl ether-maleic acid copolymer. Temperature and mixing remain constant for 60 minutes. Next, 890 grams of a 1% solution of sodium hydroxide is slowly added over a 30 minute period and the reaction is allowed to gu to completion as indicated by the stabilization of the reaction pH.
The resultant solution of the calcium zinc salt of methyl vinyl ether-maleic acid ~MVE/MA) copolymer is then dried using a drum dryer maintained at ~0-100 PSIG with hot steam to evaporate the water -' content and recover the polymeric salt with a high specific surface area, in flake form. The thus obtained dried calcium zinc MVE/MA
copolymer salt~isltheniground using an air jet or h'ammer `mill to a bulk density of about 0.7 to about 1.1 grams per oubic centimeter -while 'ma'intaining a specific sur~ace area of about'0.7 to about 1.5 square meters per ~ram. ;This-copolymer is then screened through a ~; 140-mesh sieve and the`n through a 200 ~esh sieve ~'(U.S.B.'S. sieve series)~ ~The~powder has~a pH~ofiabout`5.7-~for:a one percent solution in3water.;~ Analysis~-o~the''salt~would indicate about;50 percent of 30~ the~c`a'rboxyl grou'ps neutralized`~'with`;cal'c`ium`, 9.'9'percent ne`utràlized u~with ~zinc;andr'5% ;neutrallzed ~w'ith sodium~with"35%~carboxyl groups i~` rema~ining unreacted.'' Thisiparticular salt will-be`~`referred to here-' } ~ h ~ inafter by t~e-~abbreviat`ëdqterm, `"50% Ca/9.`9% Zn/ 5% Na'`partial salt of MVE/MA copolymer". "'~ ;i3~
~tl!S35~1 ~Et~ ThevprOduct~ whèn~used':in''conjunction with~'conYentional denture '.' -.t'`J ~ adhesives~and~'applied ~;to'~wet dentures~ with;normal``~usage,~ provides t~ "denture stabilizing'characteris,tics,~superior to'those obtàined by the particular conventionalidenture adhesive'its`el~
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WO 92/109~8 PCr/US91/09~67 Into a reaction vessel equipped with a high speed stirrer and containing 85.1 parts (7.7 kg) of purified water heated to 85-C, is slowly added 0.1 parts (9 grams) of zinc oxide and calcium hydroxide 5 1.1 parts (98.9 grams). After addition is complete, the temperature of the slurry is kept constant with high speed mixlng. While keeping heat and mixing constant add 3.9 parts (347.2 grams) of methyl vinyl ether-maleic anhydride copolymer to the reaction vessel containing the alkali dispersion over a 15 minute period. At about 15 minutes the res,ulting adhesive polymeric dispersion is characterized by an in-crease in viscosity, and a decrease iand stabilization of the reaction pH of the dispersion of said material in water, said material con-sisting of mixed partial calcium zinc salt of methyl vinyl ether-maleic acid copolymer. Temperature and mixing remain constant for 60 minutes. Next, 890 grams of a 1% solution of sodium hydroxide is slowly added over a 30 minute per~od and the reaction is allowed to go to completion as indicated by stabilization of the reaction pH. I
The resultant solution o~ the calcium zinc salt of methyl vinyl , ether-maleic acid (MVE/MA) copolymer is then dried using a drum dryer maintained at 80-100 PSI6 with hot steam to evaporate the water content and recover ~he polymeric salt with a high specific surface area,~,in flake form. The thus obtained dried;calcium zinc MVE/MA
: copolymer salt.is.then ground using an air,jet or hammer mill to a , bulk density of about 0.7~to about 1.1 grams per ~cubic centimeter ,,, 25, whi,le maintaining a~specific surface areaiof about 0.7 to about 1.5 ~square ~meters per gram. ,Thisicopolymer is- then~ screened through a ,~ ,, ,"140-mesh ,sieve, and then ,through a 200 mesh sieve ,~(U.S.B.S. sieve ,~S~Jj,lJj3~series). .~The,powder has,aipH,of,,about,6.0,fpr,~a one percent solution ,,)",,in ;water.;,," Analys,is ofljthe ~salt ~would,~"indicate about~,.6090 of the 30;~carboxyl!~groups ,ne,utr,alized,~with~calcium,,~5%,neutralized,with-zinc, .ll)," iiand,35% neutral,ized,j,with, sodium~;with,,30X,of;~,the~carboxyl ~groups re-maining,unreacted.,l~This,jparticular saltl,wil,l,~,be,, referred to here-j;,lna,fte,r, by t~hq' abbreviated~term,i"60% Ca/5%,~7n/5% Na partial salt of ' MVE/MA copolymer". '~rJ~ r~ 3..~
,"~,,35~ "~,~he,product, when,i,used~",in,jconjunction with~,conventional denture ' ,: 3,' r~ro~ ~1 adhe$i,yes;,,andyapplied ,to,,wet dentures,~withsnor~al-,~,usage; provides ,dentur,e stabilizing characteristics~superior~to those obtained by the particular conventional denture adhesive itself. , - l -, . . . -. . . .
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W~ 92/10988 PCI/US9t/09467 8 _17 Example VI
The procedure of Example I ;s repeated except that the follow;ng amounts of reactants are employed: 3.9 parts t77.3 grams) of the anhydride copolymer, 94.9 parts (1.9 kg) purified water; and 0.2 parts (3.99 grams) of zinc oxide; 0.2 parts (3.99 grams) of sodium hydroxide and 3.83 parts (16.5 grams) calcium hydroxide.
The resultant powder would have a bulk density of about 0.7 to about 1.1 grams per cubic centimeter and a specific surface area of about 0.7 to about 1.5 square meters per gram. Analysis of the salt o indicates about 45 percent calcium neutralization of the total initial carboxyl groups in the copolymer salt molecule; 9.9 percent neutrali-zation with zinc and 10% neutralization with sodium will be referred to hereinafter by the abbreviated term "45% calcium/9.9% zinc/10%
sodium partial salt of MVE/MA copolymer". -ExamPle VII
By following the general procedure of Example V, except that an appropriate amounts of zinc oxide, calcium hydroxide and sodium hydroxide are utilized to provide the tabulated substitutions, the following calcium/zinc/sodium salts of MVE/MA copolymer are obtained:
Sodium Calcium Zinc i; lC ~ 60~5 ;~ '' '' 2.5 - 65 2.5 `
- - 40 ~ ` ` 9.9 ,: 20 40 -- 9.9 -5 ; ~ 5~ - 9.9 ~Each of the indicated MVE/MA copolywer salts,~ which would have, CCfor'the minus 140-mesh U.S.B.S. sieve powder, a bulk density greater than 0.5 grams per cubic centimeter, while maintaining a specific ~.surface area greater than 0.6 ~square'meters"/per:~gram and provides markedly beneficial~'denture st'abilizing charaetèristics.~ Each of the indicated salts may be abbreviated by the percent~of,calcium/percent Z
~`of~zinc~percent sodium~neût`ralization as done in'Examples I through Y.
~,35IJ!3~ - ~ Example VIII ' '-'-Thé MVE/MA copolymeric anhydride-to-acid hydrolysis procedure outlined in Example Y ls repeated. To a vessel containing 8.5 kg of purified water heated to 85~ is added 16.5 grams of strontium hy-, .. . .

- . ' -WO 92/10988 ~ PC~/US91/09~67 droxide octahydrate. With vigorous mixing~ 99.4 grams of calcium hydroxide is slowly added. After addition is complete, the tempera-ture of the slurry is kept constant with high speed mixing. While maintaining the heat and constant mixing, 34.9 grams of methyl vinyl ether-maleic anhydride copolymer are added to the reaction vessel containing the alkali dispersion over a 20 minute period. This produces a mixed partial calcium strontium salt of methyl vinyl ether-maleic acid copolymer.
Example IX
lo Denture stabilizing powder compositions are prepared by blending together the following:
% w/w A B
A. Karaya gum 53 53 Sodium carboxymethylcellulose 16 16 Sodium borate 7 7 47.5% Ca/17.5% Zn mixed partial salt of MVE/MA
copolymer 24 --60% Ca/5% Zn/5% Na partial salt of MVE/Ma copolymer -- 24 20100 1~0 B. Sodium alginate 55 55 Sodium carboxymethylcellulose 10 10 Polyvinylpyrrolidone ~average M.W.=90,000) 15 15 65% Oa/10% Zn mixed partial salt of PVM/MA
copolymer 20 ~-60.5% Ca/2.5% Zn/ 10% Na partial salt of MVE/MA
-; " ~ -copolymer : ` -- 20; ~ , ` 100 100 `. C , ~ j; Sodium carboxymethyloellulose , 50 - 50 ;; 70% Ca/10% Na mixed partial salt of MVE/MA
copolymer~ .; '' : n ' ~ 50 30 50% Zn unmixed partial salt of MVE/MA copolymer -- 20 '' 'j ' "~ OO '100 .-.l ' ':'' , . ' - ' ' ' ~ ,' :'"' ' ' ' ' ' . : ' ' , ,' :.
:. , :, : : . - . , '. ' ' '. ' ' , WO 9Z/1098~ PCl/US91/09467 Q~8'~88 -19-D. Gantrez S-97 acid copolymer 60 30 Sodium carboxymethylcellulose 40 40 70YO Ca/10/O Na mixed partial salt of MVE/MA
copolymer -- 30 lû~ lO0 : Said free acid MVE/MA copolymer, and the indicated mixed or unmixed partial salts of MVE/MA eopolymer which would have for the minus 140-mesh U.S.B.S. sieve powder, a bulk density greater than 0.5 grams per cubic centimeter while maintaining a specific surface area greater than 0.6 square meters per gram.
In use, the above powders (typically 0.1-1 9) are placed on a premoistened denture, allowed to hydrate briefly, and the denture is inserted in the mouth and pressed into place, all in the manner of denture adhesives well-known in the art.
ExamDle X
Liquid-type denture stabilizing compositions are prepared by mixing together the following:
% w/w A B
; 20 Mineral oil, heavy 44-9 43-9 Petrolatum 3.0 3.0 Colloidal silica - 1.5 1.5 . -Sodium carboxymethylcellulose . ~ 30.5 30.5 Menthol -0.1 0.1 47.5% Ca/17.5% Zn mixed partial salt of MVE/MA copolymer 20.0 55% Ca/5% Zn/10% Na mixed~partiàl s~lt of MVE/MA
. copolymer ~ - 20.0 .. . .. . . 1 00 . 0 1 00 . 0 In use, the above l~quids (typically 0.1-1 9) are placed on a premoistened denkure, allowed to hydrate briefly, and the denture is inserted in the mouth and pressed into place, all in the manner of denture adhesives well-known in the art.

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w,~ 92J1~)988 P~/U' ,91/~9467 ~,9~ 20-Cream-type denture stabilizing compositions are prepared by mixing together the following:
% w/,~
e B
Mineral oil, heavy 24.82424.824 24.824 Sodium carboxymethylcellulose 22.00022.000 22.00,r~
Petrolatum 19.01619.016 19.016 Silicon -d,ioxide, colloidal 1.100 1.100 1.100 0 Colorant (oil so,luble red, color ~ dispersion) 0.060 0.060 0.060 47.5%Ca/17'.5%Zn, mixed partial salt of MVE/'MA copolymer 33.000 55.0%Ca/5%Zn/10%Na mixed partial salt of MVE/MA copolymer ~ 33.000 ----7,'~% Ca/10% Na partial mixed salt of MYE/MA
copolymer ---- ---- 16.500 50% Zn unmixed partial salt of MVE/MA, copolymer ---- ---- 16.500 Said free acid MVE/MA cop,olymer, and the indi,^ated mixed or unmixed part-,al salts of MVE/MA copolymer which would have ~or the minus 140-mesh U.S.B.S. sieve powder, a bulk density greater than 0.5 ?.`; :'grams per cubic centimeter while maintaini,n,g'~'a specific sùr~face area greater than 0.6 square meters per gram.
; 25 ~ ~. In~use, the above creams ~typ kally-0.1-2 g) are placed on a premoistened denture, allowed to hydrate briefly, and the denture is ; ~in$erted in the mouth and pressed into place, all in the `manner of id,enture adhesives well-known in the art.

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WHAT IS CLAIMED IS:

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.

Claims (22)

1. A lower alkyl vinyl ether-maleic acid copolymer consisting essen-tially of the repeated structural unit:
(I) wherein R represents a C1 to C4 alkyl radical, n is an integer greater than one representing the number of repeated occurrences of said structural unit in a molecule of said copolymer and n is large enough to characterize said copolymer as having a specific viscosity larger than 1.2, the specific viscosity being determin-ed in methyl ethyl ketone at 25°C and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.

2. The partial salt of a lower alkyl vinyl ether-maleic acid copolymer consisting essentially of the repeated structural unit:
(I) wherein R represents a C1 to C4 alkyl radical, n is an integer greater than one representing the number of repeated occurrences of said structural unit in a molecule of said copolymer and n is large enough to characterize said copolymer as having a specific viscosity larger than 1.2, the specific viscosity being determin-ed in methyl ethyl ketone at 25°C, said partial salts containing from about 10% to about 40% free acid, and as the cationic salt function from about 0.1% to about 85% of the total initial carboxyl groups reacted with one or more of a cationic salt function selected from the group consisting of zinc cations, strontium cations, sodium cations, calcium cations, magnesium cations, potassium cations and ammonium cations and mixtures thereof and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.

3. The partial salt of Claim 2 wherein R is methyl.

4. The partial salt of Claim 3 wherein said cationic salt function is selected from the group of zinc, strontium, calcium, and sodium cations and mixtures thereof and comprises:
(a) from about 0.1% to about 65% zinc or strontium cations; and (b) from about 0.1% to about 75% calcium cations or sodium cations or mixture thereof of the total initial carboxyl groups reacted and from about 10%
to about 40% free acid.

5. The partial salt of Claim 4 which comprises from about 2.5% to about 30% zinc cations, from about 5% to about 20% sodium cations and from about 40% to about 70% calcium cations.
of the total initial carboxyl groups reacted and from about 10%
to about 35% free acid.

6. A partial salt of Claim 5 wherein said salt has a bulk density of from about 0.6 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.6 to about 2.5 square meters per gram.

7. A denture stabilizing composition having as a stabilizing compo-nent an effective adhesive amount of a lower alkyl vinyl ether-maleic acid copolymer consisting essentially of the re-peated structural unit:
(I) wherein R represents a C1 to C4 alkyl radical, n is an integer greater than one representing the number of repeated occurrences of said structural unit in a molecule of said copolymer and n is large enough to characterize said copolymer as having a specific viscosity larger than 1.2, the specific viscosity being determin-ed in methyl ethyl ketone at 25°C and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.

8. A denture stabilizing composition having as a stabilizing compo-nent an effective adhesive amount of a mixed partial salt of a lower alkyl vinyl ether-maleic acid copolymer consisting essen-tially of the repeated structural unit:
(I) wherein R represents a C1 to C4 alkyl radical, n is an integer greater than one representing the number of repeated occurrences of said structural unit in a molecule of said copolymer and n is large enough to characterize said copolymer as having a specific viscosity larger than 1.2, the specific viscosity being determin-ed in methyl ethyl ketone at 25°C, said partial salts containing from about 10% to about 40% free acid, and as the cationic salt function from about 0.1% to about 85% of the total initial carboxyl groups reacted with one or more of a cationic salt function selected from the group consisting of zinc cations, strontium cations, sodium cations, calcium cations, magnesium cations, potassium cations and ammonium cations and mixtures thereof and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.

9. The denture stabilizing composition of Claim 8 wherein R is methyl.

10. The denture stabilizing composition of Claim 9 wherein said cationic salt function is selected from the group of zinc, strontium, calcium, and sodium cations and mixtures thereof and comprises:
(a) from about 0.1% to about 65% zinc or strontium cations; and (b) from about 0.1% to about 75% calcium cations or sodium cations or mixture thereof of the total initial carboxyl groups reacted and from about 10%
to about 40% free acid.

11. The denture stabilizing composition of Claim 10 which comprises from about 2.5% to about 30% zinc cations, from about 5% to about 20% sodium rations and from about 40% to about 70% calcium cations.
of the total initial carboxyl groups reacted and from about 10%
to about 35% free acid.

12. A denture stabilizing composition according to claim 11 wherein said salt has a bulk density of from about 0.6 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.6 to about 2.5 square meters per gram.

13. A denture stabilizing composition comprising a safe and adhesive-ly effective amount of at least two denture adhesive components, wherein one of said denture adhesive components is a lower alkyl vinyl ether-maleic acid copolymer consisting essentially of the repeated structural unit:
(I) wherein R represents a C1 to C4 alkyl radical, n is an integer greater than one representing the number of repeated occurrences of said structural unit in a molecule of said copolymer and n is large enough to characterize said copolymer as having a specific viscosity larger than 1.2, the specific viscosity being determin-ed in methyl ethyl ketone at 25°C and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.

14. A denture stabilizing composition comprising a safe and adhesive-ly effective amount of at least two denture adhesive components, wherein one of said denture adhesive components is the mixed partial salt of a lower alkyl vinyl ether-maleic acid copolymer consisting essentially of the repeated structural unit:

(I) wherein R represents a C1 to C4 alkyl radical, n is an integer greater than one representing the number of repeated occurrences of said structural unit in a molecule of said copolymer and n is large enough to characterize said copolymer as having a specific viscosity larger than 1.2, the specific viscosity being determin-ed in methyl ethyl ketone at 25°C, said partial salts containing from about 10% to about 40% free acid, and as the cationic salt function from about 0.1% to about 85% of the total initial carboxyl groups reacted with one or more of a cationic salt function selected from the group consisting of zinc cations, strontium cations, sodium cations, calcium cations, magnesium cations, potassium cations and ammonium cations and mixtures thereof and wherein said copolymer has a bulk density of from about 0.3 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.5 to about 2.5 square meters per gram.

15. The denture stabilizing composition of Claim 14 wherein R is methyl.

16. The denture stabilizing composition of Claim 15 wherein said cationic salt function is selected from the group of zinc, strontium, calcium, and sodium cations and mixtures thereof and comprises:
(a) from about 0.1% to about 65% zinc or strontium cations; and (b) from about 0.1% to about 75% calcium cations or sodium cations or mixtures thereof of the total initial carboxyl groups reacted and from about 10%
to about 40% free acid.

17. The denture stabilizing composition of Claim 16 which comprises from about 2.5% to about 30% zinc cations, from about 5% to about 20% sodium cations and from about 40% to about 70% calcium cations of the total initial carboxyl groups reacted and from about 10%
to about 35% free acid.

18. A denture stabilizing composition according to claim 17 wherein said salt has a bulk density of from about 0.6 to about 1.2 grams per cubic centimeter and a specific surface area of from about 0.6 to about 2.5 square meters per gram.

19. The denture stabilizing composition of Claim 5 wherein said polymeric material is selected from the group consisting of natural gums, synthetic polymers, saccharide derivatives, cellu-lose derivatives, and mixtures thereof.

20. The denture stabilizing composition of Claim 8 wherein said polymeric material is selected from the group consisting of natural gums, synthetic polymers, saccharide derivatives, cellu-lose derivatives, and mixtures thereof.

21. The denture stabilizing composition of Claim 12 which further comprises from about .01% to about 5.0% of menthol, menthyl lactate, peppermint oil, spearmint oil, peppermint oil, leaf alcohol, and paramenthane carboxyamides, and mixtures thereof.

22. The denture stabilizing composition of Claim 17 which further comprises from about .01% to about 5.0% of menthol, menthyl lactate, peppermint oil, spearmint oil, peppermint oil, leaf alcohol, and paramenthane carboxyamides, and mixtures thereof.