CA1089789A

CA1089789A - Enzyme and active oxygen containing denture cleanser tablet

Info

Publication number: CA1089789A
Application number: CA268,299A
Authority: CA
Inventors: Norman A. Levin; Leonard L. Kaplan
Original assignee: Johnson and Johnson
Current assignee: Johnson and Johnson
Priority date: 1975-12-22
Filing date: 1976-12-20
Publication date: 1980-11-18
Also published as: GB1527010A; US4155868A; IE44517L; AU2065376A; IE44517B1; AU510235B2

Abstract

ENZYME AND ACTIVE OXYGEN
CONTAINING DENTURE CLEANSER
TABLET

ABSTRACT OF THE DISCLOSURE
A completely water soluble effervescent denture cleanser tablet containing both an enzyme and one or more active oxygen compounds. The enzyme in said tablet is resistant to premature inactivation by the oxidizing agents in the tablet during storage and in use and therefore has the added enzymatic cleansing power not possessed by conventional tablets containing only the active oxygen compounds. A method for preparing enzyme-containing denture cleanser tablets in which the activity of the enzyme is usefully retained is also described.

Description

3'37~39 ~:-DESC~IPTION OF THE INVEN~ON
' This invention relates to denture cleanser tablets and, more particularly, is directed to an improved completely water- -soluble denture cleanser tablet contain~ng enzyma~ic cLeansing agents.

Dentures may be cleansed either by ~mmersion ~n a cleansing solution or by brushing with a cleansing agent in the manner of natural teeth. The former method is generally a preferred method, partly from the standpoint of convenience but atso where dentures are of plastic, brushing tends to mar the smooth sus~aces. Cl-ansing solutions may be preformed l~quid solution5 but for storage con~enience are usually ~n the solid form and the cleansing solutions prepared at the time of use by dissolving the solid cleanser in tap water. The solid cleanser ~ay be in the form of loose p~wder or granules or may be in the form of tablets. The ta~let ~orm is the preferred form since loose granular or powdered forms, even where promeasured, is subject to spillage and loss, and is further subjèct to ~o~sible inhalation and contact with the ~kin which should be avoide~ because of the toxic, alXaline or other hazardous nature of the cleansing agents.

., , . ~

~he usual denture cleanser tablets have, as primary active cleans~ng agent, one or m~e peroxygen or act~ve oxygen compounds such as sodium perborate monohydrate, sodium perborate tetrahydrate, pota~siU~ per~ul~ate, ~odium carbonate peroxide and the li~e, which cause the tablets to evolve m~crobubbles of nascent or active oxygen as they are dissolved in water and provide an axid~zing clean~ing action including a bleaching effect on denture stains.
Frequently, a hypochlorite ~on forming oxidizing ag~nt i5 also included to provide additional oxidizing cleansing action~
U~ually it $s dichloro$socyanuric acid or ~t~ alkali metal salt but it ~ay be sodium chloride which in the presence of ~eroxygen compound. forms hypochlorite. Generzlly, a minor amount of surfactant is also added to lower the surface tension and to enhance the cleans$ng action..

Denture cleanser tablets also contain an effervescence producing composition consisting of acids, ~uch a~ citric and tartaric acids or acid phos~hates and a carbonate such as sodium bicarbonate, the interaction of which generates carbon dioxide bubbles as the tablet dis~ol~es when it is placed in water, thereby providing a mec~anical cleansing action as well as aid to the disi~tegration of and the complete di3solution of the tablet. ~sually, to prevent the generated carbon dioxide bubbIes Çrom adhering to the dissol~ing tablet and hindering the sol~ent ac~ion of the water, they may contain an anti-foam 1~ ~ 97 ~ ~

s~licon~ such a~ dimethyl polysiloxane.

ln addition, denture cleanser tablet~ usually conta$n var~ OU5 other relatively inact~ve ingred~ents such as f~llers, ext-nders, binders, indicators or dyes and flavors, etc.
~ormulat~ons for denture cleanser tablets also contain a lubricant system which is incorporated to facilitate smooth and even flow of the dry granular materials of the formulations during tabletting operations.

~he desirability of add$ng enzymes to denture cleanser tablets has been recognized~ Food materials, mucin which is primarily a glycoprotein, and plaque which is primarily prote$n but also carbohydrate in nature may be attacked by appropriate enzymes. Plague matrix composed of salivary proteins, ~acteri~l cell~, polyglucans, etc. tend to retain h~ghly colored materials uch as berry, grape, tea, coffee and tobacco s~ains because they are embedded or ~locked into~
the plaque ~atrix. Certain stains, part$cularly berry and -grape ~tain~ ase part$cularly tenaciously held and therefore dlfficultly removed. A~though $t would be desirable to in-corporate enzymes ~n tablets, useful incorporation has not been accompll hed heretofore becaus~ of the $nactivating effect of active oxygen compounds when compressed with the enzyme.
Moreover, ce~t~in combination of ingredients are not tabletable.
Because of thl , enzymes $n denture cleanser tablets have not previously been realized successful~y snd tablets containing 108~'78~
enzymes are not readily available. In addition, since the en-zyme is rapidly deactivated ~y the active oxygen compound when the composition is placed in water for use, tabletting is avoid-ed. Although denture cleanser compositions which include dex-tranase or lipase in the composition are disclosed in U.S. Pa-tent 3,630,924 and 3,855,142 respectively, non-tablet cleans-ing compositions are illustrated and it is not shown how a proteolytic enzyme or any enzyme may be usefully incorporated in a tablet containing an active oxygen compound.
It is desirable therefore to provide for a denture cleanser in tablet form which will supply an enzymatic cleans-ing action not only to attack the food materials that are loosely bound to the mucin and plaque but preferably to attack the protein of the plaque matrix thereby removing the adhering and embedded stains, particularly stubborn stains such as ber-ry and grape while at the same time providing the oxidizing, bleaching and other cleaning functions usually provided by rea-dily available tablets.
According to the present invention, there is provided a water-soluble denture cleanser in tablet form comprising an en-zyme and at least one active oxygen compound in an effervescent composition in which each of the cleansing functions, namely the enzymatic, the oxidizing and the mechanical cleansing actions are usefully effective. The tablet is resistant to pre-mature inactivation of the enzyme by the oxidizing agent in storage and in use. mus, in the tablets of the present inven-tion the retention of the usefully effective enzymatic cleansing ~, . .

3~ 3 activity provides not only for superior cleansing but also for accomplishing it in a shorter time than heretofore possible.
In accordance with a broad aspect of the invention, there is provided a completely water-soluble enzyme and active oxygen containing denture cleanser tablet, wherein said tablet includes an effervescence producing composition comprising an acid and a carbonate compound as well as a water-soluble lubricant, and wherein said tablet contains from about 0.3 to 3.5 percent by weight of enzyme, which is present as a finely divided powder, as granules or as coated prills, from about 30 to 50 percent by weight of at least one active oxygen compound, which is present as granules, and from about 45 to 65 percent by weight of said effervescence produc-ing composition, which is present as coated granules; said amounts being based on the total weight of tablet, the mois-ture content of said tablet being no greater than about 0.1 percent based on the total weight of tablet.
! The denture cleanser tablet of the present invention is a single layered tablet in which an enzyme, active oxygen compounds and an effervescence producing composition, provide for the enzymatic, oxidative and mechanical cleansing func~
tions respectively, are incorporated in such a manner that they are retained in a usefully stable form until the tablet is ready for use. The tablets of the present invention are prepared by careful control of the particle sizes and surface treatments of selective components as hereinafter more fully described and further by Icareful control of the moisture level during the preparation as well as in the final product.
In the tablets so prepared, the enzyme is not detrimentally inactivated during storage and further is readily released on the dissolution of the tablets during use, permitting 101~9789 enzymatic cleansing activity to initiate before the dissolu-tion of the active oxygen compound reaches a level which would totally inactivate the enzyme. Moreover, the effer-vescence producing composition aids dissolution and provides mechanical cleansing action without significantly impairing the cleansing action of the other components.

-6a-~1 ., ... . . . ... , ,._ .. - - .. - .~ . . .

'7~39 In the denture cleaner tablet of the present invention, the enzyme is incorporated in and is present as a finely divid-ed powder, granules or as coated prills, the peroxygen or ac-tive oxygen compound as granules and the effervescence produc-ing compositions as coated granules. It is further critical and essential that the incorporation of the active components be carried out in a stepwise manner as hereinafter described.
Moreover, the preparation is carried out in such a manner that durinq manufacture the moisture levels at all times is no greater than about 0.5 percent and thereafter i~ further re-duced in the finished tablet to less than about 0.1 percent, preferably less than 0.05 percent. In the specification and claims when describing the components as being present as pow-der, granules or within a particular particle size range, re-ference is being made to the discrete particles which are being added to the tablet formulation and which retain their identity within the gross tablet structure.
me enzyme component of the novel tablets is at least one enzyme which is useful for acting on food, food degrada-tion products, mucin and plaque. A preferred embodiment ofthe present invention contemplates a tablet in which the enzyme is a proteolytic enzyme. However, the methods for preparing compressed denture cleanser tablets containing both enzyme and active oxygen compounds in which the enzyme is resistant to premature inactivation is applicable to all enzymes in-cluding non-proteolytic enzymes such as carbohydrases, lipa-ses, amylases, dextranases, etc. The enzymes may be of plant, animal or microbial origin. Many are available commercially under various trade names and are suitable for the present use.

.

~'3'~ ~

The enzyme~ may be in a powdered, granular or prilled form. When it is to be employed as a powder, ~t ~s generally of particle size sufficiently small to pa-cs through a No. 200 sieve. Mes~, screen or sieve number as herein employed refers to the number of openings per linear inch as set forth by the U.S. Bureau of Standards and the relationship to particle size is found ~n standard references such a ~em$nqton's Pharmaceutical Sciences, 14th edition, Mack Publ~shing Company, 1970. Generally speaking, the enzymes of particle size to pas~ through a ~o. 203 sieve are about 74: microns ~) or les~
in diameter, and may range in size from about 50 microns to abcut 74 microns. The enzyme4 are usually available commercially in a ~uitable partic~e size having been prepared by spray drying.

Preferably, to provide added stability while in the dry tablet, the enzyme may be granulated or coated with a non-detergent low ~elting solid, preferably one with a melting or softening point ~eLow about. 100F. A preferred coating agent ~-i~ micronized polyethylene glycot 6000 (polyethylene glycol with average molecular weight of 6000). When employed as granules or prills, the.particle size is no greater than that which will pass throuqh a No. 20 sieve. Prills may be formed 1()~19789 employing the ~oregoing polyethylene glycol 6000 and pril~ng by convent~onal procedures.

The peroxygen or active oxy~en component of the tablet is of at least one compound which forms hydrogen peroxide or nascent oxygen when placed in solution. $t is-to be distinsuished from other oxidizing agents such as those which form hyprochlorite ion or chlorine and which are fre~uently present in denture cleansing compositions.
This distinction i5 imnortant since the latter has been found to inactivate the enzyme on tissolution and are therefore not conte~plated as the ox~dizing agent in the instant dent~re cleanser ta~lets. In this connect$on,it is to be noted that inorganic chlorides such as sodium chloride which forms hypochlorite in the pre ence of peroxygen compounds are also to be avoided. Suitable active oxygea compounds include sodium perborate monohydrate and tetra-hydrate, potassium persulfate, sodium carbonate peroxide, diperisophthalic acid, potassium peroxydiphosphate, and sodium aluminum aminohydroperoxide.

The peroxygen or active oxygen component must ~e in a granular form and c~ particle size such as to be retained by a ~o. 200 sieve. ~hus, it is larger than about 74 microns ~ut no greater than about 840 microns, i.e., it passes through a No. 20 sieve.

.- . . , . . . ~ .
. .

The effervescence producing composition is a carbon dioxide generating mixture comprising a carbonate compound and an acid. By "carbonate compound" is meant an alkali me-tal carbonate or bicarbonate, such as for example carbonate or biearbonate of sodium or potassium. me acid component is preferably citric or tartaric acid or mixtures thereof but may be other water soluble aeids including mixtures thereof such as, for example, sodium or potassium acid phosphates, glueo-nic acid, malic acid, etc. me acid and the carbonate eom-pound are generally employed in approximately stoichiometricamounts although a very slight excess of acid may be employed to effeetively generate the potential carbon dioxide. Large excesses of acid are generally not desirable especially if the enzyme has an optimum pH in the neutral range as is the case with most proteases.
The effervescenee produeing eomposition is employed in granular eoated form. It is eontemplated that some of eaeh essential component of the effervescence producing eomposition, namely the aeid and the earbonate compound are present in eaeh diserete partiele of the granules. By granular form is meant of partiele size to pass through a No. 16 sieve but be retain-ed at least by a No~ 100 sieve (about 149 mierons) and gene-rally in the range of partieles passing through a No. 20 ~about 840 mierons) sieve but retained by a No. 70 sieve (about 210 mierons). me preparation of the granules and the desired coating thereof may be aeeomplished simultaneously.

1~)8~7~

Preferred coating agents are the polyvinylpyrrolidones, par-ticularly those of K-values (Fikentscher's viscosity coeffi~
cient) in the range of 26 to 32, which may further function as binders in tablet formation. me preparation of the coated granular effervescence producing composition may be carried out as a first step in the tablet producing procedure or may be carried out as a prior separate step. Moreover, the pre-paration may be modified to provide for inclusion of the enzy-me during the granulation step: it is not permissible to in-clude both enzyme and active oxygen compound in the granula-tion step.
A component which has no cleansing function but is necessary to provide the desirable properties and further is necessary in tablet preparation is a lubricant. In the pre-paration of the tablets of the present invention water-soluble lubricants are contemplated and the preferred lubricant is a two component system having as components (a) magnesium lauryl sulfate in the form of a dry powder having an average particle size ranging from about 12 to about 20 microns, preferably about 16 microns and (b) micronized polyethylene glycol of average molecular weight in the range 6,000 to 20,000, and which is the subject matter of Canadian Patent Application No.
1,0~1,779 issued April 3, 1979, inventor Norman A. Levin.
Alternatively, magnesium lauryl sulfate along may be employed.
Generally, for better cleaning purposes, a minor amount of surfactant is included. Suitable surfactants 9'7~ ~

~nclude anionic water-soluble salts of organic ~ul~oxy compounds having in their molecular ~tructure an alky~ or acyl radica~ of carbon content with~n the range o~ about 8 to 18. Representative groups are alkali metal al~yl sulfates, sulfoacetates and benzenesulfonates. A preferred ~urfactant is sodium lauryl ~ul~oacetate.

In ~ddition, certain optional ingredients may be ~ncorporated. Generally, an indicator dye and a flavor -~ngredient are included. In addit~on, anti-foam agent may ' be added. Since a completely water-~olubl~ tablet ~s contemplated, in~oluble f illers and nonessential ingredients other than the foregoing,are avoided.

Suitable dyes for inclusion in the tablets are those which are readily oxidized by the peroxygen compound in about fifteen to thirty minutes and may be one having cyclo-hexadienimine nucleu~ and available a~ FD~C Green ~1 (Guinea Green B), FD 6 C Blue #2, or other dyes including azo dye~. Suitable flavorinq include spray dried powders of peppermint a~d others flavor oils conventionally employed in dental preparations. ~11 components, essential o~ optional, are employed in a purity appropriate for pharmaceutical use and are readily available commercially.

J

~ 9 Tho amounts of the acti~e components w~ll vary depend~ng on the particular enzyme, active oxygen compound, acid and carbon~te compound. When broadly expressed as weight of component per total weight of tablet, it may be found to lie within the following ranges: the enzyme from ab~ut 0.8 to 3.5 percent: the act~ve oxygen compound~ from about 30 to 50 percent; the effervescence producing composition comprising an acid and an al~ali ~etal carbonate compound from about 45 to 65 percent. More specifically, the enzyme is employed in an lo amo~nt of from about 2S mg to 50 mg per 3 gram ta~let. ~he active oxygen component may be supplied as a single active oxygen compound or as a mixture ~usually two) of active oxygen compounds. ~Since different acti~e oxygen compounds supply different amounts of active oxygen, the amount of com~ound or compound~ employet ~s usually that suffic~ent to ~upply active oxygen ~n an amount of from about 3.5 percent to about 4.5 per-cent by weight based on the weight of final tablet. In the effervescence producing composition, the acid or acids and carbonata compound ara employed in substantially stoichiometric amounts and the amount emgloyed are such sufficient to produce about 8 to 12 millimoles of car~on dioxide or about ll to 18 percent by weight of casbon dioxide by weight o tablet.
It i~ contomplated that this may be accomplished by providing ~t least about 45 percent of the total weight of the tablet to be of the effer~escence producing composition. This is essential 1~ ~'3';~8~

for rapid disintegrat$on of the tablet to occur prior to substantial release of the peroxygen compound.
In addition, the amount of acid to be included in the effervescence producing composition ~ust be selected with consideration of the pH of the solution resulting when the tablet is dissolved in water. ~ailure to observe this con~ideration may result in premature deactivation of the enzyme. The formulations should be adjusted so that on dissolution of the tablet, the pH is in the range for optional enzyme activity of the particular enzyme used~ ~n the case of a neutral protease, the opt~mum pH range is from about pH 6.0 to about pH ~.5.

The other components may be employed i~ amounts herein-after designated. The poly~inylpyrrolidone coating agent ~s employed in such amounts as to constitute ab~ut ~.5 to 1 percent of the tablet weight~ It is e~ployed by initially ad~ixing with the effervescence producing composition to produce coated granule~ and the amount employed for this initial mixing is from 1 to 2 percent by weight of the ~ranules.

The amount of water-soluble lubricant employed may be up to S percent, preferably, in the range of from about 0.5 to 1 percent by weight of the tablet. When the lubricant is the preferred lubricant system comprising magnesium lauryl sulfate powder and micronized polyethylene glycol 6000, the l~t-~.

3~89 amount of the former is in the range of from about 0.1 to 0.3 percent and the latter in the range of from about 0.2 to 0.4 percent. Alternatively, magnesium lauryl sulfate alone may be employed and the amount is essentially the same as the amount employed with the polyethylene glycol.
Surfactants when added to improve wetting properties usually do not constitute more than about 3 percent of the total weight of tablet. Preferably, small amounts are added, usually in the range of from about O.S to 1 percent.
Spray dried powder flavoring, when employed, may be added in amounts of from about 1 to 3 percent. Dyes or color-ing, if employed, are usually in the range of from about 0.05 to 0.1 percent. A water-soluble dye syste~ may be usefully employed as a timing indicator of cleaning accomplished.
Thus, a dye system with a fade time of 12 to 15 minutes could be employed to indicate substantial completion of cleaning of the denture. All optional ingredients constitute no more than about 3 percent of the total weight of tablet and are contemplated to be completely water-soluble.
The denture cleanser tablets may be produced by first preparing a coated granular effervescence producing composi-tion comprising an acid and a carbonate compound mixture by adding thereto a solution of polyvinylpyrrolidone, drying to the desired moisture content, screening to the appropriate particle size: thereafter blending the coated granular ~ 8~

effervescence producing composition so prepared with appropriately dried enzyme, active oxygen compound, and other components; and finally, adding a water-soluble tablet lubricant or lubricant system, compre~sing into tablets and drying to the critical moisture level. rn order to achieve denture cleanser tablets having the desired properties, Qubstantial departure from the fore-going steps in the preparation shoula be aYoided. Thus, it i5 critical and essential that all components not be intermixed during the granulation procedure. The tablets may then be packaged for subse~uent use for effectively cleanin~ stained and soile~ dentures.

A preferred method for prepasing the denture cleanser tablets is in the following stepwise manner. As an initial step, an effervescence producing composition in the for~
of coated granules is prepared by dissolving polyvinyl-pyrrolidone in alcohol solution that can be 50% a~ueous to completely anhydrous, preferably 190 proo~ eth~l alcohol, and adding it to a dry pre-bLended mixture of acid and car~onate compound (optionally pre-blended with a dye) and thoroughly blending the result~ng mixture for severaL (3 to 5) minutes to form a granular coated effervescent compos~tion.
The wet granular mass is ~ried to a moisture level no greater than about 0.5 percent. This is convenientiy accomplished by drying in a forced air oven at temperatures in the range ~ 8~3'~8 9 of about 45 to 55 C., preferably at about 50C for about 15 to la hours. The dried mass is then screened to obta~n a granular coated effervescence producing composit~on of particle ~ize that w~Ll pass through a No. 16 sieve. The ~ranules may be $mmediately employed in the next step or stored for future use.

In the next step, the essential e~zyme and ~ctive oxygen compound cleansing components as well as remaining components are combined with the granular, coated ef~ervescence producing compositions. This is carried out by adding to the screened mass at least one active oxygen compound, at least one enzyme, a surfactant and ~f employed, flavoring and other optional ingredients and blending the resulting mixture, usually ~or about 15 to 25 minutes. It is critical and essential for the moisture level in this step to be no greater than about 0.5 percent and care is taken to employ components which have been dried previously to at least this level of dryness. Ther~after, the cleansing composition are formed into tablets by first adding to t~e m~xture a water-soluble lubricant or lubricant system, preferably the latter as a dry powdered magnesium lauryl sulfate and micronlzed polyalkylene glycol mixture, blendin~ -the resultin~ mixture for about S to }0 minutes, and then ~eedi~g into a tablet press and compressing into tablets.

, , ' ' ' .

1~ 8~7 ~ ~

The tablets are then dried to a moisture content of no greater than 0.1~ and preferably of less thanO'.05~, This is convenient~y accomplished by drying in a forced air oven in the range of from about 175 to 185 F, preferably about 180P for from 2 to 4 hours. In the tablets thus prepared, the effer~escence producin~ compcsition, the enzyme and the peroxygen comp~und retain their identity within the gross tablet structure. Moreover, surprisin~ly,useful enzyme activity is not lost during this terminal drying step and thus each component of the tablet is capable of performinq its intended function.
The preparation of the coated effervescence producing granules may be carried out as a prior separate operation althougn carrying out the preparation as an initial step in the tablet forming procedure is preferred. ~he coating agent preferably is prepared by dissolving the coating agent, polyvinylpyrrolidone, in about 9S percent aqueous alcohol~
Although ethanol is preferred, isopropyl alcohol may be employed in the coating and granulation step. Also, although 95 percent (190 proof) alcohol is preferred, anhydrous ~200 proof) alcohol may be employed, and further, in small ~atch preparations even 50 percent a~ueous alcohol may be employed without adverse effect on formation of the coated granules provided the mixing tLme is no more than three minutes and there is appropriate 1~)83';'B9 drying of the granules prior to use in subsequent tablet for-mation. me concentration of the polyvinylpyrrolidone there-in is generally in the range of 20 to 30 percent ~weight by volume). A 20 to 25 percent solution in 190 proof ethanol is preferred.
The enzyme may be precoated with a water-soluble wax such as polyethylene glycol 6000. If the enzyme is employed in a coated form, the coated enzyme may be prepared by blend-ing the dry enzyme or enzymes and polyethylene glycol 6000 or other water-soluble wax for about 10 minutes. Preferably it is prilled by blending with molten low melting wax and forcing the melt through a nozæle of a size to produce prills which will pass through a No. 20 sieve. Precoating of enzymes un-expectedly have been found to be unessential provided that the stepwise procedure is observed during the preparation of the tablet and the critical drying steps are not overlooked.
The effervescent enzyme and active oxygen containing denture cleanser tablets prepared as described are employed to clean dentures by placing in water with the denture to be cleaned for time sufficient to effect the desired cleaning.
The tablets may be from about 2.5 to 3.5 grams in total weight and are usually employed with warm water, preferably initially about 100 to 120 F in an amount sufficient to completely co-ver the denture. Generally, this amounts to from about 60 to 180 milliliters or 2 to 6 ounces. When so employed, effect-ive and desired cleaning may be achieved in about 15 to 20 minutes but in more highly stained dentures. longer .. --19--1~)89'789 periods may be desirable. ~he tablets when thus employed are found to effectively remove mucin, plaque, berry and grape stains not readily removed by tablets not containing enzymes. The tablets of the present invention also removes coffee, tea and other stains. Moreover, this is accomplished without brushing and usually without the overnight soaking necessary with the generally available tablets. Thus, unex-pectedly the desired enzyme activity is not detrimentally affected by the active oxygen compounds in the denture clean-ser tablets prepared according to the present invention.
me following examples illustrate the invention but are not to be construed as limiting:
EXAMPLE I
A coated effervescent composition is prepared first by dry blending 739 grams of anhydrous citric acid powder, 897 grams of granular sodium bicarbonate (Church and ~wight, No. 5, of particle size to be retained on No. 170 sieve), 2.7 grams of Guinea Green B (dye), and 0.1 grams of D ~ C Yellow No. 10 (dye). To the blend is added a previously prepared solution of 30 grams of polyvinylpyrrolidone (K 29-32) in 40 milliliters of a 50 percent aqueous solution of 190 proof ethanol and mixing for about 3 minutes, thereafter drying about 16 hours in a forced draft oven at 50F., and finally screening through a No. 16 screen.

:.. . , ~ '~ .. , ' 1~)8~' 89 The screened coated granular effer~escent composition thus prepared is placed in a twin shell ~lender and ~here is added thereto 555 grams of granular sodium perb,orate ~ona-hydrate, 689 grams of granular potassium monopersulfate, 63.6 grams of spray dried peppermint 1avor, 20 grams of sodium lauryl sulfoacetate, and 25 grams of bacterial protease of 3 Anson Un~ts (activity based on tyros~ne released from hemo-globin as sub~trate) and the resulting mixture blended for about L5 minutes. Thereafter, 5.13 grams of magnesium lauryl sulfate and 10.25 grams of ~icron~zed polyethylene glycol tav. m.w~ 6000) are added, the mixture blended for about 5 minutes and then fed ~nto the hoppers of a tabletting press : ::
where they are compressed into one thousand, 7/8 inch diameter, 3.05 gram tablets havin~ a Stokes hardness of 13 kilograms.

The ~lets are then dried at about 180~ F. for about 2 hours in a forced air oven to reduce the moisture from about 0.36 percent to ~.03 percent and are then strip packaged in 1 mil hermetic foil packets.

The tablets thus prepared are effective in removing oral depos~ts such as pla~ue, food particIe~ and stains which tend to accumulate on dentures. The cleaning properties may be seen employing stained acrylic pla~es as models for stained dentures.

The stained acryl~c plate models are prepared by applying via an aerosol spray to the surface of roughened acrylic plates a well-beaten mixture employing 120 grams egg yolXs, 12 grams of .

1~)8~7B5~

grape ~u~ce concentrate, and 8 grams burnt sugar coloring.
The sprayed plates are heated for two hours at 50C to set the stain.

Tn determinatIons for the effectiveness of the tablets of the present invention, the:plates are placed in 180 milliliters of tap water at 110F. and the tablets Individually dropped therein wherei~ bubbles begin to evolve immediately with complete dissolution of the tablet within about 90 seconds. ~he p~ of the solution Is approximately 6.2-6.3. Observation of the plates after 15 minutes shows that from about 70 to about 95 percent stain removal may be obtained.

. P: . - ~ .. . .................... . . ~
,:, , . :

-` 108'~f89 EXAMPt.E ~I
rn an opexation carried out i~ a manner similar to that de~cribed in Example I, an effervescent compositton first is prepared in a ~ranular form rom the following formulation:
Component Amount Citric acid ~anhydrous) 92.4 ~g Sodium bicarbonate ~Church 6 Dwight No. 5) 112.1 kg Guinea Green B (green dys) 336.2 5 10D ~ C Yellow No. 10 tyellow dye) 12.5 g ~.

Poly~inylpyrrolidone ~ 29-32) 3,750.0 g IgO proof alcohol 16.0 liters The preparat~on is carried out by (1) preblending the green and yellow dyes with 10 k~logramc each of citric acid and sodium bicarbonate, (2) admixing the preblend with the remaining citric acid and sodium bic rbonate at high speed in a production size Day Pony ~ixer for about five minutes, (3) adding thereto over a period of about one minute a solution of the polyvinylpyrrolidone in alcohol and continuing the stirring for an additional 3 minutes, and ~4) drying for 16 hours at 50C.

Tablets are prepared employing two lots of ~ranules prepared as above described together with the components .

lV~39~7t3 listed Selow:
Component Amoun~
Bacterial pro~ease t3 Anson Un~ts) 6,250.0 g.
Peppermint flavoring 15.9 kg Sodium perborate monohydrate 138.7 kg Potassium monopersulfate L72.2 kg Sod~um lauryL sulfoacetAte 5,000.0 g.
Magnesium lauryl sulfate . 1,281.2 ~.
Polye~hylene glycoL 6000, micronized 2,562.S g.

The tablet preparatio~ is carried out b~ (1) p~acing in a 30 cubic foot twin shell blender the two lots of effervescent composition granules after first screening through a No. 10 screen, .~2) adding thereto the enzyme, flavoring, surfactant and the active oxygen compounds and blending for lS minutes, ~3) adding to the resulting mixture micronized polyethylene ~lycol 6000 and magnesium lauryl sulfate ~pre-sieved through a No. 40 sieve) and blending for 5 minutes, and (4) compressing ~nto 125,000 tablets. The tablets are dried for 4 hours at 80C Ln a forced air oven w$th 750 ~eet per minute air velocity :`:
and then strip pac~aged in her~etic oil pac~ets.

-.24-.
., ~ . .

_ ~ .
lV~97~39 EXAMPLE III

Tablets prepared in a manner descriSed ~ Example II
are sub~ected to aging at room temperature and accelerated aging by ma~ntaining at temper~tures of 100F. and 120F.
for 1 mont~. At the end of this period, the t~blets are examined for cleansing effectiveness by conduct~ng duplicate stain removal studies on acrylic plates in a manner similar to that descri~ed in Example r. For comparative purposes, a tablet similar in composition but not containing en2yme (~Placebo~) and a commercial~y available non-en~yme denture cleanser tablet, simi~arly aged at room temperature are also examined for cleansing ef~ectiveness.

The results are as follows:

TAB~E I

Tablet Percent Stain Remo~al . A rage o~ Two Results Aged at room temperature ~-70F) 78.6%
n ~ 10 0 F -" ~ 120F. 65.2~ :
20 Placebo 23.9%
Commercial Tablet 24.6%

.; . ' ' ' . : ' 0~ 3~8 9 . EXAMPLE IV

Tablets prepared in a manner similar to that described~n Exa~ple I~ are highly effective ~n the removal o~ coffee and tea stains as seen by tests carried out by placing a tablet in 125 milliliter~ o~ water of 115-120P, placing thereln acrylic ti~es previously ~tained with coffee or tea and making observations at 15 minute and overnight intervals~
The average results of observat$ons and judging by seven separate panel.members are seen ln Table II.

The te~t tiles employed are approximately 1~ x 1~ of acrylate co~monly used in dentures and are stained prior to the test by pLacing the tiles in a concentrated coffee or tea solution, heating for 6 to 8 hours at 180 - 200 F, :
followed by ~aintaining it at 80C for sixteen hours to set the stain.

TAB~E ~I
Percent Stained Substrate & ?ime of ~mmersion Stain ~emoval Coffee, 15 minutes 91 -~
20 Coffee, overnight 97 :
Tea, 15 minutes 78 Tea, overni~ht 97 ~-1~)897~5~

EXAMPI,E V

Tablets prepared in the manner aescribed in ~xample II
are employed in tests to determine ef~ectiveness in removing heat set egg yolX-blueberry stain ~rom acrylic plat~ surfaces and compared with n~n-enzyme containin~ commercial tablet denture cleansers. The test s~mulates effectiveness in removal of blueberry stain locked ~n plaque on the surfaces of acrylic dentures.

For the test, three pronged acrylic plates are employed, each prong being about 2 3~4 inch x 3 inch and previously roughened to a non-reflectin~ matte finish. Each prong ~s sprayed uniformly with an aerosol spray of an egg yolk-blueberry stain prepared by blending to a syrup, 120 grams of egg yolk, . 12 gram9 of ~lueberry pie filling and 8 grams of burnt sugar coloring, then,adm~xing 66 grams of the syrup with 132 grams of water to a uni~orm dispersion and thereafter appropriately fill~ng and cha~ging in an aerosol spray can. The sprayed plate~ are placed in a forced air oven (Sl feet per minute) at 50C for 2 hours to set the stain.

In the test, each prong is placed in a separate container filled with 200 milliliters of tap water at 100F. To one container there is placed a tablet prepared as described in Example II and to each of the other containers are placed different co~mercial non-enzyme containing denture cleanser tablets identified as Commercial Tablet A and Commercial Ta~let B. The plates ar~ allowed to soak ~or 15 minutes, then r~nse dipped in the soak so~utions and drained. The plates are then examined visually to determine the percent stain remove~. The average results of five tests are as follows:

TAB~E III

Tablet . Percent Stain Removed 10 Exa~ple II 91.1 Commercial Ta~let A 15.7 Commercial Tablet B 13~3 -, .

~V~789 EXAMPLE VI
Employing tablets prepared in a manner described in Example II and aged by maintaining at 70F for six months as well as freshly prepared tablets and commercially avail-able non-enzyme containing tablets, quantitative tests are conducted to determine effectiveness in removal of locked-in blueberry stain from acrylic plates.
Blueberry-egg yolk stain prepared as described in Example V are sprayed onto weighed acrylic plates ~2"x4") the surfaces of which are previously roughened to a non-reflective matte finish with carborundum paper. After heat setting the stain as previously described, the plates are weighed to find the net weight of stain. The plates are soaked for 15 minutes in test solutions prepared by separate-ly dissolving the tablets in 180 ml. of 110F. tap water. The plates are then removed, dried and reweighed. After correct-ing for weight of stain on the portion of plate not immersed.
percent stain removed is determined. The mean results of five tests for aged, unaged and non-enzyme commercial tablets are seen in TABLE IV:
TABLE IV
Tablet Percent Stain Removed Example IV (Aged) 94.0 Commercial Tablet A 27,5 Commercial Tablet B 40,9 Example IV (Not Aged) 94.0 ~ he denture cleanser tablet desc~i~ed in the fore-going examples merely ~llustrates one of the preferred combination of ingredients, and other ingredients previously described may be substituted ~or one of the foregoing or may be included additionally within the l~mitations preYiously ::
~et fort~. Moreover, the amounts by we~ght o~ the ~ngredients in t~e preferred combination may be expressed in terms of weight based on the weight of the final tablet as follows:

1) an enzyme, about 0.8 to 1.6 percent: :

2) sod~um perborate monohydrate, about 13 to 22 percent, and potassium persulfate, about 17 to 29 percent;

3) citric acid powder, about 20 to 30 percent,

4) granular sodium bicarbonate, about 25 to 35 percent;
S) sodiwm lauryl sulfoacetate, about 0.5 to 1 percent;
6) polyvinylpyrrolidone, about 0.5 to 1 percent, 7) magnesium lauryl sulfate powder, about 0.1 to 0.3 percent, and micronized polyethylene glycol (average m.w. 6000), about 0.2 to 0.4 percent.

~ n addition, dyes, flavoring, etc., ~ay be included.
Amounts of such other com~onents generally do not exceed about 3 percent of the total weight o~ the tablet~

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A completely water-soluble enzyme and active oxygen containing denture cleanser tablet, wherein said tablet includes an effervescence producing composition comprising an acid and a carbonate compound as well as a water-soluble lubricant, and wherein said tablet contains from about 0.3 to 3.5 percent by weight of enzyme, which is present as a finely divided powder, as granules or as coated prills;
from about 30 to 50 percent by weight of at least one active oxygen compound, which is present as granules; and from about 45 to 65 percent by weight of said effervescence producing composition, which is present as coated granules; said amounts being based on the total weight of tablet; the moisture content of said tablet being no greater than about 0.1 percent based on the total weight of tablet.

2. A tablet according to claim 1 wherein the final moisture content is no greater than 0.05 percent.

3. A tablet according to claim 1 wherein the enzyme is in the form of a powder of particle size such that it will pass through a No. 200 sieve and the active oxygen compound is in the form of granules of particle size sufficient to be retained by a No. 200 sieve.

4. A tablet according to claim 1 wherein the enzyme is a protease.

5. A tablet according to claim 1 wherein the water-soluble lubricant is a lubricant mixture which also contains micronized polyethylene glycol 6000.

6. A tablet according to claim 1 wherein the enzyme is polyethylene glycol coated.

7. A tablet according to claim 4 wherein the active oxygen compound is a mixture of sodium perborate monohydrate and potassium persulfate.

8. A tablet according to claim 7 wherein the effer-vescence producing composition contains citric acid as the acid component and sodium bicarbonate as the carbonate compound component.

g. A tablet according to claim 1 which contains in addition, an anionic surfactant.

10. A completely water-soluble denture cleanser tablet containing both a proteolytic enzyme and at least one active oxygen compound as primary active cleansing agents, said tablet including an effervescence producing composition and a water-soluble lubricant, said effervescence producing composition comprising an acid and a carbonate compound, wherein in said tablet (a) the enzyme is incorporated in the form of powder which will pass through a No. 200 sieve, the active oxygen compound in a granular form of particle size sufficient to be retained by a No. 200 sieve, and the effervescence producing composition in a granular polyvinylpyrrolidone coated form of particle size sufficient to be retained by a No. 100 sieve, and (b) the amount of the components are enzyme from about 0.8 to 3.5 percent, active oxygen compound from about 30 to 50 percent, effervescence producing composition from about 45 to 65 percent, water-soluble lubricant from about 0.5 to 5 percent, said amounts being based on the total weight of tablet;
(c) the moisture content is no greater than about 0.1 percent by weight based on the total weight of tablet; and (d) said tablet, upon dissolution in an aqueous medium, having a pH of from about 6.0 to about 7.5.

11. A tablet according to claim 10 wherein the particle size of the incorporated active oxygen compound is in the range of from that retained by a No. 200 sieve to that passing through a No. 20 sieve and the effervescence produc-ing composition in the range of that retained by a No. 70 sieve screen to that passing through a No. 20 sieve.

12. A tablet according to claim 10 wherein the active oxygen compound is a mixture of sodium perborate monohydrate and potassium persulfate.

13. A tablet according to claim 10 wherein the moisture content of the final tablet is no greater than about 0.05 percent by weight based on the total weight of tablet.

14. A tablet according to claim 10 wherein the water-soluble lubricant is a mixture of magnesium lauryl sulfate and polyethylene glycol 6000.

15. A method for preparing a completely water-soluble effervescence denture cleansing tablet containing both enzyme and active oxygen compounds and in which useful enzymatic activity is retained in the presence of the active oxygen compound comprising:
(1) first preparing a granular, coated effervescence producing composition comprising at least one acid and at least one carbonate compound as essential components by (a) blending a dry pre-blended mixture of said acid and said carbonate with an alcoholic solution of polyvinylpyrroli-done, (b) drying to a moisture level of no greater than about 0.5 percent, and (c) screening to a particle size which will pass through a No. 16 sieve;
(2) adding to and blending with the granular effervescence producing composition (i) at least one enzyme in the form of a powder of particle size sufficiently small to pass through a No. 200 sieve, (ii) at least one active oxygen compound in the form of granules of particle size large enough to be retained by a No. 200 sieve, (iii) a surfactant;
(3) adding to and blending with the resulting mixture a water-soluble lubricant or lubricant system and compressing into tablets;
(4) drying the tablets to a moisture content of no greater than about 0.1 percent; and (5) formulating the ingredients in said tablet such that upon dissolution in an aqueous medium, there is obtained a pH of from about 6.0 to about 7.5;:

and wherein at least about 45 percent by weight of the total weight of the tablet is attributable to the effervescence producing composition.

16. A method according to claim 15, wherein step (2) also comprises adding ingredients each having a moisture level no greater than about 0.5 percent.

17. A method for cleaning dentures which comprises placing an enzyme and active oxygen containing denture cleanser tablet and the denture to be cleaned in an amount of water sufficient to completely cover the denture and for a time sufficient to effect the desired cleaning; wherein said tablet is a completely water soluble tablet containing both a proteolytic enzyme and at least one active oxygen compound as primary active cleansing agents and including an effervescence producing composition comprising an acid and carbonate compound, and further including a water-soluble lubricant, wherein in said tablet (a) the enzyme is incorporated in the form of powder which will pass through a No. 200 sieve, the active oxygen compound in a granular form of particle size sufficient to be retained by a No. 200 sieve, and the effervescence producing composition in a granular polyvinylpyrrolidone coated form of particle size sufficient to be retained by a No. 100 sieve; and (b) the amount of the components are enzyme from about 0.8 to 3.5 percent, active oxygen compound from about 30 to 50 percent, effer-vescence producing composition from about 45 to 65 percent, water-soluble lubricant from about 0.5 to 5 percent, said amounts being based on the total weight of tablet (c) the moisture content is no greater than about 0.1 percent by weight based on the total weight of tablet; and (d) upon dissolution in an aqueous medium the pH
is from about 6.0 to about 7.5.

18. A stable, water-soluble denture cleanser tablet providing enzymatic and active oxygen cleansing action consisting essentially of (a) from about 0.8 to about 3.5% by weight of a neutral bacterial protease enzyme of about 3 Anson Units activity which is present as a finely divided powder;
(b) from about 30 to about 50% by weight of at least one active oxygen compound which is present as granules or as coated prills and which is selected from the group of peroxygen compounds which form hydrogen peroxide or nascent oxygen when placed in solution and is further selected from the group consisting of sodium perborate monohydrate, sodium perborate tetrahydrate, potassium persulfate, sodium carbonate peroxide, diperisophthalic acid, potassium peroxydiphosphate and sodium aluminum aminohydroperoxide;
(c) from about 45 to about 65% by weight of at least one effervescence-producing composition which is present as coated granules and which is selected from the group of carbon dioxide generating mixtures consisting-essentially of at least one water-soluble organic acid selected from the group consisting of citric acid, tartaric acid, gluconic acid and malic acid and at least one alkali metal carbonate compound selected from the group consisting of sodium bicarbonate, potassium bicarbonate, sodium carbonate and potassium carbonate, and (d) from about 0.1 to about 5% by weight of at least one water-soluble lubricant selected from the group consisting of magnesium lauryl sulfate and a mixture of magnesium lauryl sulfate and polyethylene glycol having a molecular weight of from about 6000 to about 20,000;

wherein said tablet has a moisture content not greater than about 0.1 percent based on the total weight of the tablet and upon dissolution in an aqueous medium has a pH of from about 6.0 to about 7.5.

19. A tablet according to claim 18 wherein the active oxygen compound is at least sodium perborate monohydrate.

20. A tablet according to claim 18 wherein the active oxygen compound is at least potassium persulfate.

21. A tablet according to claim 18 wherein the water-soluble organic acid is at least citric acid.

22. A tablet according to claim 18 wherein the water-soluble organic acid is at least tartaric acid.

23. A tablet according to claim 18 wherein the alkali metal carbonate compound is at least sodium bicarbonate.

24. A tablet according to claim 18 wherein the alkali metal carbonate compound is at least sodium carbonate.

25. A tablet according to claim 18 wherein the lubricant is a mixture of magnesium lauryl sulfate and polyethylene glycol having a molecular weight of from about 6000 to about 20,000.

26. A method for cleaning dentures which comprises placing a water-soluble denture cleanser tablet and the denture to be cleaned in an amount of water sufficient to completely cover said denture and for a time sufficient to effect the desired cleaning wherein said tablet provides enzymatic and active oxygen cleansing action and consists essentially of:
(a) from about 0.8 to about 3.5% by weight of a neutral bacterial protease enzyme of about 3 Anson Units activity which-is present as a finely divided powder, (b) from about 30 to about 50% by weight of at least one active oxygen compound which is present as granules or as coated prills and which is selected from the group of peroxygen compounds which form hydrogen peroxide or nascent oxygen when placed in solution and is further selected from the group consisting of sodium perborate monohydrate, sodium perborate tetrahydrate, potassium persulfate, sodium carbonate peroxide, diperisophthalic acid, potassium peroxydiphosphate and sodium aluminium aminohydroperoxide;
(c) from about 45 to about 65% by weight of at least one effervescence producing composition which is present as coated granules which is selected from the group of carbon dioxide generating mixtures consisting essentially of at least one water-soluble organic acid selected from the group consisting of citric acid, tartaric acid, gluconic acid and malic acid and at least one alkali metal carbonate compound selected from the group consisting of sodium bicarbonate, potassium bicarbonate, sodium carbonate and potassium carbonate; and (d) from about 0.1 to about 5% by weight of at least one water-soluble lubricant selected from the group consisting of magnesium lauryl sulfate and a mixture of magnesium lauryl sulfate and polyethylene glycol having a molecular weight of from about 6000 to about 20,000; wherein said tablet has a moisture content not greater than about 0.1 percent based on the total weight of the tablet and upon dissolution in an aqueous medium has a pH of from about 6.0 to about 7.5.