CA1327528C - Packaged dental cream - Google Patents

Abstract

PACKAGED DENTAL CREAM
ABSTRACT

Dental cream in contact with a polyolefin resin surface of a package such as a laminate tube, a mechanical dispenser or a flexible sachet.
The dental cream contains a dentally acceptable water-insoluble alkaline earth metal salt, a liquid vehicle, a gelling agent and an additive which prevents syneresis. The liquid vehicle contains water, glycerine and sorbitol. The additive which prevents syneresis due to contact between the dental cream and the polyolefin resin is a nonionic block copolymer containing moieties of polyoxyethylene and polyoxypropylene.

Description

~ .. ` ~ @~ 13~7~28 : ;
This invention relates to a dental cream packaged in a plastic ; laminate tube, mechanical dispenser, flexible sachet or the like. In particular, it relates to a dental cream in ccmpatible contact with a polyolefin surface of a package such as a plastic laminate dental cream tube, -~ mechanical dispenser or flexible sachet.
~` Dental creams have been packaged for many years in flexible metal tubes such as wax lined lead tubes, unlined aluminum tubes or aluminum tubes having an epoxy resin lacquer coa~ing tnereon. In recent years, flexible form-retaining lamina~ed plastic tubes have been increasingly used.
Plastic laminated dental cream tu~es typically comprise in inner polyolein resin layer which is in direct contact with th~ dental cream and at ~east one intenmediate layer, including an aluminum foil layer which inhibits loss of flavor from the dental cream. Desirably, an intermediate paper layer which provides stiffness to the tube is also present. m e outer layers are typically of polyolefin resins, one of which may be colored white and bear - printed indicia with a clear polyolefin laminate overlay to protect the indicia. Additional intermediate lamunate layers of flexible plastic may also be present. b Mechanical dental crsam dispensers may also hav~ a polyolein li surface in contact with dental cream contained ~herein. In fact, ~he polyolefin itself may be the housing of the dispenser. Flexible sachet packets may also have a polyolefin surfacein contact with dental crean.
DentaI creams typically con~ain a liquid vehicle of water and humectant, a gelling agent solid vehicle and a water-insoluble dental polishing agent. A surface active is also generally included. Dental creams composed of such materials wherein the humectant ccmprises glycerine and r sorbitol and the polishing material is an alkaline earth metal salt such as '. , , ~

1~27528 ~ 62301-1513 ~ dicalcium phosphate have been successfully packaged in flexible - metal toothpaste containers includiny aluminum tubes which are unlined or which hava an internal coating of an epoxy resin ` lacquer layer. However, it is observed that when such den~al -~ creams are differently packaged in containers having an lnterior polyolefin surface such as plastic laminated dental cream tubes, mechanically operated dental cream dispensers or flexible sache~s, tha~ syneresis becomes a problem and liquids ~` separate from sollds, rendering the dental cream undesirable.
, , In earlier commonly assigned patent disclosures additives to prevent dental cream syneresis upon contact with a polyolefin surface have been disclosed for dental creams containing an alkaline earth metal phosphate or alpha-alumina trihydrate polishing agent. These disclosures are:
Canadian Patent 1,282,341, issued 2 April 1991, whereln the anti-syneresis additive for an alkaline earth phosphate dental cream is a polyethylene 01y~ol;
-`~ Canadian Patent 1,282,708, issu~d 9 April 1991, wherein the anti-syneresis additive for a dental cream in which the polishing agent is mainly an alkaline earth metal phosphate is propylena ylycol;
Canadian Patent 1,294,556, issued 21 January 1992, wherein the anti-syneresls additive for an alpha-alumina trihydrate dental cream is a vegetable oil;
and Canadian Patent 1,294,557, issued 21 January 1992, wherein the anti-syneres~s additive for an alkaline earth metal phosphate dental cream is a vegetable oil.

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~2752~ 62301-1~13 i i~
~ In each of the foregoing patent disclosures ::
~ condensates of ethylene oxlde with propylene glycol, that is ~ ~, "Pluronic*" materials, are generally disclosed as a type of surface-active material which may be present in the several ;.,i,;
dental creams containing the described particular anti~
-~ syneresis additives.
~: Japanese Public Disclosure No. 75410/85 to Ebine et al (Lion Corpora~ion) describes a dentifrice in which glycerine ~, ~:: is the sole humectant or mixed with another humectant, such as 10 sorbitol, but which glycerine is, in any event, present in :-.:
: amount greater than 20% by weight of the dentifrice, since ; .
~ lesser amounk~ would re~ult in undesirable evaporation of water . ., ~` when the dentifrice is packed in a con~ainer having a plas~ic ~I container body, at least the barrel portion of which has a :l~ water permeability of at least 5g~m2.day.50u. The high . .
glycerine dentifrice is formula~ecl to avoid evaporation and ~; weight loss in this particular type of container. The l disclosure includes a general indication that polymer of :~. e~hylene oxide and propylene oxide may be employed as surface-~,;2 20 active agent.
U.S. Patent 4,556~553 ~o Suganuma et al (Lion i Corporation) discloses dentifrices containing an aluminum oxide abrasive in a container having an , s ,' .

*Trade-mark 4 ,@æ

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. .
oxygen permeability of at least 3cc/m2.dayOatm wherein antiseptic properties are improved by the presence of polyhydric alcohol, including mixture of sorbitol and glycerine. There is a general disclosure that condensates vf ethylene oxide with propylene oxide may be used as a sur~ace-active agent in the aluminum oxide dentifrices. Some dentifrice samples are described for ccmparative purposes which contain dicalcium phosphate with sodium lauryl sulfate as the sole surface active ag~nt.
Japanese Public Disclosure 86526~78 to Naganuma et al ~Lion Den~ifrice Campany) diclo~es that liquid-solid seEkaration in toothpa~te containing an anionic surfactant and a polyo~yethylene bloek copolymer t~pe surfactant (that is, a "Pluronic" sur~actant) can be ~ver~come by employin3 a binder or gelling agent of at least one of hydroxyethyl cellulose and/or xanthan gum rather than carrageenan, gum tragacanth, sodium carbox~methyl cellulose, poly~sodium acrylate) or guar gum. The toothpastes described contain a humectant such as glycerin, sorbitol, propylene glycol or polyethylene glycol. The only mixtures of humectants described in specific formulations including those which evince separation when a gelling agent other than hydroxyethyl cellulose or xanthan is employed, contain glycerine and propylene glycol.
U.S. Pa~ent 4,353~890 to Scott (Colgate-Palmolive C4mpany) di~closes tcothpastes containing carrageenan gelling agent which is stabilized by microwave radiation to maintain viscosity. A dicalcium phosphate toothpaste containing such stabilized carrageenan with a mixed humectant of 4.5% by weight of glycerol and 17.5% by weight of sorbitol is exemplified and indicated to be subjected to storage tests, including when packaged in containers having body portions of polyethylene. m e detergent or surface-active agent employed in the exemplified toothpaste is sodium lauryl sulfate m e patent includes a ~ 132'1~2~ ~ ~

general disclosure~"Pluronics(R~" as detergents.
It is an advantage oE this invention that phase separation of a dental cream packaged in contact with a polyolefin material which would undergo phase separation but for the pxesence of an additiva which overcomes syneresis, is substan~ially prevented. Other advantages will be apparent from consideration of the following disclosurea In accor~ance with certain of i~s aspects, this invention relates to a packaged dental cream wherein said dental cream is in direct contact with a low or medium density polyethylene or polypropylene surfacé, wherein syneresis occurs in said dental cream due to said direct contact when said dental cream consists essentially of as ingredients about 20-75% by wei ~ t of a liguid ~icle consisting essentially of about 10-50% by weigh~ of water, about 5Ø15~ by weight of glycerine and sorbitol, th~ amcunt of glycerine and sorbitol together being about 15-50% by weight, the weight ratio oE glycerine to sorbitol being ~rom about 0.25:1 to about 1:1, about 0.05-10% by weight of a dental cream gelling agent selected ~Erom the group consisting of Irish ~oss, gum tragacanth, sodium carboxymethyl cellulose, hydroxyethyl cellulose, . p~lyvinyl pyrrolidone, sodium alginate, guar gum, star~h, xanthan ~nd iota-carrageenan, and about 20-75~ by weight of a dentally acceptable water-insoluble calcium or magnesium alkaline earth metal salt polishing ag~nt; said dental cream consisting essentially of said ingredients and as the s~le additive to prevent syn~resis in said dental cream upon said direct contact, about 0.1-5% by weight of a nonionic polyoxyethylene-pDlyoxypropylene block copolymer.
. In dental cream fonmulations, the liquids and solids are necessarily proportioned to form a creamy mass of desired consistency which is extrudible frcm its pa k ge. The liquids in the present dental crear co~prise chiefly ,, . ~ ~ ~3%7~8 ~
, water, glycerine and sorbitol. ~he total liquid vehicle ~mounts to about 20-75% by weight of the formulation. A gelling agent in the dental creams is a natural or synthetic gum or gumlike material, particularly, eOg. Irish Moss (carrageenan), gum tragacanth, sodium carbox~methylcellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, sodium alginate, guar gum, starch, xanthan or iota~carrageenan, including ~ixtures ~hereof. Irish Moss, sodium carboxymethyl cellulo6e, and iota-carrageenan, including mixtures thereof are compatible particularly and are preferred gelling agentsn ~he gum content is in a amount of abou~ 0~05-10~ and preferably abou~ 0.5-5% by weight of the formulation.
Water i~ incorporated into the dental cream in ~m~unt of about ~0-50% ~y weight, preferably about 15-35%. Glycerine and sorbitol together generally comprise about 15-50~ by weigh~, preferably about 2U-35~ of the dental cream, with the amount of glycerin~ being about 5.0-15% by weight and the weight ratio of glycerine to sor~itol being from about 0.25:1 to about 1:1/ typically frcm about 0.25:1 to about Oo~ l and preferably from about 0.25:1 to about 0.6:1. It is preferred to use about 6-10% by weight of glycerine and about 17-24% by weight of sorbitol. Amounts of sorbitol as used herein are of sorbitol syrup, as ccmmercially available, that is 70% by weight sorbitol in 30% by weight of water.
Dentally acceptable water-insoluble alkaline earth metal salt polishing agent is present in the dental cream in amLunt of bout 20-75% by weight, preferably about 35-60%. Typical salts include dicalcium phosphate dihydrate, anhydrous dicalcium phosphate, calcium carbonate, tricalcium phosphate, calcium pyrophosphate, dimagnesium phosphate trihydrate and magnesium carbonate including mixtures thereof. Most preferably, calcium salt, particu rly dicalcium phosphate dihydrate or mixture of dicalcium 132752g ~ ~

phosphate dihydrate and anhydrous dicalcium phosphate, is present.
In addition to the alkaline earth metal salt polishing agent, additional polishing agent such as hydrated alu~ina and calcined alumina may be present, for instance in a weight ratio of alkaline earth metal salt to alumina material of about 2.5:1 to about 4~ he total a~ount of polishing material in the dental cream beiny ~bout 25-75% by weight, The single material employed in accordance with the present invention to prevent syneresis when the dental crean is in direct contact with a low or mediu~ density polyethylene or polypropylen~ i5 a nDnionic polyoxyethylene-polyoxpropylene block copolymer. Ihe block copolymer is also effective in the dental cream as a surace-active agent. i~t is present in ~ unt of about 0~1-5% by weight, pre~erably about 0.5-3%.
The nonionic surface-active agent employed in the instant invention is a block copolymer containing polyoxyethylene and polyoxpropylene. Such block copolymers are available from Wyandotte Chenicals Corporation under the trademark "Pluronic". They may be lig~id, paste or solid and are ~enerally chemically defined in terms of the moleculr weîght of the polyoxypropylene hydrophobic moiety and the percent by weight of the polyoxyethylene hydrophilic moiety. The following block copolymers are available from ~andotte:

~ 1327~2~

Pluronic Physical Mol. Wt.
Number Character Hydrophil Hydrophobe I,121 Liquid 10 4000 L101 Liquid 10 3250 L 81 Liquid 10 2250 L 61 Liquid 10 1750 L 31 Liquid 10 350 L122 Liquid 20 4000 L 92 Liquid 20 2750,L 72 Liquid 20 2050 L 52 Liquid 20 1750 L 42 Liquid 20 1200 P 123 Paste 30 4000 P 103 Paste 30 3250 , L 63 Liquid 30 1750 -~
~ 43 Liquid 30 1200 P~104 Paste 40 ~3250 P ~4 Paste 40 2750 P 84 Paste 40 2250 P 64 Liquid 40 1750 P 44 Liquid 40 1200 P 105 Paste 50 3250 P 85 Paste 50 2250 P 75 Paste 50 2050 P 65 Paste 50 1750 P 35 Liguid 50 950 F 127 Solid 7~ 4000 F 87 Solid 7~ 2250 P 77 Solid 70 2050 .
F 108 Solid ~ 3250 F 98 Solid 80 2750 F 88 Solid ~ 2250 F 68 Solid 80 1750 F 38 Solid 80 950 ~ ~ ~327~2~ ~
.
Ihe preferred nonionic block copolymers are solid ~or flake) materials and the most preferred are Pluronic F-108 (80% polyo~yethylene: 3250 molecular weight polyoxypropylene) and F-87 (70~ Eolyoxyethylene 2250 molecular weight polyoxypropylene), F-127 ~70~ polyoxyethylene~ 4000 molecular weight poly-oxypropylene) and L-72 ~20% polyoxyethylene: 2050 molecular weight polyoxypropylene).
Since the nonionic blook copolymer anti-syneresis agent does not provide substantial foam to the dental cream, an ~nionic surface-active agent may also be provided for its foaming ~haracter and in order to enhance detergency. m e surface-active agents may achieve increased prophylactic action, assist in achieving thorough and complete dispérsign of the instant itions throughout the oral cavity and render the dental creams more cosmetically acceptable. Suitable anionic surface-~ctive materials are water-soluble salts of higher fatty acid moncglyceride monosulfates, such as the sodium salt of the monosulfa~ed monoglyceride of hydrogenated coconut oil fatty acids, higher alkyl sulfates, such as sodium lauryl sulfate, alkylaryl sulfonates, such as sodium dodecyl benzene sulfonate, olefin sulfonates, such as sodium olefin sulfonate in which the olefin group contains 12-22 arbon atams, higher alkyl sulfoacetates, higher fatty acid ester of 1,2-dihydroxy propane sulfonates, and the substantially saturated higher aliphatic acyl amides of lower aliphatic amino carboxylic acid compounds such as tho6e havin~ 12 to 16 carbon atcms in the fatty acid, alkyl or acyl radicals and the like. Examples of the last mentioned amides are N-lauroyl sarcosine, and the sodium, potassium, and ethanolamine salts of N-lauroyl, N-myristoyl or N-palmitoyl sarcosine~ which should be substantially free from soap or similar higher fatty acid material which tends to substantially-reduce the effect of these compounds in compositions of the present invention. The amides are particularly advantageous since they exhibit a prolonged and marked effect in the inhibition of acid formulation in the oral cavity due to carbohydrate breakdown in addition to exerting scme reduction in the solubility of tooth enamel in acid solutions. Another desirable material is a long chain ~atty acid sodium monoglyceride sulfonate used alone or in combination with sodium 327~28 .. . .

lauryl sulfate. It is preferr~d to use about 002-5% by weight of total surface- active agent typically about 1~3%r when anionic surface-active ~gent is present.
The dental cream suitably may also contain a fluorine-containing compourd having a beneficial effect on the care and hygiene of the oral cavity, e.g., diminution of enamel solubility in acid and protection of the teeth against decay. Ekamples thereDf include sodium fluoride, stanou$
fluoride, potassium fluoride, potassium stanno~s fluoride tSnF2.XF), sodium hexafluorostannate, stannous chlorofluoride, scdiu~ fluorozirconate and sodis~n monofluo wphosphate. These materials which disas~ociate or release fluorine-containing ions in water, suitably may ke present in c~ e~fective but ~;~on-toxic amount, usually within the range of about 0.01 t~ 1% by weiyht of e water-soluble fluorine content thereof.
The preferr~d fluorine-containing compoun~ is sodium m~nofluoro~
phosphate, typically present in an ar~ount of about 0.076 to 7.6% by weight, preferably 0.76~. A mixture of sodium nofluorophosphate and sodiun fluoride is also desirable, for instance in a weight ratio of about 2;1 based on fluoride.
Any suitable flavoring or sweetening materials may be e~ployed in fonmulating a flavor for the oomposition of the present invention. E~a~ples of suitable flavoring constituents inclu~e the flavoring oils, e.g., oils of spea~mint, peppernint, wintergreen, sassafras, clove, sage, eucaIyptus, cinnamon, lemon an~ orange, as well as ~eth~l salicylate. Suitable sweetenin~
agents inclu~e sucrose, lactose, maltose, xylitol, scdium 6~methyl-3, 4-dihy~ro-1,2,3-o~athiazine-4-one, scdium cyclamate, perillartine and scdium saccharin. Suitably, flavor an~ sweetening agents may together co~prise from about O.Ol to 54 or more of the ~ompositions of the instant invention.
Various other ~aterials may be incorporated in the dental creamr Ekamples thereof are coloring or whitening agents or dyestuf~s, preservatives such as scdium benzoate, anti-corrosive agents, silioones, chlorophylic compoun~s, ammoniate~ materials such as urea, diammonium phosphate ard muxtures thereofand other constitutents. Whitening agents, such as titaniu~

~ 2 7 ~ 2 8 dioxide, typically in amounts of about 0~5-2%, may be beneficial to the appearance of the dental composition, since upon aging, sc~e discoloration may occur.
Ihe adjuvants are incorporated in the instant ccmpositions in amounts which do not substantially adversely afect the proper~ies and characteristics desired and are selec~ed and used in proper a~ounts depending UpGn the particular type of composition involved.
Antibacterial agents may also be employed in the oral compositions of the instant invention in an amount of about 0.01-5% by weight. Typical antibacterial agents include:
Nl (4~chlorobenzyl3-N5-(2,4-dichlorob~nzyl) biguanide;
p-chlorophenyl biguanide;
-4-chlorobenzhydryl biguanide;
4-chlorobenzhydrylguanylurea;
N-3-lauroxypropyl-N5-chlorobenzylbiguanide;
1,6-dichlorophenylbiguanidohexane;
1,6-bis-(2-ethylhexylbiguanido) hexane;
l~(lauryldimethylammonium)-8-~p-chlorobenzyldimethyl-ammonium3 octane dichloride, 5,6-dichloro-2-guanidinobenzimidazole;
N -p-chlorophenyl-N -laurylbiguanide;
5-amino~1,3-bis(2-ethylhexyl) 5-methylhexahydropyrimidine and their non-toxic acid addition salts.

Ihere may be employed also various calcium and magnesium ion suppression agents for adjustment of physical properties of the comeositions.
Suitable agents are the water-soluble inorganic polyphosphate salts, such as tetrasodium pyrophosphate or disodium diacid pyrophosphate, with the partially neutralized or acid polyphosphate preferr~d. Other suitable agents are the alkali metal, preferably sodium, 5alts of oitric acid. In general, such ccmpounds will be a minor amount or proportion of tha ~onmulation. Ihe precise amount will vary depending upon the specific formulation, such as ~he ~ 3~7~28 physical characteristics of the dental cream, but will usually be from about 0.1% to about 3% by weight.
The dental creams should have a pH practicable for use. A pH range of 5 to 10 is particularly desirable. The reference to ~he pH ls meant to be the pH determination directly on the dental cream~ If desired, materials such as cltric acid may be added to adjust to the pH to say 6 to 7.
The package into which the dental cream is incorporated may be any polyolefin laminate dental cream tube.
For instance, the tube may be as elementary as is descrihed in U.S. Patent 3,260,410 to Brandt et al. As described in the example ~hereof, an aluminum foil base having a thiekness of about 0.0013 cm was heated to a temperature of approximately 177C, and one face of the heated foi.l was contacted by an extrudable film o~ a random copolymer of ethylene and acrylic acid (acid contenk 3~0.5% and melt index 8'1), while the opposite surface thereof and replacecl thereagainst a film o~
low density polyethylene. Using driven rolls, a laminated base was obtained in which khe copolymer layer was about 6 mils and the polyethylene layer was approximately 5 mils in thickness.
The base was then shaped into tubular form and sealed.
After severing the tubular form into tube bodies, the tubes can be packed with the dental cream of the present invention without the dental cream undergoing syneresis.
Polyolefin laminate dentifrice tubes containing more intermediate layers may also be successfully used with the dental cream of the present invention without undergoing syneresis. For instance, the multiple layer flexible sheet structure for dental cream tubes described as '-Prior Art" in U.S. Patent 4,418,841 to Eckstein may be employed as well as ~he more crack resistant structures described therein. In ~ 327~2~

fact, dental creams of the present invention packed in tubes oi sheet material identified as Prior Art A and A-l in U.S. Patent 4,418,841 are very satisfactory and undergo substantially no syneresis. Such tubes A and A-l are comprised of layers as set forth below, in the order of outermost layer to inner most layer.
A A-l 1.5 mil LDPE 1.5 mil LDPE
2.0 mil Pigmented LDPE 2.0 mil Pigmented LDPE
1.6 mil Paper 1.6 mil Paper 0.7 mil LDPE 2.0 mil LDPE

3.3 mll EAA 1.0 mil OPP
0.7 mil Foil 1.0 mil EAA
2.0 mil EAA 0.7 mil Foil 1.2 mil LDPE _ 2.0 mil EAA
13.0 mil Total 1.2 mil LDPE
13.0 mil Total In A and A-l the abbreviations have the follo~ing meanings, LDPE low density polyethylene EAA ethylene acrylic acid OPP oriented polypropylene Medium density polyethylene may replace low density polyethylene. In a dental cream sachet package medium density polyethylene i~ preferred.
Mechanlcally operated dispensers, such as the dispenser for, in particular, pasty substances, described in U.S. Patent 4,437,591 to von Schuckmann, may also be used with the practice of the present invention. The housing of such dispensers is commonly composed of a polyolefin resin such as polypropylene.

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132~28 m us the housing resin is in essence a layer, the inner surface of ~hich is in contact with dental cream. When the ~ental cre~ of the present inYention i5 packaged in such a polypropylene mechanical dispenser7 it un~ergoes substantially no syneresis.
m e following properties are typical of low and m~dium density polyethylene:

Low Dknsit~ Mbdium Density PDl~ethylen PDlyethylene Clarity TransparPnt Tran~parent to ~o Translucent Translucent Yield 30/000 29,500 Sq. in/lb./~.001-in (1,085,0001/065~000 sq. om/Xg./0.~01-cm) ,~
~, .
Specific 0.910-0.925 0.926-g~vity 0~940 Tensile strength 1,000- 3,5002,000- 5,000 lb./s~.in.

(6,900-24i15013,800-34,500 kPa.) Elongation 225 - 225 -~per cent) 600 500 ASTM D~882 Impact Strength 7-11 4-6 (kg-cm) Tear strength 100- 40050-300 gm~0.001 in. Elmen~orf ASTM D~1922 (250-1,000 125-750 gm/0.001 cm. Elmendorf) ,, Heat seal range 250-350 260-310 F
(120-175 125-155 &) WVTR 1.2 0~5-1.0 gm/24hr/103sq.in.@100OF
90 per cent RH (7.74 3.23-6.4 ~ 24hr~100sq~cm.@37C) ~STM E-96 .

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Low Density Mdium D2nsity lyethylene Polyethylene_ . .... . .,, j . . _ _ . _ . _ Gas transmission 02-ASTM D-1434 250-840 165-335 cc/O.OOl-in./lOOsq.in./
24 hr.@ ATM 73F~O~ RH
(150-515 100-205 cc/O.OOlcm/lOOs~.om./
24 hr.@AIM22~7 rC~0%RH) 495-5,000 500 840 cc/O.OOl-in/lOOsq.in./
24 hr.Q AlM 73+0~ RH
Gas transmission C02-ASTM D-1434 ~300-3,050 305-515 cc/O.OOl-cm/lOOsq.cm/
~4hr~@ATM22.7 ~C~0%gH) , , , _ _ ,, ,,, .,, . ,, , , ,,, ,, ~
Resistance to Varies Gbod grease an~ oils , . . . .
Maximum Use 150 180-220 F
Temperature (C) (65s5 82-105 &

~inimum Use -60 ~60 ~ ~F
:T~mperature (C) t-51 -51 j &
`:

Dimension change None None at high RH (per cent) Machine performance Fair Fair _ _ . _ _ . . . .
Printability Gbcd if treat~d Gvcd if treated .
Heat shrinkable Some Some types types _ _ _ _ Typical of polypropylene grades whi~h may be employed partisNlarly as dispenser housing for the dental cream are those 5uppli~d by 5hell Shemical Ccmpany as Polypropylene DP 5~03 an~ PDlypropylene DP 5A03S. lhese controlled rheology products cambine the processibility of 12 melt flow gr3~es with higher practical impact s~rength (as m~asured b~ fallin~ weight testing).

;: ~ ~ ~327~28 ~ i ., .

They were designed for fast processing in multicavity molds-Polypropylene grades DP 5A03 and DP 5A03S have the following typical properties: .
.
Traditional ASTM
Units SI Units l`est Melt flow 12 g/10 min 12 g/10 min D 1238 Density at 23& 0.905 g/cc 0.905 g/cc D 1505 Tensile yield strength, 2 at 5.0 om/min 5000 psi 34 MPa D 638 Yield elongation, 2 at 5.0 cm~min 9% 9% D 638 1% Secant ~odulus, 2 at 0.5 om/min 190,000 psi 1300 MPa D 638 Flexural ~cdUlUs9 at 0.13 cm/min, 5 om span 200,000 psi 1375 MP~ D 790A2 Notched Ixod impact ~ 2 ~ strength, ak 70F/230C 0.5 ft-lb/in 26 J/m j D 256?
: ' at 0 F/-18 C 0O3 ft-lb/in 15 J/m D 256 .
hardness, Rockwell R92 R92 ~ 785 ~eiat deflection temp., at 66 psi/455 kPA 220F 104& D 648 Vicat softenin~ temp. 3~5F 152C D 1525 2C~ndition 230/2.16 ASTM Type I specimen, 0032 cm thick (injection lded) The advantages of the inven~ion are also-present when the dental cream is packed in a flexible sachet h~ving an pol~olefin surface, typically of low density or medium density polyethylene.
The ~ollowing illustrative examples are further illustrative of ~he nature of ~he present invention but it is understood that the invention is not limited thereto. All amounts and proportions are by weight except as otherwise indicated.
EXAMPr.~_l Ihe following dental creams are prepared to creamy oonsistencies and packed into tubes of each of lamunated structures A and A-1, set forth above.

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Parts B

Glycerine (99.3%~ 10.00 10.00 Sorbitol (70%) 17 7 00 17.00 Sodium Carbo~ymethylcellulose 0.95 0.95 Sodium Saccharin 0.20 . 0.20 Tetrasodium Pyrophosphate0.25 0.25 Sodium Monofluorophosphate Or76 0~76 Dicalcium Phosphate Dihydrate 48.76 48.76 Sodium Lau~yl Sulfate 1.10 ~ 10 avor 0.89 0.8,9 Pluronic F-108 0~50 ~ater Q.S.to Q,S. to 100. 00 1O0D 00 Dental cream B begins to undergo syneresis and phase separation after aging for 8-10 days at room temperature. Dental cream A remains stable against such phase separation when aged at room temperature for periods exceeding one year.

Dental creams (A) and [B) are incorporated into a mechanical dispenser in accordance with U.S. Patent 4,437,591 c~mposed of polypropylene housing. Dental cream (1) retains its creamy consistency while dentifrice ~2) separates into liquid and solid phases.
Similar results to those described in the above Examples are observed when:
(i) Each of Pluronic F-127 and F-87 replaoe Pluronio F-108;
(ii) Pluronic L-72 replaces Pluronic F~
(111~ Pluronic P-84 replaces Pluronic F-108;
(iv) the ccmparative a~ounts of glyoerine and sorbitol (70%) are: 5:20 and 12:15;
~v) Eac~ of Irish Moss and iota-carrageenan replaoe sodium carboxymethyl cellulose; ~ .
- 18 ~
. ...........

132752~

(vi) The dental creams are packed in lamunated tubes in accordance with U.S. Paten~ 3,260,410;
(vii~ The dental cre~ns are packed in crack-resistant lamunated tubes in accordance with U.S. Patent 4,418,841;
(viii) lhe dental creams are packed in flexible sachets of the following structure frem outermo6t to innermost layer:
12.2 ~ polyothylene terephthalate 21.3 ~ white ethylene acrylio acid 9.9 ~ foil "
3,3 ~ ethylene acrylic acid 25,4 ~ medium density polyethylene; and (ix) Mixture of 0.3 parts o~ sc~ium carboxymethyl-cellulose and 0.6 parts of. iota-carrageenan replace of sodium carboxymethyl cellulosP as the sole gelling material.
. It is understc~d that the foregoing detailed dPscription is given merely by way of illustration and that v~riations may be made ~herein without departing from the spirit o the invsntion.

Claims (10)

1. A packaged dental cream wherein said dental cream is in direct contact with a low or medium density polyethylene or polypropylene surface, wherein syneresis occurs in said dental cream due to said direct contact when said dental cream consists essentially of as ingredients about 20-75% by weight of a liquid vehicle consisting essentially of about 10-50% by weight of water, about 5.0-15% by weight of glycerine and sorbitol, the amount of glycerine and sorbitol together being about 15-50% by weight, the weight ratio of glycerine to sorbitol being from about 0.25:1 to about 1:1 , about 0.05-10%
by weight of a dental cream selling agent selected from the group consisting of Irish Moss, gum tragacanth, sodium carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, sodium alginate, guar gum, starch, xanthan and iota carrageenan, and about 20-75% by weight of a dentally acceptable water-insoluble calcium or magnesium alkaline earth metal salt polishing agent; said dental cream consisting essentially of said ingredients and as the sole additive to prevent syneresis in said dental cream upon said direct contact, about 0.1-5% by weight of a nonionic polyoxyethylene-polyoxypropylene block copolymer.

2. The packaged dental cream claimed in Claim 1 wherein the weight ratio of glycerine to sorbitol is from about 0.25:1 to about 0.8:1.

3. The packaged dental cream claimed in Claim 1 wherein said block copolymer is a solid material.

4. The packaged dental cream claimed in Claim 3 wherein said solid block copolymer has about an 80% by weight hydrophil polyoxyethylene content and a hydrophobe polyoxypropylene molecular weight of about 3250.

5. The packaged dental cream claimed in Claim 1 wherein said gelling agent is sodium carboxymethyl cellulose, present in amount of about 0.5-5% by weight.

6. The packaged dental cream claimed in Claim 1 wherein said water insoluble alkaline earth metal salt is a calcium salt.

7. The dental cream claimed in Claim 6 wherein said calcium salt is dicalcium phosphate dihydrate.

8. The packaged dental cream claimed in Claim 1 wherein said dental cream is packaged in a plastic laminate tube the inner surface of which is low density.

9. The packaged dental cream claimed in claim 1 wherein said dental cream is packaged in a mechanical dispenser having a housing of polypropylene resin.

10. The packaged dental cream claimed in Claim 1 wherein said dental cream is packaged in a flexible sachet, the inner surface of which is low density polyethylene or medium density polyethylene.