GB2180155A

GB2180155A - Packaged dental cream

Info

Publication number: GB2180155A
Application number: GB08620687A
Authority: GB
Inventors: Robert Lee Mitchell; Michael A Kiernan; Sandra Lee Schelm
Original assignee: Colgate Palmolive Co
Current assignee: Colgate Palmolive Co
Priority date: 1985-08-30
Filing date: 1986-08-27
Publication date: 1987-03-25
Also published as: MX164113B; SE8603612L; PT83283B; SE464333B; HK102792A; CH669111A5; NZ217253A; FI863497A0; ATA228486A; GB8620687D0; DK414086A; GB2180155B; GR862225B; NO863484L; BR8604141A; DE3628359A1; OA08405A; MY100364A; FI87732C; FI863497A

Abstract

Dental cream suitable for contact with a polyolefin resin surface of a package such as a laminate tube, a mechanical dispenser or a flexible sachet contains as at least the major dentally acceptable water-insoluble polishing material a water-insoluble alkaline earth metal salt or alpha-alumna trihydrate, a liquid vehicle and a gelling agent and, when alpha-alumina trihydrate is present in substantial amount, an agent to reduce pH containing phosphate ion. The liquid vehicle contains water, glycerine and sorbitol and, as an additive to prevent syneresis due to contact between the dental cream and the polyolefin resin, polyethylene glycol of average molecular weight or about 200-1000.

Description

SPECIFICATION Packaged dental cream The present invention relates to dental cream packaged in plastic laminate tube, mechanical dispenser, flexible sachet or the like. In particuiar it relates to dental cream in compatible contact with 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 aluminium tubes or aluminium tubes having an epoxy resin lacquer coating thereon. In recent years flexible form retaining laminated plastic tubes have been increasingly used.

Plastic laminated dental cream tubes typically comprise an inner polyolefin resin layer which is in direct contact with the dental cream and at least one intermediate layer, including an aluminium foil layer which inhibits loss of flavour from the dental cream. Desirably, an intermediate paper layer which provides stiffness to the tube is also present. The outer layers are typically of polyolefin resins, one of which may be coloured white and bears printed indicia with a clear polyolefin laminate overlay to protect the indicia.

Additional intermediate laminate layers of flexible plastic may also be present.

Mechanical dental cream dispensers may also have a polyolefin surface in contact with dental cream contained therein. In fact, the polyolefin itself may be the housing of the dispenser. Flexible sachet packets may also have a polyolefin surface in contact with dental areas.

Dental creams typically contain a liquid vehicle of water and humectant, a gelling agent solid vehicle and a water-soluble dental polishing agent. Dental creams composed of such material wherein the humectant comprises glycerine and sorbitol and the polishing material is at least in major part a waterinsoluble alkaline earth metal salt or an alpha alumina trihydrate have been successfully packaged in flexible metal toothpaste containers including aluminium tubes having an internal coating of an epoxy resin lacquer layer.However, it is observed that when such dental creams are packaged in containers having an interior polyolefin surface such as plastic laminated dental cream tubes, mechanically operated dental cream dispensers or flexible sachets, that syneresis occurs and liquids separate from solids, rendering the dental cream undesirable, when the pH of the dental cream is reduced with a water-soluble material which provides phosphate ion.

The present invention aims to substantially prevent phase separation of a dental cream packaged in contact with a polyolefin material.

According to the present invention, there is provided a packaged dental cream in which the said dental cream is in direct contact with a polyolefin resin surface, the said dental cream comprising at least about 20% by weight of a liquid vehicle comprising water, glycerine, sorbitol and polyethylene glycol of average molecular weight of about 200-1000, the weight ratio of glycerine to sorbitol being from 0.25:1 to about 3:1 and the weight ratio of the total amount of glycerine and sorbitol to the said polyethylene glycol being from about 60:1 to about 6::1, a solid vehicle comprising about 0.05%10% by weight of gelling agent, about 20-75 by weight of a dentally acceptable water-soluble alkaline earth metal salt or is alphaalumina trihydrate and when alpha-alumina trihydrate is present as the major portion of the polishing material, a water-soluble material to reduce the pH of the dental cream to about 6--8 which provides phosphate ion.

In dental cream formulations, the liquids and solids are necessarily proportioned to form a creamy mass of desired consistency which is extrudible from its package. The liquids in the dental cream of the present invention comprise chiefly water, glycerine and sorbitol, together with a minor amount of polyethylene glycol of molecular weight of about 200-1000, preferably about 60O1 000. The total liquid vehicle comprises about 20% by weight of the formulation. It is preferred to use also a gelling agent in dental creams such as the natural and synthetic gums and gum-like materials, carrageenans such as Irish moss, or iota-carrageenan, gum tragacanth, sodium carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, sodium alginate, guar gum, starch, xanthan and the like, including mixtures thereof.

Irish Moss, sodium carboxymethyl cellulose and hydroxyethyl cellulose including mixtures thereof are compatible particularly and are preferred gelling agents. When the major polishing agent is water-insoluble alkaline earth metal salt, iota-carrageenan is also a preferred gelling agent. The gum content is usually in an amount of about 0.0510% and preferably about 0.55% by weight of the formulation.

Water is generally incorporated into the dental cream in amount of about 1050% by weight, preferably about 1535%. Glycerine and sorbitol together generally comprise about 1550% by weight, preferably about 2035% of the dental cream, with the weight ratio of glycerine to sorbitol being from about 0.25:1 to about 3:1, typically from about 0.25:1 to about 0.8:1 and preferably from about 0.6:1 to about 0.8:1. Amounts of sorbitol as used herein are of sorbitol syrup, as commercially available, that is 70% by weight sorbitol in 30% by weight of water.

Low molecular weight polyethylene glycol of average molecular weight of about 200-1000, preferably 600-1000, disperses readily in the liquid vehicle and is effective to prevent the dental cream from underoing syneresis when in direct contact with a polyolefin resin surface of a dental cream package. In order to effect dispersion readily, grades of polyethylene glycol which are normally solid at room temperature are heated to liquefy them. The weight ratio of the total amount of glycerine and sorbitol to polyethylene glycol is from about 60:1 to about 6:1, preferably from about 15:1 to about 12:1 in an alkaline earth metal salt polishing dental cream or about 10:1 in alpha-alumina trihydrate dental cream. Typically, at least 0.5% by weight of polyethylene glycol is present, preferably about 0.55%.

Dentally acceptable water-insoluble polishing agent is present in the dental cream in amount of about 2075% by weight, preferably about 3560%. At least the major portion, that is, about 50-100 of the polishing material is water-insoluble alkaline earth metal salt or alpha-alumina trihydrate.

Typical water-insoluble alkaline'earth metal 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, one or more calcium salts, particularly dicalcium phosphate dihydrate or mixtures of dicalcium phosphate dihydrate and anhydrous dicalcium phosphate, are present.

Dentally acceptable water-insoluble alpha-alumina toothpaste is typically employed in small particle size, e.g. wherein at least about 85% of the particles are smaller than 20 microns and is preferably hydrated, such as that classified as gibbsite (alpha alumina trihydrate) and normally represented chemically as Al2033H20 orAl(OH)3. The average particle size of gibbsite is generally about 6 to 9 microns. However, larger particle size alpha-alumina trihydrate, e.g. wherein 2070% of the particles exceed 20 microns in size, may also be used.A particularly desirable grade of alpha-alumina trihydrate, available from Alcoa as C-333 is a fine grade of gibbsite having the following size distribution: Microns Percent lessthan30 94-99 lessthan20 85--93 lessthan 10 56--67 less than 5 2S40 Unless the pH of the dental cream is adjusted, a dental cream containing a substantial amount of alpha alumina trihydrate is generally highly alkaline, e.g. the pH is about 9--10.5. Accordingly, acidic materials are often added to such dental creams in order to reduce the pH, typically to about 6 to 8. Water-soluble phosphate materials, particularly inorganic phosphate materials are effective to produce such reduction in alkalinity.Such materials include orthophosphates, particularly orthophosphoric acid and alkali metal or ammonium monoacid orthophosphates or diacid orthophosphates. Sodium diacid orthophosphate and hydrates thereof are preferred. The amount of these materials is that sufficient to adjust the pH to about 68: e.g. sodium diacid orthophosphate (monohydrate or anhydrous) is typically present in an amount of about 0.150.50% by weight. Such phosphate pH adjusting materials renderthe dental creams subject to syneresis when in contact with a polyolefin resin surface unless an additive is present to prevent syneresis.

When water-insoluble alkaline earth metal salt is the major component of the polishing material, alphaalumina trihydrate, calcined alumina or other polishing agent may optionally be present in minor amount, for instance in a weight ratio of alkaline earth metal salt to alumina material of about 2.5:1 to about 4:1, the total amount of polishing material in the dental cream being about 2575% by weight.

When alpha-alumina trihydrate is the major component of the polishing material, the minor portion of the polishing material, if present, typically comprises about 520% by weight of the polishing material, and may be a polishing agent such as dicalcium phosphate dihydrate, anhydrous dicalcium phosphate, calcium carbonate, tricalcium phosphate, calcium pyrophosphate, dimagnesium phosphate trihydrate, magnesium carbonate, calcined alumina, zirconium silicate and insoluble sodium metaphosphate.

Organic surface-active agents may be used in the dental cream of the present invention to achieve increased prophylactic action, assist in achieving thorough and complete dispersion of the compositions of the present invention throughout the oral cavity, and render the dental creams more cosmetically acceptable. The organic surface-active material may be anionic, nonionic, ampholytic or cationic in nature, but it is preferred to employ as the surface-active agent a detersive material which imparts to the composition detersive and foaming properties.Suitable types of such detergents are water-soluble salts of higher fatty acid monoglyceride monosulphates, such as the sodium salt of the monosulphated monoglyceride of hydrogenated coconut oil fatty acids, higher alkyl sulphates, such as sodium lauryl sulphate, alkylaryl sulphonates, such as sodium dodecyl benzene sulphonate, olefinsulphonates, such as sodium olefin sulphonate in which the olefin group contains 12-22 carbon atoms, higher alkyl sulphoacetates, higher fatty acid ester of 1 ,2-dihydroxy propane sulphonates, and the substantially saturated higher aliphatic acyl amides of lower aliphatic amino carboxylic acid compounds such as those having 12-16 carbon atoms 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 Nlauroyl, 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 formation in the oral cavity due to carbohydrates break-down in addition to exerting some reduction in the solubility of tooth enamel in acid solutions.

Another desirable material is a long chain fatty acid sodium monoglyceride sulphonate used alone or in combination with sodium lauryl sulphate.

Other particularly suitable surface-active materials include nonionic agents such as condensates or sorbitan monostearate with approximately 20 moles of ethylene oxide, condensates of ethylene oxide with propylene glycol ("Pluronic" materials) and amphoteric agents such as long chain (alkyl) amino-alkylene alkylated amine derivatives, which are available under the trade mark "Miranol" such as Miranol C2M.

Cationic surface-active germicides and antibacterial compounds such as di-isobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, benzyl dimethyl stearyl ammonium chloride, benzyl diethyl stearyl ammonium chloride, tertiary amines having one fatty alkyl group (of from 12-18 carbon atoms) and two (poly)oxyethylene groups attached to the nitrogen (typically containing a total of from about 2 to 50 ethanoxy groups per molecule) and salts thereof with acids, and compounds of the structure.

where R represents a fatty alkayl group containing from about 12 to 18 carbon atoms, and x, y and ztotal 3 or higher, as well as salts thereof with mineral or organic acids, may also be used. It is preferred to use from about 0.05 to 5% by weight of the foregoing surface-active materials in the dental cream. It is most preferred that the surface-active agent be an anionic material, particularly sodium lauryl sulphate.

The dental cream suitably may also contain a fluorine-containing compound having a beneficial effect on the care and hygiene of the oral cavity, e.g., diminution of enamel solubiiity in acid and protection of the teeth against decay. Examples thereof include sodium fluoride, stannous fluoride, potassium fluoride, potassium stannous fluoride (SnF2.KF), sodium hexafluorostannate, stannous chlorofluoride, sodium fluorozirconate, and sodium monofluorophosphate. These materials which disassociate or release fluorinecontaining ions in water, suitably may be present in an effective but non-toxic amount, usually within the range of about 0.01 to 1% by weight of the water-soluble fluorine content thereof.

The preferred fluorine-containing compound is sodium monofluorophosphate typically present in an amount of about 0.076 to 7.6% by weight, preferably 0.76%. A mixture of sodium monofluorophosphate and sodium fluoride is also desirable, for instance in a weight ratio of about 2:1 based on fluoride.

Any suitable flavouring or sweetening materials may be employed in formulating a flavour for the composition of the present invention. Examples of suitable flavouring constituents include the flavouring oils, e.g., oils of spearmint, peppermint, wintergreen, sassafras, clove, sage, eucalyptus, marjoram, cinnamon, leman and orange, as well as methyl salicylate, suitable sweetening agents include sucrose, lactose, maltose, xyl itol, sodium 6-methyl-3,4-dihydro-1 ,2,3-oxathiazine-4-one, sodium cyclamate, perillartine and sodium saccharin. Suitably, flavour and sweetening agents may together comprise from about 0.01 to 5% or more of the compositions of the present invention.

Various other materials may be incorporated in the dental cream. Examples thereof are colouring or whitening agents or dyestuffs, anti-corrosive agents, silicones, chlorphylic compounds, ammoniated materials such as urea, diammonium phosphate and mixtures thereof and other constituents. Whitening agents, such as titanium dioxide, typically in amounts of about 0.52%, may be beneficial to the appearance of the dental composition, since upon ageing, some discolouration may occur.

The adjpvants are incorporated in the compositions of the present invention in amounts which do not substantially adversely affect the properties and characteristics desired and are selected and used in proper amounts depending upon the particular type of composition involved.

Antibacterial agents may also be employed in the oral compositions of the present invention in an amount of about 0.015% by weight. Typical antibacterial agents include: N1-(4-chlorobenzyl)-N5-(2,4-dichlorobenzyl) biguanide; p-chlorophenyl biguanide; 4-chlorobenzyhydryl biguanide; 4-chlorobenzyhydrylguanylurea; N-3-lauroxypropyl-N5-chlorobenzylbiguanide; 1,6-di-chlorophenylbiguanidohexane; 1,6-bis-(2-ethylhexylbiguanide) hexane; 1-(lauryldimethylammonium)-8-(p-chlorobenzyldimethylammonium octane dichloride; 5,6-dichloro-2-guanidinobenzimidazole; N'-p-chlorophenyl-N5-laurylbiguanide; 5-amino-1 ,3-bis(2-ethylhexyl)-5-methylhexahydropyrimidine and their non-toxic acid addition salts.

In dental cream containing alkaline earth metal salt polishing agent there may also be employed various calcium and magnesium ion suppression agents for adjustment of physical properties of the compositions. Suitable agents are the water-soluble inorganic polyphosphate salts, such as tetrasodium pyrophosphate or disodium diacid pyrophosphate, with the partially neutralised or acid polyphosphate preferred. Other suitable agents are the alkali metal, preferably sodium, salts of citric acid. In general, such compounds will be a minor amount or proportion of the formulation. The precise amount will vary depending upon the specific formulation, such as the 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 for water-insoluble alkaline earth metal salt dental cream. The reference to the pH is meant to be the pH determination directly on the dental cream. If desired, materials such as citric acid may be added to adjust to the pH to say 6 to 7. For alpha-alumina trihydrate dental cream a pH of about 6--8, obtained by adjusting with a water-soluble material which provides phosphate ion is particularly desirable.

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 described in U.S. Patent 3,260,410 to Brandt et al. As described in the example thereof, an aluminium foil base having a thickness of about 0.0013 cm was heated to a temperature of approximately 1 77 C, and one face of the heated foil was contacted by an extrudible film of a random copolymer of ethylene and acrylic acid (acid content 3+0.5% and melt index 8j1 ), while the opposite surface thereof had placed there against a film of low density polyethylene.

Using driven rolls a laminated base was obtained in which the 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.

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 are very satisfactory and undergo substantially no syneresis. Such tubes A and A-1 are comprised of layers as set forth below in Table 1, in the order of outermost layer to innermost layer.

TABLE 1 A A-1 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 mil 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 following meanings: LDPE low density polyethylene EAA ethylene acrylic acid OPP oriented polypropylene Mechanically 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. Thus, the housing resin is in essence a layer, the inner surface of which is in contact with dental cream. When the dental cream of the present invention is packaged in such a polypropylene mechanical dispenser, it undergoes substantially no syneresis.

The advantages of the invention are also present when the dental cream is packed in a flexible sachet having a polyolefin surface, typically of low density or medium density polyethylene.

The invention may be put into practice in various ways and a number of specific examples will be described to illustrate the invention with reference to the following examples.

All amounts and proportions are by weight except as otherwise indicated.

EXAMPLES 1Ato 1D The fbllowing dental creams as set out in Table 2 below are prepared to creamy consistencies and packed into tubes of each of laminated structures A and A-1, set forth in Table 1 above: TABLE 2 Parts Example 1A 1B 1C 1D Ingredients Glycerine 8.000 - 8.000 8.000 8.000 Sorbitoi (70%) 16.000 15.000 15.500 14.000 Sodium Carboxymethyl cellulose 1.000 1.000 1.000 1.000 Sodium Saccharin 0.200 0.200 0.200 0.200 Sodium Monofluorophosphate 0.760 0.760 0.760 0.760 Sodium Diacid Orthophosphate monohydrate 0.250 0.250 0.250 0.250 Deionised water-irradiated 19.700 19.700 19.700 19.700 Alpha-alumina trihydrate (C-333) 52.000 52.000 52.000 52.000 Sodium lauryl sulphate 1.200 1.200 1.200 1.200 Flavour 0.890 0.890 0.890 0.890 Polyethylene Glycol Average M.W. 600 - 1.000 0.500 2.000 pH 7.0 7.0 7.0 7.1 After ageing for at least 13 weeks at 25"C, the dental creams of Examples 1 B, 1C and 1D remain creamy in consistency in laminate tubes of each of laminate Structures A and A-i,while the dental cream of Example 1A separates into liquid and solid phases within 1 week at 25"C in both oftubes of Structures A and A-1.

EXAMPLE 2 The dental creams of Examples 1A to 1 Dare incorporated into a mechanical dispenser in accordance with U.S. Patent 4,437,591 composed of polypropylene housing. The dental creams of Examples 1 B, 10 and 1 D retain their creamy consistency while the dentifrice of Example 1A separates into liquid and solid phases.

EXAMPLE 3 Similar results to those described above for Examples 1 and 2 are observed when: (i) the relative amounts of glycerine, sorbitol (70%) and polyethylene glycol - av. m.w. 600 are: 6:24:2 (Exampie 3(i)A) vs. 6:24:0 (Example 3(i)B - a comparison example) and 18:6:2 (Example 3(i)C)vs. 18:6:0 (Example3(i)D-a comparison example) (ii) polyethylene glycoi - av. m.wts. 200 and 1000 (Example 3(ii) A and B) are used in place of polyethylene glycol - av. m.w. 600: (iii) The dental creams are packed in laminated tubes in accordance with U.S. Patent 3,260,410 (Example 3(iii)); (iv) The dental creams are packed in crack-resistant laminated tubes in accordance with U.S.Patent 4,418,841 (Example 3(iv)); (v) The dental creams are packed in flexible sachets of the following structure from outermost to innermost layer: 12.21l polyethyleneterephthalate 21.311 white ethylene acrylic acid 9.0 pfoil 3.3 it ethylene acrylic acid 25.4 cm medium density polyethylene (Example 3(v)); (vi) Mixture of 0.3 parts of sodium carboxymethylcellulose and 0.6 parts of xanthan (Example 3(vi)) replace of sodiumcarboxymethyl cellulose as the sole gelling material; (vii) 3.000 parts of calcined alumina (Example (vii)) replace 3.000 parts of alpha-alumina trihydrate; and (viii) 10 parts of insoluble sodium metaphosphate (Exampie 3(viii)) replace 10.000 parts of alpha-alumina trihydrate (xi) sodium cyclamate (Example 3(ix)) replaces sodium saccharin.

EXAMPLES 4A and 4B The following dental creams set out in Table 3 below are prepared to cream consistencies and packed into tubes of each of laminated structures A and A-i set forth above: TABLE 3 Parts Example 4A 4B Ingredients Glycerine 10.000 10.000 Sodium Monofluorophosphate 0.760 0.760 Sodium carboxymethyl cellulose 0.950 0.950 Tetrasodium Pyrophosphate 0.250 0.250 Sodium Saccharin 0.200 0.200 Sorbitol - 70% solution 15.000 17.000 Polyethylene Glycol - av. M.W. 600 2.000 Deionised water -- irradiated 20.090 20.090 Dicalcium phosphate dihydrate 48.760 48.760 Flavour 0.890 0.890 Sodium lauryl sulphate 1.100 1.100 After ageing for at least 20 weeks at 250C the dental cream of Example 4A remains creamy in consistency in each of laminate tubes of structures A and A-1, while the dental cream of Example 4B separates into liquid and solid phases within 4 to 10 days at 25"C in both of tubes of structures A and A-1.

EXAMPLE 5 Similar results to those described above are observed when: (i) calcium carbonate (Example 6(i)) replaces dicalcium phosphate dihydrate; (ii) dimagnesium phosphate trihydrate (Example 6(ii)) replaces dicalcium phosphate dihydrate; (iii) the comparative amounts of glycerine, sorbitol (70%) and polyethylene glycol - av. m.w. 600 are: 6:24:2 (Example 6(iii)A) vs. 6:24:0 (Example 6(iii)B - a comparison example) and 18:6:2 (Example 6(iii)C) vs. 18:6::0 (Example 6(iii)D- a comparison example); (iv) polyethylene glycol - av. m.wts. 200 and 1000 (Example 6(iv) A and B) are used in place of polyethylene glycol - av. m.w. 600; (v) The dental creams are packed in laminated tubes in accordance with U.S. Patent 3,260,410 (Example 6(v)); (vi) The dental creams are packed in crack-resistant laminated tubes in accordance with U.S. Patent 4,418,841 (Example 6(vi)); (vii) The dental creams are packed in flexible sachets of the following structure from outermost to innermost layer.

12.2 p polyethylene terephthalate 21.3 p white ethylene acrylic acid 9.01I foil 3.3 cm ethylene acrylic acid 2S.4 p medium density polyethylene (Example 6(vii)) and (viii) Mixture of 0.3 parts of sodium carboxymethylcellulose and 0.6 parts of iota-carrageenan (Example 6(viii)) replace sodium carboxymethyl cellulose as the sole gelling material.

It is understood that the foregoing detailed description is given merely by way of illustration and that variations may be made therein without departing from the spirit of the invention.

Claims

1. A packaged dental cream in which the said dental cream is in direct contact with a polyolefin resin package surface, the said dental cream comprising at least about 20% by weight of a liquid vehicle comprising water, glycerine, sorbitol and polyethylene glycol of average molecular weight of about 200-1000, the weight ratio of glycerine to sorbitol being from about 0.25:1 to about 3:1 and the weight ratio of the total amount of glycerine and sorbitol to the said polyethylene glycol being from about 60:1 to about 6::1, a solid vehicle comprising about 0.0510% by weight of gelling agent, about 2075% by weight of a dentally acceptable water-insoluble polishing material, at least a major portion of which is a waterinsoluble alkaline earth metal salt or alpha-alumina trihydrate, and when alpha-alumina trihydrate is present as the major portion of the said polishing material, a water-soluble material to reduce the pH of the dental cream to about 68 which provides phosphate ion.

2. A packaged dental cream as claimed in Claim 1 in which the weight ratio of glycerine to sorbitol is from about 0.25:1 to about 0.8:1 and the weight ratio of the total amount of glycerine and sorbitol to the said polyethylene glycol is from about 15:1 to about 10:1.

3. A packaged dental cream as claimed in Claim 2 wherein the weight ratio of glycerine to sorbitol is from about 0.6:1 to about 0.8:1.

4. A packaged dental cream as claimed in any one of Claims 1 to 3 in which the average molecular weight of the said polyethylene glycol is about 600-1000.

5. A packaged dental cream as claimed in Claim 4 in which the average molecular weight of the said polyethylene glycol is about 600.

6. A packaged dental cream as claimed in any one of Claims 1 to 5 in which the said polyethylene glycol is present in an amount of at least about 0.5% by weight.

7. A packaged dental cream as claimed in Claim 6 in which the said polyethylene glycol is present in an amount of about 0.55% by weight.

8. A packaged dental cream as claimed in any one of Claims 1 to 7 in which the said alpha-alumina trihydrate is present as the sole polishing agent.

9. A packaged dental cream as claimed in any one of Claims 1 to 8 in which the said material which reduces the pH is inorganic.

10. A packaged dental cream as claimed in Claim 9 in which the said inorganic material which reduces the pH provides orthophosphate ion.

11. A packaged dental cream as claimed in Claim 10 in which the said material containing orthophosphate ion is selected from the group consisting of orthophosphoric acid, alkali metal diacid orthophosphate, ammonium diacid orthophosphate, alkali metal monoacid orthophosphate and ammonium monoacid orthophosphate.

12. A packaged material as claimed in Claim 11 in which the said material containing orthophosphate ion is a sodium diacid orthophosphate.

13. A packaged material as claimed in Claim 12 in which the sodium diacid orthophosphate is sodium diacid orthophosphate monohydrate.

14. A packaged dental cream as claimed in any one of Claims 1 to 7 in which the said water-insoluble alkaline earth metal salt is present and is a calcium salt.

15. A dental cream as claimed in Claim 14 in which the said calcium salt is dicalcium phosphate dihydrate.

16. A dental cream as claimed in Claim 1 substantially as specifically described herein with reference to any one of Examples 1 B, 1 C or 1 D; 3(i)A or 3(i)C, 3(ii)A or 3(ii)B, 3(vi), 3(vii), 3(viii) or 3(ix); 4A; 6(i), 6(ii), 6(iii)A or 6(iii)C, 6(iv)A or 6( iv) B, or 6(viii).

17. A dental cream as claimed in any one of Claims 1 to 16 in which the said dental cream is packaged in a plastic laminate tube.

18. A dental cream as claimed in Claim 17 in which the inner polyolefin resin surface of the said plastic laminate tube is polyethylene.

19. A dental cream as claimed in Claim 18 in which the said polyethylene is low density polyethylene.

20. A dental cream as claimed in any one of Claims 1 to 16 in which the said dental cream is packaged in a mechanical dispenser having a housing of polyolefin resin.

21. A dental cream as claimed in Claim 20 in which the said polyolefin resin of the said housing is polypropylene.

22. A dental cream as claimed in any one of Claims 1 to 16 in which the dental cream is packaged in a flexible sachet.

23. A dental cream as claimed in Claim 22 in which the inner polyolefin resin surface of the said sachet is low density polyethylene or medium density polyethylene.