BRPI0711979A2 - opaque toothpaste composition, opaque toothpaste and production method - Google Patents

Abstract

Opaque toothpaste composition, opaque toothpaste and production method An opaque toothpaste composition comprising: water; a zinc salt; a chelating agent for the zinc salt, the chelating agent provided with a log Ks1 as defined herein from 3.0 to 7.0; calcium carbonate from 10 to 70% by weight of the toothpaste composition; a monofluorophosphate salt; and trisodium phosphate.

Description

"Composition of Opaque Density, Opaque Density and

PRODUCTION METHOD "

The present invention relates to an opaque dentifrice composition comprising bioactive zinc salts in a chalk formulation. The invention also relates to a method for producing said composition.

EP-A1-0 740 932 (UniIever) discloses a visually clear gel-type toothpaste comprising a zinc salt that is more water soluble than zinc citrate, a zinc-binding amino acid and a silica low refractive index type abrasive.

US 5,470,561 (KIugkist) discloses an anti-plaque mouthwash comprising a zinc salt and triclosan. The composition may also comprise glycine and has a pH between 4 and 8, preferably between 5 and 7, the preferred pH being 6.

GBA-2,052,978 (UniIever) describes a dentifrice comprising glycine zinc salts and a pH of 4.5 to 8.0.

US 5,632,972 (Williams) describes a method for minimizing gum and periodontal tissue damage by sending a first component comprising zinc and a second component comprising bicarbonate.

US 4,425,325 (Sapone et al) describes an oral composition containing glycine biologically active zinc ions and having an adjusted pH of about 4.5 to 9.4.

GB 1,319,247 (Beecham INC) describes an anti-tartar non-liquid dental composition comprising a dental carrier, and a zinc, cupric or zirconium complex of a fluorinated β-diketone.

US 4,325,939 (Shah) describes an alkali metal or zinc ammonium citrate prepared for use in dental compositions and especially mouthwash compositions.

US 5,188,820 (Cummins et al) describes oral compositions such as dentifrices comprising a mixture of a stannous salt such as stannous fluoride or stannous pyrophosphate and a zinc salt such as zinc citrate.

In a first aspect of the present invention there is provided an opaque dentifrice composition according to claim 1.

Monofluorophosphate salt provides fluoride ions to the dentifrice composition, fluoride ion is an effective anti-caries agent. However, monofluorophosphate salts are not stable in chalk containing dentifrices and thus a stabilizing agent is required. Although trisodium phosphate (TSP) was a previously suitable stabilizing agent, currently it has not been possible to add TSP to zinc containing dentifrices as zinc free ions react with TSP to form zinc phosphate. Zinc phosphate is not a good bioavailable source of zinc. Therefore, by incorporating a zinc chelating agent, monofluorophosphate as well as zinc levels can be maintained after prolonged storage.

The zinc salt is present from 0.01 to 5% by weight of the toothpaste composition, preferably from 0.5 to 3.0% by weight of the composition. Where the zinc salt is moderately soluble, for example zinc citrate, the log KS1 of the zinc ion chelating binder is equal to or greater than the acid anion log KS1 and the zinc ion of the moderately zinc salt soluble. However, water soluble zinc salts are preferred. Suitable zinc salts include zinc chloride, zinc sulfate and zinc fluoride. The preferred zinc salt is zinc sulfate which in this type of formulation provides the optimal balance as described above.

The alkali metal is preferably potassium or sodium, more preferably sodium.

The alkali metal phosphate is preferably a mono, di- or tri-phosphate salt, more preferably a triphosphate.

It is preferred that the zinc salt chelating agent be provided with a KS1 Yog of 4.0 to 6.0. Yog KS1 is the Primary Stability Constant Yogarithm which is the binding affinity for a particular ligand with particular metal ion in the present invention zinc. For example, when the chelating agent is glycine, the Primary Stability Constant is the binding affinity for a free zinc ion glycine ligand and is defined by the following: KS1 = [ML] / [M]. [L] where [ML] is the concentration of the metal-binder complex, [M] is the concentration of the free metal ion and [L] is the concentration of the free ligand. Since [L] is a function of the pH of the solution due to the required initial binder deprotonation as a reference point, the described Iog Ks 1 values were recorded at pH 7.4.

The chelating agent is present from 0.001 to 6% by weight of the composition, preferably from 0.5 to 4.0% by weight of the composition. Preferred chelating agents include alkali metal salts of citric acid, alanine, glycine and serine. Most preferred are the alkali metal salts of citric acid, especially potassium citrate and more preferably tri-potassium citrate, which provides a good balance between being able to protect the zinc salt against hydrolysis (leading to the formation of carbon dioxide). carbon) in the chalk system and keep it soluble and bioavailable.

The abrasive system is present from 10 to 70% by weight of the toothpaste composition, preferably from 20 to 60% and more preferably from 35 to 45% by weight of the toothpaste composition.

Alkali metal phosphate is present from 0.01 to 2% by weight, preferably from 0.15 to 1% and especially preferably from 0.2 to 0.5% by weight of the composition. The abrasive system employed in the present invention is based on calcium carbonate. This does not prevent the use of additional non-calcium carbonate abrasives such as silicas, tungsten carbide and silicon carbide.

In one preferred embodiment, the abrasive system comprises at least 50 wt% calcium carbonate, more preferably at least 75 wt% calcium carbonate and more preferably at least 95 wt% calcium carbonate. In a more preferred embodiment of the present invention the abrasive system comprises 100 wt% calcium carbonate although mixtures of calcium carbonate and additional abrasives are possible.

Preferred calcium carbonates include finely ground natural chalk as it exhibits surprising stability with respect to its interactivity with zinc salts. The term finely ground natural chalk (CNGF) is a term known in the art and suitable examples thereof are described in US 2003/0072721 A1 (Riley) the contents of which with respect to the definition, types and categories of CNGF are incorporated herein by reference. . However, by FGNC is meant chalk that is obtained by grinding limestone or marble deposits.

Preferably, the CNGF comprises particulate material of a weight-based average particle size ranging from 1 to 15 μm and a BET surface area ranging from 0.5 to 3 m2 / g.

The composition according to the invention preferably also comprises an ion fluoride source such as an alkali metal salt of monofluorophosphate, preferably sodium monofluorophosphate. Said fluoride ion source will be present in an amount to provide free fluoride ion of 100 to 2000 ppm, preferably 900 to 1500 ppm.

The dentifrice composition according to the invention comprises additional ingredients which are common in the art, such as:

Antimicrobial agents, for example chlorhexidine, sanguinarine extract, metronidazole, quaternary ammonium compounds such as cetylpyridinium chloride; bis-guanides such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; and halogenated bisphenolic compounds, such as 2,2'-methylenebis (4-chloro-6-bromophenol);

Antiinflammatory agents such as ibuprofen, flurbiprofen, aspirin, indomethacin etc .;

Anti-caries agents such as sodium and stannous fluoride, aminofluorides, sodium monofluorophosphate, sodium trimetaphosphate and casein;

Plaque buffers such as urea, calcium lactate, calcium glycerophosphate and strontium polyacrylates;

Vitamins such as Vitamins A, C and E;

Plant extracts;

Desensitizing agents, for example potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate and strontium salts;

Anti-tartar agents, for example alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphocitrates etc .;

Biomolecules, for example bacteriocins, antibodies, enzymes, etc .;

Flavorings, for example, mint and mint oils;

Protein materials such as collagen;

Preservatives;

Opacifying agents;

Coloring agents;

PH adjusting agents;

Sweetening agents; Pharmaceutically acceptable carriers, for example starch, sucrose, water or water / alcohol systems etc .;

Surfactants such as anionic, nonionic, cationic and zwitterionic or amphoteric surfactants;

Particulate abrasive materials such as silicas, aluminas, calcium carbonates, dicalcium phosphates, calcium pyrophosphate, hydroxyapatites, trimetaphosphates, insoluble hexametaphosphates and so on, including agglomerated particulate abrasive materials, generally in amounts of between 3 and 60% by weight of the composition. dentifrice. Preferred abrasives are chalk and silica, more preferably fine crushed natural chalk;

Humectants such as glycerol, sorbitol, propylene glycol, xylitol, lactitol etc .;

Binders and thickeners such as sodium carboxymethyl cellulose, hydroxyethyl cellulose (Natrosol®), xanthan gum, arabic gum etc., as well as synthetic polymers such as polyacrylates and carboxyvinyl polymers such as Carbopol®;

Polymeric compounds that may increase active ingredient delivery such as antimicrobial agents may also be included;

Buffers and salts to buffer the pH and ionic strength of the toothpaste composition; and

Other ingredients that may be included are, for example, bleaching agents such as peroxy compounds, for example potassium peroxidiphosphate, effervescent systems such as sodium bicarbonate / citric acid systems, color change systems, and so on.

Liposomes can also be used to enhance the shipping or stability of active ingredients.

In a second aspect of the invention there is provided a method of producing an opaque dentifrice composition according to the first aspect of the method comprising the steps of forming a zinc chelate solution and buffering to a pH that is equal to or greater than that of calcium carbonate in an aqueous suspension before mixing with the suspended calcium carbonate. Additional materials such as flavorings may be added to the final mixture.

Except in the operational and comparative examples, or where otherwise explicitly indicated, all numbers in the present description indicating quantities are to be construed as modified by the word "about".

The term "comprising" is not intended to be limiting to any subsequently determined elements but rather to encompass unspecified elements of major or minor functional importance. In other words, the steps, elements, or options listed do not have to be complete. Where the words "including" or "endowed with" are used, those terms are intended to be equivalent to "comprising" as defined above.

Embodiments according to the invention will now be discussed with reference to the following non-limiting examples.

Example 1

The following example formulation is an embodiment according to the invention. It is produced by first mixing zinc sulfate heptahydrate with glycine (and smaller ones) and buffering at a pH of 8.5 to 9.5 with sodium hydroxide. Calcium carbonate, surfactant and builders are then added to the zinc-chelate mixture. The aromas are added last.

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Claims (14)

1. Opaque denture composition, comprising: water; a zinc salt; a zinc salt chelating agent, the chelating agent having a log KS1 as defined herein from 3.0 to 7.0; calcium carbonate from 10 to 70% by weight of the dentifrice composition; a monofluorophosphate salt; and alkali metal phosphate. The opaque composition as claimed in claim 1, wherein the composition has a pH of 8.0 to 10.0. The opaque dentifrice composition according to claim 1 or 2, wherein the alkali metal phosphate is trisodium phosphate. Opaque dentin composition according to any one of the preceding claims, wherein calcium carbonate is fine ground natural chalk. An opaque composition as claimed in any one of the preceding claims, wherein the composition comprises a fluoride ion source. An opaque composition according to any one of the preceding claims, wherein the zinc salt is a water-soluble zinc salt. An opaque composition according to any one of the preceding claims, wherein the zinc salt is zinc sulfate. An opaque composition according to any one of the preceding claims, wherein the chelating agent is glycine. An opaque composition according to any one of the preceding claims, wherein the chelating agent is serine. An opaque composition according to any one of the preceding claims, wherein the chelating agent is alanine. Opaque dentin composition according to any one of the preceding claims, wherein the chelating agent is an alkali metal salt of citric acid. An opaque name according to any one of the preceding claims, comprising an agent selected from the group consisting of anti-caries, anti-tartar agents, anti-odor agents, tooth whitening agents, anti-gingivitis agents. and mixtures thereof. An opaque name according to any preceding claim, wherein trisodium phosphate is present from 0.1 to 1% by weight of the composition. 14. METHOD OF PRODUCTION, of an opaque dentifrice composition wherein the dentifrice comprises water, a zinc salt, the chelating agent for zinc salt, the chelating agent having a KS1 Yog as defined herein from 3.0 to 7, 0, and a present abrasive of 10 to 70% by weight of the toothpaste composition, said abrasive comprising calcium carbonate, the method comprising: forming a zinc chelate solution and buffering to a pH that is equal to or greater than that of calcium carbonate in an aqueous suspension before mixing with calcium carbonate and optionally adding any additional materials at any stage.