WO2006081867A1

WO2006081867A1 - Toothpaste composition

Info

Publication number: WO2006081867A1
Application number: PCT/EP2005/014058
Authority: WO
Inventors: Rupesh Kumar Agarwal; Donald P Gregory; Brian Groves
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Unilever Limited
Priority date: 2005-02-04
Filing date: 2005-12-21
Publication date: 2006-08-10
Also published as: EP1843739A1; BRPI0519870A2; MX2007009239A

Abstract

A toothpaste composition comprising an inner phase disposed substantially coaxially within an outer phase, the inner phase constituting from 60 to 99.9% by volume of the composition, the outer phase being a gel and constituting from 0.1 to 40% by volume of the composition.

Description

TOOTHPASTE COMPOSITION

The present invention relates to an oral composition comprising an inner phase disposed substantially coaxially within an outer phase .

WO 99/01342 discloses apparatus for inserting plural materials into containers . The apparatus comprises a nozzle with a first hollow member and a second hollow member arranged inside the first hollow member . The nozzle is designed for directing the extrusion of multiple toothpaste phases into a toothpaste container with one phase being arranged within another .

Despite the prior art there remains the need for multiphase toothpaste compositions with improved visual impact .

The present inventors have found that improved visual impact is achieved by carefully configuring the relative amounts of each phase . Accordingly and in a first aspect , the present invention provides a toothpaste according to claim 1.

The inner phase is disposed co-axially within the outer phase . By this is meant that the longitudinal axis of the ribbon as dispensed from the toothpaste container falls within the inner phase . Similarly, the general longitudinal axis of the toothpaste as stored within the toothpaste container falls within the inner phase . Such alignment is understood to be judged by the eye and not mathematically. When looking at a section of the dispensed ribbon end-on the inner phase may extend towards or up to the exterior surface of the ribbon . Such extension may be radial , spiral or abstract and, where it is radial or spiral it may be regular or irregular . Regular radial extensions are the most preferred to the consumer . In addition the core may, in cross section be of any shape, for example, star-shaped, square shaped, triangular, etc . These shaped cores are a real plus to the younger consumers . However, it is most preferred that the inner phase comprises no extensions and instead provides nothing more than a regular core to the ribbon. This regular shape is less fussy and provide clean lines to the product which reinforces the impression of cleanliness that toothpastes aim to provide .

The improved visual impact resides in the way that the outer phase substantially surrounds in the inner phase . In fact , subsequent to dispensing onto a toothbrush, the consumer is likely to see only the outer phase because of the way that the outer phase wraps itself around the inner phase .

Consequently, any negative visual impact resident in the inner phase can be negated by using a relatively low level of a further, second composition which substantially surrounds it . By using a toothpaste composition which has a greater formulation window a formulator can concentrate on achieving the most efficacious formulation for the inner phase without worrying about any negative visual impact it might have since these can be provided merely by the second, outer phase . The second, outer phase thus provides the visual impact , e . g . a shiny surface , on behalf of the composition as a whole . Preferably, the inner phase is opaque . This maximises the formulation window available to the formulator since there is no need to make sure that individual ingredients are compatible visually with any other ingredients and also that it doesn' t matter whether ingredients are fully solubilised or not . This provides a further benefit in that it creates a silvery effect at the interface between the two phases . This is an attractive effect for the consumer .

More preferably, the inner phase comprises chalk as abrasive . Chalk provides an improved abrasive system which also polishes the teeth on brushing . Using chalk in the . inner phase also prevents the user from experiencing any negative taste associated with chalk. The chalk may be precipitated calcium carbonate or fine ground natural chalk, preferably it is fine ground natural chalk which is less reactive with other ingredients and so, again, increases the formulation window. Preferably the chalk is present at from 5 to 70% by weight of the first , inner phase .

In a further preferred embodiment the outer phase comprises abrasive silica . More preferably the outer phase comprises an abrasive silica with a low refractive index. It may be used as the sole abrasive silica, or in conjunction with a low level of other abrasive silicas, e . g . those according to EP 236070. The low refractive index silicas , used as abrasives in the present invention are preferably silicas with an apparent refractive index (R. I . ) in the range of 1.41 - 1.47 , preferably 1.435 - 1.445 , preferably having a weight mean particle size of between 5 and 15 mm, a BET

(nitrogen) surface area of between 10 and 100 m²/g and an oil absorption of about 70 - 150 cm³/100 g, but abrasive silicas with a lower apparent refractive index may also be used . Typical examples of suitable low refractive index abrasive silicas (e . g . having an R. I . of between 1.435 and 1.445) are Tixosil 63 and 73 ex Rhone Poulenc ; Sident 10 ex Degussa;

Zeodent 113 ex Zeofinn; Zeodent 124 ex Huber, Sorbosil AC 77 ex Crosfield Chemicals (having an R . I . of approximately 1.440) . The amount of these silicas in the composition generally ranges from 5-60% by weight , usually 5-20% by weight .

More preferably, the outer phase is visually clear. By visually-clear is meant that the inner, first phase can be seen through the outer, second phase .

The first phase is disposed co-axially within the visually clear gel phase . By this is meant that the longitudinal axis of the ribbon as dispensed from the toothpaste container falls within the inner, first phase . Similarly, the general longitudinal axis of the toothpaste as stored within the toothpaste container falls within the inner, first phase as stored therein . Such alignment is understood to be judged by the eye and not mathematically.

Preferably, the inner first phase constitutes from 80 to 99% and more preferably from 90 to 95% by volume of the toothpaste composition.

The first and second phases may be the same or different with regard to their principle components , i . e . thickeners , actives, structurants and abrasives . Where the first and second phases are essentially the same they may differ in minor components such as colours or flavours . Having two visually clear phases also provides an attractive composition for the consumer . The inner phase comprising the bulk of the efficacious materials with the outer phase providing the attractive appearance on behalf of the formulation as a whole . For example , the inner phase may comprise clays as structurants . Clays do not provide a visually attractive paste and so this inner phase will be surrounded by a second phase which is made up of materials which provide such a visually attractive appearance .

In a preferred embodiment at least one of the phases is coloured . Preferably, the outer, visually-clear phase is coloured . Preferred colours include green, red, orange, yellow, blue , gold and purple . This would give the impression that the whole composition is coloured where in fact it might not be, the inner phase being merely opaque and colourless .

The phases of the composition according to the invention are manufactured using standard processes . They may be extruded into a container for dispensing by equipment such as that discussed in detail in WO 99/01342 , i . e . a coaxial nozzle assembly attached to standard equipment .

In a most preferred embodiment the phases according to the composition of the invention have viscosities as measured on a Brookfield RV DV-I viscometer fitted with a Helipath stand at 25 °C and 5rpm using a spindle are from 150 000 Pa . s and

250 000 mPa . s . Such viscosities provide the best performance with regard to extrusion into the container and also from the container by the consumer. The phases within this viscosity range are much more stable , physically during extrusion, that other phases .

The toothpaste composition according to the present invention can comprise an agent selected from the group consisting of anti-carries agents , tooth whitening agents, anti-tartar agents , anti-malodour agents , anti-gingivitis agents and mixtures thereof .

The toothpaste composition will comprise further ingredients which are common in the art , such as :

antimicrobial agents , e .g . 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) ;

anti-inflammatory agents such as ibuprofen, flurbiprofen, aspirin, indomethacin etc . ;

anti-caries agents such as sodium- and stannous fluoride , aminefluorides , sodium monofluorophosphate, sodium trimeta phosphate and casein;

plaque buffers such as urea, calcium lactate, calcium glycerophosphate and strontium polyacrylates ; vitamins such as Vitamins A, C and E;

plant extracts ;

desensitising agents , e .g . potassium citrate, potassium chloride, potassium tartrate , potassium bicarbonate, potassium oxalate , potassium nitrate and strontium salts ;

anti-calculus agents , e .g . alkali-metal pyrophosphates , hypophosphite-containing polymers , organic phosphonates and phosphocitrates etc . ;

biomolecules, e . g . bacteriocins , antibodies , enzymes, etc . ;

flavours , e . g . peppermint and spearmint oils ;

proteinaceous materials such as collagen;

preservatives ;

opacifying agents ;

colouring agents ;

pH-adjusting agents ;

sweetening agents ;

pharmaceutically acceptable carriers , e . g . 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 , dicalciumphosphates , calcium pyrophosphates , hydroxyapatites , trimetaphosphates , insoluble hexametaphosphates and so on, including agglomerated particulate abrasive materials, usually in amounts between 3 and 60% by weight of the oral care composition . Preferred abrasives are chalk and silica, more preferably fine ground natural chalk.

Humectants such as glycerol , sorbitol , propyleneglycol , xylitol , lactitol etc . ;

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

polymeric compounds which can enhance the delivery of active ingredients such as antimicrobial agents can also be included;

buffers and salts to buffer the pH and ionic strength of the oral care composition; and

other optional ingredients that may be included are e . g . bleaching agents such as peroxy compounds e . g . potassium peroxydiphosphate , effervescing systems such as sodium - S -

bicarbonate/citric acid systems , colour change systems , and so on.

Liposomes may also be used to improve delivery or stability of active ingredients .

In a second aspect the present invention provides a toothpaste container comprising a first and second phase as described in the first aspect of the invention stored within a tubular container, the container comprising a tubular body which is crimped at one end and comprises a dispensing assembly at the other through which the composition is extruded by the consumer.

Preferably, the tubular container is transparent or translucent so that the inner phase can be seen within the outer phase within the container .

An embodiment of the invention is now discussed in the non- limiting example .

EXAMPLE

The first phase makes up 85% by volume of the toothpaste composition .

Claims

1. A toothpaste composition comprising an inner phase disposed substantially coaxially within an outer phase, the inner phase constituting from 60 to 99.9% by volume of the composition, the outer phase constituting from 0.1 to 40% by volume of the composition.

2. A toothpaste composition according to claim 1 wherein the inner phase is opaque .

3. A toothpaste composition according to claim 1 or 2 wherein the inner phase comprises chalk as abrasive .

4. A toothpaste composition according to any preceding claim wherein the outer phase comprises a gel .

5. A toothpaste composition according to any preceding claim wherein the outer phase comprises abrasive silica .

6. A toothpaste composition according to any preceding claim wherein the outer phase is visually clear .

7. A toothpaste composition according to any preceding claim wherein the outer phase is colourless .

8. A toothpaste composition according to any preceding claim wherein the outer phase constitutes from 0.1 to 5% by volume of the composition .