J7219/C
FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)


DUAL PHASE ABRASIVE TOOTHPASTE COMPOSITION
HINDUSTAN UNILEVER LIMITED, a company incorporated under the Indian Companies Act, 1913 and having its registered office at Hindustan Lever House, 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed


WO 2007/099060

PCT7EP2007/051747

- 1 -COMPOSITION
The present invention relates to a multi-component toothpaste composition comprising abrasives. 5
W099/55297 (Colgate) discloses a dual component dentifrice in which each component comprises a siliceous abrasive.
US-B1-6 346 235 (Colgate) discloses a dual component 10 toothpaste comprising silica abrasives.
EP-A-0 3 97 4 52 (Beecham) discloses a toothpaste composition comprising abrasives.
15 WO 99/39685 (Unilever) discloses a dual component toothpaste wherein the two separate phases are dispensed from the same container and both comprise silica abrasives.
WO 99/63960 (P&G) discloses a toothpaste comprising silicas 20 having specific refractive indices and that the toothpaste has a clear appearance.
US 2005/0163727 (Doyle) discloses two-phase compositions comprising dental abrasives. 25
EP-A-0 740 932 (Unilever) discloses visually clear gels comprising silicas.
G3 1 271 944 (Beecham) discloses a striped toothpaste 30 composition.

WO 2007/099060

PCT/EP2007/051747

- 2 -
US 6 682 717 (Alcan) discloses a tooth care composition comprising abrasive components.
US 6 521 216 (P&G) discloses a dual component toothpaste 5 comprising abrasives.
Despite the prior art there is a need for improved oral compositions comprising improved abrasive systems having better visual appearance.
10
Accordingly, the present invention provides a toothpaste which maximises the cleaning effect provided by contained abrasives while minimising the restrictive effects presented by their presence in the formulation, in particular their
15 opacifying effect on clear gels.
Accordingly, the present invention provides a toothpaste composition comprising a first formulation and a second formulation which are in contact with one another when
20 dispensed from a container, the first toothpaste formulation comprising X% by weight of an abrasive (A) having a scattering centre concentration such that its light transmittance is from 0 to 7 0% and the second composition comprising from 0.1 to 0.9X by weight of an abrasive (B)
25 having a scattering centre concentration such that its light transmittance is from 0 to 70%.
Preferably, the second composition comprises 0.2 to 0.7, more preferably from 0.4 to 0.6 and especially preferably 30 0.5X of abrasive B.

WO 2007/099060

PCT/EP2007/051747

- 3 -
Preferably, X is from 1 to 5% by weight of the first formulation, more preferably from 2 to 4% and especially 3% by weight of the first formulation.
5 The scattering centres are points within a particle which scatter light and therefore reduce the amount of light that passes through it. It can be measured quite simply by measuring the transmission of light through a mixture of the abrasive in the liquid phase of the toothpaste. This is
10 achieved by placing into a cuvette a quantity of the
abrasive in a liquid phase which, for clear gels, consists of aqueous sorbitol (at 70% in water) and water in the weight ratios of 90:10. Typically 0.5 g of the abrasive are mixed with 12 g of the 70% sorbitol in water solution
15 and the light transmission measured at 589 nm.
Preferably, the abrasive (A) in the first formulation has a scattering centre concentration such that its light transmittance is from 0 to 50% more preferably from 10 to 20 40%. Preferably, the abrasive (B) in the second formulation has a scattering centre concentration such that its light transmittance is from 0 to 50% more preferably from 10 to 40%.
2 5 Preferably, the abrasive (B) in the second formulation is the same as abrasive (A).
Preferably, the second formulation is a visually clear gel. By visually clear is meant that a person with 20:20 eyesight 30 can read a size 12 Times Roman font through a 1 ml cuvette filled with the formulation.

WO 2007/099060

PCT7EP2007/051747

- 4 -
Preferably, the first formulation of the toothpaste composition comprises from 2 to 40%, more preferably from 5 to 15% and most preferably from 8 to 12% by volume of the composition. Using a reduced level of the first formulation 5 allows the formulator greater flexibility with the second, and any further formulation in that the negative aspects to abrasive inclusion can be reduced to a minimum.
Preferably, the abrasive (A) in the first formulation is 10 selected from abrasive silica, calcium carbonate, calcium pyrophosphate, calcined alumina, tungsten carbide, perlite, silicon carbide, polypropylene, polycarbonate, dicalciumphosphates, hydroxyapatites, trimetaphosphates, insoluble hexametaphosphates and mixtures thereof. More 15 preferably, the abrasive in the first formulation is abrasive silica, perlite, silicon carbide or tungsten carbide. Most preferably, it is a silica based abrasive such as AC33 available from Ineos Silicas.
20 Preferably, the abrasive (B) in the second formulation is selected from abrasive silica, calcium carbonate, calcium pyrophosphate, calcined alumina, tungsten carbide, perlite, silicon carbide, polypropylene, polycarbonate, dicalciumphosphates, hydroxyapatites, trimetaphosphates,
25 insoluble hexametaphosphates and mixtures thereof. More preferably, the abrasive in the first formulation is abrasive silica, perlite, silicon carbide or tungsten carbide. Most preferably, it is a silica based abrasive available from Ineos Silicas.
30

WO 2007/099060

PCT/EP200 7/051747

- 5 -
Preferably, the composition is a striped toothpaste composition and the stripe comprises the first formulation. Thus, the benefits obtained by storing the bulk of the abrasive in the first formulation can be combined with the 5 better visuals provided by the striped composition.
Preferably, by using a plurality of stripes the concentrated abrasive can be spread out in the composition as a whole so as to avoid presenting onto the tooth surface concentrated abrading material.
10
Preferably, the first formulation is located coaxially within the second formulation on dispensing from the container. By coaxially is meant that the average centreline along the length of the first formulation of the dispensed
15 paste lies substantially close to the average centreline of the entire dispensed paste. The term coaxial is not meant to represent any mathematical exactness. This prevents the user from spreading concentrated abrasive onto the tooth surface and also provides the user what appears to be a completely
20 clear toothpaste, the opaque core being hidden within the gel ribbon.
Preferably, the first formulation and second formulation have substantially similar viscosities at 40°C (RV-TD at 25 5rpm). By substantially similar is meant that the
viscosities are kept within 10 000 cps of each other.
The toothpaste may also comprise further abrasives providing they do not negatively impact the appeal of the toothpaste'. 30 Preferred further abrasives include any that have a
Refractive Index matched to the Refractive Index of the

WO 2007/099060

PCTYEP2007/051747

- 6 -
aqueous sorbitol based composition. These are commonly known as the low refractive index silicas. The low refractive index silicas used as abrasives in the present invention are silicas which have a refractive index which is matched to 5 that of the aqueous sorbitol base with an apparent
refractive index 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 μm, a BET (nitrogen) surface area of between 10 and 100 m2/g and an oil absorption of about 70 -10 150 cm3/100 g.
Typical examples ox suitable low refractive index abrasive silicas having an R.I. of between 1.435 and 1.445 are Tixosil 63 and 7 3 ex Rhone Poulenc; Sident 10 ex Degussa;
15 Zeodent 113 ex Zeofinn; Sorbosil AC 7 7 ex Ineos having an R.I. of approximately 1.440. Further examples can be found in EP-A-0,549,287 (Colgate) and in WO 94/10087 (Crosfield) which are hereby incorporated by way of Reference. The amount of these silicas in the composition generally ranges
20 from 5-60% by weight, usually 5-20% by weight.
The liquid phase of the second formulation should be formulated such, that its refractive index closely matches the refractive index of the silicas as discussed above. The
25 liquid phase usually comprises water and a humectant, the latter usually being sorbitol or glycerol. Water has an RI of 1.333, sorbitol (70% aqueous solution) has an RI of 1.457 and glycerine an RI of 1.473. Other humectants such as propylene glycol, polypropylene glycol and polyethylene
30 glycol may also be present. The refractive index of the liquid phase can be calculated from the respective

WO 2007/099060

PCT/EP2007/051747

- 8 -
desensitising agents, e.g. potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate and strontium salts;
5 anti-calculus agents, e.g. alkali-metal pyrophosphates,
hypophosphite-containing polymers, organic phosphonates and phosphocitrates etc.;
biomolecules, e.g. bacteriocins, antibodies, enzymes, etc.; 10
flavours, e.g. peppermint and spearmint oils;
proteinaceous materials such as collagen;
15 preservatives;
opacifying agents;
colouring agents; 20
pH-adjusting agents;
sweetening agents;
25 pharmaceutically acceptable carriers, e.g. starch, sucrose, water or water/alcohol systems etc.;
surfactants, such as anionic, nonionic, cationic and zwitterionic or amphoteric surfactants; 30

WO 2007/099060

PCT/EP2007/OS1747

- 9 -
humectants such as glycerol, sorbitol, propyleneglycol, xylitol, lactitol etc.;
binders and thickeners such as sodium carboxymethyl-5 cellulose, 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 10 ingredients such as antimicrobial agents can also be
included. Examples of such polymers are copolymers of
polyvinylmethylether with maleic anhydride and other similar
delivery enhancing polymers, e.g. those described in DE-A-
3,942,643 (Colgate); 15
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. 20 bleaching agents such as peroxy compounds e.g. potassium peroxydiphosphate, effervescing systems such as sodium bicarbonate/citric acid systems, colour change systems, and so on.
25 Liposomes may also be used to improve delivery or stability of active ingredients.
Embodiments of the invention will now be described with reference to the following non-limiting examples. 30

WO 2007/099060

PCT/EP2007/051747

- 10 -
EXAMPLES
The following toothpaste formulations were made using known processes. 5


WO 2007/099060

PCT/EP2007/051747

AMENDED CLAIMS received by the International Bureau on 02 October 2007 (02.10.2007)
CIAIMS
1. A toothpaste composition comprising a first formulation
5 (at from 2 to 40%) and a second formulation which is a
visually clear gel, the two formulations being in contact with one another when dispensed from a container, the first toothpaste formulation comprising from 1 to 5% by weight of an abrasive (A) having a
10 scattering centre concentration such that its light transmittance is from 0 to 7 0% and the second composition comprising an abrasive (B) in an amount equal to from 0.1 to 0.9 by weight of the amount of abrasive (A) in the first formulation,, abrasive (3)
15 having a scattering centre concentration such that its light transmittance is from 0 to 70%.
2. A toothpaste composition according to claim 1 wherein
the first formulation comprises from 5 to 15% by volume
20 of the composition.
3. A toothpaste composition according to claim 1 or 2
wherein the abrasive in the first formulation is
selected from abrasive silica, calcium carbonate,
25 calcium pyrophosphate, calcined alumina, tungsten
carbide, silicon carbide, polypropylene, polycarbonate and mixtures thereof.
4. A toothpaste composition according to any preceding
30 claim wherein the abrasive in the second formulation is selected from abrasive silica, calcium carbonate, calcium pyrophosphate, calcined alumina, tungsten
AMENDED SHEET (ARTICLE 19)
11

WO 2007/099060

PCT/EP2007/051747

carbide, silicon carbide, polypropylene, polycarbonate and mixtures thereof.
5. A toothpaste composition according to any preceding
5 claim wherein the abrasive in the first formulation is a silica based abrasive.
6. A toothpaste composition according to any preceding
claim wherein the abrasive in the second formulation is
10 a silica based abrasive.
7. A toothpaste composition according to any preceding
claim wherein the composition is a striped toothpaste
composition and the stripe comprises the first
15 formulation.
8. A toothpaste composition according to any of claims 1 to
6 wherein the first formulation is located coaxially
within the second formulation on dispensing from the
20 container.
Dated this 28tn day of August 2008


05-10-2007 EP2007051747
J7219 (V) Amended claims 1st October 2007
- 1 -
CLAIMS
1. A toothpaste composition comprising a first formulation
{at from 2 to 40%) and a second formulation which is a
5 visually clear gel, the two formulations being in contact with one another when dispensed from a container, the first toothpaste formulation comprising from 1 to 5% by weight of an abrasive (A) having a scattering centre concentration such that its light
10 transmittance is from 0 to 70% and the second
composition comprising an abrasive (B) in an amount equal to from 0.1 to 0.9 by weight of the amount of abrasive (A) in the first formulation, abrasive (B) having a scattering centre concentration such that its
15 light transmittance is from 0 to 70%.
2. A toothpaste composition according to claim 1 wherein
the first formulation comprises from 5 to 15% by volume
of the composition.
20
3. A toothpaste composition according to claim 1 or 2
wherein the abrasive in the first formulation is
selected from abrasive silica, calcium carbonate,
calcium pyrophosphate, calcined alumina, tungsten
25 carbide, silicon carbide, polypropylene, polycarbonate and mixtures thereof.
4. A toothpaste composition according to any preceding
claim wherein the abrasive in the second formulation is
30 selected from abrasive silica, calcium carbonate, calcium pyrophosphate, calcined alumina, tungsten
AMENDED SHEET

05-10-2007 EP2007051747
J7219 (V) Amended claims 1st October 2007
- 2 -
carbide, silicon carbide, polypropylene, polycarbonate and mixtures thereof.
5. A toothpaste composition according to any preceding
5 claim wherein the abrasive in the first formulation is a silica based abrasive.
6. A toothpaste composition according to any preceding
claim wherein the abrasive in the second formulation is
10 a silica based abrasive.
7. A toothpaste composition according to any preceding
claim wherein the composition is a striped toothpaste
composition and the stripe comprises the first
15 formulation'.
8. A toothpaste composition according to any of claims 1 to
6 wherein the first formulation is located coaxially
within the second formulation on dispensing from the
20 container.
AMENDED SHEET