WO2000062751A2

WO2000062751A2 - Oral care compositions containing boswellia extracts

Info

Publication number: WO2000062751A2
Application number: PCT/GB2000/001396
Authority: WO
Inventors: Stephen David Watkins
Original assignee: Quest International B.V.
Priority date: 1999-04-16
Filing date: 2000-04-12
Publication date: 2000-10-26
Also published as: AU3981700A; GB9908593D0; WO2000062751A3

Abstract

A composition suitable for use in the oral cavity comprises at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof; and a carrier comprising at least one flavour ingredient. The extract, or boswellic acid or derivative thereof, is useful in preparing compositions or products with the ability to soothe irritation, or treat inflammation, in the oral cavity.

Description

Title: Compositions Containing Boswellia Extracts

Field of the Invention

The invention relates to compositions comprising at least one Boswellia extract, or at least one boswellic acid or derivative thereof.

Background of Invention

It has long been known that extracts of the Boswellia family of plants including Boswellia Serrata can produce a soothing effect to irritated skin and mucous membranes and that this activity is due to the terpenoid compounds grouped under the general name 'boswellic acids'. The different boswellic acids share the same basic pentacyclic triterpene (steroid- like) structure but differ in their side groupings.

It has been reported in the Encyclopedia of Common Natural Ingredients, 1996, 2^nd Edition, page 390, that extracts of Boswellia species have been traditionally used in the treatment of oral afflictions such as sore throats.

Additionally, JP 10114671 describes compositions such as a mouthwash comprising a Boswellia extract, where the Boswellia extract is stated to be a cell stimulant.

Typical extracts of Boswellia plants are solids or powders with a wide melting point range, normally above 80°C. To allow for easy incorporation into compositions or products which are suitable for use in the oral cavity, an extract of a Boswellia plant containing boswellic acids or derivatives thereof, or the boswellic acids or derivatives thereof themselves, need to be formulated in a suitable carrier. Although they can be dissolved in solvents such as ethanol or propylene glycol, high levels of these solvents in oral care compositions are inappropriate because of their potential toxicity or intoxicating effects if the compositions are ingested. Surfactants are also unsuitable solvents for Boswellia extracts, or boswellic acids or derivatives thereof, because they can often be irritating to the mouth or produce an unpleasant mouth feel.

Alkalies can produce aqueous solutions of boswellic acids by forming the respective salts. However, highly alkaline compositions are not suitable for oral care use as they may irritate the mouth and could be dangerous if ingested.

Summary of the Invention

According to a first aspect of the invention, there is provided a composition suitable for use in the oral cavity, comprising;

a) at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof; and

b) a carrier comprising at least one flavour ingredient.

According to a second aspect of the present invention, there is provided a method of preparing a composition suitable for use in the oral cavity, comprising forming a mixture of:

b) a carrier comprising at least one flavour ingredient.

According to a further aspect of the present invention, there is also provided a product for use in the oral cavity, comprising a composition in accordance with the invention. According to an even further aspect of the present invention, there is provided a package comprising a composition or product in accordance with the invention; and instructions for use of the composition or product for oral care.

Compositions and products in accordance with the invention may be used to treat inflammation and/or soothe irritation in the mouth of a subject.

The invention thus also includes within its scope the use of an extract of a Boswellia plant, or at least one boswellic acid or derivative thereof, in preparing a composition for use in oral care, particularly (but not exclusively) for the treatment of inflammation and/or irritation in a human mouth.

For brevity, the term "boswellia" is used in this document to refer to at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof.

The term "carrier" is used to mean a substance (including a mixture of materials) in which the "boswellia" can be intimately incorporated, typically by solution or dispersion. It is not essential that the "boswellia" be completely dissolved or dispersed in the carrier provided the materials form a mixture that can form a composition that is stable over an extended period of time, typically of at least 3 months.

The term "flavour ingredient" is used to mean a material having a flavour that is generally regarded as pleasant or at least inoffensive by consumers.

The present invention is based on the suφrising discovery that certain flavour ingredients, particularly flavour ingredients known or suitable for use in oral care compositions and products (referred to herein as "oral care flavour ingredients") function as good carriers for the "boswellia", so enabling the "boswellia" to be readily incorporated into oral care compositions or products without the need for excessive amounts of surfactant in the oral care compositions or products to solubilise or disperse the "boswellia", or the need for other solvents. Further, the dissolution or dispersion of the "boswellia" in the carrier comprising at least one flavour ingredient can enable the preparation of clear oral care compositions or products which are preferably free of particulate matter or precipitated "boswellia" .

Boswellia Extract, or Boswellic Acids or Derivatives thereof ("boswellia")

The compositions of the present invention suitably comprise a safe and effective amount, preferably from 1 % to 50% , more preferably from 3 % to 40% and even more preferably from 5 % to 30% by weight of the composition of at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof.

Suitable extracts for use herein may be derived from the following Boswellia plants including Boswellia Carterii, Boswellia Frereana, Boswellia Bhau-dajaina, Boswellia Serrata and Boswellia Thurifera. The preferred plants from which extracts are derived are Boswellia Serrata.

The extracts derived from Boswellia plants can comprise gums, oleo-gums, resins, essential oils and residues, or mixtures thereof. Preferred extracts for use herein are gums.

The Boswellia gum extract useful herein comprises a mixture of active triterpenoid compounds more commonly known as boswellic acids. All boswellic acids have a pentacyclic structure based on 12-ursen-24-oic acid with differing substituents . Many individual boswellic acid compounds have been isolated from a Boswellia extract including α- and β-boswellic acids and derivatives thereof. Of these, β-boswellic acid and derivatives thereof are thought to be the active components.

A typical extract comprising Boswellia Serrata gum resin will comprise greater than 50% by weight boswellic acids and often more than 60% by weight boswellic acids. The extracts may also undergo further purification to yield greater than 90% by weight boswellic acids. A typical extract of a Boswellia plant suitable for use herein comprises a mixture of boswellic acids comprising at least one of 3a-hydroxyurs-12-ene-24-oic acid, 3a- acetoxyurs-12-ene-24-oic acid, 3a-hydroxyurs-12-ene-l l-keto-24-oic acid and 3a- hydroxyurs-9, 12-dien-24-oic acid.

Boswellia extracts suitable for use herein are commercially available for example from Quest International, Kent, UK.

Carrier

The compositions of the invention typically comprise from 50% to 99% , preferably from 60% to 97% , and more preferably from 70% to 95 % by weight of the composition of a carrier.

The flavour ingredient preferably comprises an oral care flavour ingredient. As discussed above these are found to have good carrier properties, and clearly such materials are also well suited to use in compositions and products for use in the oral cavity.

Many oral care flavour ingredients are known and used to formulate flavours suitable for employment in oral care compositions or products. Suitable oral care flavour ingredients for use herein include peppermint oil, spearmint oil, orange oil, lemon oil, L-menthol, menthone, menthyl acetate, and L-carvone, or mixtures thereof.

The at least one flavour ingredient, preferably oral care flavour ingredient, used as a carrier in the compositions of the invention should desirably be capable of dissolving the at least one Boswellia extract, or boswellic acid or derivative thereof. However it is not essential that all of the extract, acid or acid derivative be completely soluble in the carrier, provided that the compositions can be incorporated into compositions or products suitable for oral use to produce a stable composition. The compositions of the invention may optionally additionally comprise other ingredients such as excipients conventionally added to compositions suitable for use in the oral cavity, eg a surfactant, starch, sucrose, a polyol, an abrasive material, a humectant, a binder, a thickener, an antibacterial agent, an anti-inflammatory agent, an anticaries agent, a vitamin, a potassium salt, an enzyme or an anti-calculus agent, and mixtures thereof.

The compositions of the present invention may be used in wide range of products, by which is meant consumer products i.e. for use by a consumer or end-user, particularly, but not exclusively, for use in the oral cavity. Suitable products for oral use include a mouthwash, a toothpaste, a gel, a cream, a tooth powder, a gargle, a lozenge which will dissolve in the mouth, chewing gum or dental floss.

Thus, as noted above, the present invention provides a product for use in the oral cavity, comprising a composition in accordance with the invention.

When the compositions of the invention are used in a mouthwash, the mouthwash may comprise an aqueous suspension of a composition comprising a Boswellia extract, or boswellic acid or derivative thereof dissolved in a flavouring ingredient wherein said composition may be made compatible with water by the use of a compatibilising solvent such as ethanol. Alternatively, the product could be a multicomponent mouthwash comprising a plurality of solutions containing a composition of the invention and/or additional desirable mouthwash components. These individual aqueous solutions or suspensions would preferably be mixed together before use by the user.

Optionally, the compositions or products herein, may comprise conventional orally, eg dentally acceptable ingredients normally present in compositions or products for oral use. Non-limiting examples of such ingredients include active materials such as triclosan, chlorhexidine, copper, stannous and zinc salts, such as copper sulphate, stannous pyrophosphate and zinc citrate, sanguinarine extract, metronidazole, cetylpyridinium chloride, chlorhexidine digluconate, hexetidine, octenidine, alexidine, 2,2'-methylenebis- (4-chloro-6-bromophenol); orally compatible colouring agents such as pigments e.g. titanium dioxide, or oil soluble colours as are known to be used for aesthetic reasons to produce an attractive coloured product instead of a clear colourless product; starches; sucrose; polyols; abrasive materials such as silicas, aluminas, calcium carbonates, calcium phosphates, hydroxy apatites, calcium pyrophosphates, trimetaphosphates and insoluble hexametaphosphates; humectants such as glycerol, sorbitol, propylene glycol and latitol; binders and thickeners such as sodium carboxymethylcellulose, xanthan gum, gum arabic, polyacrylates and carboxy vinyl polymers; anti-inflammatory agents such as ibuprofen, flurbiprofen, aspirin and indomethacin; anticaries agents such as sodium fluoride, stannous fluoride, amine fluorides, sodium monofluorophosphate, calcium lactate, calcium glycerophosphates, strontium salts, including strontium polyacrylates, casein and casein digests and phosphoproteins; vitamins; potassium salts such as potassium citrate, chloride or nitrate; enzymes such as dextranase, mutanase, amyloglucosidase, glucose-oxidase and neuraminidases; hydrogen peroxide generating compounds such as potassium peroxydiphosphate; and anti-calculus agents such as alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphocitrates, or mixtures thereof.

When the products herein are in the form of a toothpaste or gel, the toothpaste or gel conveniently may include an anionic surfactant, such as sodium lauryl sulphate, sodium dodecylbenzene sulphonate, sodium mono- and di-octyl phosphate and/or sodium lauroylsarcosinate. Additionally, or alternatively, the product may include one or more non-ionic surfactants and/or one or more amphoteric surfactants. Thus, the product may comprise a mixture of anionic and/or non-ionic and/or amphoteric surfactants. Non-ionic surfactants which can be used for this purpose, include, but are not limited to, polyoxyethylene alkyl ethers, polyoxyethylene alkaryl ethers, polyoxyethylene- polyoxypropylene alkyl ethers, polyoxyethylene-polyoxypropylene block copolymers, sucrose fatty acid esters, glycerol fatty acid esters, propylene glycol fatty acid esters, sorbitan fatty acid esters, alkylglycoside fatty acid esters, polyoxyethylene sucrose fatty acid esters, polyoxyethylene glycol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, alkvlglycosides, fatty acid monoethanolamide, polyoxyethylene fatty acid monoethanolamide, polyoxyethylene fatty acid diethanolamide. polyoxyethylene castor oils, polyoxyethylene hydrogenated castor oils, and polyoxyethylene beeswax derivatives. A suitable example of an amphoteric surfactant which may be useful herein is cocoamidopropyl betaine. Additionally or alternatively, when the products herein are in the form of a toothpaste or gel, colouring agents and/or active materials as discussed in the immediately preceding paragraph may also be included.

The products suitable for oral care use comprising a composition in accordance with the invention typically comprise from 0.001 % to 5.0% by weight and preferably from 0.05% to 0.5% by weight of the product of at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof.

The invention is illustrated by the following non-limiting examples.

Example 1

Carrier/Boswellia Serrata Extract Compositions

Compositions according to the invention were prepared by mixing ingredients in the amounts listed below. % w/w

Composition 1) Boswellia Extract¹ [ > 65 % boswellic acids or derivatives] 30.00

Peppermint oil 70.00

Composition 2) Boswellia Extract¹ [ > 65 % boswellic acids or derivatives] 25.00 Spearmint oil 75.00

Composition 3) Boswellia Extract¹ [ > 65 % boswellic acids or derivatives] 25.00

Orange oil 75.00

Composition 4) Boswellia Extract'[ > 65 % boswellic acids or derivatives] 30.00

Lemon oil 70.00 Composition 5) Boswellia Extract¹ [ > 65 % boswellic acids or derivatives] 20.00 L-Carvone 80.00

Composition 6) Boswellia Extract¹ [ > 75 % boswellic acids or derivatives] 30.00 Peppermint oil 70.00

Composition 7) Boswellia Extract'[ > 75 % boswellic acids or derivatives] 15.00 L-Carvone 85.00

1. Boswellia Serrata Gum Resin Extract

Compositions 1 to 7 were prepared by mixing together the Boswellia Extract and flavour ingredient with gentle heating until the Boswellia Extract dissolved to the desired extent.

Example 2

Typical compositions according to the invention include:

% by weight peppermint oil 60.0

Composition 8) menthone 3.0 menthyl acetate 5.0

L-menthol 12.0

Boswellia Serrata Gum Extract 20.0

% by weight peppermint oil 55.0 lemon oil 0.5

Composition 9) 1 -methoxy-4-propenylbenzene 4.5

L-menthol 18.0 menthyl acetate 7.0 Boswellia Serrata Gum Extract 15.0

% by weight spearmint oil 55.0

Composition 10) menthone 8.0

L-menthol 5.0

L-carvone 2.0

Boswellia Serrata Gum Extract 30.0

% by weight spearmint oil 54.5 orange oil 1.0 menthyl acetate 5.5

Composition 11) lemon oil 0.5 peppermint oil 8.5

Boswellia Serrata Gum Extract 30.0

Compositions 8 to 11 were prepared according to the method described in Example 1 above, where the Boswellia Extract was added to the combined flavour ingredients and the mixture gently heated until the Boswellia Extract dissolved to the desired extent.

Typical products for use in the oral cavity according to the invention are given in Examples 3 to 5 :

Example 3

Toothpaste

% w/w sorbitol solution 61.15 water 15.00 sodium carboxymethyl cellulose 1.50 silica 20.00 sodium lauryl sulphate 0.50 sweetener (sodium saccharin) 0.50 flavour and Boswellia [composition 8 above] 1.00 fluoride (sodium fluoride) 0.35

Example 4

Mouth Wash

% w/w water 88.00 polysorbate 20 1.50 flavour and Boswellia [composition 10 above] 0.20 ethanol 10.00 sweetener 0.30

Example 5

Chewing Gum

% w/w gum base 28.30 sorbitol 56.00 sorbitol [70% soln.] 6.00 xylitol 3.00 glycerine 5.00 artificial sweeteners 0.10 flavour and Boswellia [composition 9 above] 1.60 Example 6

Comparative mouthwash A (using ethanol as a carrier for the Boswellia extract) and mouthwash B (using a mixture of flavour ingredients as a carrier for the Boswellia extract in accordance with the invention) were prepared according to the following formulations:

(A) %w/w (B) %w/w

Spearmint oil 0.155 0.155 Menthone 0.030 0.030 L-menthol 0.010 0.010 L-carvone 0.005 0.005 Boswellia Serrata Extract 0.060

Polysorbate 20 1.500 1.500

Water 88.240 88.240

Ethanol 10.000 10.000

Boswellia Serrata Extract 0.060

Comparative Mouthwash A

Mouthwash A was prepared by combining the flavour ingredients, to which polysorbate 20 was added. This mixture was then added to water.

Separately, the Boswellia Serrata Extract was added to ethanol with stirring and mixed until dissolved. Following dissolution of the Boswellia Extract in the ethanol, the mixture was added to the water/flavour/poly sorbate 20 mix. The resulting mouthwash was slightly turbid and had an insoluble precipitate.

Mouthwash B

Mouthwash B in accordance with the invention, was prepared by mixing the flavour ingredients together with the Boswellia Serrata Extract. To this mixture was added polysorbate 20.

The mixture containing the flavour ingredients, Boswellia Extract and polysorbate 20 was added to water. Finally, ethanol was added to this mixture.

The resulting mouthwash was crystal clear with no precipitate.

Claims

1. A composition suitable for use in the oral cavity comprising;

b) a carrier comprising at least one flavour ingredient.

2. A composition according to claim 1, wherein the extract comprises a Boswellia Serrata gum resin.

3. A composition according to claim 1 or 2, wherein said at least one extract of a Boswellia plant comprises a mixture of boswellic acids comprising at least one of 3a- hydroxyurs-12-ene-24-oic acid, 3a-acetoxyurs-12-ene-24-oic acid, 3a-hydroxyuιs-12-ene- l l-keto-24-oic acid and 3a-hydroxyurs-9, 12-dien-24-oic acid.

4. A composition according to any one of the preceding claims, wherein the flavour ingredient is an oral care flavour ingredient.

5. A composition according to claim 4, wherein the oral care flavour ingredient comprises at least one ingredient selected from peppermint oil, spearmint oil. orange oil, lemon oil,

L-menthol, menthone, menthyl acetate and L-carvone, or mixtures thereof.

6. A composition according to any one of the preceding claims, wherein the amount of the at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof present in the composition is in the range 1 % to 50% by weight of the composition.

7. A composition according to any one of the preceding claims, wherein the composition additionally comprises a surfactant, starch, sucrose, a polyol, an abrasive material, a humectant, a binder, a thickener, an antibacterial agent, an anti-inflammatory agent, an anticaries agent, a vitamin, a potassium salt, an enzyme, or an anti-calculus agent, and mixtures thereof.

8. A composition according to any one of the preceding claims, wherein the at least one extract of a Boswellia plant is a Boswellia Serrata gum resin extract which comprises greater than 50% by weight boswellic acids.

9. A product for use in the oral cavity, comprising a composition according to any one of claims 1 to 8.

10. A product according to claim 9, wherein the product is a mouthwash, a toothpaste, a gel, a cream, a tooth powder, a gargle, a lozenge, chewing gum or dental floss.

11. A product according to claim 9 or 10, wherein the amount of the at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof present in the product is in the range 0.001 % to 5.0% by weight of the product.

12. A product according to claim 11 , wherein the amount of the at least one extract of a Boswellia plant, or at least one boswellic acid or derivative thereof present in the product is in the range 0.05% to 0.5% by weight of the product.

13. A method of preparing a composition suitable for use in the oral cavity, comprising forming a mixture of:

b) a carrier comprising at least one flavour ingredient.

14. A package comprising a composition or product in accordance with any one of claims 1 to 12; and instructions for use of the composition or product for oral care.

15. The use of an extract of a Boswellia plant, or at least one boswellic acid or derivative thereof, in preparing a composition for use in oral care, particularly for the treatment of inflammation and/or irritation in a human mouth.