NZ515900A - Wound cream composition comprising emu oil and an powdered extract from centella asiatica - Google Patents

Abstract

An aqueous formulation for topical application includes emu oil, powdered extract of centella asiatica, organic acids and physiologically acceptable carriers, characterized in that he formulation has a synergistic wound healing effect by reducing scar tissue, reducing swelling and by preventing microbial infection. The use of the formulation in the manufacture of a medicament for the treatment of a wound, a method of treating non-human animals and a method of producing the formulation as a cream are described.

Description

New Zealand Paient Spedficaiion for Paient Number 515900 PATENTS FORM NO. 5 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 515900 Dated: 4 June 2002 James & Wells Ref: 18832/ 29 Intellectual Property Office of NZ - * JUN 2003 received WOUND CREAM WE Bomac Laboratories Limited, a New Zealand company of 102 Wiri Station Road, Manukau City, Auckland, NEW ZEALAND hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: 1 WOUND CREAM TECHNICAL FIELD The present invention relates to a dermatological medicament for topical use on 5 animals, which is based on naturally occurring plant and animal oils. In particular, it is intended for treating of wounds in two manners thus giving an improved effect for wound healing.

BACKGROUND ART Compositions capable of healing wounds have been long valued for both human and non-human treatments.

Wounds have traditionally been treated using dressings and a variety of 15 pharmaceutically active medicaments. Such medicaments typically contain synthetically derived solutions of chemical products and/or antibiotics. Chemical products and antibiotics however have their own disadvantages.

Antibiotics can exhibit toxicity and produce irritation at the site of application, 20 and can result in the appearance of resistance in certain strains of bacteria.

Solutions of chemical products are known to exhibit weakening characteristics to the cells around the injury, and may be only partially effective in assisting healing of the wound.

In an effort to address the above problems and to provide alternative therapies, products have been developed that are often based on naturally occurring plant based materials and/or materials derived from animals or marine life.

One ingredient considered in wound healing has been oil derived from emu. Emu oil is obtained from a large, approximately five feet tall, flightless bird of Australia known as an emu, Dromideius novaehollandiae. Emus are farmed for 2 their meat, which is low in cholesterol and fat. The oil rendered from the emu is actually a semi-solid fat (i.e., fat and oil mixture) at room temperature, but will herein be referred to as an oil.

The fat and oil mixture is stripped from the carcass of the emu and can be melted to further liquify the oil. Emu oil obtained in this manner is yellow and is olfactorially offensive. It is possible, through refining processes, to remove the yellow color from the oil and reduce its odour. PCT/AU91/00517 refers to removing the yellow color from emu oil by exposing it to sunlight, and by subjecting it to chemical oxidation by mixing it with benzoyl peroxide in an organic solvent.

Emu oil has been used, particularly by aboriginal people, for many years for a wide variety of ailments. A number of patents exist that teach of using emu oil for applications as diverse as insecticides (US5626882), a promotor of hair growth (US5662921) and as a minor ingredient in anaesthetitics (US6416772). One particular application, for use as an anti-inflammatory has seen particular attention, (W092/08470).

Problems however exist with such anti-inflammatory medicaments. In W092/08470, which describes the use of emu oil for decreasing lipoproteins, a problem inherent to many processes is that 'emu oil alone is unable to reduce inflammation. In W092/08470 miscible diluent is added such as isopropyl alcohol, amyl alcohol or acetate etc. to achieve an anti-inflammatory effect'.

Another example of a patent requiring diluents is, US6103246 which teaches of topical creams and lotions for treatment of humans that require the use of diluents including lactic acid, glycolic acid and pyruvic acid.

Whilst helpful, the above diluents introduce undesirable chemical products in order to obtain a useful end product. In addition such additives also add to the expense of the product and may in fact, as a result of these additives, cause side effects to wound healing for the patient. 3 A further alternative ingredient considered at least in part for wound healing is centella asiatica. Centella asiatica is a saponin type plant. Like emu oil, a number of uses for centella asiatica have been considered including: in vivo 5 medicaments for liver cell treatment (US6417349) and cosmetic formulations (US6361804 and US6261605).

Would healing medicaments including centella asiatica have been considered in t tc/ro/rnna/f i : a i_ : j :t to con A uou^u/^u ana asiatica extracts such as asiauc auiu 111 In US6267996, one embodiment uses a formulation comprising a wide variety of natural plant extracts including centella asiatica as an acne treatment. Whilst centella asiatica appears as only a minor component, it is however purported as having some effect as an anti-acne agent.

US5834437 teaches of several methods of extracting active ingredients from centalla asiatica to form active ingredients for wound healing applications. Such methods result in creating a 'non-natural' product and once again require the use of chemical products not desirable for such therapeutic applications, particularly 20 where a natural image is to be portrayed.

Of note from the above patents is that none combine emu oil with centella asiatica in a medicament. In addition the patents described generally lead away from such a combination.

For example, in patents US6417349, US6361804 and US6261605, which utilise centella asiatica, oils are not used as additional medicinal agents and are not even pointed to for such a use. Vegetable oils only are mentioned however, only as a carrier substance, a common usage for such oils.

Emu oil patents similarly avoid the use of other plant based materials as additives, and in particular, centella asiatica. The problems associated with such extracts including the need for diluents appear to be the focus of such patents. 4 One patent that does address the combination of both emu oil and centella asiatica is that of US6342208. This composition is a two phase oil in water emulsion for cleansing a skin surface, for treating human skin, for treating against parasites 5 belonging to the phylum Arthropoda and for protecting human skin from sunlight. There are no examples of wound healing applications disclosed. In addition, both emu oil and centella asiatica are clearly minor ingredients in what appears to be a very detailed composition containing an enormous variety of components.

The present invention overcomes disadvantages associated with the use of chemical products, antibiotics, diluents, and the need for specialised extraction processes, whilst at the same time providing a homogenous, easy to use topical preparation.

An object of the present invention is to provide a topical treatment with a combination of emu oil and centella asiatica, giving an improved wound treatment remedy.

It is a further object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term 'comprise' may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process.

Further aspects and advantages of the present invention will become apparent from the ensuing description, which is given by way of example only.

DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided an aqueous formulation for topical application to animals, said formulation including: emu oil; powdered extract of centella asiatica; organic acids; and physiologically acceptable carriers; characterised in that the formulation has a synergistic wound healing effect by reducing scar tissue, reducing swelling and by preventing microbial infection.

According to a further aspect of the present invention there is provided the use of an improved wound healing aqueous formulation substantially as described above, said formulation including: emu oil; powdered extract of centella asiatica; organic acids; and physiologically acceptable carriers.

It is understood by the applicant that the particular combination of centella asiatica and emu oil and organic acids has an improved effect on wound healing.

That is, the combination of the centella asiatica, in reducing scar tissue, and emu oil, in reducing swelling, improves wound healing by fighting infections and prevents formation of scar tissue (debriding).

In the preferred embodiment, the formulation is a cream. It will be appreciated that alternative aqueous formulations are also possible including ointments and lotions. Aqueous formulations are preferred as they are easiest to administer to an animal body surface such as skin rather than having a poultice which must be held in place, or a powder which is easily rubbed off by the animal.

Intellectual Property Office of NZ 6 17 JUN im The solution is applied topically to the animal. Preferably the solution is applied, typically via rubbing, onto a localised area of the animal body or surface skin of an animal body part.

In the preferred embodiment, this cream is to be applied to animals. It is envisaged by the applicant that this cream will be especially useful for treating animals prone to external wounds, particularly where the animal has significant value. Specific examples include horses, deer, cattle, sheep, dogs and cats.

In preferred embodiments, physiologically acceptable carriers are added to the active ingredients to form the desired formulation. Physiologically acceptable carriers are selected from the group including at least one: oil; wax; acid; viscosity control agent; pigment dispersing agent; emulsifier; stabiliser; humectant; antioxidant; water; and combinations thereof.

In preferred embodiments the oil utilised is sesame oil. Sesame oil is a known solvent and oleaginous vehicle, useful for such applications and is a natural product.

In preferred embodiments, the acid utilised is a naturally occurring acid. Most preferably selected from the group including: malic acid; salicylic acid; benzoic acid; and combinations thereof. It is known that these acids have anti-microbial properties and it is the applicants understanding that such activity will further enhance the wound healing formulation efficacy.

In preferred embodiments, the wax utilised is: beeswax; paraffin wax and other waxes; and combinations thereof. Waxes aid in setting the consistency of the formulation.

In preferred embodiments, the antioxidant used is butylated hyroxy toluene (BHT). BHT is a common antioxidant used in foods, cosmetics and other applications where antioxidant materials are beneficial. Other antioxidants such as BHA and Vitamin E may also be used in combination or alone. 7 In preferred embodiments, the humectant used is propylene glycol. Other humectants may also include glycerine and/or polyethylene glycol (PEG).

In one preferred embodiment, the wound healing formulation includes a combination of; centella asiatica extract; emu oil; beeswax; light liquid paraffin wax; sesame oil; white petroleum; glyceryl monostearate; propylene glycol; monomuls 90-018; dehymuls PGPH; malic acid; benzoic acid; salicylic acid; butylated hyroxy toluene (BHT); magnesium sulfate heptahydrate; water; and characterised in that the formulation has a synergistic wound healing effect by reducing scar tissue, reducing swelling and by preventing microbial infection.

In the above embodiment, the wound healing formulation is made up of; 1% (w/w) of centella asiatica extract; 10% w/w emu oil; 10% w/w beeswax; 18% w/w light liquid paraffin; 10% w/w sesame oil; 5% w/w white petroleum; 4% w/w glyceryl monostearate; 1.7% w/w propylene glycol; 2% w/w monomuls 90-018; 2% w/w dehymuls PGPH; 0.36% w/w malic acid; 0.024% w/w benzoic acid; 0.006% w/w salicylic acid; 0.01% w/w butylated hyroxy toluene (BHT); 0.7% w/w magnesium sulfate heptahydrate; and 35% w/w water.

According to a further aspect of the present invention there is provided a method of producing a cream formulation that has a synergistic wound healing effect by reducing scare tissue, reducing swelling and by preventing microbial infection that is topically applied to non-human animals, wherein said method includes the steps of; (a) melt together oil carriers, wax and emulsifier ingredients at 70-75°C to form a mixture; (b) add emu oil and antioxidant to the mixture in (a) and heat to 75-80°C mixing thoroughly to dissolve the oil and antioxidant; (c) prepare a second mixture by dissolving the acids, water and magnesium sulfate heptahydrate together; (d) prepare a third mixture by mixing a suspension of centella asiatica powder in humectant, and during mixing, maintain the suspension at a temperature of 45- (e) add the mixture formed in step (c) to the mixture formed in step (b) slowly with rapid stirring; (f) continue mixing at approximately 50°C and add the suspension prepared in step (d) and stir until the mixture thickens to form a cream; 55°C; 8 Intellectual Properly Office of NZ 17 JUM 2004 (g) stir thoroughly, reducing the temperature to approximately 40°C; (h) pour the mixture after step (g) into a storage vessel and allow to cool to ambient temperature.

According to a further aspect of the present invention there is provided a method of producing an aqueous formulation that has a synergistic wound healing effect by reducing scar tissue, reducing swelling and by preventing microbial infection that is topically applied to non-human animals, as described above wherein said method includes the steps of; (a) melt together sesame oil carriers, beeswax, light liquid paraffin, and emulsifier ingredients at 70-75°C to form a mixture; (b) add emu oil and antioxidant butylated hyroxy toluene (BHT) to the mixture in (a) and heat to 75-80°C mixing thoroughly to dissolve the oil and antioxidant; (c) prepare a second mixture by dissolving the acids, water and magnesium sulfate heptahydrate together; (d) prepare a third mixture by mixing a suspension of centella asiatica powder in humectant and during mixing, maintain the suspension at a temperature of 45-55°C; (e) add the mixture formed in step (c) to the mixture formed in step (b) slowly with rapid stirring; (f) continue mixing at approximately 50°C and add the suspension prepared in step (d) and stir until the mixture thickens to form a cream; (g) stir thoroughly, reducing the temperature to approximately 40°C; (h) pour the mixture after step (g) into a storage vessel and allow to cool to ambient temperature.

The above formulation and method of preparation gives a formulation that provides an alternative 'natural' remedy for aiding wound healing in animals.

The formulation overcomes disadvantages associated with the use of chemical products, antibiotics, diluents, and the need for specialized extraction processes, whilst at the same time providing a homogenous, easy to use topical preparation.

Intellectual Property Office of NZ 9 1 7 JUN 2004 ■ ECEIVED BEST MODES FOR CARRYING OUT THE INVENTION A method of preparation of a wound healing cream is disclosed below.

Materials used The materials used are as follows: centella asiatica extract, propylene glycol, Dl-malic acid, benzoic acid, salicylic acid, butylated hyroxy toluene (BHT) (food grade), emu oil, beeswax, light liquid paraffin, white petroleum, sesame oil, monomuls 90-018, dehymuls PGPH, glyceryl monostearate and magnesium sulfate.

Method of Preparation (a) melt together the sesame oil, beeswax, light liquid paraffin, and emulsifier ingredients at 70-75°C to form a mixture; (b) add emu oil and butylated hyroxy toluene (BHT) to the mixture in (a) and 15 heat to 75-80°C mixing thoroughly to form dissolve the emu oil and BHT; (c) prepare a second mixture by dissolving the malic acid, benzoic acid, salicylic acid, water and magnesium sulfate heptahydrate together; (d) prepare a third mixture by mixing a suspension of centella asiatica powder in propylene glycol. During mixing, the suspension is held at 45-55°C; (e) the mixture formed in step (c) is added to the mixture formed in step (b) slowly with rapid stirring; (f) continue mixing at approximately 50°C and add the suspension prepared in (d) and stir until the mixture begins to thicken to form a cream; (g) stir thoroughly until the mixture reduces in temperature to approximately 25 40°C; (h) pour into a storage vessel and allow to cool to ambient temperature.

Final formulation The final formulation is disclosed based on the above methodology. The 30 ingredients are expressed on a percentage weight for weight of the cream formula listed in the table below.

Ingredients %w/w Kg per 1000 Kg batch Each gram contains Centella Extract 1 Kg O.Olg Propylene Glycol 1.7 17 Kg 0.017g Malic Acid 0.36 3.6 Kg 0.0036g Benzoic Acid 0.024 0.24 Kg 0.00024g Salicylic Acid 0.006 0.06 Kg 0.00006g Butylated hyroxy toluene (BHT) 0.01 0.1 Kg O.OOOlg Emu Oil 100 Kg O.lg Beeswax 100 Kg O.lg Light Liquid Paraffin 18 180 Kg 0.18g White Petroleum 50 Kg 0.05g Sesame Oil 100 Kg 0.10g Monomuls 90-018 2 Kg 0.02g Dehymuls PGPH 2 Kg 0.02g Glyceryl monostearate 4 40 Kg 0.04g Magnesium sulfate heptahydrate 0.7 7 Kg 0.007g Water 350 Kg 0.350g Total 99.8 998 Kg 0.998g Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims 11

Claims (8)

WHAT WE CLAIM IS;

1. An aqueous formulation for topical application to animals, said formulation including: emu oil; powdered extract of centella asiatica-, organic acids; and physiologically acceptable carriers; characterised in that the formulation has a synergistic wound healing effect by reducing scar tissue, reducing swelling and by preventing microbial infection.

2. A formulation as claimed in claim 1 wherein the formulation is in a form selected from the group including: a cream; an ointment; a lotion.

3. A formulation as claimed in claim 1 or claim 2 wherein the formulation is applied to the surface of a wound on a non-human animal.

4. A formulation as claimed in any one of the above claims wherein the animal is selected from the group including: a horse; a deer; cattle; sheep; a dog; and a cat.

5. A formulation as claimed in any one of the above claims wherein the physiologically acceptable carrier is selected from the group including at least one: oil; wax; acid; viscosity control agent; pigment dispersing agents; emulsifier; stabiliser; humectant; antioxidant; water; and combinations thereof.

6. A formulation as claimed in claim 5 wherein the oil is sesame oil.

7. A formulation as claimed in claim 5 or claim 6 wherein the acid is selected from the group including: malic acid; salicylic acid; benzoic acid; and combinations thereof. Intellectual Property Office of NZ 1 7 JUN 2004 12

8. A formulation as claimed in any one of claims 5 to 7 wherein the wax is selected from the group including: beeswax; liquid light paraffin wax; and combinations thereof

9. A formulation as claimed in any one of claims 5 to 8 wherein the antioxidant is butylated hyroxy toluene (BHT).

10. A formulation as claimed in any one of claims 5 to 9 wherein the humectant is propylene glycol.

11. An aqueous formulation for topical application to animals, said formulation including a combination of: centella asiatica extracts; emu oil; bees wax; liquid light paraffin wax; sesame oil; white petroleum; glyceryl monostearate; propylene glycol; monomuls 90-018; dehymuls PGPH; malic acid; benzoic acid; salicylic acid; butylated hyroxy toluene (BHT); magnesium sulfate heptahydrate; water; and characterised in that the formulation has a synergistic wound healing effect by reducing scar tissue, reducing swelling and by preventing microbial infection.

12. A formulation as claimed in claim 11 wherein the formulation is made up of: 1% (w/w) of centella asiatica extract; 10% w/w emu oil; 10% w/w beeswax; 18% w/w light liquid paraffin; 10% w/w sesame oil; 5% w/w white petroleum; 4% w/w glyceryl monostearate; 1.7% w/w propylene glycol; 2% w/w monomuls 90-018; 2% w/w dehymuls PGPH; 0.36% w/w malic acid; 0.024% w/w benzoic acid; 0.006% w/w salicylic acid; 0.01% w/w butylated hyroxy toluene (BHT); 0.7% w/w magnesium sulfate heptahydrate; and 35% w/w water.

13. The use of a formulation as claimed in any one of claims 1 to 12 in the manufacture of a medicament for the treatment of a wound on an animal.

14. A method of treatment of a non-human animal including application of a InteMectual Property 13 Office of NZ 17 JUN 2004 formulation as claimed in any one of claims to 1 to 12 to the wound of the non-human animal. A method of producing a cream formulation that has a synergistic wound healing effect by reducing scar tissue, reducing swelling and by preventing microbial infection that is topically applied to non-human animals, wherein said method includes the steps of; (a) melt together oil carriers, wax and emulsifier ingredients at 70- 7Vr tn frirm a mivtiirf I V V VV V A ill M UIKIVMI Vj (b) add emu oil and antioxidant to the mixture in (a) and heat to 75-80°C mixing thoroughly to dissolve the oil and antioxidant; (c) prepare a second mixture by dissolving the acids, water and magnesium sulfate heptahydrate together; (d) prepare a third mixture by mixing a suspension of centella asiatica powder in humectant and during mixing, maintain the suspension at a temperature of 45-55°C; (e) add the mixture formed in step (c) to the mixture formed in step (b) slowly with rapid stirring; (f) continue mixing at approximately 50°C and add the suspension prepared in step (d) and stir until the mixture thickens to form a cream; (g) stir thoroughly, reducing the temperature to approximately 40°C; (h) pour the mixture after step (g) into a storage vessel and allow to cool to ambient temperature. A method of producing a formulation as claimed in claim 15 wherein the oil, wax, and emulsifier ingredients in step (a) are sesame oil, bees wax and light liquid paraffin wax. A method of producing a formulation as claimed in either claim 15 or claim 16 wherein the antioxidant in step (b) is butylated hyroxy toluene (BHT). 14 Intellectual Property Office of NZ 1 7 JUN 2004

18. A method of producing a formulation as claimed in any one of claims 15 to 17 wherein the acids in step (c) are selected from: malic acid; benzoic acid; salicylic acid; and combinations thereof.

19. A method of producing a formulation as claimed in any one of claims 15 to 18 wherein the humectant in step (d) is propylene glycol.

20. A formulation containing emu oil and centella asiatica substantially as hereinbefore described and with reference to the example.

21. The use of a formulation containing emu oil and centella asiatica as a synergistic wound healing treatment in the manufacture of a medicament, substantially as claimed in claim 13, substantially as hereinbefore described and with reference to the example.

22. A method of wound treatment of a non-human animal by use of a formulation containing a synergistic combination of emu oil and centella asiatica substantially as hereinbefore described and with reference to the example.

23. A method of producing a wound healing formulation containing a synergistic combination of emu oil and centella asiatica substantially as hereinbefore described and with reference to the example. BOMAC LABORATORIES by their authorised agents Intellectual Property Office of N.Z. JAMES & WELLS per: ' 2 9 JUN 200^ 15