WO2006010214A1

WO2006010214A1 - Natural sunscreen composition

Info

Publication number: WO2006010214A1
Application number: PCT/AU2005/001109
Authority: WO
Inventors: Leo Fung
Original assignee: Cream Holdings Pty Ltd
Priority date: 2004-07-28
Filing date: 2005-07-28
Publication date: 2006-02-02
Also published as: AR050362A1; TW200607529A

Abstract

A natural sunscreen composition comprising synergistically effective amounts of zinc oxide and a plant-derived oil. The composition allows for the provision of a natural sunscreen which is water resistant and has a high SPF rating. A method and process are also described.

Description

NATURAL SUNSCREEN COMPOSITION

Field of the Invention

The present invention relates to a sunscreen composition comprised of natural substances, to a method for use therewith for protecting the skin against sun damage, and to a process.

Background of the Invention

The harmful effects of the sun's rays on the skin are well known. The effects of overexposure to the sun, resulting mainly from ultraviolet (UV) radiation, range from short term effects such as sunburn (erythema) to long term effects such as premature aging of the skin and skin cancer.

This is a particular problem in countries, such as Australia, in which residents spend a large amount of time in the sunshine due to the popularity of outdoor activities including sport and leisure activities. Furthermore, the problem of sun damage to the skin is increasing with the decrease in the ozone layer and resulting higher UV exposure, especially in certain parts of the world.

Numerous sunscreen preparations have been developed to assist in protecting the skin from harmful UV rays (in the form of UVA and UVB radiation). The majority of these sunscreens are described as "chemical" (organic) or "physical" (inorganic) sunscreens depending on the nature of the active ingredients which act to screen out UVA or UVB radiation. These sunscreens generally act by absorbing UV radiation and/or by scattering the UV radiation.

The efficacy of sunscreens is typically measured by an SPF (Sun Protection Factor) rating, which is a measure of the increase in exposure time to UV radiation required to induce erythema. A higher rating generally indicates protection for a greater length of time against sunburn. More specifically, the SPF number is derived from the time or dose required to produce a minimal reddening of the skin divided into the time or dose required to produce the same degree of skin reddening with the product applied as follows: SPF = Time or dose to minimal erythema on unprotected skin

Time or dose to minimal erythema on unprotected skin

The SPF is usually expressed as a number followed by a "+", for example 15+ and 30+ are SPF ratings commonly in use in Australia. Dermatologically acceptable SPF ratings vary from country to country.

Physical sunscreens are generally preferred over chemical sunscreens in that chemical sunscreens are known to have a number of disadvantageous qualities. Many chemical sunscreens are known to be photosensitive and may be degraded or altered by UV radiation. In addition, chemical sunscreens often cause irritation, allergies or damage to the skin of users, in some cases due to the production of free radicals by the chemical sunscreen product. Free radicals are known to be toxic to skin and to cause damage to skin DNA.

Physical sunscreens, in particular those containing zinc oxide, have the benefit of being UV stable and in general do not cause adverse effects on contact with skin. However, a limiting factor in the use of such physical sunscreens is that these sunscreens appear white on the skin due to the excessive scattering of light from particles contained within the sunscreen. This is an undesirable factor for cosmetic and marketability reasons where a clear and unobtrusive sunscreen is desirable. As a result, it has often been necessary to add chemical agents to a physical sunscreen composition to produce a product that is acceptable for cosmetic and marketing reasons.

There have been attempts to develop and use sunscreens containing zinc oxide of very small particle size to try and reduce the whiteness and improve the transparency of sunscreen formulations. Some of these reports have described the use of nano- sized particles of zinc oxide in a sunscreen formulation which appears to provide a product that results in a dermatologically acceptable SPF rating without the use of any chemical UV screening agents.

However, the disclosures reporting sunscreen formulations comprised chiefly of physical screening agents, do not discuss the water resistance of these products. The water resistance of sunscreens is of major importance given that many outdoor activities requiring sunscreen use are carried out in or around areas having water such as swimming, surfing and sailing, or are activities that involve physical exertion and thus sweating of the individual exposed to the sun. Thus, effective sunscreens are required to be substantially water resistant to ensure that the sunscreen does not simply wash off if the user enters the water, or sweats whilst carrying out an activity.

Furthermore, difficulties have been encountered by sunscreen chemists in producing a waterproof sunscreen that is acceptable to consumers. In general, the substances used to achieve the waterproof requirements are chemical based waterproof agents or film formers, such as acrylates, t-octylpropenamide copolymer, tricontanyl polyvinylpyrrolidine and others, which have the usual disadvantages of chemical products. These known waterproof agents also often have poor cosmetic acceptability, feeling "sticky", "greasy" or "heavy" to the user.

As outlined above, there is a need for a sunscreen that does not comprise chemical substances due to the disadvantages of these products to the skin and the potential long term harmful effects of many chemical products. Attempts have been made to produce sunscreens comprising naturally occurring substances but these results have either produced products with unacceptable SPF ratings or have still relied on the use of components having disadvantageous properties such as titanium dioxide which can cause DNA damage.

Thus, there is a need for a sunscreen composition with a dermatologically effective

SPF rating that comprises largely of natural (non-chemical) components and that is at least water resistant for a convenient length of time to prevent frequent re-application of the sunscreen. There is also the need for a sunscreen that is substantially clear so as to be cosmetically pleasing.

It is against the above background that the present invention has been devised.

References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.

Summary of the Invention

The present invention provides a natural sunscreen composition comprising synergistically effective amounts of zinc oxide and a plant-derived oil.

The active ingredients of zinc oxide and the plant-derived oil are preferably present in amounts to provide a substantially water resistant composition on application to skin of a user.

Furthermore, the zinc oxide and the plant-derived oil are preferably present in amounts to provide a dermatologically acceptable level of SPF and broad spectrum protection from UVA and UVB radiation such that in use the composition provides sun protection to the skin with an acceptable SPF.

Preferably the zinc oxide and the plant-derived oil are present in amounts to provide a composition that is substantially water resistant for a period of at least about 1 - 4 hours on application to skin of a user.

Preferably, the sunscreen composition has a dermatologically acceptable level of SPF of greater than 8+. More preferably, the acceptable level of SPF is greater than 15+. hi a preferred form of the invention, the sunscreen composition has a dermatologically acceptable level of SPF of greater than 30+.

Preferably the sunscreen composition has an SPF level of 30+ to 38+ after application of the sunscreen to skin of a user and exposure to water for a period of 1 - 4 hours. More preferably the sunscreen composition has an SPF level of 30+ to 38+ after application of the sunscreen to skin of a user and exposure to water for a period of 2 - 3 hours. In a preferred form, the SPF of the sunscreen composition is 31+ after application of the sunscreen to skin of a user and exposure to water for a period of 3 hours.

It has been unexpectedly found that the combination of the components of the sunscreen of this invention produces a substantially water-resistant product that does not readily wash off the skin of the user. The water resistance of the sunscreen of this invention is considerably higher than either the water resistance of each component alone, or the water resistance that would be expected from the cumulative water resistances of each component, hi addition, the combination of the components of the sunscreen of this invention allows for the provision of a sunscreen with a high SPF, and importantly an SPF of 30+ or greater.

Preferably zinc oxide is present in the composition in the range of 5 - 25% by weight. More preferably, zinc oxide is present in the composition in the range of 15 — 23.5% by weight.

Preferably the zinc oxide is in the form of nano-particles. More preferably the nano- sized particles have a mean particle size in the range of 15 - 500nm. More preferably the zinc oxide particles are in the range of 25 - 200nm. Preferably the nano-particles have a narrow particle size distribution. The narrow particle size distribution is preferably defined in that, based on a number-weighted size distribution measured by photo-correlation spectroscopy, the number-weighted size distribution has a standard deviation of less than 20nm.

Preferably the plant-derived oil is one or more of grape seed oil, sunflower seed oil, macadamia seed oil, avocado oil, rice bran oil, calendula oil, jojoba oil, sesame oil, soy oil, almond oil, canola oil, castor oil, coconut oil, olive oil, palm oil, peanut oil, safflower oil, wheatgerm oil, rosehip, or any vegetable oil.

hi a preferred form, the plant-derived oil comprises a combination of grape seed oil, macadamia seed oil and sunflower oil. Preferably the total plant-derived oil component is present in the composition in the range of 1.50 - 68% by weight. More preferably, the plant-based oil is present in the composition in the range of 28 - 51 % by weight.

The sunscreen composition preferably further comprises one or more natural waxes such as candellila wax, carnauba wax or beeswax.

The composition may further comprise one or more of an anti-oxidant vitamin such as vitamin E or vitamin C. The vitamin may be in a suitable form such as Vitamin E acetate.

The composition may also comprise other suitable cosmetic components such as triglycerides, for example capric and caprylic triglycerides.

The sunscreen may further comprise an emollient such as one or more of sesame, jojoba or avocado oil.

Further, the composition may comprise anti-oxidant herbs such as green tea, calendula or lavender.

One or more natural preservatives such as tea tree, citrus seed, oregano or lemon grass, may be added to the composition. However, since the composition is generally an anhydrous formulation, preservatives are usually not required.

Preferably a mixture of one or more emulsifiers and/or humectants is added to the composition. Preferably the mixture of one or more emulsifiers and/or humectants is one or more of lecithin powder, glycerol or xanthum gum.

The composition may further comprise perfumed natural products such as lavender, rose and jasmine essential oils as appropriate.

In another form, the invention provides a method for protecting the skin against sun damage, the method comprising applying to the skin a protective amount of a natural sunscreen composition comprising synergistically effective amounts of zinc oxide and a plant-derived oil. The active ingredients of zinc oxide and the plant-derived oil are preferably present in amounts to provide a substantially water resistant composition on application to skin of a user.

Furthermore, the active ingredients of zinc oxide and the plant-derived oil are preferably present in amounts to provide a dermatologically acceptable level of SPF and broad spectrum protection from UVA and UVB radiation such that in use the composition provides sun protection to the skin with an acceptable SPF.

Preferably, the sunscreen composition has a dermatologically acceptable level of SPF of greater than 8+. More preferably, the acceptable level of SPF is greater than 15+. In a preferred form of the invention, the sunscreen composition has a dermatologically acceptable level of SPF of greater than 30+.

Preferably zinc oxide is present in the composition in the range of 5 - 25% by weight. More preferably, zinc oxide is present in the composition in the range of 15 - 23.5% by weight.

Preferably the zinc oxide is in the form of nano-particles. More preferably the nano- sized particles have a mean particle size in the range of 15 - 500nm. More preferably the zinc oxide particles are in the range of 25 - 200nm. Preferably the nano-particles have a narrow particle size distribution. The narrow particle size distribution is preferably defined in that, based on a number- weighted size distribution measured by photo-correlation spectroscopy, the number-weighted size distribution has a standard deviation of less than 20nm.

Preferably the plant-derived oil is one or more of grape seed oil, sunflower seed oil, macadamia seed oil, avocado oil, rice bran oil, calendula oil, jojoba oil, sesame oil, soy oil, almond oil, canola oil, castor oil, coconut oil, olive oil, palm oil, peanut oil, safflower oil, wheatgerm oil, rosehip or any vegetable oil.

In a preferred form, the plant-derived oil comprises a combination of grape seed oil, macadamia seed oil and sunflower oil.

Preferably the total plant-derived oil component is present in the composition in the range of 1.50 - 68% by weight. More preferably, the plant-based oil is present in the composition in the range of 28 — 51 % by weight.

The invention further provides a process for the preparation of a natural sunscreen composition comprising blending together synergistically effective amounts of zinc oxide and a plant-derived oil.

Preferably the zinc oxide and the plant-derived oil are present in amounts to provide a substantially water resistant composition on application to skin of a user.

Preferably the process comprises heating the plant derived oil followed by the addition of zinc oxide to obtain a clear mixture. More preferably the process comprises heating the plant derived oil to a temperature of about 95 to IOOC followed by removal of the heat and addition of zinc oxide with stirring until a temperature of 40 to 45C is reached.

The process preferably comprises the steps of:

i) combining the components of grapeseed oil, macadamia seed oil, sunflower oil, capuacu butter, candellila wax, beeswax, carnauba wax, lecithin powder, vegetable oils, tocopheryl acetate (natural) and heating to a temperature of 95 to IOOC;

ii) removing the heat, adding zinc oxide and stirring until the mixture cools to 40- 45C ; and iii) adding capric/caprylic triglycerides, green tea extract and chamomile extract with stirring until the resulting composition reaches room temperature.

More preferably, the components are present in the following relative weight percentages:

i) 28.75% grapeseed oil, 10% macadamia seed oil, 5% sunflower oil, 3% capuacu butter, 1.5% candellila wax, 4.5% beeswax, 0.5% carnauba wax, 0.5% lecithin powder, 6.5% vegetable oils, 0.25% tocopheryl acetate;

ii) 23.1% zinc oxide; and

iii) 14.3% capric/caprylic triglycerides, 0.5% green tea extract and 0.5% chamomile extract.

In another form of the invention, the process may comprise mixing zinc oxide and rice bran oil by anchor/propeller to form a homogenous mixture.

Preferably, the process further comprises the steps of:

i) mixing rice bran oil and micronised zinc oxide to form a homogenous first mixture;

ii) mixing aloe vera juice, ascorbic acid and green tea infusion to form a homogenous second mixture;

iii) heating shea butter, beeswax, sunflower oil, calendula oil, jojoba oil, sesame oil, vitamin E Acetate (tocopheryl), soy lecithin (soy oil) to melting to form a homogenous liquid mixture;

iv) cooling the liquid mixture to 4OC;

v) mixing the cooled liquid mixture and the first mixture by anchor mixing;

vi) mixing the second mixture with the mixture resulting from step v);

vii) cooling the mixture resulting from step vi) to about 3OC and adding lavender oil to form the sunscreen composition.

The components are preferably present in the following relative weight percentages:

i) 50.77% rice bran oil and 20% micronised zinc oxide;

ii) 10% aloe vera juice, 0.1% ascorbic acid and 0.33% green tea infusion;

iii) 0.1% shea butter, 5% beeswax, 4% sunflower oil, 1.5% calendula oil, 4% jojoba oil, 1% sesame oil, 2% vitamin E Acetate (tocopheryl), 1% soy lecithin (soy oil); and

iv) 0.2% lavender oil.

The zinc oxide is preferably present in the form of nano-particles. The nano-particles preferably have a mean particle size in the range of 15 - 500nm. More preferably the nano-particles have a mean particle size in the range of 25 - 200nm.

It is to be understood that the term "composition" may include an emulsion (such as a cream or a lotion), a gel, a dispersion, a spray, a lotion, a stick, or any other suitable preparation for use in application to a skin for use in assisting in the protection of skin damage by the sun. The phrase "sunscreen composition" as used throughout the specification and claims is understood to include cosmetic and therapeutic compositions such as cosmetic foundations, skin moisturisers and barrier creams where these cosmetic and therapeutic compositions include a component performing at least partially as a sunscreen agent. Thus the phrase "sunscreen composition" is understood to include for example cosmetic face foundations having a sunscreen component such that the overall foundation acts as a sunscreen.

The terms "sunscreen" and "UV blocking agent" as used in this specification are not intended to imply that 100% blockage of UV radiation occurs. The terms are used merely to describe the roles that these agents or compositions have in reducing or limiting the extent to which UV radiation is able to access or penetrate the skin of the user.

The term "water resistance" as used in respect of the sunscreen of the present invention, is not intended to imply that the composition forms a 100% barrier to water and water-based products such as sweat. It is intended to mean that, in the context of sunscreens, in use the composition forms a layer on the skin which is not readily removed from the skin when the skin is in contact with water or water-based components.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the working of the invention.

Description of Preferred Embodiments of the Invention

Preferred embodiments of the invention will now be described by way of example only. A first embodiment of a natural sunscreen composition comprises the constituents made up to lOOg as shown in Table 1 below.

PART A

(%w/w)

Grapeseed Oil 28.750

Macadamia Seed Oil 10.000

Sunflower oil (or Avocado Oil) 5.000

Capuacu Butter 3.000

Candellila Wax 1.500

Beeswax 4.500

Carnauba Wax 0.500

Lecithin Powder 0.500

Vegetable Oils 6.500

Tocopheryl Acetate (Natural) 0.250

PART B

Zinc Oxide 23.100

Capric/Caprylic Triglycerides 15.400

PART C

Green Tea Extract 0.500

Chamomile Extract 0.500

TOTAL 100.000

TABLE 1 In a preferred form of the sunscreen of the first embodiment, the zinc oxide is present in nano- particle size.

The sunscreen according to the first embodiment is prepared by combining the Part A components and heating these components to 95 — 100 C until the components have melted. The resulting mixture is stirred to obtain a uniform composition. The heat is then removed and the zinc oxide is added and the mixture is stirred to obtain a relatively clear mixture. Stirring of the mixture is continued until the temperature drops to 40 - 45C. The remaining Part B components are added, followed by the Part C components and stirring is continued until the mixture has cooled to room temperature.

The sunscreen composition of the first embodiment was measured to have an SPF of 38+ in the static state, that is prior to immersion in water. After 4 hours of immersion in water, the sunscreen of this embodiment was found to have an SPF of 35+. hi addition, the sunscreen of the first embodiment is clear on application to the skin. It is also non-sticky and non-greasy.

In general, zinc oxide on its own when applied to the skin washes off in a very short time, typically a few minutes, so that a sunscreen formed of zinc oxide alone has a negligible SPF+ and is thus not effective as a sunscreen when used in the presence of water. Similar results are obtained for plant-derived oils on their own so that these oils are also not effective on their own as sunscreen agents when used in the presence of water. However, the synergistic effect of the combination of the zinc oxide and plant-derived oil produces an effective sunscreen agent.

A second embodiment of a natural sunscreen composition comprises the constituents made up to lOOg as shown in Table 2 below. (% w/w)

Rice Bran Oil 50.770

Zinc Oxide, Micronised 20.000

Total Phase 1 Materials 70.770

Aloe Vera Juice 10.000

Ascorbic Acid 0.100

Green Tea Infusion 0.330

Total Phase 2 Materials 10.430

Shea Butter 0.100

Beeswax 5.000

Sunflower Oil (or Avocado Oil) 4.000

Calendula Oil 1.500

Jojoba Oil 4.000

Sesame Oil 1.000

Vitamin E Acetate (Tocopheryl) 2.000

Soy Lecithin (Soy Oil) 1.000

Total Phase 3 Materials 18.600

Lavender Oil 0.200

Total Phase 4 Materials 0.200

TOTAL 100.00

TABLE 2

The composition of the second embodiment is prepared by slow anchor/propellor mixing in a first vessel the zinc oxide and the rice bran oil, in several portions and stirring until homogeneous to form a Phase 1 mixture. The Phase 2 materials are added to a second vessel and mixed slowly until homogeneous. The Phase 3 components are added to a third vessel and heated until they have melted and are homogeneous. The Phase 3 mixture is cooled to 4OC before proceeding.

The Phase 3 mixture is then mixed under high anchor mixing whilst at the same time slowly adding the Phase 1 mixture. The mixture is stirred until the resulting composition is homogeneous. Mixing of this composition is continued at anchor level whilst slowly adding the Phase 2 mixture to the composition. The mixture emulsifies and the viscosity increases.

The resulting composition is cooled to 3OC and the Phase 4 mixture is added and mixed until a final homogeneous composition is produced.

The sunscreen composition of the second embodiment was measured to have an SPF of 28+ in the static state, that is prior to immersion in water. After 4 hours of immersion in water, the sunscreen of this embodiment was found to have an SPF of 17+.

The composition of the present invention may be provided in any suitable cosmetic or pharmaceutical form such as a lotion or gel. Furthermore, the composition may of course be provided in combination with any cosmetic product such as a face cream, or in combination with a pharmaceutical product such as an insect repellent cream.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. For example, natural perfumes or insect repellent may be added to the composition to impart fragrance or other desirable comfort features to the composition. All such variations and modifications together with others that would be obvious to a person of ordinary skill in the art are considered to be within the scope of the present invention.

Claims

1. A natural sunscreen composition comprising synergistically effective amounts of zinc oxide and a plant-derived oil.

2. A sunscreen composition according to claim 1 wherein the zinc oxide and the plant-derived oil are present in amounts to provide a substantially water resistant composition on application to skin of a user.

3. A sunscreen composition according to claim 1 or claim 2 wherein the zinc oxide and the plant-derived oil are present in amounts to provide a dermatologically acceptable level of SPF and broad spectrum protection from UVA and UVB radiation.

4. A sunscreen composition according to any one of claims 1 to 3 wherein the zinc oxide and the plant-derived oil are present in amounts to provide a composition that is substantially water resistant for a period of at least about 1 - 4 hours on application to skin of a user.

5. A sunscreen composition according to any one of the preceding claims wherein the composition has a dermatologically acceptable level of SPF of greater than 8+.

6. A sunscreen composition according to claim 5 wherein the dermatologically acceptable level of SPF is greater than 15+.

7. A sunscreen composition according to claim 6 wherein the dermatologically acceptable level of SPF is greater than 30+.

8. A sunscreen composition according to claim 5 wherein the sunscreen composition has an SPF level of 30+ to 38+ after application of the sunscreen to skin of a user and exposure to water for a period of 1 - 4 hours.

9. A sunscreen composition according to claim 8 wherein the sunscreen composition has an SPF level of 30+ to 38+ after application of the sunscreen to skin of a user and exposure to water for a period of 2 - 3 hours.

10. A sunscreen composition according to claim 9 wherein the SPF of the sunscreen composition is 31+ after application of the sunscreen to skin of a user and exposure to water for a period of 3 hours.

11. A sunscreen composition according to any one of the preceding claims wherein zinc oxide is present in the composition in the range of 5 — 25% by weight.

12. A sunscreen composition according to claim 11 wherein zinc oxide is present in the composition in the range of 15 - 23.5% by weight.

13. A sunscreen composition according to any one of the preceding claims wherein the zinc oxide is in the form of nano-particles.

14. A sunscreen composition according to claim 13 wherein the nano-particles have a mean particle size in the range of 15 - 500nm.

15. A sunscreen composition according to claim 14 wherein the nano-particles have a mean particle size in the range of 25 - 200nm.

16. A sunscreen composition according to any one of claims 13 to 15 wherein the nano-particles have a narrow particle size distribution.

17. A sunscreen composition according to any one of the preceding claims wherein the plant-derived oil is one or more of grape seed oil, sunflower seed oil, macadamia seed oil, avocado oil, rice bran oil, calendula oil, jojoba oil, sesame oil, soy oil, almond oil, canola oil, castor oil, coconut oil, olive oil, palm oil, peanut oil, safflower oil, wheatgerm oil, rosehip, or any vegetable oil.

18. A sunscreen composition according to claim 17 wherein the plant-derived oil comprises a combination of grape seed oil, macadamia seed oil and sunflower seed oil.

19. A sunscreen composition according to claim 17 or claim 18 wherein the total plant-derived oil component is present in the composition in the range of 1.50 - 68% by weight.

20. A sunscreen composition according to claim 19 wherein the plant-based oil is present in the composition in the range of 28 - 51 % by weight.

21. A sunscreen composition according to any one of the preceding claims further comprising one or more natural waxes such as candellila wax, carnauba wax or beeswax.

22. A sunscreen composition according to any one of the preceding claims further comprising one or more of an anti-oxidant vitamin such as vitamin E or vitamin C.

23. A sunscreen composition according to claim 22 wherein the vitamin is in the form of Vitamin E acetate.

24. A sunscreen composition according to any one of the preceding claims further comprising other suitable cosmetic components such as triglycerides including capric and caprylic triglycerides.

25. A sunscreen composition according to any one of the preceding claims further comprising an emollient such as one or more of sesame, jojoba or avocado oil.

26. A sunscreen composition according to any one of the preceding claims further comprising anti-oxidant herbs such as green tea, calendula or lavender.

27. A sunscreen composition according to any one of the preceding claims further comprising one or more natural preservatives such as tea tree, citrus seed, oregano or lemon grass.

28. A sunscreen composition according to any one of the preceding claims further comprising a mixture of one or more emulsifiers and/or humectants.

29. A sunscreen composition according to claim 28 wherein the mixture of one or more emulsifiers and/or humectants is one or more of lecithin powder, glycerol or xanthum gum.

30. A sunscreen composition according to any one of the preceding claims wherein the composition further comprises perfumed natural products such as lavender, rose and jasmine essential oils.

31. A sunscreen composition according to any one of the preceding claims wherein the composition comprises a mixture of the following components:

i) grapeseed oil, macadamia seed oil, sunflower oil, capuacu butter, candellila wax, beeswax, carnauba wax, lecithin powder, vegetable oils, tocopheryl acetate (natural);

ii) zinc oxide and capric/caprylic triglycerides; and

iii) green tea extract and chamomile extract.

32. A sunscreen composition according to claim 31 wherein the relative weight percentages of the components are:

ii) 23.1% zinc oxide, 14.3% capric/caprylic triglycerides; and

iii) 0.5% green tea extract and 0.5% chamomile extract.

33. A sunscreen composition according to any one of claims 1 to 30 wherein the composition comprises a mixture of the following components:

i) rice bran oil and micronised zinc oxide;

ii) aloe vera juice, ascorbic acid and green tea infusion;

iii) shea butter, beeswax, sunflower oil, calendula oil, jojoba oil, sesame oil, vitamin E Acetate (tocopheryl), soy lecithin (soy oil); and

iv) lavender oil.

34. A sunscreen composition according to claim 33 wherein the relative weight percentages of the components are:

i) 50.77% rice bran oil and 20% micronised zinc oxide;

ii) 10% aloe vera juice, 0.1% ascorbic acid and 0.33% green tea infusion;

iv) 0.2% lavender oil.

35. A method for protecting the skin against sun damage, the method comprising applying to the skin a protective amount of a natural sunscreen composition comprising synergistically effective amounts of zinc oxide and a plant-derived oil.

36. A method according to claim 35 wherein the zinc oxide and the plant-derived oil are present in amounts to provide a substantially water resistant composition on application to skin of a user.

37. A method according to claim 35 or claim 36 wherein the zinc oxide and the plant-derived oil are present in amounts to provide a dermatologically acceptable level of SPF and broad spectrum protection from UVA and UVB radiation.

38. A method according to any one of claims 35 to 37 wherein the zinc oxide and the plant-derived oil are present in amounts to provide a composition that is substantially water resistant for a period of at least about 4 hours on application to skin of a user.

39. A method according to any one of claims 35 to 38 wherein the sunscreen composition has a dermatologically acceptable level of SPF of greater than 8+.

40. A method according to claim 39 wherein the sunscreen composition has a dermatologically acceptable level of SPF of greater than 30+.

41. A process for the preparation of a natural sunscreen composition comprising blending together synergistically effective amounts of zinc oxide and a plant-derived oil.

42. A process according to claim 41 wherein the zinc oxide and the plant-derived oil are present in amounts to provide a substantially water resistant composition on application to skin of a user.

43. A process according to claim 41 or claim 42 comprising heating the plant derived oil followed by the addition of zinc oxide to obtain a clear mixture.

44. A process according to claim 43 comprising heating the plant derived oil to a temperature of about 95 to IOOC followed by removal of the heat and addition of zinc oxide with stirring until a temperature of 40 to 45C is reached.

45. A process according to claim 41 comprising the steps of:

ii) removing the heat, adding zinc oxide, and stirring until the mixture cools to 40-

45C ; and

iii) adding capric/caprylic triglycerides, green tea extract and chamomile extract with stirring until the resulting composition reaches room temperature.

46. A process according to claim 45 wherein the components are present in the following relative weight percentages:

ii) 23.1 % zinc oxide; and iii) 14.3% capric/caprylic triglycerides, 0.5% green tea extract and 0.5% chamomile extract.

47. A process according to claim 41 comprising mixing zinc oxide and rice bran oil by anchor/propeller to form a homogenous mixture.

48. A process according to claim 41 comprising the steps of:

iv) cooling the liquid mixture to 4OC;

v) mixing the cooled liquid mixture and the first mixture by anchor mixing;

vi) mixing the second mixture with the mixture resulting from step v);

vii) cooling the mixture resulting from step vi) to about 30C and adding lavender oil to form the sunscreen composition.

49. A process according to claim 48 wherein the components are present in the following relative weight percentages:

i) 50.77% rice bran oil and 20% micronised zinc oxide;

ii) 10% aloe vera juice, 0.1% ascorbic acid and 0.33% green tea infusion;

iii) 0.1% shea butter, 5% beeswax, 4% sunflower oil, 1.5% calendula oil, 4% jojoba oil, 1% sesame oil, 2% vitamin E Acetate (tocopheryl), 1% soy lecithin (soy oil); and iv) 0.2% lavender oil.

50. A process according to any one of claims 41 to 49 wherein the zinc oxide is present in the form of nano-particles.

51. A process according to claim 50 wherein the nano-particles have a mean particle size in the range of 15 - 500nm.

52. A process according to claim 51 wherein the nano-particles have a mean particle size in the range of 25 - 200nm.

53. A sunscreen composition substantially as herein described with reference to the accompanying examples.

54. A method substantially as herein described with reference to the accompanying examples.

55. A process substantially as herein described with reference to the accompanying examples.