NZ264108A - Uv sun screen composition comprising at least one flavonoid (or derivative); uses in various compositions - Google Patents

Description

264 1 08 Priority Date(s): Complete Specification Fil#d: Claw: (0) Publication Data: P.O. Journal No: PATENTS FORM NO. 5 Fee No. 4: $260.00 PATENTS ACT 1953 f!OMPT ,ETE SPECIFICATION After Provisional No: 264108 Dated: 27 July 1994 '*27 SEP 1995 IMPROVEMENTS IN AND RELATING TO UV SCREENS I/WE Comvita New Zealand Limited, a New Zealand company of Old Coach Roach (no street number), Te Puke, New Zealand do hereby declare the invention for which I/We pray that a patent may be granted to me/us, and the method by which it is to be performed to be particularly described in and by the following statement: 26 4 10 IMPROVEMENTS IN AND RELATING TO UV SCREENS TECHNICAL FlELP The present invention is directed to methods and compositions for screening UV radiation. Emphasis will be given to sunscreens and 5 cosmetics having UV filtering properties.

Background art For simplicity, the description of the present specification will be directed primarily to UV-screening compositions such as sunscreens though it should be appreciated that the UV screening abilities of flavonoids and 10 compositions described herein may also find use in other applications wherever a UV screening effect is required.

In the case of skin applied sunscreens, a selected range of UV filtering compounds is known and commonly used in commercial products. Unfortunately, a small yet significant proportion of the population 15 exhibits some adverse affect to at least a proportion of the commonly used compounds.

It is unusual for any single compound to exhibit broad spectrum protection across the entire UV band and thus more effective sunscreen compositions will comprise several compounds which each exhibit UV 20 absorption bands at various points within the UV region. This increases the likelihood of any specific sunscreen compositions containing a component which some members of the public cannot tolerate.

Any broad spectrum UV sunscreen will, in reality, exhibit a plurality of UV absorption peaks rather than a broad UV absorption band. It is up to 2 264108 the manufacturer to determine the best choice of compounds to provide an effective UV absorption pattern. However, this is limited by the properties of the currently used range of UV filtering compounds and problems may present themselves if desirable compounds cannot be used 5 because of an intolerance by a significant proportion of the population.

The introduction of new compounds may necessitate a period of delay while testing to satisfy different regulations i3 performed. In some instances natural products, especially those for which testing or human use has been previously performed (e.g. propolis), may bypass the need for 10 such extensive or exhaustive testing.

Accordingly, there is a need for a greater degree of choice for manufacturers of various UV screening compositions and products.

It i3 an object of the present invention to address the foregoing problems or at l^ast to provide the public with a useful choice.

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

DISCLOSURE OF INVENTION Summary According to one aspect of the present invention there is provided a UV-screening composition which includes at least one flavonoid and/or flavonoid derivative.

According to another aspect of the present invention there is provided a UV-screening composition substantially as described above in which a 25 flavonoid is selected from the group comprising: chalcones, flavanones, 3 264 1Q § flavones, flavonols, dihydroflavonols, flavanols, anthocyanins, and isoflavones.

According to another aspect of the present invention there is provided a UV-screening composition substantially as described above in which a 5 flavonoid derivative is selected from the group comprising: flavonoid glycoside derivatives, biosynthetically related flavonoid compounds, and biosynthetically related flavonoid compounds derivable from shikamate pathways.

According to another aspect of the present invention there is provided a 10 method of screening UV radiation substantially as described above which includes either or both of a flavonoid or flavonoid derivative exhibiting at least one UV absorption peak in the region of 280-320nm.

According to another aspect of the present invention there is provided a method of screening UV radiation substantially as described above which 15 includes either or both of a flavonoid or flavonoid derivative exhibiting at least one UV absorption peak in the region of 320-400nm.

According to another aspect of the present invention there is provided a method of screening UV radiation substantially as described above which includes at least one member of the group: baicalein, apigenin, luteolin, 20 isoscutellarein, galangin, kaempferol, quercetin, pinocembrin, cinnamic acid, 4-hydroxy cinnamic acid, 3,4-dihydroxy cinnamic acid, 3,4,5-trihydroxy cinnamic acid, rutin, taxifolin, naringenin, or their derivatives.

According to another aspect of the present invention there is provided a 25 UV screening composition substantially as described above which 4 26 4 1 OS includes at least one of a pharmacologically acceptable carrier, an emollient, a non-flavonoid UV absorber, and a UV reflector.

According to one aspect of the present invention there is provided a skin applicable sun-screening composition substantially as described above 5 which is in the form of a skin toning lotion.

According to one aspect of the present invention there is provided a skin applicable sun-screening composition substantially as described above which is in the form of a cosmetic foundation.

According to one aspect of the present invention there is provided a skin 10 applicable sun-screening composition substantially as described above which is in the form of a lip stick or cream.

According to one aspect of the present invention there is provided a UV-screening composition substantially as described above in the form of a hair applicable sun-screening composition.

According to one aspect of the present invention there is provided a UV-screening composition substantially as described above in the form of a nail lacquer.

According to one aspect of the present invention there is provided a UV-screening composition substantially as described above in the form of a 20 fabric coating agent.

According to one aspect of the present invention there is provided a UV-screening composition substantially as described above in the form of a paint stain or coating. 26 4 1 o8 According to one aspect of the present invention there is provided a UV-screening composition substantially as described above in the form of a fade resistant ink.

According to one aspect of the present invention there is provided a UV-5 screening composition substantially as described above in the form of a dye.

According to another aspect of the present invention there is provided a UV-screening plastics material which includes a UV-screening composition substantially as described above.

According to another aspect of the present invention there is provided a skin applied cosmetic having UV screening properties substantially as described above which includes at least one tinting agent or pigment, and a pharmacologically acceptable base or carrier.

According to one aspect of the present invention there is provided a 15 method for conferring UV-screening properties comprising the inclusion of at least one flavonoid or flavonoid derivative to a composition.

According to one aspect of the present invention there is provided a method substantially as described above in which a said composition to which UV screening properties are conferred comprises at least one of: a 20 skin applicable sun screening composition, a moisturiser, a skin toner, a cosmetic foundation, a lip stick or cream, a nail lacquer, a hair applicable sun-screening composition, a hair shampoo, a hair conditioner, a hair colorant, a fabric coating or protectant, a laundry fabric conditioner, a laundry fabric cleanser, a paint stain or coating, a fade resistant ink, or a 25 dye. 6 264 1 0 8 According to another aspect of the present invention there is provided a method of sun protection for the skin comprising the application to the skin of a composition substantially as described above.

General Description Flavonoids are a class of compounds, all of which are C6-C3-C6 compounds. Falling within the definition of flavonoids are many chalcones, flavanones, flavones, flavonols, dihydroflavonols, flavanols, anthocyanins, isoflavones and other biosynthetically related compounds (such as those derivable from shikamate pathways - see below). Many 10 flavonoid compounds may be biosynthesised by similar combinations of acetate/malonate and shikimate pathways. Common flavonoids may also occur as glycosides ue. attached to sugars) which is the form in which they generally appear when they occur naturally in plants. Glycosidation increases the water solubility of the flavonoid. Such flavonoid glycosides 15 are encountered, for instance, in the leaves, fruit and pollen of plants.

Some other naturally occurring flavonoids occur as aglycones (ie. no attachment to sugars). These flavonoids are generally lipophilic and largely insoluble in water. Commonly, such flavonoids are found in leaf waxes and in propolis derived therefrom. For the purpose of this 20 specification the term 'flavonoid' shall include flavonoid based derivatives, such as the glycosides and aglycones above.

Flavonoids (including flavone and flavonol glycosides) all exhibit UV-absorption bands. Two significant UV-absorption bands are characteristic of most flavonoids; often one is in the region of 25 approximately 270-285 nm, and the other at approximately 320-385 nm; though there is often still significant absorption between these bands. 7 264 1 Some lipophilic flavonoids absorb in the mid-range between these bands, though this still depends upon the flavonoid structure.

The term 'plant extracted flavonoid' shall refer to a flavonoid compound, or a flavonoid containing composition, which has been derived from plant material. This may be accomplished by chemical or biochemical extraction and separation processes although a plant portion which may have been derived from purely physical processes such as pressing, would also fall within the definition.

The term 'preferred UV-absorbing flavonoid' shall be defined as a flavonoid compound having at least one significant absorption peak in the desirable UV region. The term will also include extracts and compositions containing such a flavonoid, as in many cases a flavonoid will not be processed to a pure and isolated form according to most methods of production according to the present invention.

The term 'UV screening composition' shall refer to any composition having UV filtering properties. While most of such compositions according to the present invention will be skin applicable sunscreens for the specific purpose of filtering or screening UV radiation, the term shall also include other cosmetics and compositions where UV screening is a secondary consideration — see also later.

The present invention makes use of flavonoid compounds to absorb UV radiation, thus providing for a screening effect in compositions and materials in which they are incorporated. Cinnamic acids (e.g. cinnamic acid, 4-hydroxy cinnamic acid, 3,4-dihydroxy cinnamic acid, and 3,4,5-trihydroxy cinnamic acid etc.) also exhibit useful UV absorbing properties and may be included in various embodiments of the present 8 26 4 1 0 8 invention. In some instances the cinnamic acids co-occur in nature with flavonoids - two examples are pollen and propolis which are two preferred natural sources of UV absorbers for use in the present invention.

The UV absorption properties of most flavonoids, as well as cinnamic acids, make them useful in this respect. As may be appreciated, while significant UV absorption peaks often occur in two bands (270-280 nm and 320-385 nm), different flavonoid compounds will exhibit different UV absorption peaks.

Accordingly, there exists an opportunity to use various flavonoid compounds whose aggregate UV absorption provides the general UV absorption characteristics required by the user, e.g a composition of broad spectrum UV absorption across the recognised UV-A and UV-B bands (320-400, and 280-320 nm respectively).

The quantities present will at least be partially dependent upon the degree of UV-absorption required and vice versa. The overall degree of UV absorption will also be affected by the specific UV absorption profile of individual components. However, it is envisaged that to be useful it is likely that a UV screening product or composition according to the 20 present invention will block (due to the included flavonoids and/or derivatives) at least 25% of incident UV radiation in the region 280-400mm inclusive. More preferably 50% or greater will be blocked. While the thickness of the applied composition will have a bearing, techniques such as used for testing to current SPP sunscreen ratings may be used as 25 a guide for determining UV blocking, or the techniques used for measuring absorption (refer Figures 1 and 2 and accompanying explanation). 9 264 1 o 8 Flavonoid compounds may also be combined with other existing UV absorbing products to cover regions of the UV band in which the existing compounds do not adequately absorb. This provides for greater user choice, and introduces an extended range of compounds which may be 5 relied on by the art to address any problems with compounds currently used as UV filtering/screening agents in UV screening compositions.

Flavonoid compounds used in various embodiments of the present invention may be of synthetic origin, though it is also envisaged that plant extracted flavonoid compounds, and flavonoid containing compositions, 10 will be used. Depending on the fickleness of the public, the use of plant extracted flavonoids are currently desirable from a marketing point of view, though typically economics, and the compatibility of various derived compounds and compositions with manufacturing techniques, will often determine what source is best suited for a particular product.

Flavonoids are ubiquitous in land based green plants. The prior art has identified a number of flavonoid compounds in various plants, and this information may be relied upon to identify which plant types are best suited for the extraction of specific flavonoid compounds. Extraction techniques are also well-known and the prior art may be relied upon for 20 the techniques for isolating the desired flavonoid compounds from selected plant matter. One method of extraction will be described later within this specification by way of example.

The nature of different embodiments may also vary considerably. Even for purely UV-screening lotions, there is a significant variation in the 25 properties of commercially available lotions and products. For instance, many provide varying levels of UV protection, whilst other areas in which there is choice include the degree of water resistance; special 264 1 0 8 sports formulations to resist perspiration; non-oily and non-comodogenic formulations; and hypoallergenic formulations which may be free of one or more recognised UV absorbing compounds to which various proportions of the populous may be allergic or intolerant. Many 5 embodiments of the present invention may provide the same properties as the formulations just described, or formulated according to current practice in UV screening preparations. It is therefore envisaged that techniques of the art may be relied upon to produce various embodiments of UV screening lotions and compositions which include flavonoids as 10 UV screening agents.

Accordingly, it is envisaged that many such compositions will include pharmacologically acceptable carriers and bases and, perhaps as well, or alternatively, other UV blocking or screening agents and UV reflecting agents.

It is also considered that flavonoids may find their way into cosmetics in which UV screening is not the primary consideration or purpose of the cosmetic preparation. Some examples include foundations, in which (other than bases and carriers), the composition is likely to contain at least one of tinting agents, pigment and moisturising agents. Other 20 cosmetic compositions include toning and moisturising compositions wherein, in the case of toning fluids, volatile components may evaporate on use leaving the flavonoid compounds to provide some sunscreen activity. Moisturising compositions (which are not generally volatile), may include the flavonoids dispersed in their composition. As can be 25 appreciated, the flavonoids can be included or dispersed in a wide range of cosmetic products which are routinely used by a large proportion of the population. 11 264 1 It should also be appreciated that a wide range of hydrophilic and lipophilic flavonoids are known. This provides manufacturers with the choice as to which flavonoid compound or compounds are used depending upon whether the resulting composition is predominantly aqueous or oil based. This provides flexibility, not only in the number of different existing compositions into which flavonoid substances can be introduced or substituted but also in the number of new compositions based on flavonoids which are able to be produced.

It should also be appreciated that while UV screening compositions for use on skin and in cosmetics are the main envisaged use of flavonoid compounds, they may also find use in other areas. For instance, many pigments (especially fluorescent pigments) are readily degraded upon prolonged exposure to UV light. Incorporation of flavonoid compounds into paint, pigments, dyes and inks can extend the life of the product upon exposure to sun or UV radiation. While fluorescence is often dependent on the incidence of UV radiation, limiting the amount of UV radiation to which a dye or pigment etc. is exposed may be desirable. Accordingly, it is envisaged that flavonoids may be incorporated into paint, pigment, dye and ink formulations as a UV screening agent.

It is also envisaged, that the agents may be used as a treatment or application for materials of various types. For instance, fabrics could be rinsed or washed in flavonoid containing compositions, in which a proportion of flavonoids are left to coat the fibres of the fabric. While this may be part of a commercial process, perhaps applied to bulk material before it is sold or put to use, it could also be part of an ongoing repetitive short-term process. For instance, flavonoids could be introduced into fabric conditioners so that every time a fabric was washed, some degree of 12 264 1 o UV protection (and therefore resistance to fading) would result. It is envisaged that flavonoid deposition characteristics could be readily introduced into various cleaning methods and fabric protection services and compositions.

It is envisaged that lipophilic, and only partially soluble flavonoids, are likely to be most useful for these applications. However flavonoids which bond (physically and/or chemically) to fibres may also b •. used. The use of conjugate bridging compounds to bind the flavonoids to the fibres may also be considered.

It is also envisaged that flavonoids could be introduced into hair conditioners and shampoos. Many shampoos and conditioners include a UV filtering agent, and thus flavonoids are an alternative to those substances already commonly used. While plant extracts are used in hair formulations, they are not included for UV filtering properties. Consequently, it is not a consideration of manufacturing processes to ensure added plant extracts are rich in, or indeed contain any flavonoids.

Many other uses are envisaged, including incorporation into plastics and screening materials. Transparent plastic sheeting, including flavonoid compounds, will find use in applications where it is desirable to screen people or plants beneath the cover provided by same and to ameliorate UV-induced degradation. 13 264 1 08 brief description of drawings Figure 1 is a graph of UV absorption of some embodiments of the present invention, and Figure 2 is a graph of UV absorption of a modification to an 5 embodiment of Figure 1.

Best Modes for Carrying out the Invention Examples 1 With regard to skin applicable sunscreen and UV-screening lotions, the typical formulations used, or based on those used, by the prior art may be 10 employed in the present invention. Preferred embodiments of the present invention either partially or folly substitute flavonoid compounds for the UV-screening agents used in the prior art formulations. The proportions and choice of flavonoid compounds included will depend upon the choice and requirements of the manufacturer and user. Because of the large 15 number of flavonoid compounds, and various permutations and combinations of same, it is anticipated that a small degree of trial and experimentation may be required for a manufacturer to tailor a formulation to their specific requirements. Where less specificity is required then such trial and experimentation would not be required. 20 The current Australian and New Zealand standard ("Sunscreen Products - Evaluation and Classification"(AS/NZs 2604:1993) sets current guidelines for the manufacture and classification of various sunscreen lotions. Examples of some sunscreens are given therein.

While virtually all flavonoid compounds, providing they are tolerable by a 25 user of the product, will show some useful UV absorption properties, 14 264 t 0 8 some currently preferred flavonoid and biosynthetically .related compounds, with their significant absorption peaks in the UV region, are given below: Baicalein 274 323 Apigenin 267 336 Luteolin 253/267 349 Isoscutellarein 280 305 330sh 364sh Galangin 267 359 Kaempferol 266 322sh 367 Quercetin 255/269 370 Pinocembrin 289 325sh Naringenin 289 326sh Taxifolin 293 332sh 4-Hydroxy cinnamic acid 310 3,4-Dihydroxy cinnamic acid 324 The absorption peaks detailed above generally have ^-values (extinction co-efficient) in the range 14,000-30,000 and their positions can be altered by changing the pH, or by metal complexing. Whilst a compound such as isoscutellarein (and others not listed) blocks the critical 290-360 nm region by itself, other flavonoids such as luteolin may need to be combined with one of the cinnamic acids, or taxifolin/naringenin to provide the desired range or amount of UV absorption. Generally, there are no problems associated with the combining of flavonoids if this is necessary.

Accordingly, the invention provides a cosmetic composition having UV 25 screening properties which includes at least one of the foregoing flavonoid or biosynthetically related compounds. 264108 Example la Plant derived flavonoids may be used in various compositions. Where a plant derived source is used, then the extraction processing method should be such to optimise the flavonoid content in the resulting product. 5 Synthetically derived flavonoid compounds may also be used to increase the level of flavonoid substances in or offered by the plant extracts or products.

In other embodiments the use of purified plant extracts, or synthetically obtained or enhanced flavonoids and compositions, may be desirable. 10 Some plants induce undesirable reactions in some people. It may therefore be desirable to eliminate or reduce in a final product any substances (from the plant) responsible for adverse reactions. In many cases the choice of another plant source may be feasible though it is envisaged that in some cases this may not be economically desirable for a 15 manufacturer.

Example lb Two preferred sources of UV absorbers are pollen and propolis, both sources of UV absorbing flavonoids and cinnamic acids. Accordingly both may be used in the production of different compositions and products 20 according to the present invention. In some instances, extraction procedures will be applied to extract the UV absorbing components.

Examples 2 It is noted that most flavonoids are generally stable to ultraviolet light. For instance, flavonoids occurring in the external leaf waxes of many 25 desert plants survive exceptionally well. While such long term stability is not generally necessary for cosmetic preparations which are often only 16 264 1 08 present for a day, long term UV stability is a consideration for applications in dyes and pigments, fabrics, hair conditioners, or inclusion into other material such as plastics. Accordingly, a consideration is that such products will often provide long term UV 5 stability.

Some examples of skin applicable compositions envisaged by the applicants follow: F.vnmplft 9.a Skin Toning Lotion Typically this will comprise a conventional skin toning lotion which includes a flavonoid as herein defined. It is envisaged that lighter flavonoids (as opposed to the waxy flavonoids found in some plants) will be used in these types of compositions as the purpose of most toning lotions is to remove residues from the skin not removed by cleansing. 15 Skin toning compositions which contain, or exclude, alcohol are known. Various flavonoids exhibit various degrees of solubility in water or alcohols and may be selected as appropriate for the carrier and other components in these skin toning compositions. Skin toning compositions are known to which flavonoids may be introduced, and need not be 20 described in further detail here.

T^ynmplft 2h Moisturiser Moisturising compositions may also benefit from sunscreening properties. Many moisturising compositions are meant to be absorbed or 25 provide a barrier on the skin and in many respects may represent a more effective vehicle for UV screening flavonoids than toning lotions. Various flavonoids may be introduced, as required, to provide the necessary level 17 264 1 08 and spectrum of UV absorption in a final product. Moisturising compositions to which flavonoids may be introduced are well known, and will not be described in further detail herein.

Example 3q 5 Cosmetic Foundations Cosmetic foundations also represent a suitable vehicle for introducing UV-screening flavonoids. Flavonoids and their derivatives may be readily introduced to liquid and cake foundations. It is also possible that heavier and waxier flavonoids may be introduced to these and face 10 powders though the method by which these products are applied are likely to provide less UV-screening capability than makeup foundations which are relatively evenly applied to the skin. Lighter flavonoids may be preferred in non-comodogenic preparations.

Flavonoids can be introduced into other cosmetic products including 15 concealers, make-up fixing bases, bronzing powders, blushers, eyeliners, eyepencils, mascaras, eyeshadows etc.

Lipsticks Lipsticks and creams also represent a suitable vehicle for the application 20 of UV screening flavonoids. It is envisaged that heavier and waxier flavonoids will find use in lipsticks and cream compositions. This is typically because the products are waxy in their composition, and also as products are typically more readily removed from this region (by activities such as eating and drinking) than the parts of the face. 18 264 1 08 Various compositions may be clear or pigmented according to user requirements. Lipstick and cream formulations are well known and will not be described in farther detail herein.

Example 2e Hand Creams and Barrier Creams Many hand creams and barrier creams also represent a good vehicle for the application of UV-screening flavonoids. Many such compositions to which flavonoids may be introduced are known and will not be described in further detail herein.

Example 3 Other uses of the present invention by people and animals include uses other than application to the skin. One such other area in which UV-screening is becoming popular is the protection of the hair. UV damage is recognised as a factor in hair damage, bleaching and the alteration of artificial colourants and treatments.

UV-screening flavonoids may be introduced to the hair in a number of ways, some of which are as follows: Example 3a Shampoos and Conditioners For a hair shampoo and/or conditioner, typically a flavonoid dispersed in the hair cleaning and/or conditioning composition is relied upon. A small but reasonable proportion of the flavonoid will remain on the hair, coating and helping protect against UV damage. The use of lipophilic and/or heavier/waxier flavonoids is likely to be most preferable to avoid removal during rinsing. However it is desirable to avoid the use of quantities, or specific flavonoids, which leave a coating on the hair which 19 264 1 08 affects its manageability or other desirable characteristics. This will depend partially on the nature of the hair, and desirable properties to be attained after cleansing, thereby requiring some minor experimentation by a manufacturer to select the best flavonoid for their needs.

Example 3b Leave-in Conditioners Leave-in conditioners, treatments and split ends repair compositions, are used relatively often by the public. They also represent a useful vehicle for coating hair with a protective flavonoid layer. In addition these 10 products are not immediately removed from the hair once applied, in the manner that a shampoo is rinsed off shortly after application. This allows the use of flavonoids which may be readily removed during later washing - rather than being restricted to those which are not readily removed during removal of the shampoo or standard conditioner by 15 rinsing.

A wide range of leave-in contidioners and hair treatments are known to which various flavonoids may be introduced. Their compositions will not be described in any detail here.

Example 3c 20 Styling Fixatives and Compositons As for leave-in conditioners and treatments, styling aids and fixatives are often left in hair until their later removal by washing or repeated brushing. They too represent a suitable vehicle for the introduction of UV-screening flavonoids. Examples of these types of products, to which 25 flavonoids may be introduced, include mousses, hairsprays, gels, styling creams, styling waxes, and other styling fixatives and agents. The compositions of these products are well known and will not be described 26 4108 in any greater detail here. As these are generally left in the hair while the style is being worn, the use of flavonoids is not necessarily restricted to the heavier or waxier types which are left after rinsing.

Example 4 A specific embodiment of the present invention suitable for use in sunscreeny, and which may also be incorporated into other cosmetic and hair products, is based on propolis and rutin. Details are as follows: Propolis tincture (20/1) sourced from Comvita and containing 22.5% W/W of extract was diluted 10,000 times with methanol to produce a solution 10 with Xmax292 and an optical density (OD) of 0.81 — see Figure 1. A solution of plant sourced rutin containing 5.3 mg/100 ml was made up in methanol to give a A,max365 with an OD of 0.76 - see also graph 1.

An admixture of these very dilute solutions in a 1:1 ratio gave an absorption spectrum which did not drop below an OD of .45 over the range 15 280-387nm - see also Figure 1.

This range can be extended out to 414nm if the pH is increased to approximately 9.5 by the addition, for example, of sodium acetate — see Figure 2. This level of absorption is obtained in 1ml of solution with only 53 micrograms of rutin and 23 micrograms of propolis tincture solid. 20 This combination effectively covers the required range set out in standard AS/NZS 2604:1993 (320-360nm).

Propolis tincture without the addition of rutin is only slightly less effective — see Figure 1. To obtain the same minimum OD of 0.45 over the range 320-360 nm, a solution containing 30 micrograms of propolis 25 tincture solid per 1ml solvent would be required. 21 264 1 0® Rutin is relatively available as a commercial product, as is propolis tincture.

Rutin could be replaced in the UV screening base of this example by any number of flavonoids. Some naturally occuring examples include: 5 materials sourced from Gingko biloba, from members of the Pinaceae family (e.g. Pinus), members of the Theaceae family (including tea producing Camelia varieties), onions and various other fruits and vegetables.

Example 5 Flavonoids containing UV-screening compositions may be used in other areas. The fabric and textile industries represent one area in which use may be made. While flavonoids may be introduced at the stage of fibre production or processing, they may also be introduced during subsequent textile processes such as bleaching, dyeing, printing, or as a specific 15 treatment step etc.

A further major use of UV screening flavonoids in this area of application is in the post- and on-ongoing treatment of fabrics and textiles, including carpets etc. Some specific examples follow: Example 5a 20 Fabric Conditioner Laundry cleansers and conditioners represent a suitable vehicle for the introduction of flavonoids to fabrics and textiles. Existing compositions may include one or more flavonoids which are typically choscn so as to leave a residue, once the cleaning process is completed, on the fabric or 25 textile. The use of less hydrophilic flavonoids may be relied upon in 22 26 4^0^ various compositions. Compositions in which the flavonoids are.present as a non-aqueous emulsion or fraction may be relied upon.

It is envisaged that for most applications involving laundry cleansers and conditioners, the level of flavonoids may be relatively small so as to 5 provide some supplementary UV screening properties to the fabric. It may be desirable that any heavy duty or longer lasting UV protection is acquired by the use of treatments at the textile manufacture stage, or the use of aftermarket protectants.

Example 5b 10 Fabric Protectants After market fabric protectants are known and available to the public. Many of these represent a useful vehicle for the introducing of flavonoids for treating various textiles and fabrics etc. Flavonoids may also be introduced into these compositions. As most aftermarket protectants are 15 intended to provide medium to long term protection for an article to which they are applied, the use of non-aqueous, or heavier waxier flavonoids may be relied upon. The use of non-aqueous carriers may be required to disperse the flavonoids, with the carrier's eventual evaporation or removal leaving a protective deposit of flavonoid material.

Many cleaning shampoos (more typically carpet shampoos) also include protectants for the carpet or textile. These products may also provide a suitable vehicle for the introduction of UV-screening flavonoid coatings.

Example 6 Paints and coatings may also benefit from the incorporation of flavonoids. 25 Fading of pigment is a serious problem in the paint and coating industries. A similar problem exists for clear coatings which may be 23 26 4 10® applied over other paint finishes or bare wood. For exterior use prolonged UV exposure may result in degradation of the underlying finishes or materials. In some instances degradation of the clear coating also occurs.

It is envisaged that the UV screening flavonoids may be introduced into many paint stains and coatings. Many paint stains and coatings are non-aqueous and thus the introduction of a wide range of flavonoids is possible. Most paints and stains provide an excellent vehicle for the introduction of flavonoids which will generally be held in the resulting 10 coating, or in the case of stains will penetrate into, and/or remain as a surface coating/deposition, the material to which the stain has been applied.

Water base coatings are also known though should not represent great difficulty for the introduction of most flavonoids. Water miscible 15 flavonoids are known (including the glycocide derivatives). In other instances emulsions of less miscible flavonoids may exist in the composition, or the flavonoids attracted to the organic components or phase of the paint or stain composition.

Example 6a Various other dyes, inks and pigments may also include flavonoids.

These include dyes and pigments for textiles, paper, various printing processes, etc. Dyes and colourants for hair may also benefit from the inclusion of UV-screening flavonoids Example 7 A plastics material having UV screening properties may be prepared which has dispersed within it at least one flavonoid compound having at 24 264 108 least one major absorption peak in the UV region - typically in a range addressing UV degradation of the plastics material and/or protection to articles (or people) that the material is intended to screen.

Plastics materials may find a wide range of uses. For instance improved 5 packaging which protects the contents against UV radiation would be very useful. Various forms of packaging including solid or moulded materials, as well as products based on films (e.g. bags and envelopes) are likely. This may allow the use of transparent or translucent packaging without the use of excessive UV exposure for the content.

Another major area in which flavonoids introduced to plastics may find use are in the building industry. Plastic sheet materials, typically for roofing and conservatories, are relatively well known. However the existing materials provide little if any protection for persons inside the building from the sun's UV rays. Accordingly, materials suitable for use 15 in construction and which provide UV screening for occupants can be readily produced.

Example 7 Plant Extraction Procedures Flavonoid glycosides and the commonly co-occuring cinnamic acid 20 conjugates are generally stable compounds and may be extracted from dried, ground plant material with cold or hot solvents. The solvents of choice are combinations of water with methanol, ethanol or acetone (1:5 to 1:1), the required portion of water being lower (eg. 1:5) if fresh, undried plant material is extracted.

Although flavonoid aglycones are rarely encountered as internal constituents, they are frequently found on the external surfaces of leaves 264 1 08 and fronds. These flavonoids tend to be of less polar type, often methylated or acylated, and as such require less polar solvents such as ether, hexane, dichloromethane, etc., for their extraction. Simply soaking fresh plant material in such solvents for a few minutes is sufficient to 5 extract these compounds. The fats and waxes which are also dissolved may be separated by subsequent chromatography.

An example of a specific extraction technique for obtaining a flavonoid/cinnamic acid mix with potential for use as a UV screening base for sunscreens.

Fresh pollen (3g) is ground to a powder and extracted twice for 12 hours with diethyl ether (100 ml) to remove coloured carotenoids. The ether extract is removed by filtration and discarded. The ether extracted pollen is next extracted twice at room temperature with 70:30 ethanol:water (100 ml) for 15 hours and the extracts combined and taken to dryness in 15 vacuo. This procedure yielded a mix of flavonoids and cinnamic acid derivatives which had intense absorption throughout the 280-325 nm (UV-B) range. The absorption level of a solution of this material in 100 ml of methanol was 42 optical density units throughout this range. Two dimensional paper chromatographic analysis and absorption 20 spectroscopy confirmed that the UV-absorbing constituents are of the flavonoid and cinnamic acid type.

Generally, for use as an effective broad spectrum UV screen this extract would need the addition of a UV-A absorbing flavonoid such as quercetin or rutin (commercially available) which absorb strongly in the 320-370 25 nm region. 26 26 4 1 0 8 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. 27

Claims (64)

26 4 1 0 8 WHAT WF, CT.AIM IS:

1. A UV-screening composition which includes at least one flavonoid or flavonoid derivative.

2. A UV-screening composition as claimed in claim 1 in which a flavonoid is selected from the group comprising: chalcones, flavanones, flavones, flavonols, dihydroflavonols, flavanols, anthocyanins, isoflavones, and their derivatives.

3. A UV-screening composition as claimed in either claim 1 or claim 2 in which a flavonoid derivative is selected from the group comprising: flavonoid glycoside derivatives, biosynthetically related flavonoid compounds, and biosynthetically related flavonoid compounds derivable from shikimate and/or malonate pathways.

4. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of an aglycone flavonoid or flavonoid derivative.

5. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of a lipophilic flavonoid or flavonoid derivative.

6. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of a flavonoid or flavonoid derivative extracted from plants.

7. A UV-screening composition as claimed in any one of preceding ; 264 1 08

8. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of a flavonoid or flavonoid derivative derived from pollen. 9. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of a flavonoid or flavonoid derivative derived from bee propolis.

9. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of a flavonoid or flavonoid derivative derived from Gingko biloba, plants of the Pinaceae family, and/or plants of the Theaceae family.

10. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of a flavonoid or flavonoid derivative exhibiting at least one UV absorption peak in the region of 280-320nm.

11. A UV-screening composition as claimed in any one of the preceding claims which includes either or both of a flavonoid or flavonoid derivative exhibiting at least one UV absorption peak in the region of 320-400nm.

12. A UV-screening composition as claimed in any one of the preceding claims which includes at least one member of the group: baicalein, apigenin, luteolin, isoscutellarein, galangin, kaempferol, quercetin, pinocembrin, cinnamic acid, 4-hydroxy cinnamic acid, 3,4-dihydroxy cinnamic acid, 3,4,5-trihydroxy cinnamic acid, rutin, taxifolin, naringenin, or their derivatives.

13. A UV-screening composition as claimed in any one of the preceding claims which includes a pH buffer. 29 26 4 1 0 8

14. A UV-screening composition as claimed in any one of the preceding claims which includes a non-flavonoid UV absorbing compound or substance.

15. A UV-screening composition as claimed in any one of the preceding claims in the form of a skin applicable sun-screening composition.

16. A skin applicable sun-screening composition as claimed in claim 15 which is non-comodogenic.

17. A skin applicable sun-screening composition as claimed in any one of the preceding claims which includes either or both cinnamic acid or at least one cinnamic acid derivative.

18. A skin applicable sun-screening composition as claimed in any one of claims 15 through 17 which is hypo-allergenic.

19. A skin applicable sun-screening composition as claimed in any one of claims 15 through 18 which is water-resistant.

20. A skin applicable sun-screening composition as claimed in any one of claims 15 through 19 which includes a moisturising agent.

21. A skin applicable sun-screening composition as claimed in any one of claims 15 through 20 which includes a UV reflecting compound or substance.

22. A skin applicable sun-screening composition as claimed in any one of claims 15 through 21 which includes a tinting agent.

23. A skin applicable sun-screening composition as claimed in any one of /»*. •" claims 15 through 22 which includes a fragrance. ^ x •«, /*• ' ' '■ " f; ;y'V -"A ■$! i;a' 30 %/v E.V 7/ 26 4 103

24. A skin applicable sun-screening composition as claimed in any one of claims 15 through 23 which is in the form of a moisturising lotion or cream.

25. A skin applicable sun-screening composition as claimed in any one of claims 15 through 18 which is in the form of a skin toning lotion.

26. A skin applicable sun-screening composition as claimed in any one of claims 15 through 23 which is in the form of a cosmetic foundation.

27. A skin applicable sun-screening composition as claimed in any one of claims 15 through 23 which is in the form of a lip stick or cream.

28. A UV-screening composition as claimed in any one of claims 1 through 14 in the form of a hair applicable sun-screening composition.

29. A hair applicable sun-screening composition as claimed in claim 28 which is in the form of a hair shampoo and/or hair conditioner.

30. A hair applicable sun-screening composition as claimed in claim 28 which is in the form of a styling mousse, gel, creme, spray or other hair fixing agent.

31. A hair applicable sun-screening composition as claimed in claim 28 which is in the form of a hair colouring composition.

32. A UV-screening composition as claimed in any one of claims 1 through 14 in the form of a nail lacquer.

33. A UV-screening composition as claimed in any one of claims 1 through 14 in the form of a fabric coating agent. 31 # i 2*6 -4 1 0 $

34. A fabric coating agent as claimed in claim 33 in the form of a fabric cleaning agent or shampoo.

35. A fabric coating agent as claimed in claim 33 in the form of a user applicable residual protectant.

36. A fabric coating agent as claimed in claim 33 in the form of a laundry fabric conditioner.

37. A fabric coating agent as claimed in claim 33 in the form of a laundry cleansing agent.

38. A fabric coating agent as claimed in claim 33 in the form a tumble drier additive.

39. A UV-screening composition as claimed in any one of claims 1 through 14 in the form of a paint stain or coating.

40. A paint coating as claimed in claim 39 which comprises a clear finish.

41. A paint stain or coating as claimed in claim 39 which is formulated for exterior use.

42. A UV-screening composition as claimed in any one of claims 1 through 14 in the form of a paint stain or coating additive.

43. A UV-screening composition as claimed in any one of claims 1 through 14 in the form of a fade resistant ink.

44. A UV-screening composition as claimed in any one of claims 1 through 14 in the form of a dye.

45. A UV-screening composition as claimed in any one of the preceding claims which includes a non-aqueous carrier. 32 26 4 1 0 #

46. A UV-screening plastics material which includes a UV-screening composition as claimed in any one of claims 1 through 14.

47. A UV-screening plastics material as claimed in claim 46 which is transparent or translucent.

48. A UV-screening plastics material as claimed in either claim 46 or claim 47 which is in the form of a plastic film or bag.

49. A UV-screening plastics material as claimed in either claim 46 or claim 47 which is in the form of a building construction sheeting material.

50. A UV-screening composition, substantially as described herein with reference to the accompanying drawings and examples.

51. A UV-screening composition in the form of at least one of the following: a skin applicable sun screening composition, a moisturiser, a skin toner, a cosmetic foundation, a lip stick or cream, a nail lacquer, a hair applicable sun-screening composition, a hair shampoo, a hair conditioner, a hair colourant, a fabric coating or protectant, a laundry fabric conditioner, a laundry fabric cleanser, a paint stain or coating, a fade resistant ink, or a dye; substantially as described herein with reference to the accompanying drawings and examples.

52. A method for conferring UV-screening properties comprising the inclusion of at least one flavonoid or flavonoid derivative to a composition.

53. A method as claimed in claim 52 in which a flavonoid is selected from the group comprising: chalcones, flavanones, flavones, flavonols, dihydr-flavonols, flavanols, anthocyanins, and isoflavones. 33 26 4 1 0 8

54. 64. A method as claimed in either claim 52 or claim 53 in which a flavonoid derivative is selected from the group comprising: flavonoid glycoside derivatives, biosynthetically related flavonoid compounds, and biosynthetically related flavonoid compounds derivable from shikamate pathways.

55. A method as claimed in any of claims 52 through 54 which includes the use of either or both of an aglycone flavonoid or flavonoid derivative.

56. A method as claimed in any of claims 52 through 55 which includes the use of either or both of a lipophilic flavonoid or flavonoid derivative.

57. A method as claimed in any of claims 52 through 56 which includes the use of either or both of a flavonoid or flavonoid derivative extracted from at least one of the following sources: plants, plant leaves, pollen, bee propolis, or material from Gingko biloba, plants of the Pinus family, and/or plants of the Camellia family.

58. A method as claimed in any of claims 52 through 57 which includes the use of either or both of a flavonoid or flavonoid derivative exhibiting at least one UV absorption peak in the region of 280-320nm.

59. A method as claimed in any of claims 52 through 58 which includes the use of either or both of a flavonoid or flavonoid derivative exhibiting at least one UV absorption peak in the region of 320-400nm.

60. A method as claimed in any of claims 52 through 59 which includes the use of at least one member of the group: baicalein, apigenin, luteolin, isoscutellarein, galangin, kaempferol, quercetin, pinocembrin, cinnamic ' acid, 4-hydroxy cinnamic acid, 3,4-dihydroxy cinnamic acid, 3,4,5- 34 264 1 08 trihydroxy cinnamic acid, rutin, taxifolin, naringenin, or their derivatives.

61. A method as claimed in any one of claims 52 through 60 in which a said composition to which UV screening properties are conferred comprises at least one of: a skin applicable sun screening composition, a moisturiser, a skin toner, a cosmetic foundation, a lip stick or cream, a nail lacquer, a hair applicable sun-screening composition, a hair shampoo, a hair conditioner, a hair colourant, a fabric coating or protectant, a laundry fabric conditioner, a laundry fabric cleanser, a paint stain or coating, a fade resistant ink, or a dye.

62. A method of sun protection for the skin comprising the application to the skin of a composition as claimed in any one of claims 1 through 28.

63. A method of sun protection for the skin, substantially as described herein with reference to the accompanying drawings and examples.

64. A method for conferring UV-screening properties, substantially as described herein with reference to the accompanying drawings and examples. COMVTTA NEW ZEALAND LTD by its Attorneys JAMES & WELftS . r o , * ^ ^ END OF CLAIMS v 27 SEP 1995 ml 35