WO2024114951A1

WO2024114951A1 - Sunscreen composition

Info

Publication number: WO2024114951A1
Application number: PCT/EP2023/062342
Authority: WO
Inventors: Ramón CALDERÓN NÁJERA; Paola STRASSER VELASCO
Original assignee: Biowell, S.L.
Priority date: 2022-11-29
Filing date: 2023-05-10
Publication date: 2024-06-06

Abstract

The present invention is directed to a biologic composition for providing sunscreen protection. More particularly, the invention is directed to a composition comprising a green seaweed from the genus Chlorella or a composition derived thereof and a cyanobacteria from the species Arthrospira maxima or a composition derived thereof. The invention particularly relates to the field of cosmetics and/or beauty products.

Description

SUNSCREEN COMPOSITION

FIELD OF THE INVENTION

BACKGROUND ART

Although the exposure of individuals to moderate sunlight has many beneficial effects, including the synthesis of vitamin D and the killing of certain pathogens, over-exposure of human skin to sunlight and, in particular, to the ultraviolet band of the spectrum, has many deleterious effects, including sunburn, phototoxicity, photoallergic reactions, photoaging, and the promotion of skin cancers. As a result of concerns about the deleterious effects of over-exposure to sunlight, much research has been directed to the development of both topical and systemic photoprotective agents and preparations for use in cosmetics and sunscreens.

In general, topical photoprotective preparations or sunscreens can be chemical, physical, or mixed. Regarding the use of inorganic substances or physical filters, titanium dioxide and zinc oxide reflect and scatter UV radiation. Although these compounds have a wide range of UV protection, they present difficulties in the final product, as the particle size (between 10-100 nanometres) is key to providing an adequate "screen" of protection, and this same size is a limiting factor in the manufacturing processes of formulas with homogeneous dispersions. Organic compounds or chemical sunscreens have UVR-absorbing chromophore groups in their structure, and their effectiveness depends largely on their broad UVR absorption spectrum and stability to long periods of exposure; however, some UV filters are photoinstable, promoting the formation of photo-products that alter their absorbance spectrum and thus reduce their photo-protective effect. These organic filters and their photolysis products have also been found to generate contact and photo-contact dermatitis respectively. In addition to the above mentioned drawbacks, several studies have shown sufficient evidence for some organic sunscreens, used in traditional formulations, which pass through the deep layers of the skin, showing systemic absorption, with the consequent consequences of loss of efficacy (lower SPF), and possible local and systemic toxic effects. In addition, most UV filters are by design stable, non-biodegradable molecules, which can affect the growth of phytoplankton and algae, and cause damage to coral reef ecosystems, promoting viral infections leading to coral bleaching and necrosis.

Therefore, there is a need to improve the efficacy of sunscreens by new sources of photo-protective compounds that can replace or reduce the concentrations of traditionally used sunscreens.

One possible source of these compounds could be certain organisms, especially those exposed to intense radiation, which have developed adaptive mechanisms, including the production of antioxidant secondary metabolites capable of absorbing UV radiation. Thus, research on the use of natural extracts or natural compounds has increased in recent years. An advantage of many natural compounds as photoprotective agents is that, in addition to their ability to absorb UV radiation, they possess antioxidant and anti-inflammatory effects, which may open up new possibilities for the treatment and prevention of UV damage.

Algae are one of the most studies organisms by sunscreen manufacturers. Algae are a relevant source of organic substances that can support sun protection. Algae offer natural organic substances that can be included in the formulation of mineral sunscreens to supplement them with further protection factors. One of the most studied classes of compounds by sunscreen manufacturers is mycosporine-like amino acids (MAAs), which can be found in algae and bacteria.

The study of Susana C. M. Fernandez et al., ACS Applied Materials & Interfaces, 2015 described novel UV-protective materials that exclusively consist of natural compounds based on chitosan and MMAs. They found that these materials have the potential to provide an efficient protection against both types of UV radiations and overcome several shortfalls of the current UV-protective products.

The document CN110151676A discloses a sunscreen composition extracted from algae. The composition comprises a spiral seaweed extract, a coralline algae extract, a kelp seaweed extract, a Phaeodactylum Tricornutum extract and a Porphyra extract.

The document ES2317741A1 describes a composition for solar protection based on extracts of algae and lichens. This document describes the potential use as antioxidant substances of MAAs, specifically of porphyra-334 isolated from the red algae Porphyra Leucosticta and of mycosporine-gly isolated from the lichen Lichina Pygmaea. Other studies have focused on cyanobacterial metabolites as a possible source of sunscreens. For example, the work of Peyman Derikvand et al., European Journal of Phycology, 2016 studies the potential of different cyanobacterial metabolites as sunscreens. In this study they analyse the potential of MAAs and scytonemin and they conclude that both compounds offer biotechnological opportunities for exploitation by the cosmetics industry.

However, despite the fact that research related to the use of natural compounds in sunscreens is greatly increasing, the number of synthetic sunscreens is still much higher than those containing compounds derived from algae and bacteria. In addition, most "natural" or "organic" sunscreens available on the market also contain chemical or physical sunscreen agents.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a biologic sunscreen composition with a high sun protection factor (SPF) without the need for using chemical sunscreen agents or physical sunscreen agents.

The authors of the present invention have developed a novel sunscreen composition comprising natural compounds that can be founded in algae and bacteria. In particular, they have developed a novel sunscreen composition comprising a green seaweed from the genus Chlorella or a composition derived thereof and a cyanobacteria from the species Arthrospira maxima or a composition derived thereof.

Thus, in a first aspect the present invention relates to a sunscreen composition (hereinafter the sunscreen composition of the invention) comprising:

(i) a green seaweed from the genus Chlorella or a composition derived thereof, and

(ii) a cyanobacteria from the species Arthrospira maxima or a composition derived thereof.

In a second aspect the present invention relates to a method for protecting skin and /or hair from the solar or ultraviolet radiation comprising the step of contacting the skin and/ or the hair with an effective amount of the sunscreen composition of the invention.

In a third aspect, the present invention relates to a packaged product comprising a container, the sunscreen composition of the invention within said container, and instructions for topical application of said composition to provide photoprotection. DETAILED DESCRIPTION OF THE INVENTION

The authors of the present invention have discovered that the combination of some natural compounds that can be founded in algae and bacteria, provides compositions having excellent UV-A and UV-B absorbance capability. In particular, they have found an unexpected, advantageous effect of a composition comprising a green seaweed from the genus Chlorella or a composition derived thereof and a cyanobacteria from the species Arthrospira maxima or a composition derived thereof, which maintains its activity for long time on exposure to sunlight and can reach a sun protection factor (SPF) of between 15 and 50. Moreover, the sunscreen composition developed by the inventors is particularly advantageous in that it has antioxidant activity and consists exclusively of biodegradable components and, thereof, is environmentally friendly and has no toxic effect on corals, fish, algae or marine mammals.

Thus, in a first aspect, the invention relates to a sunscreen composition, hereinafter the sunscreen composition of the invention, comprising:

The term "a sunscreen composition" as used herein, is meant to include a composition for topically application to sun-exposed areas of the skin and/or hair of mammals, especially humans. The term "skin" as used herein, is meant to include skin on the face and body (e.g., neck, chest, back, arms, underarms, hands, legs, buttocks and scalp) and especially to the sun exposed parts thereof. The composition of the invention is also of relevance to applications on any other keratinous substrates of the human body other than skin e.g. hair where products may be formulated with specific aim of providing photoprotection.

The first component (i) of the composition of the invention is a green seaweed from the genus Chlorella or a composition derived thereof.

In a particular embodiment, the composition derived from the green seaweed from the genus Chlorella is a homogenised green seaweed. The term “homogenised green seaweed” refers to a green seaweed from the genus Chlorella which has undergone a process of homogenisation, in which the various substances and components of the green seaweed are combined to produce a uniformly consistent mixture. In another particular embodiment, the composition derived from the green seaweed from the genus Chlorella is a lysate. The term “lysate” as used herein, refers to a material obtained by cell lysis of the cells of the green seaweed from the genus Chlorella, thus causing the release of the intracellular biological constituents naturally contained in said cells. The lysate used is formed by all or part of the intracellular biological constituents and constituents of the cell walls and membranes. Methods for preparation of the lysate are, but not limited, cavitation, mechanical lysis, chemical lysis, enzymatic lysis, detergent lysis, osmotic lysis, ultrasonic lysis, freeze-thaw lysis, electric lysis, microfluidic lysis and laser lysis.

In another particular embodiment, the composition derived from the green seaweed from the genus Chlorella comprises a pigment or a combination of pigments. The term “pigments” refers to the substances or molecules that produce a variety of colours in the plant world. In a more particular embodiment, the composition derived from the green seaweed from the genus Chlorella comprises phycocyanin, chlorophyll or a combination of phycocyanin and chlorophyll.

Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein family, along with allophycocyanin and phycoerythrin. Phycocyanins are found in some organisms such as cyanobacteria or seaweeds.

Chlorophyll is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Several chlorophylls are known. All are defined as derivatives of the parent chlorin by the presence of a fifth, ketone-containing ring beyond the four pyrrole-like rings. Based on their structure, 6 groups of chlorophylls are known: chlorophyll a, b, c1 , c2, d and f. The most widely distributed form in terrestrial plants is chlorophyll a. The only difference between chlorophyll a and chlorophyll b is that the former has a methyl group where the latter has a formyl group.

In a particular embodiment, the chlorophyll of the composition derived from the green seaweed from the genus Chlorella is selected from chlorophyll a, b, f or a combination thereof, preferably is a combination of chlorophyll a, b and f.

The green algae or green seaweeds are a group consisting of the Prasinodermophyta. Green algae have chloroplasts that contain chlorophyll a and b, giving them a bright green colour, as well as the accessory pigments beta carotene (red-orange) and xanthophylls (yellow) in stacked thylakoids. Chlorella is a genus of unicellular green algae in the phylum Chlorophyta. Chlorella genus includes, but is not limited to the species Chlorella autotrophica, Chlorella minutissima, Chlorella pyrenoidosa, Chlorella sorokiniana, Chlorella variabilis and Chlorella vulgaris.

The second component (ii) of the composition of the invention is a cyanobacteria from the species Arthrospira maxima or a composition derived thereof.

Cyanobacteria, also known as Cyanophyta, are a phylum of Gram-negative bacteria that obtain energy via photosynthesis. Arthrospira is a genus of cyanobacteria in the family Microcoleaceae.

In a particular embodiment, the composition derived from the cyanobacteria from the species Arthrospira maxima is a homogenised cyanobacteria. As used herein, the term “homogenised cyanobacteria” refers to a cyanobacteria from the species Arthrospira maxima which has undergone a process of homogenisation, in which the various substances and components of the cyanobacteria are combined to produce a uniformly consistent mixture.

In another particular embodiment, the composition derived from the cyanobacteria from the species Arthrospira maxima is a lysate. The term “lysate”, as used herein, refers to a material obtained by cell lysis of the cells of the cyanobacteria from the species Arthrospira maxima, thus causing the release of the intracellular biological constituents naturally contained in said cells. The lysate used is formed by all or part of the intracellular biological constituents and constituents of the cell walls and membranes.

In another particular embodiment, the composition derived from the cyanobacteria from the species Arthrospira maxima comprises a pigment or a combination of pigments. In a more particular embodiment, the composition derived from the cyanobacteria from the species Arthrospira maxima comprises phycocyanin, chlorophyll or a combination thereof.

The terms “phycocyanin” and “chlorophyll” have been defined or explained above, and these definitions are applicable to the composition derived from the cyanobacteria from the species Arthrospira maxima.

In a more particular embodiment, the chlorophyll of the composition derived from the cyanobacteria from the species Arthrospira maxima is selected from chlorophyll a, b, f or a combination thereof, preferably is a combination of chlorophyll a, b and f. In the sunscreen composition of the invention the green seaweed from the genus Chlorella or the composition derived thereof and the cyanobacteria from the species Arthrospira maxima or the composition derived thereof can be in different concentrations. Thus, in a particular embodiment, the sunscreen composition of the invention comprises a green seaweed from the genus Chlorella or a composition derived thereof in an amount from 70-97% and a cyanobacteria from the species Arthrospira maxima or a composition derived thereof in an amount from 3-30%.

In a more particular embodiment, the sunscreen composition of the invention is selected from:

(i) a composition comprising 70-80% green seaweed from the genus Chlorella or a composition derived thereof and 16-30% cyanobacteria from the species Arthrospira maxima or a composition derived thereof,

(ii) a composition comprising 80-90% green seaweed from the genus Chlorella or a composition derived thereof and 15-20% cyanobacteria from the species Arthrospira maxima or a composition derived thereof, and

(iii) a composition comprising 70-97% green seaweed from the genus Chlorella or a composition derived thereof and 3-30% cyanobacteria from the species Arthrospira maxima or a composition derived thereof.

The percentages of the green seaweed from the genus Chlorella or the composition derived thereof and the cyanobacteria from the species Arthrospira maxima or the composition derived thereof refer to the percentage of these compounds with respect to the total sunscreen composition.

As explained above, one of the major problems existing in the state of the art is that most sunscreens comprise other photoprotective compounds as physical or chemical sunscreen agents. These compounds can pass through the deep layers of the skin, showing systemic absorption, with the consequent consequences of loss of efficacy (lower SPF), and possible local and systemic toxic effects. One of the objectives of the present invention is to provide a sunscreen composition without the need for using chemical sunscreen agents or physical sunscreen agents.

Thus, in a particular embodiment, the sunscreen composition of the invention does not comprise other photoprotective compounds. The term “photoprotective compounds” as used herein refers to compounds intended for photoprotecting the skin and/or hair against the near visible-ultraviolet radiation. The term “photoprotection” will be defined later.

Most sunscreens available on the market today contain either physical sunscreen agents or chemical sunscreens agents. The sunscreen composition of the present invention does not comprise chemical or physical sunscreen agents.

Thus, in a particular embodiment, the sunscreen composition of the invention does not comprise chemical sunscreen agents.

The “chemical solar filters” or “chemical solar agents” correspond with compounds of organic nature which absorb in a determined range of wavelengths. It is well known that said chemical filters are classified as UVA filters and UVB filters. UVA filters mainly absorb radiation in the region between 320 and 400 nm of the spectrum. UVA filters are for example: benzophenones, camphor derivatives, dibenzoylmethane derivatives, anthranilates, bisimidazylate. UVB filters mainly absorb radiation in the region between 280 and 320 nm of the ultraviolet spectrum. UVB filters are for example: 1,3,5-triazines, cinnamates, p-aminobenzoic acid (PABA) and derivatives thereof, salicylates, camphor derivatives, benzimidazole and derivatives thereof, octocrilene and urocanic acid. There are also near visible radiation chemical solar filters and chemical solar filters capable of absorbing UVA and UVB radiation, such as for example: anisotriazine, drometrizole trisiloxane, methylene bisbenzotriazolyl tetramethylbutylphenol.

In another particular embodiment, the sunscreen composition of the invention does not comprise physical sunscreen agents.

The “physical solar filters” or “physical solar agents” correspond to photoprotective agents such as metal oxide pigments or nanopigments capable of physically blocking both type A and type B UV radiation as well as near visible radiation by diffusion and/or reflection. Examples of physical solar filters are zinc oxide, titanium oxide, talc, iron oxide and mica. These physical solar filters have been used in state of the art in different suspensions and particle sizes.

The sunscreen composition of the present invention can comprise a wide range of other optional components. The CTFA Cosmetic Ingredient Handbook, Sixteen Edition (2016), describes a wide variety of non-limiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the sunscreen composition of the present invention. Examples include: healing agents, anti-aging agents, anti-wrinkle agents, moisturizers, antibacterial agents, pesticides, antifongic agents, anti-inflammatory drugs, antiviral agents, anti-acne agents, the agents modulating the differentiation, proliferation or pigmentation of the skin and agents accelerating penetration, cleaning agents, hair conditioning agents, skin conditioning agents, hair styling agents, hair growth promoters, fragrances, pigments, film formers, hair colours, make-up agents, detergents, thickening agents, emulsifiers, humectants, emollients, antiseptic agents, deodorant actives, dermatologically acceptable carriers, surfactants, abrasives, absorbents, aesthetic components such as fragrances, colourings/colorants, essential oils, skin sensates, astringents, etc. (e.g., clove oil, menthol, camphor, eucalyptus oil, eugenol, menthyl lactate, witch hazel distillate), anti-caking agents, antifoaming agents, antimicrobial agents (e.g., iodopropyl butylcarbamate), antioxidants, binders, biological additives, enzymes, enzymatic inhibitors, enzyme-inducing agents, coenzymes, plant extracts, ceramides, peptides, buffering agents, bulking agents, chelating agents, cosmetic astringents, cosmetic biocides, denaturants, drug astringents, external analgesics, film formers or materials, e.g., polymers, for aiding the film- forming properties and substantivity of the composition (e.g., copolymer of eicosene and vinyl pyrrolidone), quaternary derivatives, agents increasing the substantivity, opacifying agents, pH adjusters, propellants, reducing agents, skin bleaching and lightening agents (e.g., hydroquinone, kojic acid, ascorbic acid, magnesium ascorbyl phosphate, ascorbyl glucosamine), skinconditioning agents (e.g., humectants, including miscellaneous and occlusive), skin soothing and/or healing agents and derivatives (e.g., panthenol and derivatives (e.g., ethyl panthenol), aloe vera, pantothenic acid and its derivatives, allantoin, bisabolol, and dipotassium glycyrrhizinate), skin treating agents, thickeners, serums, tonics, antistains, occlusive and emollient products and vitamins and derivatives thereof, and lignans.

In a particular embodiment, the sunscreen composition of the invention comprises cosmetically acceptable carriers.

The term "cosmetically acceptable" means compatible with the skin and/or integuments thereof, having a pleasant colour, odour and texture and not giving rise to unacceptable discomfort (tingling, tightness, redness), liable to dissuade the consumer from using the composition.

The “carrier” or “vehicle” which forms part of the sunscreen composition of the invention can be one or more substances which are physiologically compatible with the sunscreen and does not normally cause an allergy reaction or a similar adverse reaction in the skin and/or hair, when it is administered into animals, more particularly into human beings. The selection of these ingredients is a routine task for the person skilled in the art depending on the type of product in which the composition is formulated. The carrier can act as a diluent or dispersant for the other ingredients of the composition, and is therefore intended to ensure that they can be readily applied to and distributed evenly over the skin and /or hair at an appropriate concentration.

Cosmetically acceptable carriers or vehicles suitable for use in this invention may include mineral oils, silicone oils, synthetic or natural esters, and alcohols. The appropriate amount of carrier can readily be determined by those skilled in the art according to the SPF desired.

In another particular embodiment, the sunscreen composition of the invention can comprises other components such as water, waterproofing agents, preservatives, binders and liquids such as humectants and thickeners.

The sunscreen composition of the invention can comprise waterproofing agents such as polymers and copolymers based on PVP and acrylic or methacrylic esters.

Preservatives can be incorporated into the sunscreen composition of the invention to protect against the growth of potentially harmful microorganism. Suitable traditional preservatives can be used, for example, alkyl esters of para-hydroxybenzoic acid. Other preservatives which have more recently come into use include hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds.

The term “humectants” as used herein refers to chemical substances that moisturises and softens the skin. Humectants are surface-active substances; this means that they work by dissolving in water causing a lower contact angle between a substance and a hydrophobic surface. The surfactant adsorbs to the grease and solid surface, promoting the migration of water particles. In another particular embodiment, the sunscreen composition of the invention can comprises a humectant such as glycerine, propylene glycol, sorbitol, hyaluronic acid, vitamin E or butylene glycol. Other natural humectants that can be used in the sunscreen composition of the invention are shea butter, honey or Phytessence Wakame (a Japanese alga).

Thickening agents are substances which, when added to a mixture, increase its viscosity and improve its texture. As known to those skilled in the art, the precise amount of thickeners can vary depending upon the consistency and thickness of the composition which is desired. In another particular embodiment, the sunscreen composition of the invention can comprise a thickening agent such as xanthan gum, sodium carboxymethyl cellulose, hydroxyalkyl and alkyl celluloses, and cross-linked acrylic acid polymers.

The sunscreen composition of the invention can comprise another components, such as antioxidants, antimicrobial agents, vitamins or pH adjusters.

Thus, in another particular embodiment, the sunscreen composition of the invention comprise an antioxidant selected from the group consisting of beta glucan, curcumin, carnosine, polyphenolics, superoxide dismutase (SOD), catalase, glutathione peroxidase, oligomeric proanthocyanidins, bioflavonoids, oligomeric procyanidolic complexes, leuco anthocyanin, anthocyanidin, alpha-lipoic acid, coenzyme Q-l 0, selenium, vitamin E, vitamin C, lycopene, tocotrienols, or glutathione.

In another particular embodiment, the sunscreen composition of the invention comprises an antimicrobial agent selected from the group consisting of triclosan, povidone, iodine, proflavine, honey, hydrogen peroxide, clotrimazole, parabens, phenoxyethanol, diazolidinyl urea, chlorphenesin or sulphur.

In another particular embodiment, the sunscreen composition of the invention comprises vitamins wherein the said vitamin is selected from the group consisting of vitamin A, B1 , B2, B3, B5, B6, B7, B9, B12, C, Ester-C, D, E, F, or K, or any combination of any of the foregoing.

In another particular embodiment, the sunscreen composition of the invention comprises pH adjusters such as amino acids, sodium bicarbonate, distilled water, aminomethyl propanol, aminomethylpropane diol, triethanolamine, triethylamine, citric acid, sodium hydroxide, acetic acid, potassium hydroxide, lactic acid, and any combination of any of the foregoing.

In another particular embodiment, the sunscreen composition of the invention comprise other minor adjunct ingredients that can include fragrances, opacifiers and colorants, each in their effective amounts to accomplish their respective functions.

In another particular embodiment, the sunscreen composition of the invention may additionally comprise a skin lightening agent. The skin lightening agent is preferably chosen from a vitamin B3 compound or its derivative e.g. niacin, nicotinic acid, niacinamide or other well-known skin lightening agents e.g. aloe extract, ammonium lactate, azelaic acid, kojic acid, citrate esters, ellagic acid, glycolic acid, green tea extract, hydroquinone, lemon extract, linoleic acid, magnesium ascorbyl phosphate, vitamins like vitamin B6, vitamin B12, vitamin C, vitamin A, a dicarboxylic acid, resorcinol derivatives, hydroxycarboxylic acid like lactic acid and their salts e.g. sodium lactate, and mixtures thereof.

The effectiveness of a composition as a photoprotectant may be evaluated by several different criteria. Among these are the following:

(1) Determination of the absorption spectrum of the composition. If the absorption spectrum of a composition shows specific absorption in the ultraviolet band from 290- 400 nm, and particularly with peak absorption at 290-320 nm, the composition may be considered as a photoprotectant against sunburn reaction (which is usually caused by 290-320 nm solar radiation).

(2) Determination of the minimum dose of solar radiation needed to induce immediate pigment darkening with and without application/administration of the composition. The immediate pigment darkening (IPD) reaction can be induced by long wave ultraviolet radiation (320-400 nm). The reaction, which is most noticeable in light brown or tanned skin, is a transient darkening of the skin that becomes apparent upon termination of UVA exposure. It results from an oxidation reaction of pre-existing melanin in the skin. The IPD reaction can be inhibited by antioxidants or, because the reaction requires oxygen, by depriving the skin of oxygen. The minimum dose of UVA radiation that produces a visible darkening of the skin can be determined by exposing the skin to graded doses of UVA radiation ranging from 0.5 to 10 J/cm². The lowest dose of UVA radiation that produces visible darkening of the skin immediately after irradiation is scored as the minimum dose for IPD.

(3) Determination of the minimal erythematic dose with and without application/administration of the composition. The minimal erythematic dose (MED) is defined as the minimal dose of ultraviolet radiation of 290-320 nm that produces perceptible sunburn reaction in human skin with detectable boundaries at 20-24 hours after exposure. The MED may be determined by exposing the skin to graded doses of UVB radiation. The MED ranges from approximately 20 to 80 mJ/cm² of UVB radiation for fair-skinned individuals and from approximately 70-120 mJ/cm² in brown or darkly pigmented persons. It should be noted that MED values vary with the wavelengths of the ultraviolet spectrum. Shorter wavelength (290-320 nm) radiation is 500 to 1000 times more erythematic than longer wavelength (320-400 nm). Therefore, MEDs for longer wavelength radiation are higher (e.g., 20 to 50 J/cm²).

(4) Determination of the minimal melanogenic dose with and without application/administration of the composition. The minimal melanogenic dose (MMD) is defined as the minimal dose of ultraviolet radiation (UVB or UVA) that produces persistent or lasting pigmentation of the skin that is visible 72 to 120 hrs after exposure and does not fade soon thereafter. If the skin is examined microscopically, the pigment cells show increased population density (melanocytes per cm²), increased dendritic processes, and increased levels of melanin pigmentation. The MMD may be determined by exposing the skin to graded doses of ultraviolet radiation (290-400 nm) and noting the lowest dose that induces persistent pigmentation.

(5) Determination of the minimal phototoxic dose with and without application/administration of the composition. In the determination of MED, it is known that shorter wavelength (290-320 nm) radiation is more erythemogenic than longer wavelength (320-400 nm) radiation. However, in the presence of a photoreactive chemical or drug (e.g., 8-methoxypsoralen, 5-methoxypsoralen), the longer wave UVA radiation can become much more erythemogenic. This is due to a phototoxic reaction in which the skin shows redness (erythema) at a much reduced dose of UVA radiation. The minimal dose of UVA radiation required to produce phototoxic reaction after application/administration of a photoreactive chemical or drug is defined as the minimal phototoxic dose (MPD). The MPD may be determined by topically applying or orally administering a photoreactive chemical or drug prior to exposing the skin to graded doses of UVA radiation and noting the lowest dose that induces a phototoxic reaction 48 to 72 hours after exposure.

The term "photoprotection", as used herein, means (1) the inhibition or retardation of erythema or sunburn reaction and tissue damage to skin and/or (2) the inhibition or retardation of the immediate pigment darkening reaction and/or (3) the inhibition or retardation of the delayed erythema or MMD reaction and/or (4) the inhibition or retardation of sun damage reaction. A compound providing such photoprotection is said to be "photoprotective" and may be referred to as a "photoprotectant."

For commercial products, the effectiveness of a photoprotective composition is usually expressed as its "sun protection factor" (SPF). The SPF indicates how long a person can stay in the sun with protected skin compared to unprotected skin until the appearance of erythema, and is defined in terms of the MED of protected and unprotected skin according to the following equation:

MED of sunscreen protected skin SPF= - - -

MED of untreated control skin

As an expert may know there are several systems for the determination of SPF. The methodology varies between them, and it is possible that different SPF values can be obtained for the same product, depending on the method used. The authors of the present invention have used the ISO 24444:2019 method to calculate the SPF of the sunscreen composition of the invention.

The SPF allows a classification according to the level of photoprotection. A sunscreen composition has a low level of photoprotection when its SPF is below 15, has a medium level of photoprotection when its SPF is between 15 and 29, has a high level of photoprotection when its SPF is between 30 and 49 and has a very high level of photoprotection when its SPF is over 50.

In a particular embodiment, the sunscreen composition of the invention provides a sun protection factor (SPF) of at least 10.

In a more particular embodiment, the sunscreen composition of the invention provides a sun protection factor of at least 15, i.e. the sunscreen composition of the invention provides a medium level of photoprotection.

In another particular embodiment, the sunscreen composition of the invention provides a sun protection factor of at least 30, i.e. the sunscreen composition of the invention provides a high level of photoprotection.

In another particular embodiment, the sunscreen composition of the invention provides a sun protection factor of 50, i.e. the sunscreen composition of the invention provides a very high level of photoprotection.

Depending on the percentages in which the components of the sunscreen composition, i.e. the green seaweed from the genus Chlorella or a composition derived thereof and cyanobacteria from the species Arthrospira maxima or a composition derived thereof, are present, the sunscreen composition of the invention has a medium, high or very high level of photoprotection. Furthermore, depending on the purity of the components, the composition can achieve protection factors of over 50. Thus, in a particular embodiment, the sunscreen composition of the invention comprising 70-80% green seaweed from the genus Chlorella or a composition derived thereof and 16-30% cyanobacteria from the species Arthrospira maxima or a composition derived thereof provides a medium level of photoprotection, with a SPF of 15.

In another particular embodiment, the sunscreen composition of the invention comprising 80-90% green seaweed from the genus Chlorella or a composition derived thereof and 15-20% cyanobacteria from the species Arthrospira maxima or a composition derived thereof provides a high level of photoprotection, with a SPF of 30.

In another particular embodiment, the sunscreen composition of the invention comprising 70-97% green seaweed from the genus Chlorella or a composition derived thereof and 3-30% cyanobacteria from the species Arthrospira maxima or a composition derived thereof provides a very high level of photoprotection, with a SPF of 50.

As defined above, the term "a sunscreen composition" as used herein, is meant to include a composition for topical application to sun-exposed areas of the skin and/or hair of mammals, especially humans.

Thus, in another particular embodiment, the composition is for topical application to human skin and/or hair. Skin include skin on the face and body (e.g., neck, chest, back, arms, underarms, hands, legs, buttocks and scalp) and especially to the sun exposed parts thereof. The sunscreen composition of the invention can be applicate to other keratinous parts of the body, for example, to the hair.

It is known that light radiation with wavelengths of between 280 nm and 400 nm makes possible browning of the human epidermis and that rays with wavelengths of between 280 nm and 320 nm, known under the name of IIV-B radiation, result in erythemas and cutaneous burns which can be harmful to the development of natural tanning.

It is also known that IIV-A rays with wavelengths of between 320 and 400 nm, which result in browning of the skin, are capable of bringing about a detrimental change in the latter, in particular in the case of sensitive skin or of skin continually exposed to solar radiation. IIV-A rays are more penetrating than IIV-B rays and result in particular in a loss of elasticity of the skin and the appearance of wrinkles, leading to premature aging. They promote the triggering of the erythemal reaction or enhance this reaction in some subjects and can even be the cause of phototoxic or photoallergic reactions. As an expert may know, solar or ultraviolet radiation have some beneficial effects, mainly in the production of vitamin D. However, an excessive exposure to the solar radiation have many deleterious effects, such as erythema, severe sunburns, sun- induced premature aging of the skin, regulation of biochemical deterioration caused by free radicals, photocarcinogenesis, melanoma or non-melanoma skin cancer.

In a particular embodiment, the sunscreen composition of the invention is used in a method for protecting human skin and/or hair against the deleterious effects of solar or ultraviolet radiation.

The sunscreen composition of the invention is applicable both on healthy subjects in order to prevent the damaging effects produced by solar radiation or other radiation of a natural or artificial origin, as well as on subjects affected by any of those effects in order to minimize them.

The sunscreen composition of the invention can be applied to the skin and/or hair in different ways and can therefore be present in different forms.

Thus, in a particular embodiment, the sunscreen composition of the invention which protects the skin against ultraviolet rays, is in the form of a lotion, a suspension, a dispersion, an emulsion, a gel, a cream-gel, an ointment, a solid tube, an aerosol mousse or a spray.

In another particular embodiment, the sunscreen composition of the invention which protects the hair against ultraviolet rays, is in the form of a shampoo, a lotion, a gel, a rinse-out composition, a styling or treating lotion or gel, a blow-drying or hairsetting lotion or gel, a permanent-waving, straightening, dyeing or bleaching composition for the hair or a hair lacquer.

In another aspect, the present invention relates to a method (hereinafter the method of the invention) for protecting skin and /or hair from the solar or ultraviolet radiation comprising the step of contacting the skin and/ or the hair with an effective amount of the sunscreen composition of the invention.

The term "effective amount" means any amount of the sunscreen composition of the invention which, when administered to a subject, is sufficient to produce the desired effect. The effective amount may vary depending on, for example, the mode and timing of administration. By “contacting” or "administering" or "application" it is meant that the sunscreen composition of the invention is delivered to the subject in such a way that it can achieve the desired purpose. The sunscreen composition of the present invention can be administered to any suitable subject including animals, humans, and other organisms. In the context of animals, the compositions of the present invention can also be used for veterinary administration to any suitable animal subject such as, for example, cats, dogs, or horses.

As an expert may know, the frequency with which the skin and/or hair has to be in contact with the sunscreen composition of the invention will depend on whether or not the subject is continuously exposed to solar radiation and the time of exposure. In addition, this frequency will depend on the level of photoprotection of the sunscreen composition. For example, when the sunscreen composition of the invention has a medium level of photoprotection (i.e. an SPF of 15), it has to be applied to the skin and/or hair with a higher frequency than when the sunscreen composition of the invention has a very high level of photoprotection (i.e. an SPF of 50).

In a particular embodiment, the skin and/or hair contact to the sunscreen composition of the invention is done before the subject is exposed to the solar radiation. In a more particular embodiment, is done between 30 minutes and 1 hour before the subject is exposed to the solar radiation.

In another particular embodiment, the skin and/or hair contact to the sunscreen composition of the invention is done when the subject is continuously exposed to the solar radiation. The frequency with which the skin and/or hair has to be in contact with the sunscreen composition of the invention will depend on the level of the photoprotection of the sunscreen composition.

Thus, in a particular embodiment, when the subject is exposed to solar radiation, the skin and/or hair contact to the sunscreen composition with a medium level of photoprotection (i.e. and SPF of 15) is performed every 3-4 hours.

In another particular embodiment, when the subject is exposed to solar radiation, the skin and/or hair contact to the sunscreen composition with a high level of photoprotection (i.e. an SPF of 30) is performed every 5-6 hours.

In another particular embodiment, when the subject is exposed to solar radiation, the skin and/or hair contact to the sunscreen composition with a very high level of photoprotection (i.e. an SPF of 50) is performed every 7-8 hours. In another particular embodiment, the skin and/or hair contact to the sunscreen composition of the invention is done after the subject has been exposed to the solar radiation.

In some embodiments, for best results, the skin and/or hair contact to the sunscreen composition of the invention is every day.

As an expert may know, a wide variety of packaging can be employed to store and deliver the sunscreen composition of this invention. Packaging is often dependent upon the type of personal care end-use.

Thus, in another aspect, the invention relates to a packaged product comprising a container, the sunscreen composition of the invention within said container, and instructions for topical application of said composition to provide photoprotection.

The container for the sunscreen composition of the invention can be a plastic container with an opening at a dispensing end covered by a closure, when the sunscreen composition of the invention is in the form of a cream, lotion, shampoo, conditioner and shower gel. Typical closures are screw-caps, non-aerosol pumps and flip-top hinged lids. Alternatively these types of cosmetic products may be delivered in a stick composition formulation in a container with propel-repel mechanism where the stick moves on a platform towards a dispensing orifice. Metallic cans pressurized by a propellant and having a spray nozzle serve as packaging for the sunscreen composition of the invention when it is in the form of a spray or an aerosol mousse.

The packaged product also includes instructions for topical application of the sunscreen composition of the invention. These instructions may be present in the above-mentioned packaged product in a variety of ways. One form in which these instructions may be present is as printed information on a suitable medium or substrate, e.g., a sheet or sheets of paper on which the information is printed. Another medium that may be present is a website address that can be used via the Internet to access information at a remote site. Any convenient means may be present in the packaged product.

EXAMPLES

1. of the com

Composition: a green seaweed from the genus Chlorella, and a cyanobacteria from the species Arthrospira maxima.

The components were mixed in 6-hour cycles with rest, minimum 4 hours, and maximum 10 hours per cycle.

2. Sunscreen performance test

The most important parameter of efficacy for sunscreen products is the sun protection factor (SPF). The SPF gives a measure of how much longer a subject can stay in the sun until a sunburn occurs when the subject is protected with the sunscreen related to an unprotected stay in the sun.

The authors of the present invention have done a study to determine in vivo the sun protection factor (SPF) UVB of the sunscreen products according to the ISO 24444: 2019. In addition, they have done a study to determine in vitro the SPF UVA of the sunscreens products according to the ISO 24443:2012. This methods establish the degree of sun protection by calculating the minimum dose that produces redness, erythema, in protected skin compared to skin that is not protected by a photo protector.

In vivo study

65 volunteer subjects (all women) were recruited according to the inclusion and exclusion criteria specified in ISO 24444:2019. The mean age in the study was 49.6 with a standard deviation of 15. The minimum age was 41 and the maximum age was 59. They included 30 subjects with phototype II and 35 subjects with phototype III. Type II (scores 7-13) phototype refers to subjects that usually burns, tans minimally (light coloured but darker than fair). Type III (scores 14-20) phototype refer to subject that sometimes mild burn, tans uniformly (golden honey or olive).

The authors of the present invention have tested 2 bioactive compounds, chlorophyll from a green seaweed from the genus Chlorella, and phycocyanin from a cyanobacteria from the species Arthrospira maxima. The inventors have tested compositions with different percentages of the 2 bioactive compounds. They have tested (i) a composition comprising 70-80% of chlorophyll and 16-30% of phycocyanin in 20 subjects (10 with phototype II and 10 with phototype III), (ii) a composition comprising 80-90% of chlorophyll and 15-20% of phycocyanin in 20 subjects (10 with phototype II and 10 with phototype III) and (iii) a composition comprising 70-97% of chlorophyll and 3-30% in 25 subjects (10 with phototype II and 15 with phototype III). An amount of 2.0 mg/cm² (± 0.05 mg/cm²) test product was applied to the test areas (back and arm). A method of weighing by loss was done.

All products were shaken before weighing, to ensure uniform dispersion. The application was performed by a technician with a naked finger. After application was completed, and before commencement of the UV exposure doses, the application was checked with an ultraviolet-A lamp, that was capable to visualize the uniformity of the application.

Visual evaluation of the minimal erythemal dose (MED) was performed 16 to 24 hours after the irradiation.

MED evaluation was performed according to ISO 24444:2019.

The analysis of data was performed according to ISO 24444:2019.

Test data were deemed invalid and were rejected under the circumstances given in the ISO 24444: 2019.

Table 1. Summary of SPF Test Results

The authors of the present invention have demonstrated that a SPF of at least 50 (type of sun protection: very high) can be labelled with the sunscreen composition of the invention. In particular, with a sunscreen composition comprising 70-97% of chlorophyll from a green algae from the genus Chlorella and 3-30% of phycocyanin from a cyanobacteria from the species Arthrospira maxima.

The authors of the present invention have demonstrated that with different concentrations chlorophyll (from Chlorella) and phycocyanin (from Arthrospira maxima) they can obtain different sunscreen compositions with different SPF (a medium or a high type of sun protection).

The mean protection factor in the SPF 15 group was 15.7 with a standard deviation of 0.2. The mean protection factor in the SPF 30 group was 30.5 with a standard deviation of 0.2 and the mean protection factor in the SPF 50 group was 51 with a standard deviation of 0.2.

In vitro study

ISO 24443:2012 specifies an in vitro procedure to characterize the UVA protection of sunscreen products. Specifications are given to enable determination of the spectral absorbance characteristics of UVA protection in a reproducible manner. It consists of evaluating UV transmission on a rough surface that has been previously coated with sunscreen.

The authors of the present invention tested the composition comprising chlorophyll from a green seaweed from the genus Chlorella, and phycocyanin from a cyanobacteria from the species Arthrospira maxima. The inventors have tested compositions with different percentages of the 2 bioactive compounds. They have tested (i) a composition comprising 70-80% of chlorophyll and 16-30% of phycocyanin (ii) a composition comprising 80-90% of chlorophyll and 15-20% of and (iii) a composition comprising 70-97% of chlorophyll and 3-30%.

A film of sunscreen is applied onto PMMA plates which imitates skin roughness. Drying is completed. The UV Spectrum is measured. Then the plates are subjected to UV light equivalent to the expected in use performance of the sunscreen. The UV Spectrum is then re-measured. The UVAPF, as well as the Critical Wavelength are determined and both broad spectrum and UVA ratio calculated from that data.

Transmittance of a dried down film is measured between 290 nm and 400 nm. Requirements can be extrapolated by conversion of the ratios determined. Challenge of the sample film is required by pre irradiation with a compliant light source which designed to imitate sunlight. The spectral curve is measured, using a purpose built spectrophotometer which has been fitted with an integrating sphere device. The substrate for measurement is moulded Polymethylmethacrylate (PMMA) Plates. A thin film of the test product, at a thickness of 1.3 mg/sq cm, is applied, by a standard application technique. This involves applying a series of around 30 dots over the area of the plate and then rubbing out evenly with the finger which has been preimpregnated to saturation with the same product. The dose of UV light for preirradiation is calculated in order to arrive at the required dose appropriate to the expected UVAPF performance of the product. Measurements are taken against a matching blank glycerine loaded PM MA plate, at increments of 1 nm between the range of 290 and 400 nm. Calculations are completed by input of the data onto the standard ISO spreadsheet.

Claims

CLAIMS A sunscreen composition comprising:

(i) a green seaweed from the genus Chlorella or a composition derived thereof and

(ii) a cyanobacteria from the species Arthrospira maxima or a composition derived thereof. The sunscreen composition according to claim 1, wherein the composition derived from the green seaweed from the genus Chlorella is a homogenised green seaweed or a lysate, or wherein the composition comprises a pigment or a combination of pigments. The sunscreen composition according to claim 2, wherein the composition derived from the green seaweed from the genus Chlorella comprises a phycocyanin, a chlorophyll or a combination thereof. The sunscreen composition according to claim 1, wherein the composition derived from the cyanobacteria from the species Arthrospira maxima is a homogenised cyanobacteria or a lysate, or wherein the composition comprises a pigment or a combination of pigments. The sunscreen composition according to claim 4, wherein the composition derived from the cyanobacteria from the species Arthrospira maxima comprises a phycocyanin, a chlorophyll or a combination thereof. The sunscreen composition according to any of claims 1 to 5, wherein the composition comprises a green seaweed from the genus Chlorella or a composition derived thereof in an amount from 70-97% and a cyanobacteria from the species Arthrospira maxima or a composition derived thereof in an amount from 3-30%. The sunscreen composition according to claim 6, wherein the composition is selected from:

(i) a composition comprising 70-80% green seaweed from the genus Chlorella or a composition derived thereof and 16-30% cyanobacteria from the species Arthrospira maxima or a composition derived thereof, (ii) a composition comprising 80-90% green seaweed from the genus Chlorella or a composition derived thereof and 15-20% cyanobacteria from the species Arthrospira maxima or a composition derived thereof, and

8. The sunscreen composition according to any of claims 1 to 7, wherein the chlorophyll is selected from chlorophyll a, b, f or a combination thereof.

9. The sunscreen composition according to claim 8, wherein the chlorophyll is a combination of chlorophyll a, b and f.

10. The sunscreen composition according to any of claims 1 to 9, wherein the composition does not comprise other photoprotective compounds.

11. The sunscreen composition according to any of claims 1 to 10, wherein the composition does not comprise chemical sunscreen agents.

12. The sunscreen composition according to any of claims 1 to 10, wherein the composition does not comprise physical sunscreen agents.

13. The sunscreen composition according to any of claims 1 to 12, wherein the composition further comprises cosmetically acceptable carriers.

14. The sunscreen composition according to any of claims 1 to 13, wherein the composition provides a sun protection factor (SPF) of at least 10.

15. The sunscreen composition according to claim 14, wherein the composition provides a sun protection factor of at least 15.

16. The sunscreen composition according to any of claims 1 to 15, wherein the composition is for topical application to human skin and/or hair.

17. The sunscreen composition according to any of claims 1 to 16 for use in a method for protecting human skin and/or hair against the deleterious effects of solar or ultraviolet radiation.

18. A sunscreen composition according to any of claims 1 to 16 for protecting the skin against ultraviolet rays, characterized in that it is in the form of a lotion, a suspension, a dispersion, an emulsion, a gel, a cream-gel, an ointment, a solid tube, an aerosol mousse or a spray. 19. A sunscreen composition according to any of claims 1 to 16 for protecting the hair against ultraviolet rays, characterized in that it is in the form of a shampoo, a lotion, a gel, a rinse-out composition, a styling or treating lotion or gel, a blow- drying or hair setting lotion or gel, a permanent-waving, straightening, dyeing or bleaching composition for the hair or a hair lacquer. 20. A method for protecting skin and /or hair from the solar or ultraviolet radiation comprising the step of contacting the skin and/ or the hair with an effective amount of the composition according to any of claims 1 to 16.

21. A packaged product comprising a container, a sunscreen composition according to any of claims 1 to 16 within said container, and instructions for topical application of said composition to provide photoprotection.