Sunscreen compositions and method of making

Abstract

A sunscreen composition, comprising an emulsion with an aqueous phase and an oil phase, a UV filter system, an emulsification system comprising at least one natural emulsifier that promotes liquid crystals which mimic the lipid bilayer of the skin; and at least one stabilizer for the emulsification system; and a solvent system comprising one or more of an emollient and a dispersant.

Description

SUNSCREEN COMPOSITIONS AND METHOD OF MAKINGTECHNICAL FIELD[00011 The present disclosure relates generally to protective sunscreens and more particularly, but not by way of limitation, to protective sunscreens for use with dispersion systems.BACKGROUND

[0002] This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.

[0003] The prolonged exposure to ultraviolet (UV) and visible light radiation can increase the risk of skin cancers, such as melanoma, and accelerate skin aging, such as loss of skin elasticity and wrinkling. Studies demonstrate that skin damage associated with visible light and UV light, induces hyperpigmentation due to cumulative effects to chromophores, as well as Reactive Oxygen Species formation, which may lead to DNA damage. Although numerous topical sunscreen compositions are commercially available with varying ability' to protect the body from the harmful effects of ultraviolet and visible radiation, there exists a need to provide sunscreen compositions that provide effective broader protection against both UV and visible radiation.SUMMARY OF THE INVENTION

[0004] This summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it to be used as an aid in limiting the scope of the claimed subject matter.

[0005] Embodiments of the invention are directed to a sunscreen composition, comprising an emulsion with an aqueous phase and an oil phase, a UV filter system comprising either a mineral UV filter or an organic UV filter or combinations thereof, an emulsification system comprising at least one natural emulsifier that promotes liquid crystals which mimic the lipidbilayer of the skin; and at least one stabilizer for the emulsification system which is a liquid polymer; and a solvent system comprising one or more of an emollient and a dispersant.

[0006] In certain embodiments, the emulsion is an oil-in-water emulsion. In other embodiments, the emulsion is a water-in-oil emulsion. Certain embodiments of the invention are directed to bi-continuous emulsions, where the oil and aqueous phases are present in equal parts.DETAILED DESCRIPTION

[0007] It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. The section headings used herein are for organizational purposes and are not to be construed as limiting the subject matter described. Reference will now be made to more specific embodiments of the present disclosure and data that provides support for such embodiments. However, it should be noted that the disclosure below is for illustrative purposes only and is not intended to limit the scope of the claimed subject matter in any way.

[0008] Sunscreen products are used to protect a user’s skin from ultraviolet (UV) radiation. Sunscreens often include one or more of a mineral-based ingredient and one or more chemicalbased ingredients. Mineral-based ingredients can block and / or scatter UV radiation before they penetrate the skin. Chemical-based ingredients can absorb UV radiation to prevent the UV radiation from penetrating the skin. The sunscreen compositions disclosed herein provide protection from UV radiation and usable with a highly effective dispersion system to make application of the sunscreen composition easy. In some aspects, the sunscreen compositions disclosed herein include only a mineral-based UV filter. In some aspects, the sunscreen compositions disclosed herein include a mineral-based UV filter and an organic-based UV filter.

[0009] In some aspects, a sunscreen composition comprises a stable emulsion that includes aqueous and oil phases. In some aspects, the aqueous and oil phases are present in the sunscreen composition in a weight ratio of aqueous components to oil components in a range from about>1 : 1. In certain embodiments, the emulsion is a bi-continuous emulsion with equal parts of the oil and aqueous phases. In other embodiments, the emulsion contains a greater portion of the oil phase relative to the aqueous phase (water-in-oil). In further embodiments, the emulsion contains a greater portion of the aqueous phase relative to the oil phase (oil-in-water).

[0010] The sunscreen composition may be used with a highly effective dispersion system, such as a bag on valve system (BOV system). The sunscreen composition includes a UV filter system. The UV filter system may include one or both of a mineral UV filter and an organic UV filter. The UV filter system has a weight ratio of the at least one mineral UV filter to the at least one organic UV filter of about 2: 1 to about 3: 1. Suitable filters include: aminobenzoic acid (PABA) (up to 15%); avobenzone (up to 3%); cinoxate (up to 3%); dioxybenzone (up to 3%); ensulizole (up to 4%); homosalate (up to 15%); meradimate (up to 5%); octinoxate (up to 7.5%); octisalate (up to 5%); octocrylene (up to 10%); oxybenzone (up to 6%); padimate O (up to 8%); sulisobenzone (up to 10%); titanium dioxide (up to 25%); trolamine salicylate (up to 12%); and zinc oxide (up to 25%).

[0011] Certain embodiments of the sunscreen composition contain at least one mineral UV filter. Other embodiments contain at least one organic UV filter. In some embodiments, the sunscreen composition contains at least one mineral UV filter and at least one organic UV filter.

[0012] In some aspects, the sunscreen composition provides water resistance. In certain embodiments, the water resistance is conferred by acrylate copolymers.

[0013] In certain embodiments, the sunscreen composition includes an emulsification system having at least one natural emulsifier that promotes liquid crystals which mimic the lipid bilayer of the skin. Natural emulsifiers include various glucosides. Examples of emulsifier used in embodiments of the invention include Cetearyl Olivate, Sorbitan Olivate, Poly glyceryl -3 Methylglucose Distearate, alkydpolyglucoside, Polyglyceryl-4 Olivate / Polyricinoleate, Ceteary l Glucoside, Cetearyl Alcohol, PEG-8 Stearate, Glyceryl Stearate, Ceteary l Alcohol, Sorbitan Oleate, Sodium Stearoyl Glutamate. Acrylates / C10-30 alkyl acrylate crosspolymer, Ceteary 1 Alcohol, Cetyl Palmitate, Sorbitan, Palmitateand Sorbitan Oleate The emulsification system also includes at least one stabilizer. In certain embodiments, the stabilizer may be a sprayable liquid polymer, such as hydroxyethyl aery late / sodi urn acryloyldimethy l tauratecopolymer, and a high polarity dispersant. In some aspects, the phase ratio of the emulsifier and stabilizer is from about 1.0 to 1.5. In some aspects, the high polarity dispersant is greater than about 5% and less than about 10% by weight.

[0014] In certain embodiments, the sunscreen composition also includes a solvent system that includes one or more of an emollient and a dispersant. Emollients include glycerin, squalane, caprylic / capric triglyceride, C 15-19 alkane, butyrospermum parkii (Shea) butter, ethylhexyl palmitate, C12-15 Alkyl Benzoate, cyclomethicone, Isopropyl Palmitate, Coco- Caprylate / Caprate, isostearyl isostearate, isododecane. Dispersants include butylene glycol dicaprylate / dicapricate, polyhydroxy stearic acid. PEG-26-PPG-30 phosphate, dimethicone PEG / PPG-12 / 14 phosphate, neopentyl glycol diethylhexanoate and neopentyl glycol diisostearate, sorbitan sesqui oleate, polyglyceryl-3 diisostearate, PEG-100 stearate, polysorbate-20, polysorbate-80, and phenethyl benzoate.

[0015] In some aspects, the sunscreen composition includes thickening and gumming agents that help control viscosity of the sunscreen composition. Examples of thickening and gumming agents include cellulose, carbomer, xanthan gum, hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, sclerotrium gum. bentonite, sodium polyacrylate, sodium acrylyldimethyltaurate / VP crosspolymer. ammonium acrylyldimethyltaurate / VP crosspolymer, dimethicone (and) dimethicone / vinyl, dimethicone crosspolymer, and hydroxypropyl starch phosphate.WORKING EXAMPLES

[0016] Reference will now be made to particular materials and methods utilized by various embodiments of the present disclosure. However, it should be noted that the materials and methods presented below is for illustrative purposes only and is not intended to limit the scope of the claimed subject matter in any way.

[0017] A method of making a bag-on-valve (BOV) sunscreen includes adding a solvent to a first vessel. The solvent may be. for example, water in an amount ranging between about 51- 65% w / w. The solution is mixed with a high shear batch mixer that emulsifies, homogenizes, solubilizes, suspends, disperses, and disintegrates solids, set at about 20-30 Hz while simultaneously mixing with a sidesweep mixer operating at about 30-40 Hz. The methodincludes adding to the vortex formed from the mixing a viscosity controlling agent and mixing until the viscosity controlling agent is solubilized (e.g., for 10-25 minutes). The solution continues to be mixed with the high shear batch mixer at about 20-30 Hz and the sidesweep mixer at about 30-40 Hz (e.g., for 10-15 minutes).

[0018] After the above mixing, a skin conditioning agent is added. In various aspects, 1-3 skin conditioning agents are added. The skin conditioning agents can be one or more of propanediol (and) citric acid (and) albatrellus confluens (mushroom) extract, helianthus annuus (sunflower) seed Oil (and) ethyl ferulate (and) rosmarinus officinalis (rosemary) leaf extract (and) tocopherol, caprylic / capric triglyceride (and) myrothamnus flabellifolia leaf / stem extract, water (aqua) (and) pelvetia canaliculata extract, PPG-24-glycereth-24, caprylic / capric triglyceride (and) myrothamnus glabellifolia leaf / stem extract, coffea arabica (coffee) seed oil, pyrus malus (apple) fruit extract (and) glycerin, cocos nucifera (coconut) oil, hydrolyzed sodium hyaluronate, undaria pinnatifida extract, isononyl isononanoate, and bisabolol. Next, 1-2 preservatives are added. The preservatives can be one or more of. the lower alkyl esters of para-hydroxybenzoates such as methylparaben, propylparaben, isobutylparaben, and mixtures thereof, benzyl alcohol, DMDM Hydantoin, and benzoic acid. This mixture is heated to about 70-75 °C and mixed using the high shear batch mixer at about 20-30 Hz and sidesweep mixer at about 30 Hz. Next, a transfer pump is attached to the first vessel and used at a recirculation speed of about 20-30 Hz to recirculate any bulk and help mix the solution until solubilized. Temperature is maintained between about 68-79 °C and the solution is mixed until solubilized (e.g., for about 8-25 minutes).

[0019] In a second vessel, the following are mixed together: 1-4 antioxidant materials; 1-4 emollients; 1-2 solvents; 1-3 skin conditioning agents; and 1-2 surfactants.

[0020] Antioxidant materials include water, propanediol, glycerin, olea europaea (olive) fruit extract, xanthan gum, brassica oleracea acephala leaf extract, glycerin (and) nasturtium officinale extract, glycerin (and) punica granatum pericarp extract, helianthus annuus (sunflower) seed oil (and) aloe barbadensis leaf extract (and) rosmarinus officinalis (rosemary) leaf extract, tocopherol, glycerin (and) aqua (and) nasturtium officinale flower / leaf extract, tetrahexyldecyl ascorbate, ascorbyl glucoside, ferulic acid, and tocopheryl acetate.

[0021] Surfactants include sodium stearoyl glutamate, cetearyl glucoside, cetearyl alcohol, glyceryl stearate, sorbitan isostearate, polyglyceryl-6 polyricinoleate, poly glyceryl- 10 dioleate, cetyl PEG / PPG-10 / 1 dimethicone, polyglyceryl-4 isostearate, Bis-PEG / PPG-14 / 14 dimethicone, and polyglyceryl-3 diisostearate. Emollients and skin conditioning agents include those set forth above.

[0022] Solvents include alcohols, water, volatile solvents such as ether solvents, and combinations thereof. Examples of suitable volatile ether solvents include dimethyl ether, diethyl ether, and combinations thereof. Examples of suitable commercially available volatile ether solvents include Cosmetic Fluid CF-76 (INCI designation: ethyl perfluorobutyl ether / ethyl perfluoroisobutyl ether) and Cosmetic Fluid CF-61 (INCI designation: methyl perfluorobutyl ether / methyl perfluoroisobutyl ether), In a preferred embodiment, the carrier is an alcohol. The alcohol may be a glycol, such as ethylene glycol, propylene glycol, buty lene glycol, pentylene glycol, hexylene glycol, dipropylene glycol, ethoxy diglycol, and the like. Other examples of suitable alcohols include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and the like. Preferably, the alcohol is a specially denatured alcohol.

[0023] The ingredients are heated to about 40-50 °C, and mixed using an in-line high shear mixer set between about 55-65 Hz along with a sidesweep or central mixer set between about 20-30 Hz. This solution is then mixed again for about 8-25 minutes using a transfer pump attached to the vessel at a recirculation speed of 30-40 Hz to recirculate bulk and help mix product while maintaining temperature between 40-50 °C. Next. 1-2 UV filters are added to the solution and heated to about 70-75 °C. The solution is then mixed for about 30-40 minutes to ensure the raw materials are completely dispersed. Mixing is done with the sidesweep or central mixer set between about 20-30 Hz, the in-line high shear mixer set at about 55-65 Hz, and the transfer pump recirculation speed set at about 50-65 Hz. After about 30 minutes of mixing, and when the temperature of the solution reaches between about 68-79 °C, 1-2 stabilizers and / or cleansing agents / surfactants are added to the solution and the solution is mixed for about 10-15 minutes to ensure that all raw materials are completely dispersed. Mixing is done with the sidesweep or central mixer set between about 20-30 Hz and the in-line high shear mixer set between about 57-64 Hz.

[0024] After the mixtures in the first and second vessels are uniformly mixed and the temperatures of the mixtures are between about 68-79 °C, the solution in the second vessel is added to the solution in the first vessel using a transfer pump. The transfer should take about 10-15 minutes, with the transfer pump speed set between about 8-25 Hz during the transfer. The in-line high shear mixer should remain on for the second vessel during the transfer. The sidesweep mixer for the first vessel should be set at about 25-30 Hz and in-line high shear mixer should be set at about 30-40 Hz. After the mixture from the second vessel is completely transferred to the first vessel, mixing is continued in the first vessel for about 20-25 minutes with the sidesweep mixer set at about 25-30 Hz, the in-line high shear mixer set at about 40-45 Hz. and the transfer pump recirculation speed set at about 25-30 Hz. Temperature in the first vessel is maintained between about 68-79 °C.

[0025] After mixing for about 20-25 minutes, the first vessel is cooled to about 25-30 °C. During cooling, the sidesweep mixer is set at about 20-30 Hz, the in-line high shear mixer is set at about 15-25 Hz, and the transfer pump is set to recirculate at a speed of about 25-30 Hz. Next, viscosity is controlled by controlling the temperature of the first vessel to be below or at about 40 °C. After cooling, 1-2 stabilizers of an emulsification system, which could be a liquid polymer and / or a high polarity dispersant, are added to the first vessel. The solution is then mixed for about 10-15 minutes to ensure that the raw materials are completed dispersed. Mixing is done with the sidesweep mixer set between about 20-30 H , the in-line high shear mixer set at about 15-25 Hz, and the recirculation transfer pump set at about 25-35 Hz. To control homogeneity, the solution is mixed for about 5 minutes until bulk is homogenous with the sidesweep mixer set at about 30 Hz, the in-line high shear mixer set at about 60 Hz, and the recirculation transfer pump speed set at about 30 Hz.

[0026] After the 5 minutes of mixing, the mixer speed is lowered. The solution is then cooled to about 25 °C. Mixing is continued during cooling with the and sidesweep mixer set at about 20 Hz. in-line high shear mixer set to about 20 Hz. Once the solution has cooled to about 25 °C, the mixers are turned off, and the transfer pump is used to transfer the finished product into a clean and sanitized container.

[0027] Although various embodiments of the present disclosure have been described in the foregoing Detailed Description, it will be understood that the present disclosure is not limitedto the embodiments disclosed herein, but is capable of numerous rearrangements, modifications, and substitutions without departing from the spirit of the disclosure as set forth herein.

[0028] The term “substantially'’ is defined as largely but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art. In any disclosed embodiment, the terms “substantially”, “approximately”, “generally”, and “about” may be substituted with “within [a percentage] of’ what is specified, where the percentage includes 0.1, 1, 5, and 10 percent.

[0029] The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the disclosure. Those skilled in the art should appreciate that they may readily use the disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the disclosure. The scope of the invention should be determined only by the language of the claims that follow. The term “comprising” within the claims is intended to mean “including at least” such that the recited listing of elements in a claim are an open group. The terms “a”, “an”, and other singular terms are intended to include the plural forms thereof unless specifically excluded.#

[0030] Conditional language used herein, such as, among others, “can”, “might”, “may”, “e.g.”, and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and / or states. Thus, such conditional language is not generally intended to imply that features, elements and / or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and / or states are included or are to be performed in any particular embodiment.

[0031] While the above detailed description has shown, described, and pointed out novel features as applied to various embodiments, it will be understood that various omissions,substitutions, and changes in the form and details of the devices or algorithms illustrated can be made without departing from the spirit of the disclosure. As will be recognized, the processes described herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some features can be used or practiced separately from others. The scope of protection is defined by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

[0032] Although various embodiments of the method and apparatus of the present invention have been described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth herein.#

Claims

CLAIMSWhat is claimed is:

1. A sunscreen composition, comprising: an emulsion comprising an oil phase and an aqueous phase; a UV filter system; an emulsification system comprising: at least one natural emulsifier that promotes liquid crystals which mimic the lipid bilayer of the skin; and at least one stabilizer for the emulsification system which is a liquid polymer; and a solvent system comprising one or more of an emollient and a dispersant.

2. The composition of claim 1, wherein the UV filter system comprises at least one organic UV filter.

3. The composition of claims 1 or 2, wherein the UV filter system comprises at least one mineral UV filter.

4. The composition of claim 1 further comprising at least one compound that confers water resistance.

5. The composition of claim 4, wherein the at least compound is an acrylate copolymer.

6. The sunscreen composition of claim 1, wherein the composition is disposed within a dispersion system.

7. The sunscreen composition of claim 6, wherein the dispersion system is a bag on valve system.

8. The sunscreen composition of claim 3, wherein the UV filter system has a weight ratio of the at least one mineral UV filter to the at least one organic UV filter of about 2: 1 to about 3: 1.

9. The sunscreen composition of claim 1 , wherein the at least one emulsifier includes glucosides.

10. The sunscreen composition of claim 1, wherein the at least one stabilizer of the emulsification system is a liquid polymer that includes Hydroxyethyl Acrylate / Sodium Acryloyldimethyl Taurate Copolymer.

11. The sunscreen composition of claim 1, wherein the dispersant is a high polarity dispersant.

12. The sunscreen composition of claim 1, wherein the aqueous phase and the oil phase are present in the composition at a weight ratio of aqueous components to oil components in a range from about >1: 1.

13. The sunscreen composition of claim 1 , wherein the aqueous phase and the oil phase are present in equal parts.

14. The sunscreen composition of claim 1. wherein the emulsion is an oil-in-water emulsion.

15. The sunscreen composition of claim 1, wherein the emulsion is a water-in-oil emulsion.

16. The sunscreen composition of claim 1, wherein the phase ratio of the emulsifier and stabilizing emulsifiers is from about 1.0 to 1.5.

17. The sunscreen composition of claim 1, wherein the dispersant is not less than 5% or more than 10% by weight of the composition.

18. The sunscreen composition of claim 1. where the composition is sprayable.

19. The sunscreen composition of claim 1, wherein the composition is water resistant.