Skin Tightening and Smoothing Personal Care Products

Abstract

The present invention relates to the manufacture of personal care products that have desirable texture and viscosity and exhibit skin firming, smoothing, or cooling properties. These personal care products contain a specific mixture of carrageenans to obtain these desired properties. More specifically, a topical formulation is described that includes a carrageenan component, the carrageenan component including 7-12% by weight of kappa type carrageenan, 15-25% by weight of iota type carrageenan, and 60-80% by weight of lambda type carrageenan, the carrageenan component comprising 0.2-3% by weight of the topical formulation.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 325,776, filed March 31, 2022, U.S. Provisional Patent Application No. 63 / 374,729, filed September 6, 2022, and U.S. Provisional Patent Application No. 63 / 378,887, filed October 10, 2022, each of which is incorporated by reference in its entirety herein.

[0002] FIELD OF THEINVENTION The present invention relates to the preparation of personal care products that have desirable texture and viscosity and exhibit skin firming, smoothing, or cooling properties. These personal care products contain specific mixtures of carrageenans to obtain these desired properties. [Background technology]

[0003] Carrageenan is a family of natural linear sulfated polysaccharides typically extracted from red edible seaweed. The best known and most important red algae used to make carrageenan is Chondrus crispus (Irish moss), a parsley-like, deep red plant that grows attached to rocks. Carrageenan is a large, flexible molecule that forms curled helical structures in solution or mixture. These properties give carrageenan the ability to form a variety of different gels at room temperature, and it is widely used in the food industry for its gelling, thickening, and stabilizing properties, but it has also gained interest in many other applications due to these properties. Carrageenan is known to be an effective ingredient in many personal care applications.

[0004] There are three main commercial classes of carrageenan (kappa, iota, and lambda), although other forms such as mu and nu exist. Kappa forms strong, firm gels in the presence of cations such as sodium, potassium, and calcium ions and reacts with milk proteins. It is sourced primarily from Kappaphycus alvarezii. Iota forms soft gels in the presence of calcium ions. It is produced primarily from Eucheuma denticulatum. The lambda form does not gel and is often used to thicken dairy products.

[0005] The main difference affecting the properties of carrageenans, including kappa, iota, and lambda carrageenans, is the number and position of sulfate ester groups on the repeating galactose units. Higher levels of sulfate esters reduce the melting temperature of the carrageenan, producing lower strength gels or contributing to gel inhibition (e.g., lambda carrageenan).

[0006] All are soluble in hot water, but in cold water only the lambda form (and the other two sodium salts) are soluble. Summary of the Invention

[0007] The use of various forms of carrageenan is known in a wide variety of commercial environments, each of which has positive and negative functional attributes. It would be desirable to have a formulation that can utilize the collective positive attributes of the various forms without being negatively affected. However, due to the different properties of the different forms of carrageenan, it is very difficult to predict the properties of any mixture of forms.

[0008] The present disclosure relates to the surprising discovery that a particular blend of kappa, lambda, and iota type carrageenans has highly desirable abilities to firm and smooth the skin.

[0009] In one aspect, the present invention provides a topical formulation comprising a carrageenan component, the carrageenan component comprising: a) 7 to 12% by weight of kappa type carrageenan; b) 15 to 25% by weight of iota type carrageenan; c) 60 to 80% by weight of lambda type carrageenan; wherein the carrageenan component comprises 0.2-3% by weight of the topical formulation.

[0010] Another aspect is a method of firming or smoothing human skin comprising applying to the skin a topical formulation comprising a carrageenan component, the carrageenan component comprising: a) 7 to 12% by weight of kappa type carrageenan; b) 15 to 25% by weight of iota type carrageenan; c) 60 to 80% by weight of lambda type carrageenan; wherein the carrageenan component comprises 0.2-3% by weight of the topical formulation.

[0011] Another aspect is a method of tightening the skin of a human comprising applying to the skin a topical formulation comprising a carrageenan component, the carrageenan component comprising: a) 7 to 12% by weight of kappa type carrageenan; b) 15 to 25% by weight of iota type carrageenan; c) 60 to 80% by weight of lambda type carrageenan; wherein the carrageenan component comprises 0.2-3% by weight of the topical formulation.

[0012] Another aspect is a method of soothing human skin comprising applying to the skin a topical formulation comprising a carrageenan component, the carrageenan component comprising: a) 7 to 12% by weight of kappa type carrageenan; b) 15 to 25% by weight of iota type carrageenan; c) 60 to 80% by weight of lambda type carrageenan; wherein the carrageenan component comprises 0.2-3% by weight of the topical formulation.

[0013] Another aspect is a method of cooling human skin comprising applying to the skin a topical formulation comprising a carrageenan component, the carrageenan component comprising: a) 7 to 12% by weight of kappa type carrageenan; b) 15 to 25% by weight of iota type carrageenan; c) 60 to 80% by weight of lambda type carrageenan; wherein the carrageenan component comprises 0.2-3% by weight of the topical formulation.

[0014] In another aspect, the present invention provides a method for producing a composition comprising: a) 7 to 12% by weight of kappa type carrageenan; b) 15 to 25% by weight of iota type carrageenan; c) 60-80% by weight of lambda type carrageenan. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Explanations of abbreviations and terms used in this disclosure are provided to aid in understanding and practicing the invention.

[0016] Unless specifically stated otherwise, all percentages of components of compositions, blends or formulations referred to herein by "percentage" refer to weight percent (wt %).

[0017] Unless otherwise stated, all parameter ranges disclosed are inclusive of the endpoints and all values ​​therebetween.

[0018] Representative features are presented in the following description, which may be used alone or in any combination with one or more features disclosed elsewhere in the description and / or drawings herein.

[0019] As used in the specification and claims, the terms "comprise" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted as excluding the presence of other features, steps or components.

[0020] Carrageenan The basic structure of carrageenan is a linear polysaccharide composed of a repeating disaccharide sequence of β-D-galactopyranose and α-D-galactopyranose residues linked through the 1,3 positions (A residues) and 1,4 positions (B residues), respectively. The regular backbone structure of the carrageenan basic structure is disrupted by a more or less regular distribution of sulfate groups. Some galactose units have sulfate groups attached, while others are not. The three main types of carrageenan molecules (iota, kappa, and lambda) differ by (1) the type of linkage between the galactose units, and (2) the attachment points and number of sulfate groups on each galactose unit. These apparently small differences in chemical composition and structure result in major differences in the properties of each type of molecule.

[0021] [ka]

[0022] Gelation in carrageenan is caused by helix formation and can only occur in repeating structures where B residue is in 1-C-4 conformation. Lambda carrageenan (theoretically has 3 sulfate groups per repeating unit) has both sugar residues in 4-C-1 conformation and does not form gel. Therefore, it is known to those skilled in the art that if gelation is a strong requirement for the end use of the formulation containing carrageenan, lambda carrageenan should be avoided.

[0023] All gelling types of carrageenan, including the kappa type (theoretically having one sulfate group per repeat unit and being the most naturally abundant type of carrageenan molecule) and the iota type (theoretically having two sulfate groups per repeat unit and being the least naturally abundant type of carrageenan molecule), all contain 3,6-anhydro bridges on the B units, which take the sugars from a 4-C-1 conformation to a 1-C-4 conformation, which can then form a crosslinked network and gel.

[0024] Some types of seaweed species contain relatively pure carrageenan fractions. Kappaphycus Alvarezii contains mainly kappa carrageenan and mu carrageenan which can be converted to kappa carrageenan by alkali treatment. Eucheuma Denticulatum contains a high degree of iota carrageenan as well as some new carrageenan precursors. Other seaweeds are more mixed in their carrageenan content. Furcellarum contains a strong gelling type of carrageenan that is a mixture of kappa and beta carrageenan in a ratio of about 3:2. Other seaweed types such as Chondrus crispus and Gigartina types contain not only a mixture of kappa and lambda types of carrageenan but also a type of carrageenan polymer that is essentially a block copolymer of different carrageenan types. This gives carrageenan made from Gigartina or Chondrus seaweed species quite different properties than those made from Eucheuma type species from Southeast Asia.

[0025] Many red algae species produce different types of carrageenan during various stages of their developmental history, for example, the genus Gigartina produces primarily kappa carrageenan during its gametophyte stage and lambda carrageenan during its sporophyte stage.

[0026] Carrageenan isolated from natural seaweed sources contains long polymers substituted with various numbers of sulfate structures. Carrageenan is not just one type of repeating unit. Therefore, isolated carrageenan can be more or less one "type" based on the degree of sulfate substitution and different linkages. Those skilled in the art will understand that the genus of seaweed, the location of harvest, and the developmental stage will affect the type of carrageenan isolated. Furthermore, carrageenan samples can be analyzed by methods known in the art to determine what proportion of the monomer residues of the polymer are of what type. (See, for example, Aguibal et.al., Botanica Marina, Vol 46, (2003), pp 179-192; and Knutsen et.al., Carbohydrate Research, 331, (2001), 101-106).

[0027] The term "kappa type" as used herein refers to a form of carrageenan that contains more than 80% of its monomer residues in kappa form. In some embodiments, the kappa type contains more than 85% of its monomer residues in kappa form. In some embodiments, the kappa type contains 80%-95% of its monomer residues in kappa form.

[0028] The term "iota type" as used herein refers to a form of carrageenan that contains more than 80% of its monomer residues in iota form. In some embodiments, the iota type contains more than 85% of its monomer residues in iota form. In some embodiments, the iota type contains 80%-95% of its monomer residues in iota form.

[0029] The term "lambda type" as used herein refers to a form of carrageenan that contains more than 20% of its monomeric residues in lambda form. In some embodiments, lambda type contains more than 24% of its monomeric residues in lambda form. In some embodiments, lambda type contains 15%-30% of its monomeric residues in lambda form.

[0030] Various forms of carrageenan are commercially available from various commercial producers. For example, the carrageenan utilized in the present disclosure is commercially available from Cargill under the trade names VPC 614 kappa type, VPC 430 lambda type, and VPC 508 iota type. As with any natural product, carrageenan is a natural product isolated from cultivated or harvested seaweed, and the exact content of any carrageenan extract will vary slightly depending on the time of harvest or season.

[0031] [Table 1] * The values ​​in the table represent the average content from 7 or more samples. ND means that the amount of this form was not detected.

[0032] Personal Care Compositions In one aspect, the present invention is the use of the carrageenan mixture disclosed herein in various personal care products.The personal care composition may be prepared by making a water phase that is mainly water and adding the carrageenan while mixing.The mixing is often performed at high temperature (about 75°C) to facilitate complete incorporation.The type of mixing is not critical, and typical mixing equipment used in the art can be used with the present composition.Medium or high shear equipment is desirable to promote faster and more efficient mixing.

[0033] The carrageenan may be added as a premix or separately. Additional ingredients may then be added to the formulation and the pH adjusted as desired. The mixture is cooled with or without stirring to obtain the final personal care composition. The personal care composition may contain other active or inactive ingredients, moisturizers, or emollients. Active ingredients are those that have a physiological effect on the skin or hair. The composition may be an emulsion containing emollients, colorants, active ingredients, and / or other quality improving agents.

[0034] With the temperature still above the gel point, the pH can be adjusted to about 5.5-6.0 by adding an acid such as citric acid. Additional salts or electrolytes are added to the mixture as preservatives and / or to manage the gelling properties of the carrageenan. The amount of salt or electrolyte can vary depending on the texture to be achieved. Typically, the amount of salt or electrolyte is about 0.25%-1% of the composition. In some embodiments, it is about 0.5%. The mixture may then be cooled. Typically, high shear mixing is avoided after the addition of salt or electrolyte and during cooling to preserve the texture of the final product.

[0035] The amount of carrageenan utilized in the personal care formulation can be varied by those skilled in the art to achieve the desired texture. In some embodiments, the amount of carrageenan is 0.2% to 3%. In other embodiments, the amount is 0.5% to 2%. In another embodiment, the percentage of carrageenan in the personal care formulation is 0.5% to 1.5%.

[0036] 1.Aqueous phase Topical preparations may contain aqueous phase.Aqueous phase can comprise or consist of water, in particular demineralized water, floral water such as cornflower water, mineral water such as Vittel water, Lucas water, La Roche Posay water, and / or spring water.In some embodiments, demineralized water, floral water, or a combination of both are used as the aqueous phase utilized by the present invention.

[0037] In some embodiments, the amount of aqueous phase in the topical formulation may be 50% to 99.5% by weight. In some embodiments, the amount of aqueous phase in the topical formulation may be 90% to 98% by weight. The aqueous phase may optionally contain other soluble components (e.g., alcohols or polyols). In some embodiments, the aqueous phase may contain glycerol. In some embodiments, the topical formulation contains 1 to 4% by weight of glycerol.

[0038] 2. Emulsion In some embodiments, the personal care formulation may be an emulsion.An emulsion may be defined as a mixture that contains two immiscible liquids, one of which is dispersed throughout the other liquid as droplets or globules.The dispersed liquid is called the dispersed phase, and the other liquid is called the continuous phase.In an oil-in-water emulsion, as in the present invention, oil is the dispersed phase or oil phase, and water is the continuous phase or water phase.

[0039] The topical formulation may further contain an oil phase dispersed in the aqueous phase. As used herein, the term "dispersed" refers to the oil phase forming droplets within the aqueous phase. The droplets may have any size and shape. Preferably, the droplets are uniformly distributed throughout the aqueous phase. The nature of the oil phase of the emulsion is not critical. Thus, the oil phase may consist of any fatty substance conventionally used in the cosmetic or dermatological fields. In particular, the oil phase may comprise at least one oil, i.e., any fatty substance that is substantially or completely in liquid form at room temperature (20-25°C) or at elevated temperature (40-70°C) and atmospheric pressure (760 mmHg).

[0040] A preferred oil phase comprises at least one oil, which may be: a hydrocarbon-based oil, i.e. an oil containing mainly hydrogen and carbon atoms, and optionally oxygen, nitrogen, sulfur and / or phosphorus atoms, for example in the form of hydroxyl or acid radicals; a silicone oil, i.e. an oil containing at least one silicon atom, preferably at least one Si-O group; a fluoro oil, i.e. an oil containing at least one fluorine atom; a non-fluorinated oil, or a mixture thereof.

[0041] The hydrocarbon-based oils may be of animal or vegetable origin, such as liquid triglycerides of fatty acids containing from 4 to 20 carbon atoms, examples being coconut oil, canola oil, rapeseed oil, sunflower oil, corn oil, soybean oil, cucumber oil, grapeseed oil, sesame seed oil, hazelnut oil, apricot oil, macadamia oil, arara oil, castor oil, cocoa butter almond oil, avocado oil, babassu oil, caprylic / capric triglycerides, such as those sold by Stearineries Dubois or those sold under the names Miglyol 810, 812 and 818 by Dynamit Nobel, Simmondsia Chinensis (Jojoba) Seed Oil sold under the trade name Jojoba Oil Golden by Desert Whale, beta-carotene sold under the trade name Betatene 30% OLV by Cognis (BASF), Nestle World Trade Co. under the trade name Rosehip Seed Oil; shea butter oil; and mixtures thereof.

[0042] The hydrocarbon base oil may be a straight or branched chain hydrocarbon of mineral or synthetic origin, or may be a synthetic ether, synthetic ester, a fatty alcohol that is liquid at room temperature having a branched and / or unsaturated carbon-based chain containing 12 to 26 carbon atoms, a higher fatty acid of C12 to C22, or a mixture thereof.

[0043] The personal care composition may further comprise at least one additional ingredient, which may include, but is not limited to, a preservative, a salt, a vitamin, an emulsifier, a quality improver, a nutrient, a micronutrient, a sugar, a protein, a polysaccharide, a polyol, glucose, sucrose, glycerol, sorbitol, a pH adjuster, an emollient, a dye, a pigment, a skin active, a wax, or a silicone.

[0044] Topical preparations The ingredients provided herein are useful in the manufacture of topical formulations, such as personal care products or cosmetics. The inventors have unexpectedly discovered that formulations containing specific ratio combinations of carrageenan ratios have many desirable properties, as further described below.

[0045] In one aspect, the present invention is a topical formulation comprising the emulsion described herein.As used herein, the term "topical formulation" refers to a formulation that can be directly applied to a part of the body.The term "formulation" is used herein to indicate the composition of various components in various weight ranges according to the present invention.

[0046] Formulations made with the ingredients described herein are suitable (and applicable) for use on the hair, scalp, nails and skin to deliver cosmetic or active agents to the skin or hair, for cleansing, conditioning, providing moisturization, minimizing or treating skin imperfections, reducing skin oiliness, providing fragrance to the hair or skin, etc.

[0047] "Personal care" means and includes any cosmetic, hygiene, toiletry, and topical care products, including, but not limited to, leave-on products (i.e., products that are left on the keratin substrate after application), rinse-off products (i.e., products that are washed or rinsed off from the keratin substrate during or within minutes of application), shampoos; hair curling and straightening products; hairstyle maintenance and hair conditioning products; lotions and creams for the nails, hands, feet, face, scalp, and / or body; hair care products, such as shampoos, conditioners, and hair straighteners; and hair care products. These include, but are not limited to, hair dyes; facial and body make-up; nail care products; astringents; deodorants; antiperspirants; anti-acne medications; anti-aging; depilatories; colognes and fragrances; skin protection creams and lotions (such as sunscreens); skin and body cleansers; skin conditioners; skin toners; skin firming compositions; skin tanning and whitening compositions; liquid soaps; bar soaps; bath products; shaving products; and oral hygiene products (such as toothpaste, oral suspensions, and mouth care products).

[0048] The texture of such personal care formulations is not limited, and may be, among others, but not limited to, liquids, gels, sprays, emulsions (such as lotions and creams), shampoos, pomades, foams, tablets, sticks (such as lip care products), make-up, suppositories, any of which may be applied to the skin or hair or tonic and are typically designed to remain in contact with it until removed, such as by rinsing with water or washing with shampoo or soap. Other forms may be gels, which may be soft, hard or squeezable. Sprays may be non-pressurized aerosols delivered from hand-pumped finger-actuated sprayers, or pressurized aerosols such as mousses, sprays or foam-forming compositions in which chemical or gaseous propellants are used.

[0049] Topical formulations containing the emulsions disclosed herein may be lotions, serums, creams, etc. Advantageously, the serums or creams may contain specific ratios of lambda, kappa, and iota types of carrageenan.

[0050] The formulations prepared using the ingredients disclosed herein generally have a clear colorless or bright white color that is considered aesthetically appealing. In some cases, the formulations herein may be further processed to produce a colored final product. In such cases, the colorless color is beneficial because it allows additional pigments to stand out without affecting the final color.

[0051] Furthermore, the formulations prepared using the components of the present invention have a pleasant feel on the skin and good spreadability.The use of the components of the present invention improves the texture and body of personal care products.The texture feels pleasant to the touch and to apply.Furthermore, the consistency is such that good product pick-up can be achieved.Good product pick-up means that the user's fingers can collect enough product (i.e., not too much, not too little).

[0052] Personal care products used to tighten the skin can be applied by spreading the product on the skin with the hands, or by using a brush, cotton swab, cotton pad (round or square), or cloth. The frequency of use can be determined by the user, and application can be daily or multiple times per day.

[0053] In one aspect, the components of the present disclosure are particularly useful in sunscreen applications. Sunscreens contain ingredients intended to block ultraviolet light from reaching the skin. The ultraviolet light blocking agent can be a physical or chemical salt, such as ZnO, or TiO2, or a chemical (maximum approved levels are given), such as butyl methoxydibenzoylmethane (5%), octocrylene (10%), titanium dioxide (25%), ethylhexyl salicylate (5%), ethylhexyl methoxycinnamate (10%), bis-ethylhexyloxyphenol methoxyphenyl triazine (10%). The emulsions of the present disclosure can be used with any type of ultraviolet light blocking agent or mixture of ultraviolet light blocking agents known in the art.

[0054] blend As used herein, the term "blend" refers to a physical mixture of two or more substances. In one aspect, the present invention includes blends of carrageenans useful in preparing the personal care compositions described herein. In another aspect, the present invention refers to blends of carrageenans comprising 7-12% by weight of kappa type carrageenan, 15-25% by weight of iota type carrageenan, and 60-80% by weight of lambda type carrageenan. In another aspect, the blends comprise 8-12% by weight of kappa type carrageenan, 17-23% by weight of iota type carrageenan, and 65-75% by weight of lambda type carrageenan. In another aspect, these blends are used to prepare personal care formulations or topical formulations, such formulations may be used to firm or smooth the skin.

[0055] Additionally, the personal care compositions and methods of the present invention may be prepared using a blend of carrageenans comprising or consisting of 23-34% by weight kappa carrageenan, 29-37% by weight iota carrageenan, 12-20% by weight lambda carrageenan, 2-8% by weight mu carrageenan, and 12-19% by weight nu carrageenan.

[0056] The blend of carrageenan may further contain other dry ingredients, such as quality improvers, colorants, flavors, fragrances, etc., as desired in the final personal care composition. In one embodiment, the blend further comprises a quality improver. Quality improvers useful in the present invention include, but are not limited to, cellulose and its derivatives, synthetic polymers such as acrylates and carbomers, scleroglucan, and xanthan gum. The quality improver may be present in any useful or desired amount.

[0057] The blends may be prepared according to methods of blending dry ingredients known in the art. Use of standard mixing equipment for a sufficient period of time will readily prepare the blends described herein.

[0058] In another aspect, the present invention relates to the use of any blend of individual types of carrageenan or individual types of carrageenan in personal care compositions useful for smoothing or firming the skin. The blend may contain all types of carrageenan or only two or more types. In another aspect, these blends are used to prepare personal care formulations or topical formulations, and such formulations can be used to firm or smooth the skin.

[0059] The application of carrageenan to skin has surprisingly been shown to affect the overall topography of the skin surface. Despite its long history of use in personal care compositions to modify the texture and viscosity of products, this effect on skin has not been reported. Skin topography is affected in two different ways. First, the application of this product has been shown to reduce the height of small peaks and the depth of microfolds on the skin. This shows a smoothing effect, thereby reducing the roughness of the skin. Furthermore, the application of this product has been shown to narrow the width of microfolds on the skin, tightening the skin and eliminating or reducing the visibility of these microfolds. This effect can also be referred to as wrinkle reduction, fine line reduction, or crow's feet reduction around the eyes. The term tightening encompasses any of these alternative descriptions, or any description that embodies the concept of reducing the width of microfolds on the skin.

[0060] Example 1:

[0061] [Table 2]

[0062] Step 1: An aqueous phase of demineralized water and rose water was prepared and heated to about 70°C.

[0063] Step 2: The carrageenan was slowly added while continuing to mix, after addition the solution was mixed for 5 minutes using an UltraTurrax set at 5000 rpm.

[0064] Step 3: Glycerol was added and the mixture was stirred with an UltraTurrax set at 5000 rpm for 3 minutes.

[0065] Step 4: Aqueous potassium sorbate and sodium benzoate were added and stirring was continued until a homogenous mixture was obtained. The pH was adjusted to 5.0-5.5 by the addition of 50% citric acid solution.

[0066] The resulting product was a slightly imperfect gel that was still easily pumpable. It has a pleasant water-repellent effect on application.

[0067] Example 1A: Example 1A was prepared in the same manner as Example 1, except that 2% of the carrageenan blend was used instead of the 1% blend.

[0068] Example 2:

[0069] [Table 3]

[0070] The product of Example 2 was made according to the method of Example 1 (without the addition of glycerol). This slightly viscous gel was evaluated for its ability to smooth and firm human skin. The firming and smoothing evaluation was performed using a Polytec TMS-500 optical interferometer using topographic analysis. Polytec TMS 3.8 software was used to measure the firmness of a single application (2 mg / cm2) of the composition of Example 2. 2 The surface microrelief of the skin explants was evaluated before and 10 minutes after application of the test compound. The skin explants contain a measurable topography of high and low points as well as deeper microfolds. In evaluating smoothing, a Polytec device is used to measure the change in high and low points of the skin sample after application of the test compound. In evaluating the tightening effect, a device is used to measure the width of the microfolds in the skin sample before and after application of the test compound.

[0071] result After application of the sample of Example 2, there was a surprising and immediate improvement in skin smoothness of 11%. In addition, the median width of the microfolds was reduced from 147 μm to 129 μm (11%), indicating a tightening effect. Furthermore, a tightening effect was observed by 74% of individuals in the sensory panel. Therefore, this formulation can be used as a concealer to visibly smooth the skin and reduce fine lines.

[0072] When Example 1A was applied, a tightening effect was evident after 3 hours (10% reduction in microfold depth and 12.8% improvement in skin smoothness) and after 6 hours (6.6% reduction in microfold depth and 8.8% improvement in skin smoothness).

[0073] Application of Example 1 and Example 1A has been shown to improve skin firmness. Skin firmness can be measured using a commercially available device from Dynaskin. Dynaskin blows air perpendicular to the skin or at a 45 degree angle, causing reproducible and measurable deformation on the skin surface. Measurements before and after application of test compound can evaluate any effect on skin firmness.

[0074] 10 minutes after application of the sample of Example 1, the firmness of the skin is improved such that the volume of deformation is reduced by 5.6% and the depth of deformation is reduced by 5.9%. 10 minutes after application of the sample of Example 1A, the firmness of the skin is improved such that the volume of deformation is reduced by 10.7% and the depth of deformation is reduced by 6.6%. The test of Example 1 was repeated, but measurements were taken 3 hours and 6 hours after application. At the 3 hour time point, the volume of deformation is reduced by 10.7% and the depth of deformation is reduced by 9.7%. At the 6 hour time point, the volume of deformation is reduced by 7.8% and the depth of deformation is reduced by 8.4%.

[0075] The test was repeated for Example 1A, with measurements taken 3 and 6 hours after application. At 3 hours, the volume of deformation was reduced by 11.9% and the depth of deformation was reduced by 7.1%. At 6 hours, the volume of deformation was reduced by 10% and the depth of deformation was reduced by 6.3%.

[0076] Importantly, these effects were observed in serum formulations with pleasant texture, stability, and spreadability. The use of kappa-type carrageenan alone is challenging. Typically, it is difficult to produce an acceptable formulation with kappa-type carrageenan alone, as syneresis is an issue at the levels required to thicken the formulation. Syneresis is the contraction of the gel accompanied by separation of the liquid. In the case of kappa-type carrageenan, at high concentrations the gel undergoes syneresis over time. For this reason, it is not preferred to use kappa-type carrageenan alone.

[0077] In a further aspect, the carrageenan disclosed herein has been shown to have a surprising cooling effect when applied to the skin. A clinical evaluation of the cooling effect was conducted by applying test samples to the forearms of 20 Caucasian female volunteers, ages 22-77. Each individual had four test areas identified, two on each arm. One area was not treated and was kept as a control. Three samples were applied to the other areas with the fingers until absorbed by the skin (2 μl / cm). 2 ). Skin temperature was monitored with an infrared camera for 15 minutes. The three samples included Example 1, Example 1A, and a commercial benchmark sold in the market for cooling. The benchmark sample had a maximum decrease in skin temperature of 2.4°C. Example 1A also showed a maximum temperature decrease of 2.4°C, while Example 1 showed a maximum temperature decrease of 2.7°C. Surprisingly, both Example 1 and Example 1A showed a longer cooling period and a greater overall cooling effect than the commercial benchmark.

[0078] stability Stability is visually assessed by observing the stability of the personal care formulation over time. A formulation fails if the phases separate or begin to separate. Significant pooling of oil or water droplets on the surface or significant changes in the visual color or texture of the sample also indicate failure of the formulation. In addition, the viscosity may be checked again and a significant decrease (greater than 20%) indicates failure of the formulation.

[0079] The carrageenan-containing formulations disclosed herein have good stability with little or no degradation or separation between phases over extended periods of time (e.g., 4 weeks, 8 weeks, or 12 weeks) when measured at room temperature and at 45° C. Thus, they can be used to manufacture products that require a long shelf life (e.g., topical formulations).

Claims

1. A mixture of carrageenans, comprising: a) 8 to 12% by weight of kappa-type carrageenan; b) 17 to 23% by weight of iota-type carrageenan; c) 65 to 75% by weight of lambda type carrageenan; A mixture of carrageenans, including

2. A mixture of carrageenans as described in claim 1, wherein the kappa-type carrageenan contains more than 80% kappa monomer units, the iota-type carrageenan contains more than 80% iota monomer units, and the lambda-type carrageenan contains more than 20% lambda monomer units.

3. A mixture of carrageenans as described in claim 1, wherein the kappa-type carrageenan contains 80% to 95% kappa monomer units, the iota-type carrageenan contains 80% to 95% iota monomer units, and the lambda-type carrageenan contains 15% to 30% lambda monomer units.

4. A topical formulation comprising 0.2 to 3% by weight of a mixture of carrageenans as described in claim 1.

5. 5. The topical formulation of claim 4, which is a lotion, serum, or cream.

6. Use of the topical formulation of claim 5 for firming or smoothing human skin.

7. 7. Use of the topical formulation of claim 6, which is a lotion, serum, or cream.

8. 5. The topical formulation of claim 4, which is a sunscreen.