WO2026015769A1 - Emulsions comprising carboxyalkyl microfibrillated cellulose - Google Patents

Abstract

The present technology relates to an emulsion comprising C1-C4 carboxyalkyl microfibrillated cellulose. The invention extends to personal care and pharmaceutical formulations comprising the emulsion of the technology. The invention also relates to methods for preparing emulsions and the use of C1-C4 carboxyalkyl microfibrillated 5 cellulose for improving the texture, sensory and/or stability of an emulsion.

Description

EMULSIONS COMPRISING CARBOXYALKYL MICROFIBRILLATED CELLULOSE

FIELD OF THE INVENTION

[0001] The technology relates to an emulsion suitable for use in the preparation of personal care and pharmaceutical formulations. In particular, the emulsion comprises carboxyalkyl microfibrillated cellulose. The invention extends to personal care and pharmaceutical formulations comprising the emulsion of the technology.

BACKGROUND OF THE INVENTION

[0002] Emulsions are one of the most common types of formulation used in personal care and pharmaceutical products. An emulsion is a heterogeneous system which is a mixture of two or more liquids that would not normally mix, i.e. it is a mixture of two or more liquids that are immiscible or of limited miscibility. Emulsions include oil-in-water (O/W) or water-in-oil (W/O) emulsions. Oil-in-water (O/W) emulsions have water as a continuous phase and oil as a dispersed phase. Water-in-oil (W/O) emulsions have oil as a continuous phase and water as a dispersed phase.

[0003] Emulsions have the advantage of being able to act as vehicles for providing the skin with a large amount of lipids, liposoluble ingredients and/or hydrophilic ingredients, leaving the skin feeling pleasant and, for example, smooth, soft and/or moisturized. However, emulsions are thermodynamically unstable systems and require stabilization by, for example, surfactants or polymers, to prevent separation of the phases over an extended period of time. However, most stabilizing ingredients are synthetic, or are surface-active molecules and so can disrupt the skin barrier. Also, there is a growing interest in the use of ingredients that are biodegradable and environment-friendly for consumer products.

[0004] Moreover, there is a high demand, especially in the personal care industry, of formulations that have satisfactory texture and sensory attributes. Texture and sensory properties are some of the key aspects influencing consumers' choice of personal care products.

[0005] Cellulose is the main component of primary cell wall of green plants and some algae, and it is the most abundant natural polymer in the world. Cellulose is widely used in the preparation of paper, food, pharmaceuticals, cosmetics, for example. Cellulosic products are used as thickeners and suspension aids in home care, personal care and pharmaceutical formulations. In particular, microfibrillated cellulose (or microfibrous cellulose) (MFC) has been shown to efficiently structure different types of formulations and provide satisfactory suspending properties. It is believed that the suspension properties achieved by using microfibrillated cellulose in formulations takes place through the fibrillar network formed by hydrogen bonds between the fibers, combined with the concentration.

[0006] WO2016166179 discloses beauty balm creams (water-in-oil emulsions) comprising microfibrous cellulose. However, one of the problems of microfibrous cellulose is that it may lead to emulsions that are rougher, opaque and non-homogeneous.

[0007] WO2022029579 discloses oil-in-water emulsions comprising microcrystalline cellulose and diutan gum, and optionally, sodium carboxymethyl cellulose.

[0008] There is still an on-going need for emulsions that not only show high stability but also have improved texture and sensory during the application of the product. Texture and sensory aspects are extremely important for the acceptance of products in the market. Particularly, MFC may be required to be used in high concentrations in emulsions, leading to undesirable texture and unpleasant sensory which can result in low acceptance by consumers.

[0009] The present invention sets out to meet some or all of the above-identified needs and to solve some or all of the above-identified problems.

SUMMARY OF THE INVENTION

[0010] The disclosed technology relates to emulsions comprising C1-C4 carboxyalkyl microfibrillated cellulose that show improved texture, appearance and sensory at an acceptable use level, which valuably increase consumer acceptance. The emulsions of the present technology also show improved stability and optimal viscosity.

[0011] Thus, in a first aspect the invention relates to an emulsion comprising: a. an oil phase; b. a water phase; c. an emulsifier; and d. a C1-C4 carboxyalkyl microfibrillated cellulose.

[0012] In particular, the emulsion can be in the form of oil-in-water (O/W) emulsion.

[0013] In one aspect, the invention relates to a personal care or pharmaceutical formulation comprising the emulsion of the first aspect.

[0014] Methods for preparing an emulsion according to the first aspect comprising the step of mixing an oil phase with a water phase in the presence of an emulsifier, wherein the emulsion comprises a C1-C4 carboxyalkyl microfibrillated cellulose are also contemplated herein.

[0015] In one aspect, the invention relates to the use of a C1-C4 carboxyalkyl microfibrillated cellulose to improve the texture, the sensory and/or stability of an emulsion.

[0016] A method of improving the texture, sensory and/or stability of an emulsion comprising adding to the emulsion a C1-C4 carboxyalkyl microfibrillated cellulose is also contemplated herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1. Visual inspection of microfibrillated cellulose (MFC) and carboxymethyl microfibrillated cellulose (CM-MFC) dispersions with polarized light at 100X. A, Dispersion at 1 ,200 rpm for 5 minutes. B, Dispersion at 10,000 rpm (Ultraturrax®) for 10 minutes.

[0018] Figure 2. Emulsion stability after centrifugation test (13,000 rpm/10min). A, 1 wt.% MFC; B, 1 wt.% MFC + 0.05 wt.% diutan gum; C, 1 wt.% CM-MFC; D, 1 wt.% CM- MFC + 0.05 wt.% diutan gum; E, 0.05 wt.% diutan gum.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Various preferred features and embodiments will be described below by way of non-limiting illustration.

[0020] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article unless the context clearly indicates otherwise. By way of example, "an element" means one element or more than one element.

[0021] Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about". The term “about” as used herein, e.g. when referring to a measurable value (such as an amount or weight of a particular component or temperature), refers to variations of ±20%, ±10%, ±5%, ±1 %, ±0.5%, or, particularly, ±0.1% of the specified amount. Except where otherwise indicated, all numerical quantities in the description specifying amounts or ratios of materials are on a weight basis. [0022] As used herein, the term “comprising”, which is inclusive or open-ended and does not exclude additional unrecited elements or method steps, is intended to encompass as alternative embodiments, the phrases “consisting essentially of” and “consisting of” where “consisting of’ excludes any element or step not specified and “consisting essentially of” permits the inclusion of additional unrecited elements or steps that do not materially affect the essential or basic and novel characteristics of the composition or method under consideration.

[0023] While overlapping weight ranges for the various components and ingredients that can be contained in the disclosed compositions have been expressed for selected embodiments and aspects of the disclosed technology, the amount of each component in the disclosed compositions is selected from its disclosed range such that the sum of all components or ingredients in the composition will total 100 weight percent. The amounts employed will vary with the purpose and character of the desired product and can be readily determined by one skilled in the art.

[0024] The term "personal care" as used herein when applied to formulations/products includes but is not limited to cosmetics, toiletries, cosmeceuticals, beauty aids, insect repellents, personal hygiene, women’s health, sanitary protection and cleansing products applied to the body, including the skin, hair, scalp, and nails of humans and animals.

[0025] The term “cosmetically acceptable” and "pharmaceutically acceptable" as used herein refers to compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of a subject (e.g. human) without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. Each carrier, excipient, etc. must also be "acceptable" in the sense of being compatible with the other ingredients of the formulation.

[0026] Embodiments and aspects described herein may be combinable with other embodiments and/or aspects despite not being expressly exemplified in combination.

[0027] “Emulsion stability” can be defined as the emulsion's ability to resist changes in its physicochemical properties over time. An emulsion is usually considered stable if it is resistant to physical changes over a practical length of time. The stability of an emulsion can be tested by several methods including centrifugation, filtration, shaking or stirring, low intensity ultrasonic vibration, thermal stress (e.g. heating), or simply by observing it as it sits over a period of time. Instability in an emulsion leads to the floating of droplets of the dispersed phase to the surface, creaming precipitation, cohesion between droplets, coalescence of the droplets, and, finally, to separation of the phases.

Carboxyalkyl microfibri Hated cellulose (CA-MFC)

[0028] The emulsion of the present technology comprises a C1-C4 carboxyalkyl microfibrillated cellulose (CA-MFC). The CA-MFC of the present technology can be prepared from chemical modification of microfibrillated cellulose (MFC). Microbrillated cellulose, is also known as “microfibrillar cellulose”, “microfibrous cellulose” or “cellulose microfibrils” and refers to a cellulose that is characterized by a structure in the form of microfibrils. The MFC can be obtained from any source containing cellulosic material. In particular, the MFC used in the present technology can be obtained from plant material. Non-limiting examples of vegetal sources include hardwood, softwood, soybean, cotton, wheat straw, sisal, hemp, fruit fiber, sugar bagasse and others.

[0029] The microfibrillated cellulose can be produced according to any process known in the art. Typically, MFC can be prepared via mechanical means by applying high intensity shear forces that lead to the individualization of the fibrils, optionally, in combination with chemical and/or enzymatic methods. The production of MFC may include the step of passing a suspension of cellulose or cellulose slurry through an orifice or orifices of very small diameter, for example, from 0.01 to 700 pm or from 0.1 to 500 or from 0.5 to 100 pm, or from 1 to 100 pm, by using high pressure forces. The method can also include, in addition or alternatively, the step of subjecting the slurry to continuous impacts to produce the MFC. Methods for obtaining MFC are disclosed, for example in WO2021/226693A1 and US4483743, incorporated herein by reference.

[0030] The CA-MFC can be obtained by chemical derivatization of the MFC by processes known in the art. Methods for obtaining CA-MFC are disclosed, for example in US6602994, incorporated herein by reference. The alkyl of the carboxyalkyl group, can be independently, a C1 to C4, C1 to C3, C1 to C2, or C1 alkyl group or mixtures thereof. Particularly, each alkyl group can be, independently, C1 to C3, or C1 to C2, or C1 alkyl group. More particularly, the carboxyalkyl microfibrillated cellulose of the present invention is a carboxymethyl microfibrillated cellulose (CM-MFC).

[0031] The degree of substitution of carboxyalkyl can be adjusted by controlling the amount of the carboxyalkylating agent to be reacted. The degree of carboxyalkyl substitution of cellulose per anhydrous glucose unit can be from 0.01 to 0.50. The degree of carboxyalkyl substitution can be 0.05 or more, 0.10 or more, 0.15 or more, 0.20 or more, 0.25 or more, or 0.30 or more. [0032] In one embodiment, the C1-C4 CA-MFC has an average fiber diameter from 0.1 to 500 pm. Particularly, the average fiber diameter can be from 0.5 to 100 pm, more particularly 1 to 100 pm. The C1-C4 carboxyalkyl microfibrillated cellulose can be a carboxymethyl microfibrillated cellulose having an average fiber diameter from 0.1 to 500 pm. Particularly, the C1-C4 carboxyalkyl microfibrillated cellulose can be a carboxymethyl microfibrillated cellulose having an average fiber diameter from 0.5 to 100 pm, more particularly from 1 to 100 pm.

[0033] In one embodiment, the C1-C4 CA-MFC is CM-MFC having an average fiber diameter from 0.1 to 500 pm and a degree of carboxyalkyl substitution of cellulose per anhydrous glucose unit of from 0.01 to 0.50.

[0034] In one embodiment, the C1-C4 CA-MFC is CM-MFC having an average fiber diameter from 0.5 to 100 pm and a degree of carboxyalkyl substitution of cellulose per anhydrous glucose unit of from 0.01 to 0.50.

[0035] In one embodiment, the C1-C4 CA-MFC is CM-MFC having an average fiber diameter from 1 to 100 pm and a degree of carboxyalkyl substitution of cellulose per anhydrous glucose unit of from 0.01 to 0.50.

[0036] The C1-C4 carboxyalkyl microfibrillated cellulose has improved dispersion and lower initial viscosity in water which makes it easier to formulate than non-modified MFC, which allows the formulation to better blend formulation components and shorter processing times.

[0037] In some embodiments, the C1-C4 CA-MFC can be present in an amount of from 0.05 to 5 wt.%, or from 0.5 to 2 wt.%, based on the total weight of the emulsion. More particularly, the C1-C4 CA-MFC can be in a concentration of from 0.75 to 1 .5 wt.%, based on the total weight of the emulsion.

Emulsion

[0038] The emulsion of the present technology can be an oil-in-water (O/W) emulsion, a water-in-oil emulsion (W/O), or an oil-in-polyol (e.g. glycerol) emulsion. The emulsion can also be a multiple emulsion, in which O/W and W/O emulsions exist in a single system. In a multiple emulsion, the dispersed phase is itself an emulsion containing droplets of another phase. The dispersed phase can be a multiple emulsion such as a water-in-oil-in-water emulsion (W/O/W) or an oil-in-water-in-oil emulsion (O/W/O).

[0039] In particular, the emulsion of the present technology can be an O/W emulsion, with the water phase forming the continuous phase and the oil phase forming the dispersed phase. When the emulsion of the present technology is an O/W emulsion, the oil phase may be present in an amount of from 1 to 50 % by weight based on the total weight of the emulsion. The oil phase may be present in an amount greater than or equal to 4%, particularly greater than or equal to 5% or 10% by weight based on the total weight of the emulsion. The oil phase may be present in an amount of from 4 to 40 %, particularly 5 to 25%, more particularly from 10 to 20% by weight based on the total weight of the emulsion.

[0040] The emulsion of the present technology necessarily comprises an emulsifier or emulsifier system. Emulsifiers are interface-active substances which can prevent the interfacial tension between oil and water phase by positioning themselves preferably at the interface between these two phases. This is made possible as a result of their amphiphilic molecular structure: emulsifiers have at least one polar (hydrophilic) group and at least one nonpolar (lipophilic) group. As a result, they are soluble both in the hydrophilic phase and in the lipophilic phase. The part which is more soluble in the corresponding phase protrudes into this phase and as a result lowers the interfacial tension between the two phases. The person skilled in the formulation art would be aware of the large number of options of available emulsifiers and emulsifier system for formulating stable emulsions.

[0041] One of the advantages of C1-C4 CA-MFC, and particularly, carboxymethyl microfibrillated cellulose, is that it improves the efficacy of emulsifiers and improves the stability of the emulsion.

[0042] The emulsifier system can comprise a single emulsifier agent or a combination of emulsifier agents. In one embodiment, the emulsifier system can have a hydrophilic-lipophilic balance (HLB) of 4 or higher, more particularly 9 or higher. More particularly, the emulsifier system can have a HLB of from 8 to 12, or from 9 to 11. The HLB of the emulsifier system can be 10. The HLB of the emulsifier system can be from 4 to 23. The HBL of the emulsifier system can be determined by the HLB of the oil phase.

[0043] Of particular interest in the context of the present technology are emulsifiers or emulsifier systems comprising anionic surfactants and/or non-ionic surfactants.

[0044] In particular, the anionic surfactant can be an amino acid surfactant. Suitable amino acid surfactants can be selected from a N-acyl amino acid of the formula: wherein R is a saturated or unsaturated, straight or branched alkyl chain containing 7 to 17 carbon atoms, R12 is H or a methyl group, R13 is H, COO"M⁺, CH2C00"M⁺ or COOH, n is 0 to 2, X is COO" or SO3" and M independently represents H, sodium, potassium, ammonium or triethanolammonium. More particularly, the amino acid-based surfactant can be a glutamate surfactant according to the formula: wherein R is a saturated or unsaturated, straight or branched alkyl chain containing 8 to 24 carbon atoms, particularly 14 to 20 carbon atoms, more particularly 16 to 18 carbon atoms, n is 0 to 2, and M independently is H, sodium, potassium, ammonium or triethanolammonium.

[0045] Non-limiting examples of glutamate surfactants are di-potassium capryloyl glutamate, di-potassium undecylenoyl glutamate, di-sodium capryloyl glutamate, disodium cocoyl glutamate, di-sodium lauroyl glutamate, di-sodium stearoyl glutamate, disodium undecylenoyl glutamate, potassium capryloyl glutamate, potassium cocoyl glutamate, potassium lauroyl glutamate, potassium myristoyl glutamate, potassium stearoyl glutamate, potassium undecylenoyl glutamate, sodium capryloyl glutamate, sodium cocoyl glutamate, sodium lauroyl glutamate, sodium myristoyl glutamate, sodium olivoyl glutamate, sodium palmitoyl glutamate, sodium stearoyl glutamate, sodium undecylenoyl glutamate, and mixtures thereof. In one embodiment, the glutamate surfactant is sodium stearyl glutamate.

[0046] Non-ionic surfactants of particular interest in the context of this technology include, but are not limited to, fatty alcohol ethoxylates, glucoside esters and alkyl glucoside esters.

[0047] In one embodiment, the non-ionic surfactant is selected from the group consisting of cetearyl olivate, sorbitan fatty acid and mixtures thereof. Particularly, the sorbitan fatty acid can be sorbitan olivate. More particularly, the non-ionic surfactant can comprise a combination of cetearyl olivate and sorbitan olivate.

[0048] In one embodiment, the emulsifier comprises, consists essentially of or consist of an alkyl glucoside ester. Alkyl glucoside esters are prepared by reacting a fatty acid or ester with an alkyl glucoside. In particular, the alkyl glucoside ester is a methyl glucoside ester. The methyl glucoside ester can be selected from the group consisting of a polyethylene glycol methyl glucose sesquistearate, methyl glucose sesquisterate, methyl glucose, methyl glucose dioleate, and combinations thereof.

[0049] It has been seen that in the context of the present technology, where the emulsion comprises a C1-C4 CA-MFC, particularly a carboxymethyl microfibrillated cellulose, emulsifier systems combining at least two different emulsifiers wherein the emulsifier system comprises (i) a first emulsifier having a HLB value higher than 10 and (ii) a second emulsifier having a HLB value lower than 10, allow to obtain emulsions with high stability and optimal viscosity and texture. In particular, the emulsion can have a Brookfield viscosity of from 6,000 to 14,000 mPa-s at 25 °C and 20 rpm.

[0050] In one embodiment, the emulsifier comprises a combination of a polyethylene glycol methyl glucose sesquistearate and a methyl glucose ester selected from methyl glucose dioleate or methyl glucose sesquistearate. The emulsifier can comprise a combination of PEG-20 Methyl Glucose Sesquistearate and a methyl glucose ester selected from methyl glucose dioleate or methyl glucose sesquistearate. PEG-20 Methyl Glucose Sesquistearate and methyl glucose dioleate are available, for example, from Lubrizol Advanced Materials, Inc. under the trade names Glucamate™ SSE-20 and Glucate™ DO, respectively.

[0051] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier, comprising a combination of polyethylene glycol methyl glucose sesquistearate and a methyl glucose ester selected from methyl glucose dioleate or methyl glucose sesquistearate; d. a C1-C4 carboxyalkyl microfibrillated cellulose; e. C4-C26 fatty alcohol, particularly a cetyl alcohol or cetearyl alcohol; and f. a glyceryl ester, particularly glyceryl stearate.

[0052] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier, comprising a combination of polyethylene glycol methyl glucose sesquistearate and a methyl glucose ester selected from methyl glucose dioleate or methyl glucose sesquistearate; d. from 0.05 wt.% to 5 wt.% of carboxymethyl microfibrillated cellulose; e. from 0.1 to 5 wt.% of C4-C26 fatty alcohol, particularly a cetyl alcohol, stearyl alcohol or cetearyl alcohol; and f. from 0.1 to 0.5 wt.% of a glyceryl ester, particularly glyceryl stearate, wherein all the weights are based on the total weight of the emulsion.

[0053] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier, comprising a combination of polyethylene glycol methyl glucose sesquistearate and a methyl glucose ester selected from methyl glucose dioleate or methyl glucose sesquistearate; d. from 0.05 wt.% to 5 wt.% of carboxymethyl microfibrillated cellulose; e. from 0.1 to 5 wt.% of C4-C26 fatty alcohol, particularly a cetyl alcohol or cetearyl alcohol; and f. from 0.1 to 0.5 wt.% of a glyceryl ester, particularly glyceryl stearate, wherein all the weights are based on the total weight of the emulsion.

[0054] In one embodiment, the emulsifier comprises a combination of an alkyl glucoside ester and a monoglyceride. In particular, the alkyl glucose ester can be methyl glucose sesquistearate and the monoglyceride can be glyceryl stearate, more particularly glyceryl stearate citrate.

[0055] In one non-limiting embodiment, the emulsifier comprises a crosslinked copolymer of (meth)acrylic acid and C10 to C30 alkyl esters of (meth)acrylic acid, more particularly an acrylates/C10-C30 Alkyl Acrylate Crosspolymer. Advantageously, the use in the emulsion of the present invention of a combination of acrylates/C10-C30 Alkyl Acrylate Crosspolymer with C1-C4 CA-MFC allows to obtain emulsion with high viscosity. In particular, the emulsion can have a Brookfield viscosity of from 12,000 to 18,000 mPa s at 25 °C and 20 rpm.

[0056] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier, comprising an acrylates/C10-C30 alkyl acrylate crosspolymer; d. a C1-C4 carboxyalkyl microfibrillated cellulose; e. C4-C26 fatty alcohol, particularly a cetyl alcohol or cetearyl alcohol; and f. a glyceryl ester, particularly glyceryl stearate.

[0057] In one non-limiting embodiment, the emulsifier comprises a cetyl phosphate, more particularly a potassium cetyl phosphate. In this embodiment, the emulsion can have a Brookfield viscosity of from 8,000 to 12,000 mPa s at 25 °C and 20 rpm.

[0058] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier, comprising a cetyl phosphate. d. a C1-C4 carboxyalkyl microfibrillated cellulose; e. a C4-C26 fatty alcohol, particularly a cetyl alcohol or cetearyl alcohol; and f. a glyceryl ester, particularly glyceryl stearate.

[0059] The emulsifier or emulsifier system can be in a concentration of from 0.01 to 5 wt.%, particularly from 0.5 to 3 wt.% based on the total weight of the emulsion.

[0060] The present technology also relates to a method for preparing an emulsion as disclosed herein comprising the step of mixing an oil phase with a water phase in the presence of an emulsifier, wherein the emulsion comprises a C1-C4 carboxyalkyl microfibrillated cellulose.

[0061] One of the advantages of the present technology is that due to its improved dispersibility the C1-C4 CA-MFC, and more particularly CM-MFC, can be incorporated into the water phase before the water phase is mixed with the oil phase or can be added once the emulsion is already formed.

[0062] Thus, in one embodiment, the present technology relates to a method for preparing an emulsion comprising the steps of: i) Dispersing a C1-C4 carboxyalkyl microfibrillated cellulose in a water phase; and ii) Mixing said water phase with an oil phase in the presence of an emulsifier to form an emulsion.

In particular, the emulsion can be an oil-in-water emulsion.

[0063] In another embodiment, the present technology relates to a method for preparing an emulsion comprising the steps of: i) Mixing an oil phase with a water phase in the presence of an emulsifier to form an emulsion; and ii) Adding a C1-C4 carboxyalkyl microfibrillated cellulose.

In particular, the emulsion can be an oil-in-water emulsion.

[0064] C1-C4 CA-MFC, and particularly CM-MFC, improves the texture of emulsions.

The emulsions show homogeneous appearance, do not show agglomerates, are smooth and have reduced stringiness. Emulsions with reduced stringiness are easier to pick up, while products which are very stringy could be perceived as sticky and unpleasant, which trigger negative emotions in the consumer and reduce acceptance of formulations.

[0065] Thus, in one aspect the invention relates to the use of C1-C4 CA-MFC to improve the texture of an emulsion, particularly an oil-in-water emulsion. [0066] In addition, emulsions with C1-C4 CA-MFC, and particularly CM-MFC, have improved sensory aspects. In particular, emulsions with C1-C4 CA-MFC show a reduced whiteness appearance and better absorbency perception on application. The sensory of emulsions after application is also improved as they show reduced pilling, i.e. absence of pills or balls on the skin.

[0067] Thus, in one aspect the invention relates to the use of a C1-C4 CA-MFC to improve the sensory of an emulsion, particularly an oil-in-water emulsion. The invention also relates to the use of a C1-C4 CA-MFC to improve the sensory of a personal care or pharmaceutical formulation comprising an emulsion, particularly an oil-in-water emulsion. [0068] Thus, in one aspect the invention relates to the use of a C1-C4 CA-MFC to improve the sensory of an emulsion, particularly an oil-in-water emulsion, or a personal care or pharmaceutical formulation comprising an emulsion. Particularly, the invention relates to the use of a C1-C4 CA-MFC to reduce the whiteness appearance and/or pilling on the skin of an emulsion, particularly an oil-in-water emulsion, or a personal care or pharmaceutical formulation comprising an emulsion.

[0069] In one aspect, the invention relates to the use of a C1-C4 CA-MFC to improve the stability of an emulsion.

[0070] In particular, the invention can relate to the use of a C1-C4 CA-MFC to improve the texture and the sensory of an emulsion. More particularly, the invention can relate to the use of a C1-C4 CA-MFC to improve the texture, the sensory and the stability of an emulsion.

[0071] The present invention also relates to a method of improving the texture, sensory and/or stability of an emulsion comprising adding to the emulsion a C1-C4 CA- MFC, in particular a carboxymethyl microfibri Hated cellulose (CM-MFC). The C1-C4 CA- MFC can be added to the emulsion at an amount of from 0.05 to 5 wt.% based on the total weight of the emulsion, more particularly 0.5 to 2 wt.%, still more particularly 0.75 to 1.5 wt.%. The C1-C4 CA-MFC can be added, for example, to the emulsion disclosed herein.

Water phase

[0072] The emulsion of the present technology comprises a water phase. The water phase comprises water and can contain, e.g., other components that are water soluble. The water phase can comprise at least 90 wt.%, at least 95 wt.%, or at least 98 wt.% water, based on the total weight of the water phase. [0073] In view of its hydrophilic character, typically, the C1-C4 CA-MFC is present in the aqueous phase, i.e. the water phase comprises the C1-C4 CA-MFC.

Oil phase

[0074] The oil phase may comprise at least one ester oil, vegetable oil, alcohol, paraffin oil or silicone. The oil phase can comprise one or more oils chosen from mineral oils such as paraffin oil, petroleum jelly, isoparaffins or white mineral oils; oils of animal origin, such as squalene or squalane; vegetable oils, such as phytosqualane, sweet almond oil, coconut oil, castor oil, jojoba oil, olive oil, rapeseed oil, peanut oil, sunflower oil, wheat germ oil, corn germ oil, soybean oil, cottonseed oil, alfalfa oil, poppy oil, pumpkin oil, evening primrose oil, millet oil, barley oil, rye oil, safflower oil, bancoulier oil, passionflower oil, hazelnut oil, palm oil, shea butter, apricot kernel oil, coriander seed oil, beech oil, calophyllum oil, sysymbrium oil, avocado oil, calendula oil, oils from flowers or vegetables ethoxylated vegetable oils; synthetic oils such as fatty acid esters such as butyl myristate, propyl myristate, isopropyl myristate, cetyl myristate, isopropyl palmitate, octyl palmitate, butyl stearate, hexadecyl stearate, isopropyl stearate, octyl stearate, isocetyl stearate, dodecyl oleate, hexyl laurate, propylene glycol dicaprylate, esters derived from lanolic acid, such as isopropyl lanolate, isocetyl lanolate, monoglycerides, diglycerides and triglycerides of fatty acids such as glycerol triheptanoate, alkylbenzoates, hydrogenated oils, poly (alpha-olefins), polyolefins such as poly (isobutane), synthetic isoalkanes such as isohexadecane, isododecane, perfluorinated oils; silicone oils such as dimethylpolysiloxanes, methylphenylpolysiloxanes, amino-modified silicones, fatty acid- modified silicones, alcohol-modified silicones, alcohol-modified silicones and fatty acids, silicone-modified silicones polyether groups, modified epoxy silicones, silicones modified by fluorinated groups, cyclic silicones and silicones modified by alkyl groups.

[0075] In one embodiment, the oil phase comprises, consists essentially of or consist of caprilyc/capric triglycerides.

[0076] The oil phase can contain, e.g., other components that are oil soluble. The oil phase can comprise at least 90 wt %, at least 95 wt %, or at least 98 wt %, of one or more than one oils or oil soluble components, based on the total weight of the oil phase.

[0077] Advantageously, the emulsion of the present invention can comprise a C4-C26 fatty alcohol and/or ether thereof, and/or C12-C26 fatty acid and/or ester thereof. The combination of C1-C4 carboxyalkyl microfibrillated cellulose with a C4-C26 fatty alcohol and/or ether thereof, and/or C12-C26 fatty acid and/or ester thereof, synergistically increases the viscosity of the emulsion. [0078] Fatty alcohols suitable for use in the emulsions of the technology include, in particular, saturated C4-C26 fatty alcohols. Exemplary fatty alcohols include capryl alcohol, pelargonic alcohol, capric alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, isocetyl alcohol, stearyl alcohol, isostearyl alcohol, cetearyl alcohol, palmitoleyl alcohol, elaidyl alcohol, behenyl alcohol, lignoceryl alcohol (1-tetracosanol), ceryl alcohol (1-hexacosanol), and mixtures thereof. Fatty alcohols are widely available and can be obtained through the hydrogenation of esterified vegetable and animal oils and fats. In particular, the fatty alcohol can be a C12-C22 fatty alcohol, more particular a C16-C18 fatty alcohol. In one embodiment, the emulsion of the present technology can comprise a fatty alcohol selected from the group consisting of cetyl alcohol, cetearyl alcohol, stearyl alcohol, behenyl alcohol and mixtures thereof. More particularly, the emulsion can comprise a fatty alcohol selected from the group consisting of cetyl alcohol, cetearyl alcohol, stearyl alcohol and mixtures thereof.

[0079] C4-C26 fatty alcohol ethers are alkoxylated fatty alcohols formed from the reaction of a fatty alcohol with an alkylene oxide, generally ethylene oxide or propylene oxide. Suitable ethoxylated fatty alcohols are adducts of fatty alcohols and polyethylene oxide. The fatty alcohol ether can be represented by the formula R¹-(OCH2CH2)n-OH, wherein R¹ represents the aliphatic residue of the parent fatty alcohol and n represents the number of ethylene oxide units. In particular, R¹ can derived from a fatty alcohol containing 4 to 26 carbon atoms and ‘n’ can be an integer ranging from 2 to 150, or from 2 to 50, or from 3 to 25, or from 3 to 10. Exemplary fatty alcohols ethers include, but are not limited to capryl alcohol ethoxylate, lauryl alcohol ethoxylate, myristyl alcohol ethoxylate, cetyl alcohol ethoxylate, stearyl alcohol ethoxylate, cetearyl alcohol ethoxylate, sterol ethoxylate, and behenyl alcohol ethoxylate, wherein the number of ethylene oxide units in each of the foregoing ethoxylates can range from 2 to 150. It is to be recognized that the propoxylated adducts of the foregoing fatty alcohols and mixed ethoxylated/propoxylated adducts of the foregoing fatty alcohols are also contemplated within the scope of the present technology. The ethylene oxide and propylene oxide units of the ethoxylated/propoxylated fatty alcohols can be arranged in random or in blocky order. In one embodiment, the fatty alcohol ethoxylate is selected from the group consisting of lauryl alcohol ethoxylate, myristyl alcohol ethoxylate, cetyl alcohol ethoxylate, cetearyl alcohol ethoxylate, stearyl alcohol ethoxylate, behenyl alcohol ethoxylate and mixtures thereof. More particularly, the emulsion of the present technology can comprise a fatty alcohol ethoxylate selected from the group consisting of cetyl alcohol ethoxylate, cetearyl alcohol ethoxylate, stearyl alcohol ethoxylate, and mixtures thereof. [0080] Advantageously, the fatty alcohol or ether thereof can be in a concentration of from 0.1 to 5 wt.%, or from 0.5 to 4 wt.%, or from 1 to 3 wt.% based on the total weight of the emulsion.

[0081] Suitable fatty acids useful in the context of the present technology include, in particular, saturated C12 to C26 fatty acids. Exemplary fatty acids include, but are not limited to, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, and mixtures thereof.

[0082] In particular, the emulsion of the present invention can comprise a fatty acid selected from the group consisting of myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and mixtures thereof. More particularly, the emulsion comprises a fatty acid selected from the group consisting of palmitic acid, stearic acid, and mixtures thereof. Even more particularly, the emulsion can comprise stearic acid.

[0083] Fatty acid esters can be formed by esterifying a fatty acid with an alcohol. In particular, the fatty acid ester of the present technology can be a glyceryl fatty acid ester. Exemplary glyceryl fatty acid esters include, but are not limited to, glyceryl laurate, glyceryl myristate, glyceryl palmitate, glyceryl stearate, glyceryl arachidate, glyceryl behenate, glyceryl lignocerate and mixtures thereof. In particular, the emulsion of the present technology can comprise a glyceryl palmitate, glyceryl stearate, and mixtures thereof. Even more particularly, the emulsion of the present technology comprises glyceryl stearate.

[0084] The fatty acid or fatty acid ester can be in a concentration of from 0.1 to 5 wt.%, or from 0.5 to 3.5 wt.%, preferably from 1 to 3 wt.% based on the total weight of the emulsion.

[0085] In one embodiment, the emulsion of the present technology comprises a combination of a fatty alcohol or a fatty acid with a fatty acid ester. Particularly, the fatty acid ester is a glyceryl fatty acid, more particularly glyceryl palmitate or glyceryl stearate, preferably glyceryl stearate. One of the advantages is that the viscosity and stability of the emulsion is increased, while texture and sensory is improved.

[0086] In one embodiment, the emulsion of the present technology comprises a combination of cetyl alcohol, cetearyl alcohol or stearyl alcohol, with a fatty acid ester. Particularly, the fatty acid ester is a glyceryl fatty acid, more particularly glyceryl palmitate or glyceryl stearate, preferably glyceryl stearate.

[0087] Advantageously, the emulsion of the present technology can comprise a combination of cetearyl alcohol and glyceryl stearate, which improves the stability and viscosity of the emulsion while providing optimal viscosity when combined with CA-MFC. [0088] In one embodiment, the emulsion of the present technology comprises a combination of palmitic acid or stearic acid with a fatty acid ester. Particularly, the fatty is a glyceryl fatty acid, more particularly glyceryl palmitate or glyceryl stearate, preferably glyceryl stearate. More particularly, the emulsion of the present technology comprises a combination of stearic acid with glyceryl stearate, which improves the stability and viscosity of the emulsion.

[0089] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. a C1-C4 carboxyalkyl microfibrillated cellulose; and e. a C4-C26 fatty alcohol, particularly cetyl alcohol, cetearyl alcohol or stearyl alcohol.;

The emulsion can further comprise a glyceryl ester, particularly glyceryl stearate.

[0090] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. from 0.5 to 2 wt.% of a C1-C4 carboxyalkyl microfibrillated cellulose; and e. from 0.1 to 5 wt.% of a C4-C26 fatty alcohol, particularly cetyl alcohol, cetearyl alcohol or stearyl alcohol; wherein all the weights are based on the total weight of the emulsion. The emulsion can further comprise a glyceryl ester, particularly glyceryl stearate.

[0091] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. a C1-C4 carboxyalkyl microfibrillated cellulose; and e. a C12-C26 fatty acid, particularly stearic acid.

The emulsion can further comprise a glyceryl ester, particularly glyceryl stearate.

[0092] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. from 0.5 to 2 wt.% of a C1-C4 carboxyalkyl microfibrillated cellulose; and e. from 0.1 to 5 wt.% of a C12-C26 fatty acid, particularly stearic acid; wherein all the weights are based on the total weight of the emulsion. The emulsion can further comprise a glyceryl ester, particularly glyceryl stearate.

Gum of natural origin

[0093] In some embodiments, the emulsion of the present technology can further comprise a natural gum. Natural gums are non-cellulose polysaccharides derived from botanical sources, seaweeds, or produced via bacterial fermentation.

[0094] The natural gum can be present in an amount of from 0.01 to 1 wt.% based on the total weight of the emulsion. Particularly, the natural gum can be in an amount of from 0.05 to 0.5 wt.%, or from 0.05 to 0.15 wt.%, based on the total weight of the emulsion. [0095] In one embodiment, the natural gum is a gum from microbial origin. By gum of microbial origin is meant a gum which is or can be produced by microbial fermentation. As used herein, a biogum of microbial origin is a polymer, such as a polysaccharide, obtained or obtainable by fermentation of a microorganism. In this context, the term “polymer” can be interchanged with the term “biopolymer”. In particular, the gum of microbial origin is obtained or is obtainable by fermentation of a carbohydrate by a microorganism. The microorganism can be chosen from bacteria or fungi. The fermentation can be aerobic fermentation.

[0096] The gum of microbial origin can be chosen from xanthan gum, pullulan gum, sphingan exopolysaccharides, and mixtures thereof. Thus, the gum of microbial origin can be a gum chosen from xanthan gum, pullulan gum and sphingan exopolysaccharides, or it can be a mixture of biogums chosen from xanthan gum, pullulan gum and sphingan exopolysaccharides.

[0097] Xanthan gum is a gum which can be produced by fermentation of bacteria of the genus Xanthomonas, for example, bacteria of the species Xanthomonas campestris. More specifically, xanthan gum is a polysaccharide which can be produced, i.e., is obtainable, by fermentation of a carbohydrate by bacteria of the genus Xanthomonas, for example, bacteria of the species Xanthomonas campestris. In particular, the xanthan gum is produced by fermentation of a carbohydrate by bacteria of the species Xanthomonas campestris. Xanthan gum is a water-soluble, high-molecular weight (of the order of 1000 kDa) polysaccharide. Xanthan gum comprises (or primarily consists of) the following hexose units: D-glucose, D-mannose, and D-glucuronic acid.

[0098] Pullulan gum is a gum which can be produced by fermentation of the fungus Aureobasidium pullulans. More specifically, pullulan is a polysaccharide which can be produced, i.e., is obtainable, by fermentation of a carbohydrate, in particular starch, by the fungus Aureobasidium pullulans. Pullulan is a polysaccharide consisting of maltotriose units (three glucose units connected by a-1 ,4 glycosidic bonds) connected to each other by an a-1 ,6 glycosidic bond.

[0099] The terms “sphingan exopolysaccharide” and “sphingan” are used interchangeably herein. Sphingans are gums which can be produced by bacteria of the genus Sphingomonas. Sphingans are structurally closely related bacterial exopolysaccharides produced by members of the genus Sphingomonas. Sphingan expolysaccharides can be produced, i.e., are obtainable, by fermentation of a carbohydrate by bacteria of the genus Sphingomonas. The most commonly known sphingans include gellan, welan, rhamsan and diutan and these exhibit excellent rheological properties. Sphingans are structurally related by a backgone that comprises the sugars D-glucose, D-glucuronic acid and L-rhamnose (or L-mannose) but differ in the nature and location of their side-chains and in the presence or absence of acyl groups. Details of the structures of sphingans can be found in the literature, for instance in a book by Glaeser S.P., Kampfer P. (2014) The Family Sphingomonadaceae, and in Rosenberg E., DeLong E.F., Lory S., Stackebrandt E., Thompson F. (eds), The Prokaryotes, Springer, Berlin, Heidelberg. The gum of microbial origin can be chosen from the group of sphingan exopolysaccharides consisting of gellan, welan, diutan gum and mixtures thereof. Thus, the gum of microbial origin can be a gum chosen from gellan, welan and diutan gum, or it can be a mixture of biogums chosen from gellan, welan and diutan gum. [0100] In one embodiment the gum of microbial origin is diutan gum. Diutan gum, also known as heteropolysaccharide S-657, is a biogum which is produced by fermentation of a bacteria strain from genus Shingomonas, for example, a bacteria strain from genus Shingomonas deposited in the American Type Culture Collection (ATCC) with deposit number ATCC 53159. More specifically, diutan gum is an exopolysaccharide that can be produced, i.e. is obtainable, by fermentation of a carbohydrate by bacteria from the genus Shingomonas, and, in particular, a bacteria strain from genus Shingomonas having a deposit number ATCC 53159. Diutan generally exhibits a hexameric repeat unit consisting of four sugars in the backbone (glucose-glucuronic acid- glucose-rhamnose) and a side chain of two rhamnose residues attached to one of the glucose residues. One non-limiting example of commercially available diutan gum is Kelcocare™ diutan gum from CP Kelco. Diutan gum is also commonly referred as S-657 polysaccharide. More particularly, the diutan gum can be in a concentration of from 0.05 to 0.15 wt.% based on the total weight of the emulsion. Advantageously, diutan gum improved the stability of the emulsions and provided optimal viscosity showing a synergistic effect with CM-MFC.

[0101] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. a C1-C4 carboxyalkyl microfibrillated cellulose; e. a C4-C26 fatty alcohol, particularly cetyl alcohol, cetearyl alcohol or stearyl alcohol; f. a glyceryl ester, particularly glyceryl stearate; and g. a natural gum, particularly a diutan gum.

[0102] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. from 0.05 to 5 wt.% of a C1-C4 carboxyalkyl microfibrillated cellulose; e. from 0.1 to 5 wt.% of a C4-C26 fatty alcohol, particularly cetyl alcohol, cetearyl alcohol or stearyl alcohol; f. from 0.1 to 5 wt.% of a glyceryl ester, particularly glyceryl stearate; and g. from 0.05 to 0.15 wt.% of a natural gum, particularly a diutan gum; wherein all the weights are based on the total weight of the emulsion.

[0103] Advantageously, the emulsion has stability, optimal viscosity, and improved texture, appearance and sensory.

[0104] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. from 0.5 to 2 wt.% of a C1-C4 carboxyalkyl microfibrillated cellulose; e. from 1 to 3 wt.% of a C4-C26 fatty alcohol, particularly a cetyl alcohol or cetearyl alcohol; f. from 1 to 3 wt.% of a glyceryl ester, particularly glyceryl stearate; and g. from 0.05 to 0.15 wt.% of a diutan gum; wherein all the weights are based on the total weight of the emulsion.

[0105] The emulsion of the present technology can comprise: a. an oil phase; b. a water phase; c. an emulsifier; d. from 0.5 to 2 wt.% of a C1-C4 carboxyalkyl microfibrillated cellulose; e. from 1 to 3 wt.% of cetearyl alcohol; f. from 1 to 3 wt.% of glyceryl stearate; and g. from 0.05 to 0.15 wt.% of a diutan gum; wherein all the weights are based on the total weight of the emulsion.

[0106] The emulsion of the present technology can comprise: a. from 4 to 50 wt.% of an oil phase; b. a water phase; c. 0.5 to 3 wt.% of an emulsifier, comprising comprises a combination of a polyethylene glycol methyl glucose sesquistearate and a methyl glucose ester; d. from 0.5 to 2 wt.% of a C1-C4 carboxyalkyl microfibrillated cellulose; e. from 1 to 3 wt.% of a C4-C26 fatty alcohol, particularly a cetyl alcohol or cetearyl alcohol; f. from 1 to 3 wt.% of a glyceryl ester, particularly glyceryl stearate; and g. from 0.05 to 0.15 wt.% of diutan gum; wherein all the weights are based on the total weight of the emulsion. In particular, the emulsion can have a Brookfield viscosity of from 8,000 to 14,000 mPa s at 25 °C and 20 rpm.

[0107] The emulsion of the present technology can comprise: a. from 4 to 50 wt.% of an oil phase; b. a water phase; c. 0.5 to 3 wt.% of an emulsifier, comprising comprises a combination of a polyethylene glycol methyl glucose sesquistearate and a methyl glucose ester; d. from 0.5 to 2 wt.% of a C1-C4 carboxyalkyl microfibrillated cellulose; e. from 1 to 3 wt.% of cetearyl alcohol; f. from 1 to 3 wt.% of glyceryl stearate; and g. from 0.05 to 0.15 wt.% of diutan gum; wherein all the weights are based on the total weight of the emulsion. In particular, the emulsion can have a have a Brookfield viscosity of from 8,000 to 14,000 mPa s at 25 °C and 20 rpm.

[0108] In the foregoing emulsions, the C1-C4 carboxyalkyl microfibrillated cellulose can be, in particular, carboxymethyl microfibrillated cellulose, more particularly a carboxymethyl microfibrillated cellulose having an average fiber diameter from 0.1 to 500 pm, or from 0.5 to 100 pm, or from 1 to 100 pm.

Personal care and pharmaceutical formulations

[0109] The emulsion of the present technology is suitable for use in the preparation of personal care and pharmaceutical formulations.

[0110] The personal care formulation can be in the form of a lotion, cream or gel cream, or any form of emulsion known in the art. Of particular interest in the context of the present technology are personal care formulations for skin care or hair care. In one embodiment, the personal care formulation is a skin care formulation.

[0111] The pharmaceutical formulation can be in particular a dermopharmaceutical formulation. ‘Dermopharmaceutical’ as used herein refers to pharmaceutical preparation to be used in contact with the skin, hair, nails and mucoses. Particularly the dermopharmaceutical preparation is applied on the skin.

[0112] The personal care and pharmaceutical formulations can also be included in fabrics, non-woven fabrics, garments, medical devices and means for immobilizing the compounds to them. The preferred fabrics, non-woven fabrics, garments and medical devices are bandages, gauzes, t-shirts, socks, tights, underwear, girdles, gloves, diapers, sanitary napkins, dressings, bedspreads, wipes, adhesive patches, non-adhesive patches, occlusive patches, microelectric patches and/or face masks.

[0113] The personal care pharmaceutical formulations may contain many different ingredients that can be oil soluble, water soluble or non-soluble. Non-limiting examples of said ingredients include, preservatives (such as phenoxyethanol, formaldehyde solution, pentanediol or sorbic acid), perfumes, humectants or solvents such as alcohols, polyols such as glycerol and polyethylene glycols, sun filters or sunscreen ingredients, alpha hydroxyacids, antimicrobial, vitamins and their precursors (such as Vitamin A, B, C, D, F and precursors thereof), skin care active ingredients or agents, botanical extracts, insect repellents, essential oils, pigments (such as oxides and silicates, iron oxide, particularly coated iron oxides, and/or titanium dioxide, and ceramic materials such as boron nitride), deodorant or antiperspirant agents, depilatory agents, hair care agents (such as condition agents, hair dyes, hair relaxer, etc), antioxidant agents (such as EDTA and its salts, citric acid, tartaric acid, oxalic acid, BHA (butylhydroxyanisol), BHT (butylhydroxytoluene), tocopherol derivatives such as tocopherol acetate), and combinations thereof, as well as any other cosmetically or pharmaceutically acceptable excipient known by the personal skilled in the formulation art.

[0114] The personal care formulation may further include any personal care active ingredients or pharmaceutically active agents known, purported, or thought to have a beneficial effect on the chosen subject. In the context of this technology, the ‘personal care active ingredients’ as used herein refers to ingredients that improve or enhance the physical appearance. They are also commonly known as ‘cosmetic active ingredients’.

[0115] Among the personal care or pharmaceutically acceptable ingredients contained in the formulations described in this technology are ingredients commonly used in cosmetic or pharmaceutical compositions, for example and, not restricted to, antiwrinkle agents and/or anti-aging agents; firming agents, skin elasticity agents and/or restructuring agents; moisturizing agents; anti-photoaging agents, and/or blue-light protector agents; DNA protecting agents, DNA repair agents, and/or stem cell protecting agents; free radical scavengers and/or anti-glycation agents, detoxifying agents, antioxidant and/or anti-pollution agents; agents which increase the percutaneous absorption of any active compounds present therein; anti-perspirant agents; melanin synthesis stimulating or inhibiting agents; whitening or depigmenting agents; propigmenting agents; self-tanning agents; lipolytic agents or agents stimulating lipolysis, adipogenic agents, wound healing, burn healing and/or scar reducing agents; skin or keratin color changes; topical drugs, etc.

[0116] The formulations according to the present technology are also suitable for sunscreen or suncare products. Thus, the formulations may include ingredients typically used for sunscreening purposes. Non-limiting examples include, but are not limited to, benzoic acid derivatives, para-aminobenzoic acid (PABA), in particular the monoglycerol esters of PABA, the ethyl esters of N, N-propoxy PABA, the ethyl esters of N, N-diethoxy PABA, the ethyl esters of N, N-dimethyl PABA, the esters methyl, N, N-dimethyl PABA, butyl esters of N, N-dimethyl PABA; anthranilic acid derivatives such as homomenthyl-N- acetyl anthranilate; salicylic acid derivatives such as amyl salicylate, homomenthyl salicylate, ethylhexyl salicylate, phenyl salicylate, benzyl salicylate, (p-isopropanol phenyl salicylate); cinnamic acid derivatives such as ethylhexyl cinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, p-methoxypropyl cinnamate, p- methoxyisopropyl cinnamate, p-methoxyisoamyl cinnamate, p-methoxyoctyl cinnamate, (p-methoxy 2-ethylhexyl) cinnamate, (p-methoxy 2-ethoxy ethyl) cinnamate, (p-methoxy cyclohexyl) cinnamate, ethyl-ocyano-3-phenyl cinnamate, (2-ethyl hexyl) -o cyano-3- phenyl cinnamate, glyceryl diparamethoxy mono-2-ethylhexanoyl cinnamate; the family of benzophenone derivatives such as 2,4-dihydroxy benzophenone, 2,2'-dihydroxy 4- methoxy benzophenone, 2,2 ',4,4'-tetrahydroxy benzophenone, 2-hydroxy 4-methoxy benzophenone, 2-hydroxy 4-methoxy 4'-methyl benzophenone, 2-hydroxy 4-methoxy benzophenone- 5-sulfonate, 4-phenyl benzophenone, (2-ethyl hexyl) 4'- phenyl benzophenone-2-carboxylate, 2-hydroxy 4-(n-octyloxy) benzophenone, 4-hydroxy 3- carboxy benzophenone; 3- (4'-methyl benzylidene) d, l-camphor, 3- (benzylidene) d,l- camphor, benzalkonium methosulfate camphor; urocanic acid, ethyl urocanate; sulfonic acid derivatives such as 2-phenyl benzimidazole-5 sulfonic acid and its salts; the family of triazine derivatives such as hydroxyphenyl triazine, (ethylhexyloxy) (hydroxyphenyl) (4- methoxy phenyl) triazine, 2,4,6-trianillino-(p-carbo-2'-ethylhexyl-T-oxy)-1 ,3,5-triazine, 4,4 -((6 - ((((1 , 1-dimethyl ethyl) amino) carbonyl) phenyl) amino) -1 , 3,5-triazine-2, 4-diyl diimino) bis (2-ethyl hexyl) ester of benzoic acid, 2-phenyl-5-methyl benzoxazole, 2- (2'- hydroxy 5'-methyl phenyl) benzotriazole, 2- (2 '-hydroxy 5'-t-octyl phenyl) benzotriazole, 2-(2'-hydroxy 5'-methyl phenyl) benzotriazole; dibenzazine; dianisoylmethane, 4-methoxy 4 "-t-butyl benzoyl methane; 5- (3,3-dimethyl 2-norbornylidene) -3-pentan-2-one; diphenylacrylate derivatives such as (2-ethyl hexyl) 2-cyano 3,3-diphenyl 2-propenoate, ethyl-2-cyano 3,3-diphenyl 2-propenoate; polysiloxanes such as benzylidene siloxane malonate; inorganic solar filters, also called "mineral screens" such as titanium oxides, zinc oxides, cerium oxide, zirconium oxide, yellow, red or black iron oxides, chromium oxides.

[0117] The emulsion, personal care formulation or pharmaceutical formulation of the present technology can have a viscosity of from 1 ,000 to 20,000 mPa s, or from 3,000 to 15,000 mPa s, or from 6,000 to 14,000 mPa s or from 5,000 to 12,000 mPa s when determined in mPa s with a Brookfield LVT viscometer at 20 rpm at 25°C.

[0118] The present invention will be better understood by reference to the following examples, which serve to illustrate the invention, but not to limit the same.

EXAMPLES

Abbreviations

C16= cetyl alcohol

C18= stearyl alcohol

C16:18= cetearyl alcohol

CM-MFC= carboxymethyl microfibri Hated cellulose DG= diutan gum GS= glyceryl stearate

MFC= Microfibrillated cellulose (non-chemically modified)

S18= stearic acid

XG= xanthan gum

YV=yield value

Determination of viscosity

[0119] Unless otherwise specifically indicated, viscosity was determined as Brookfield viscosity with a viscometer at 20 rpm at 25°C. The spindle used was selected according to the expected viscosity of the formulation. As a reference spindle S5 was used for viscosities of 10,000-20,000 mPa s, S4 for viscosities of 3,000-10,000 mPa s and S3 for viscosities <3,000 mPa s.

[0120] Brookfield yield values are calculated as Brookfield Yield Value = (Apparent Viscosity at 0.5 rpm - Apparent Viscosity at 1 rpm)/100 and expressed as dyn/cm2.

EXAMPLE 1

Dispersion in aqueous medium

[0121] MFC and CM-MFC at concentrations of 1 wt.% of total solids were dispersed in water using different methods:

- Method A (dissolver stirrer): 1 ,000 rpm for 5 minutes

- Method B (high shear): 10,000 rpm (Ultraturrax® disperser) for 10 minutes.

[0122] As shown in Figure 1 , the dispersion of CM-MFC was much better than that of MFC at both conditions. Fiber agglomeration was evident for the MFC sample after stirring and homogenizing MFC in water, while the fibers were very well dispersed for the CM-MFC.

[0123] Other methods of dispersion were used and CM-MFC was seen to be very easy to disperse regardless of the method as the method did not significantly impact the dispersion results.

[0124] In addition, particle size distribution of the dispersions obtained by method A and B were determined by laser diffraction using a MasterSizer 3000. The particle size of dispersions of CM-MFC was homogeneous and about 200 nm for both Method A and method B. This demonstrates that no agglomerates were present. EXAMPLE 2

Synergy with fatty materials

[0125] A standard emulsion containing MFC (1 wt.%) or CM-MFC (1 wt.%) were prepared in accordance with the following formulas:

Table 1. Emulsion formulations without fatty materials

¹ TS=Total solids

[0126] The formula was prepared using hot process, heating Part A to 65-70°C. Part B was added to Part A under mixing, followed by homogenization at 10,000 rpm/2min. (T 25 digital Ultraturrax®). The pH was adjusted to about 6 and phenoxyethanol and ethylhexylglycerin were added as preservatives.

Table 2. Viscosity values of emulsions without fatty materials.

[0127] Fatty alcohol in combination with glyceryl stearate (i.e. fatty materials) was added to the standard emulsion formulated according to the table below and viscosity was measured after 24 hours. The results were compared with a control formula without polymers. Table 3. Emulsion formulations with fatty materials

¹ Total solids

[0128] The viscosity was significantly increased by combining cetearyl alcohol and glyceryl stearate with MFC or CM-MFC.

Table 4. Viscosity of emulsions with fatty materials.

[0129] The lower initial viscosity of CM-MFC and superior synergy with the fatty materials allows the formulator an efficient control over the blending of formulation components, shorter processing times, and better adjust viscosity.

EXAMPLE 3

Synergy with diutan gum [0130] The natural gum Sphingomonas Fermented Extract (Kelco-Care™ diutan gum from CP Kelco) at 0.05 wt.% was added to improve stability of the emulsions of Table 3. Results are summarized in Table 5. Table 5. Viscosity and stability of emulsions with CM-MFC

¹ YV= Yield value n.d.= not determined

[0131] CM-MFC provided better stability compared to MFC. The addition of gum further increased viscosity and improved stability, especially at high temperatures. The improvement in viscosity was better for the combination of CM-MFC with gum than for MFC with gum.

[0132] Emulsion stability was also determined after centrifugation test (13,000 rpm/10min). As shown in Figure 2, CM-MFC significantly improved the stability of the emulsion. The addition of diutan gum further improved stability, allowing to obtain a homogeneous phase when CM-MFC and diutan gum were combined. Emulsions with MFC (either alone or in combination with diutan gum) and diutan gum alone did not provide satisfactory texture.

EXAMPLE 4

Stringiness determination

[0133] The stringiness of the emulsions of T able 3 comprising CM-MFC and/or diutan gum was determined. Reduced stringiness can be seen as an improved pick-up as products which are very stringy could be perceived as sticky and unpleasant, triggering negative emotions in the consumer.

[0134] Stringiness was determined with a texture analyzer from Stable Micro Systems. The sample was placed in the texture analyzed and the probe put in contact with the sample. Stringiness was determined as the distance (cm) or which a product hangs on the probe when the probe is withdrawn Parameters used were: Test speed, 3 mm/s; Post-test speed, 10 mm/s; Distance, 23 mm; Sample temperature, 25°C.

[0135] Stringiness was improved by adding CM-MFC in the emulsions as less stringiness was observed for emulsion comprising CM-MFC compared to diutan alone.

Table 6. Stringiness of emulsions

[0136] Emulsions with MFC were also tested, but were rougher, opaque and non- homogeneous.

EXAMPLE 5

Additional synergy examples

[0137] The influence on viscosity of different fatty alcohols or fatty acid combined or not with glyceryl stearate was assessed for CM-MFC by using the following formulations (Tables 7 A, B and C).

Table 7A - Formulations

¹ Kelco-care™ Diutan Gum from CP Kelco (DG).

² Keltrol™ CG xanthan gum from CP Kelco (XG).

³ Crodamol™ GTCC from Croda.

⁴ Glucamate™ SSE-20 emulsifier from Lubrizol Advanced Materials, Inc. ⁵ Glucate™ DO emulsifier from Lubrizol Advanced Materials, Inc.

⁶ Hidrolite® 6 from Symrise.

⁷ Symsave® H from Symrise.

Table 7B- Formulations

¹ Kelco-care™ Diutan Gum from CP Kelco. ² Keltrol™ CG xanthan gum from CP Kelco.

³ Crodamol™ GTCC from Croda.

⁴ Glucamate™ SSE-20 emulsifier from Lubrizol Advanced Materials, Inc.

⁵ Glucate™ DO emulsifier from Lubrizol Advanced Materials, Inc. ⁶ Hidrolite® 6 from Symrise.

⁷ Symsave® H from Symrise.

Table 7C- Formulations

¹ Kelco-care™ Diutan Gum from CP Kelco. ² Keltrol™ CG xanthan gum from CP Kelco.

³ Crodamol™ GTCC from Croda.

⁴ Glucamate™ SSE-20 emulsifier from Lubrizol Advanced Materials, Inc.

⁵ Glucate™ DO emulsifier from Lubrizol Advanced Materials, Inc.

⁶ Hidrolite® 6 from Symrise. ⁷ Symsave® H from Symrise.

[0138] Stability and viscosity results at room temperature or 50°C are shown in Tables 8 and 9, respectively. Table 8 - Stability at room temperature

Table 9 - Stability at 50°C

N.S.= not stable

[0139] Viscosity and stability were improved when CM-MFC was used. Xanthan gum and diutan gum significantly increased viscosity, however formulations with these ingredients alone undesirably showed high stringiness and soaping effect. Stability was improved with CM-MFC even in the absence of fatty materials.

[0140] Formulations with fatty materials alone showed low viscosity and long-term stability. Viscosity and stability of formulations with fatty materials was increased by the addition of CM-MFC. Combinations of CM-MFC with cetyl alcohol, stearyl alcohol, cetearyl alcohol, stearic acid and glyceryl stearate showed higher viscosity. The texture of the formulations was the most optimal for formulations when CM-MFC was combined with glyceryl stearate in addition to either cetyl alcohol, stearyl alcohol, cetearyl alcohol and stearic acid.

EXAMPLE 6

Sensory Evaluation

[0141] Sensory evaluations were conducted on formulations intended for use on human skin (Table 10) including CM-MFC or other comparative ingredients. Formulations were evaluated by a panel consisting of 7 trained panelists who were requested to rate the following attributes for each formulation (where higher rating is preferred):

- Spreadability: ease of moving the product over the skin.

- Richness: heavy, having cushion, high residue, and opposite of light. Evaluated throughout the rub-out phase.

- Absence of Oiliness: amount of oil perceived in the product.

- Absence of Stickiness: degree to which the fingers and palm adhere to the skin

- Softness: smooth, agreeable to touch, having no residue.

- Absence of Whiteness: Reference to soaping effect - amount the product forms suds or soap while rubbing on the skin.

- Absorbency: ease of penetration in the skin

- Matte effect: amount of light reflected from the skin

- Absence of pilling: amount the products pills/balls on the skin Table 10 - Formulations for sensory evaluation

¹ Carboxymethyl microfibrillated cellulose of the invention.

² Kelco-care™ Diutan Gum from CP Kelco.

³ Keltrol™ CG xanthan gum from CP Kelco. ⁴ Carbopol® Ultrez 10 polymer from Lubrizol Advanced Materials, Inc.

Table 11A - Sensory evaluation during application Table 11 B - Sensory evaluation after application (about 2 minutes after application).

[0142] CM-MFC showed optimal sensorial aspects. Particularly, compared to diutan and xanthan gum CM-MFC allowed to obtain formulations with absence of whiteness and haver a better absorbency perception on application. Softness after application was better for CM-MFC with absence of pilling. The sensory profile of CM-MFC formulation resembles that of formulations with silicone, but CM-MFC offers a more natural, biodegradable and sustainable alternative. EXAMPLE ?

Viscosity and stability with different emulsifiers

[0143] The efficacy of CM-MFC when combined with different emulsifiers was tested. Formulations were prepared as set out in Table 12: Table 12 - Emulsion formulations with different emulsifiers

¹ Kelco-care™ Diutan Gum from CP Kelco.

² Keltrol™ CG xanthan gum Gum from CP Kelco. ³ Glucate™ SS emulsifier from Lubrizol Advanced Materials, Inc.

⁴ Glucamate™ SSE-20 emulsifier from Lubrizol Advanced Materials, Inc.

⁵ Emulsifier used as detailed in Table 13A and Table 13B. Table 13A - Stability and viscosity at room temperature

¹ Pemulen™ EZ-4U polymer

N.S., not stable Table 13B - Stability and viscosity at 50°C.

¹ Pemulen™ EZ-4U polymer

N.S., not stable [0144] CM-MFC showed a high compatibility with a broad variety of emulsifier systems. Of note, CM-MFC improved stability of the emulsions compared to emulsion without CM-MFC. Remarkably none of the emulsions, except those using PEG-20 Methyl Glucose Sesquistearate + Methyl Glucose Sesquistearate, and Acrylates/C 10-30 Alkyl Acrylate Crosspolymer were stable at long term at 50 °C in the absence of CM-MFC. [0145] Viscosity was also increased when CM-MFC was used. Viscosity was synergistically increased when combining CM-MFC with emulsifier systems combining 2 types of emulsifiers (low and high HBL).

[0146] Combinations of CM-MFC with Glyceryl stearate citrate + Methyl Glucose Sesquistearate or PEG-20 Methyl Glucose Sesquistearate + Methyl Glucose Sesquistearate or Sodium stearyl glutamate + Methyl Glucose Sesquistearate, provided high viscosity.

[0147] The invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

Claims

CLAIMS:

1. An emulsion comprising: a. an oil phase; b. a water phase; c. an emulsifier; and d. a C1-C4 carboxyalkyl microfibrillated cellulose.

2. The emulsion of claim 1 , wherein the C1-C4 carboxyalkyl microfibrillated cellulose is in an amount of from 0.05 to 5 wt.% based on the total weight of the emulsion.

3. The emulsion of claim 2, wherein the C1-C4 carboxyalkyl microfibrillated cellulose is in an amount of from 0.5 to 2 wt.%, preferably from 0.75 to 1.5 wt.% based on the total weight of the emulsion.

4. The emulsion of any one of the previous claims, wherein the C1-C4 carboxyalkyl microfibrillated cellulose is carboxymethyl microfibrillated cellulose.

5. The emulsion of any one of the previous claims, wherein the C1-C4 carboxyalkyl microfibrillated cellulose has an average fiber diameter from 0.1 to 500 pm.

6. The emulsion of any one of the previous claims, wherein the C1-C4 carboxyalkyl microfibrillated cellulose has an average fiber diameter from 0.5 to 100 pm, preferably from 1 to 100 pm.

7. The emulsion of any one of the previous claims, wherein the emulsion is in the form of an oil-in-water (O/W) emulsion.

8. The emulsion of the previous claims, wherein the emulsion comprises a C4-C26 fatty alcohol and/or ether thereof.

9. The emulsion of claim 8, wherein the fatty alcohol or ether thereof is in a concentration of from 0.1 to 5 wt.%, or from 0.5 to 4 wt.%, or from 1 to 3 wt.% based on the total weight of the emulsion.

10. The emulsion of any of the previous claims, wherein the emulsion comprises a C12- C26 fatty acid and/or ester thereof.

11 . The emulsion of claim 10, wherein the fatty acid or ester thereof is in a concentration of from 0.1 to 5 wt.%, or from 0.5 to 3.5 wt.%, preferably from 1 to 3 wt.% based on the total weight of the emulsion.

12. The emulsion of claim 10 or claim 11 , wherein the ester is a glyceryl ester.

13. The emulsion of any one of the previous claims, wherein the emulsion comprises a fatty alcohol selected from the group consisting of cetyl alcohol, cetearyl alcohol, stearyl alcohol, behenyl alcohol and mixtures thereof.

14. The emulsion of any of the previous claims, wherein the emulsion comprises cetearyl alcohol and glyceryl stearate.

15. The emulsion of any of the previous claims, wherein the emulsion comprises stearic acid.

16. The emulsion of any of the previous claims, wherein the emulsion comprises stearic acid and glyceryl stearate.

17. The emulsion of any of the previous claims, wherein the emulsion comprises a natural gum.

18. The emulsion of claim 17, wherein the natural gum is a gum from microbial origin.

19. The emulsion of claim 18, wherein the gum is a sphingan exopolysaccharide, preferably diutan gum.

20. The emulsion of any one of claims 17 to 19, wherein the gum is in an amount of from 0.01 to 1 wt.% based on the total weight of the emulsion.

21 . The emulsion of any one of claims 17 to 20, wherein the gum is in an amount of from 0.05 to 0.15 wt.% based on the total weight of the emulsion.

22. The emulsion of any of the previous claims, wherein the emulsifier comprises an alkyl glucoside ester.

23. The emulsion of any of the previous claims, wherein the emulsifier comprises methyl glucose dioleate, methyl glucose sesquistearate and/or PEG-20 methyl glucose sesquistearate.

24. The emulsion of any of the previous claims, wherein the oil phase is in an amount of from 4 to 50 wt.% based on the total weight of the emulsion.

25. The emulsion of any one of the previous claims, wherein the oil phase is in an amount of from 5 to 25 wt.%, preferably from 10 to 20 wt.% based on the total weight of the emulsion.

26. A personal care or pharmaceutical formulation comprising the emulsion of any one of the previous claims.

27. The emulsion according to any one of claim 1 to 25 or the personal care or pharmaceutical formulation of claim 26 having a Brookfield viscosity from 3,000 to 15,000 at 25 °C and 20 rpms.

28. Method for preparing an emulsion according to any of claims 1 to 25 or 27 comprising the step of mixing an oil phase with a water phase in the presence of an emulsifier, wherein the emulsion comprises a C1-C4 carboxyalkyl microfibri Hated cellulose.

29. Use of a C1-C4 carboxyalkyl microfibri Hated cellulose to improve the texture, the sensory and/or the stability of an emulsion.

30. Method of improving the texture, sensory and/or stability of an emulsion comprising adding to the emulsion a C1-C4 carboxyalkyl microfibrillated cellulose.