Oil-in-water emulsions with long-term stability

Abstract

An oil-in-water emulsion having long-term stability comprising (I) an oil phase present in the emulsion in the form of droplets, (II) an aqueous phase, and (III) a polymeric component. The polymer component includes (A) a starch component comprising a specific hydrophobically modified starch; (B) a non-starch polysaccharide; and (C) a crosslinked starch. The emulsions exhibit stability of at least 4 weeks at room temperature.

Description

Technical Field

[0001] This disclosure generally relates to oil-in-water emulsions with long-term stability. More specifically, this disclosure relates to oil-in-water emulsions comprising hydrophobically modified starch. Background Technology

[0002] Oil-in-water (O / W) dispersions are widely used in emulsions, creams, and moisturizers to provide hydration, moisturization, and other benefits to the skin. However, these dispersions may suffer from long-term stability issues, which can cause changes in texture and appearance over time, leading to consumer dissatisfaction.

[0003] The following are some common issues regarding the long-term stability of oil-in-water dispersions. When oil droplets rise to the top of the dispersion, buoyancy occurs, resulting in a creamy or thick layer on the surface. This is typically caused by the density difference between the oil and water phases and can be exacerbated by temperature changes, agitation, or aging. Phase separation occurs when the oil and water phases separate, resulting in a clear layer of oil floating on top of the water layer. This can occur due to various factors, including inadequate emulsification, temperature changes, and aging. Flocculation occurs when oil droplets in the dispersion aggregate to form larger clusters that may settle or float to the top of the product. This can be caused by a variety of factors, including pH changes, ionic strength, and the presence of certain components. Agglomeration occurs when oil droplets in the dispersion fuse together, producing larger droplets that may settle or float to the top of the product.

[0004] These stability issues can lead to a variety of problems, including changes in product texture, appearance, and performance, as well as shortened shelf life and consumer dissatisfaction. Addressing these issues requires careful formulation design and ingredient selection, along with appropriate manufacturing and storage conditions to ensure long-term stability.

[0005] Traditionally, synthetic materials, including small molecules, have been used as emulsifiers. However, some small molecule emulsifiers can cause skin irritation and negatively interact with cosmetic functional materials in formulations. Furthermore, some small molecule emulsifiers may not provide the required long-term emulsion stability.

[0006] Hydrophobically modified crosslinked acrylate polymers, such as Carbopol and Pemulen, have been used to stabilize emulsions to overcome van der Waals forces and gravity. Van der Waals forces lead to flocculation and agglomeration, while gravity causes the dispersed phase in the emulsion to float or settle. However, known solutions to these problems include synthetic non-natural polymers.

[0007] Therefore, there are still opportunities for improvement. Furthermore, the desired features and characteristics of this disclosure will become apparent from the following detailed description and appended claims, in conjunction with the background technology and accompanying drawings. Summary of the Invention

[0008] This disclosure provides an oil-in-water emulsion with long-term stability. The emulsion comprises: an oil phase, comprising about 5 to 60% by weight of active ingredient based on the total weight of the emulsion, wherein the oil phase is present in the emulsion in the form of droplets; an aqueous phase, comprising about 30 to 94.5% by weight of active ingredient based on the total weight of the emulsion; and (III) a polymer component, comprising about 0.5 to 10% by weight of active ingredient based on the total weight of the emulsion. The polymer component includes a starch component, comprising about 15 to 45% by weight of active ingredient based on the total weight of the polymer component, and contains at least one hydrophobically modified starch having the following structure: ; Where R 1 It is C3 to C 19 Branched or straight-chain alkyl or alkenyl groups, R 2 It is H or an alkyl group having 1 to 10 carbons. The Starch represents amylose and / or amylopectin fractions or modified amylose and / or amylopectin fractions. The polymer component further includes: a non-starch polysaccharide, comprising about 0 to about 40% by weight of active ingredient based on the total weight of the polymer component; and cross-linked starch, comprising about 3 to about 75% by weight of active ingredient based on the total weight of the polymer component. The emulsion exhibits stability for at least 4 weeks at room temperature. Attached Figure Description

[0009] This disclosure will be described in conjunction with the following figures, wherein: Figure 1A This is a schematic diagram illustrating the differences between emulsion flocculation, aggregation, and flotation; and Figure 1B This is a graph showing the relationship between the system energy and the distance between droplets in an oil-in-water emulsion, illustrating the first and second energy barriers for aggregation, as well as the energy valley for flocculation. Detailed Implementation

[0010] The following specific embodiments are exemplary in nature and are not intended to limit the present composition. Furthermore, they are not intended to be construed as being limited by any theory presented in the foregoing background or the following specific embodiments.

[0011] Embodiments of this disclosure generally relate to emulsions, compositions comprising such emulsions, and methods of forming such emulsions. For the sake of brevity, conventional techniques associated with the preparation of emulsions and such compositions may not be described in detail herein. Furthermore, the various tasks and process steps described herein may be incorporated into a more comprehensive procedure or process with additional steps or functions not described in detail herein. Specifically, the various steps in the manufacture of emulsions and related compositions are well known; therefore, for the sake of brevity, many conventional steps will be described only briefly or will be omitted entirely without providing well-known process details.

[0012] In this disclosure, the term "about" can be described in various embodiments as a value ±0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. Furthermore, it should be understood that, in consideration of various non-limiting embodiments, all numerical values ​​provided herein, other than actual embodiments, are approximate values, wherein endpoints or specific values ​​should be understood as "about" or "approximate" to said values. It is also understood that all isomers and chiral options of each compound described herein are expressly considered for use in various non-limiting embodiments.

[0013] Throughout this disclosure, the term "active ingredient percentage" as generally accepted in the art refers to the percentage amount of active or actual compound or molecule present, for example, compared to the total weight of the solvent and a diluted solution of that compound. Some compounds, such as solvents, are not described relative to the active ingredient percentage because their active ingredient percentage is known to be approximately 100% active. Those skilled in the art will understand that any one or more values ​​described herein can alternatively be described as an active ingredient percentage.

[0014] In various embodiments, the term "free of" describes an embodiment containing less than about 5, 4, 3, 2, 1, 0.5, or 0.1% by weight (or % by weight of active ingredient) of the relevant compound or element, using an appropriate weight basis as understood by those skilled in the art. In other embodiments, the term "free of" describes an embodiment in which the weight percentage of the relevant compound or element is zero.

[0015] The term "consistently composed of" can describe various non-limiting embodiments that do not contain one or more optional compounds described herein and / or do not contain one or more polymers, surfactants, additives, solvents, etc.

[0016] It should be understood that the subscripts of polymers are usually described as average values ​​because the synthesis of polymers typically results in a distribution of various individual molecules.

[0017] The emulsions, polymers, and compositions disclosed herein may suitably comprise, consist of, or substantially consist of the components, elements, and process delineations described herein. The exemplary embodiments disclosed herein may be suitably implemented in the absence of any elements not specifically disclosed herein.

[0018] In various embodiments, the term "modification" applied to starch refers to starch molecules in which one or more of their hydroxyl groups have been reacted. In other embodiments, the term "hydrophobic modification" describes starch molecules that have been modified by one or more aliphatic or aromatic, saturated or unsaturated, linear, branched or cyclic C8-C groups. 30Hydrocarbon-chain substituted starch molecules. Typically, the “weight” of any starch or cellulose material is reported on a dry weight basis. In various embodiments, the terms “stability” or “long-term stability” can describe the stability of the emulsion over a period of at least 28 days, measured using a TURBISCAN® LAB stability analyzer at 22°C and 45°C, as described in more detail below.

[0019] This disclosure provides an oil-in-water (O / W) emulsion with long-term stability, which will be described in more detail below.

[0020] More specifically, the emulsion comprises (I) an oil phase, which, based on the total weight of the emulsion, contains about 5 to about 60% by weight of active ingredient, wherein the oil phase exists in the emulsion in the form of microdroplets, the microdroplets having a D v The size 50 can be from about 0.2 to about 50 micrometers. The emulsion also includes (II) an aqueous phase, which comprises about 30 to about 94.5% by weight of active ingredient based on the total weight of the emulsion. The emulsion further provides (III) a polymer component, which comprises about 0.5 to about 10% by weight of active ingredient based on the total weight of the emulsion. The polymer component itself includes (A) a starch component, which comprises about 15 to about 45% by weight of active ingredient based on the total weight of the polymer component. The starch component comprises hydrophobically modified starch.

[0021] In one embodiment, the hydrophobically modified starch has the following structure: ; Where R 1 It is C3 to C 19 Branched or straight-chain alkyl or alkenyl groups, R 2 It is H or an alkyl group having 1 to 10 carbons. Furthermore, the term "starch" represents amylose and / or amylopectin fractions or modified amylose and / or amylopectin fractions. Alternatively, the term may be described as representing amylose and / or amylopectin or modified amylose and / or amylopectin fractions, wherein the hydrogen atoms of the hydroxyl groups of the dehydrated glucose units of the amylose and / or amylopectin or modified amylose and / or amylopectin fractions are substituted. The polymer component also includes (B) a non-starch polysaccharide, which is present in an amount of about 0 to about 40% by weight of active ingredient based on the total weight of the polymer component. The polymer component further includes (C) cross-linked starch, which is present in an amount of about 3 to about 75% by weight of active ingredient based on the total weight of the polymer component. The emulsion exhibits stability for at least 4 weeks at room temperature. Each item will be described in detail below. oil-in-water emulsion

[0022] As is known in the art, an oil-in-water (O / W) emulsion is a mixture or dispersion in which small oil droplets in an oil phase are suspended within a continuous phase (e.g., an aqueous or water-based phase). In O / W emulsions, the oil droplets are typically dispersed in the continuous phase when the interfacial tension between the oil and the continuous phase decreases, allowing them to mix and form a stable dispersion. Most commonly, the continuous phase of the emulsions of the present invention is an aqueous phase (water-based phase), as described below. However, the aqueous phase is not necessarily entirely water and may include or exclude one or more of the components described below. The emulsion can be formed using any method known in the art.

[0023] In personal care products, O / W lotions are commonly used as a means of delivering oil-based active ingredients or moisturizers to the skin in an easy-to-apply and non-greasy form. The aqueous phase of an O / W lotion acts as a carrier for the oil phase, helping to evenly distribute the oil-based ingredients throughout the product and ensuring their effective delivery to the skin.

[0024] In various embodiments, the emulsion is present at room temperature. For some oils with a freezing point below about 100°C, the emulsion may also be a formulation in which the oil is initially dispersed in water, but may solidify to some extent upon cooling to room temperature. Typically, the aqueous phase forms a continuous phase, and the oil is insoluble in the aqueous phase. In one embodiment, the solubility in the aqueous phase is 0.1% by weight, typically 0.05% by weight, or less.

[0025] In various embodiments, the emulsion is defined as a plurality of oil droplets substantially uniformly distributed or dispersed in a liquid medium. Typically, the emulsion exists in this form at room temperature. For some oils with a freezing point below about 100°C, the emulsion may also be a formulation in which the oil is initially dispersed in water, but may solidify to some extent upon cooling to room temperature. The liquid medium forms a continuous phase, and the oil is insoluble in the liquid medium. In one embodiment, the solubility in the liquid medium is about 0.1% by weight, typically about 0.05% by weight, or less. Some non-limiting examples of suitable liquid media include water, ethanol, methanol, isopropanol, glycerol, propylene glycol, or acetone, or mixtures thereof. In one embodiment of this disclosure, the liquid medium is water and a mixture of one or more of ethanol, methanol, isopropanol, glycerol, glycols (such as propylene glycol), or acetone. In various non-limiting embodiments, all numerical values ​​and ranges, including those described above and those between them, are expressly considered to be used herein. Long-term stability

[0026] The oil-in-water emulsion exhibits long-term stability. The term "long-term stability" means, for example, that the emulsion, when measured using a TURBISCAN® LAB stability analyzer at any temperature from about 5 to about 45°C (e.g., room temperature), may exhibit stability for at least 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weeks (or any value or range thereof). For example, the emulsion's "stability" can be quantitatively measured using a TURBISCAN® LAB stability analyzer, which acquires the initial backscattered signal of the emulsion sample. The sample can be stored at any temperature from about 0 to about 45°C or 50°C (or any value or range thereof, e.g., room temperature) and then periodically scanned over periods of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 weeks. In various embodiments, when measured using a TURBISCAN® LAB stability analyzer, the emulsion may be stable at room temperature for at least any of the aforementioned numbers of weeks. In other embodiments, when measured using a TURBISCAN® LAB stability analyzer, the emulsion may be stable at 45°C for at least any of the aforementioned number of weeks. In all non-limiting embodiments, all numerical values ​​and ranges, including those described above and those falling between them, are expressly intended for use herein.

[0027] To determine stability, the emulsion can be added to a glass vial provided by Formulaction. The vial is approximately 1 inch in diameter and 2 inches in height. Add the emulsion sample to the vial, ensuring there are no air bubbles or cavities in the liquid. The filling height is approximately 1 5 / 8 inches, or 42 millimeters. After filling, the TurbiScan sample can be conditioned for one day under the desired aging conditions before the initial scan. TurbiScan readings are typically taken when the sample has cooled to approximately 22°C.

[0028] The backscattered signal measured over time can be compared to the signal of the initial sample. More specifically, if the maximum difference between the subsequent backscattered signal and the initial signal is greater than 20%, the number of days it takes to reach this 20% difference can be recorded as a measure of stability, or "TurbiScan® time." The longer this time, the more stable the emulsion. This technology is well-suited for detecting potential instability in a sample before such instability is visually apparent. The software included with TurbiScan is used for data analysis, including not only backscattered intensity but also changes in oil droplet size over time. oil phase

[0029] Typically, the emulsion comprises an oil phase dispersed in water or an aqueous-based medium (as an aqueous phase). In various embodiments, the oil phase is or comprises a cosmetically acceptable oil that can provide the consumer with a feel, protection, repair, UV protection, occlusiveness, smoothness, moisturizing, or free radical scavenging ability. The cosmetically acceptable oil may be selected from hydrocarbon-based oils and natural oils. Non-limiting examples of cosmetically acceptable oils include: palm oil, mineral oil, petrolatum, petroleum jelly, silicone, dimethylsiloxane, emu oil, castor oil, squalene, avocado oil, almond oil, coconut oil, cocoa butter, grapeseed oil, lanolin, peanut oil, sesame oil, jojoba oil, olive oil, silicone oil, sunflower seed oil, safflower oil, shea butter, and wheat germ oil. Other oils include: argan oil, sweet almond oil, avocado oil, rosehip oil, tea tree oil, and lavender oil. In one embodiment, the cosmetically acceptable oil may be an aerosol propellant.

[0030] The oil phase may be present in the emulsion in any amount chosen by those skilled in the art. In various embodiments, the oil phase is present in the emulsion in an amount of at least about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 80% by weight. In other embodiments, the oil phase is present in the emulsion in an amount less than about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 80% by weight. In still other embodiments, the oil phase is present in the emulsion in an amount of about 5 to about 60, about 10 to about 55, about 15 to about 50, about 20 to about 45, about 25 to about 40, about 10 to about 40, or about 30 to about 35% by weight. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​above and values ​​between the values ​​above, are expressly intended to be used herein.

[0031] In various embodiments, the oil phase exists in the form of microdroplets. The size of the microdroplets is not particularly limited. In various embodiments, the average microdroplet size is about 0.2 micrometers to about 100 micrometers, about 0.2 to about 50 micrometers, about 0.5 micrometers to about 35 micrometers, about 1 to about 30 micrometers, about 1 to about 25 micrometers, or about 5 to about 30 micrometers. In other embodiments, the microdroplet size is about 10 to about 25 micrometers or about 15 to about 20 micrometers. In other embodiments, the average microdroplet size of the oil droplets in the emulsion is about 0.2 micrometers to about 100 micrometers. In another embodiment, the average microdroplet size is about 0.5 micrometers to about 35 micrometers. In other embodiments, the lower limit of the average microdroplet size can be 0.2 micrometers, 0.5 micrometers, and 1 micrometer, respectively, while the upper limit can be 100 micrometers, 35 micrometers, and 25 micrometers, respectively, and the range of embodiments can be a combination of these lower and upper limits. For example, the average microdroplet size can be measured by any light scattering technique known to those skilled in the art and / or described herein. In all non-limiting embodiments, all numerical values ​​and ranges, including the values ​​mentioned above and those in between, are hereby explicitly considered for use.

[0032] The droplet size may be further defined as Dn10, Dn50, Dn90, Dv10, Dv50, or Dv90. Alternatively, the droplet size may be further defined as any one of Dn1-100 or Dv1-100, as understood in the art. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​described above and values ​​between the values ​​described above, are expressly intended to be used herein.

[0033] In various implementations, droplet size can be determined using a particle size analyzer (e.g., Malvern MS2000, 3000, 3000E, etc.). However, any droplet size analyzer can be used. Volume distribution can be easily converted to many other types of distributions using a particle size analyzer, such as surface area, length, or number distribution. Therefore, the volume and number distribution of droplets can be determined in the form of equivalent spheres using laser particle size determination. Volume distribution provides information about the volume of particles within each droplet size subrange. In volume distribution, the contribution of each particle is related to its volume, so the relative contribution of each particle will be proportional to the cube of its size [i.e., (droplet size)³]. Therefore, larger particles are disproportionately represented in volume distribution (and vice versa; smaller particles are underrepresented). However, number distribution provides information about the number of particles within each droplet size subrange. That is, in number distribution, each particle is given an equal weight, regardless of its size; that is, the relative contribution of each particle in the distribution is equal. Therefore, the quantity distribution provides information about the relative number (percentage of total number) of particles within each droplet size subrange, while the volume distribution provides information about the relative volume (percentage of total volume) of particles within each droplet size subrange. Throughout this process, the term "droplet" may be replaced with "particle" where appropriate, as understood by those skilled in the art.

[0034] Therefore, the Dv10 value means that 10% of the sample volume is smaller than this droplet size, while the Dn10 value corresponds to the largest droplet size that makes up 10% of the total number of particles in the sample. Thus, these parameters relate to different physical properties of any given particulate material and have very different values. Similar considerations apply to other claimed parameters (e.g., D...). 50 D 90 wait).

[0035] Any Dv or Dn parameter of a droplet is not an absolute characteristic of the droplet itself, but rather a construction based on mathematical approximations of laser diffraction data (“equivalent spheres”). The value of each of these parameters can be significantly influenced by the conditions used to measure them. Typically, the standard operating procedure for measuring droplets is a program pre-programmed into the droplet size analyzer itself. These parameters can be selected according to the international standard ISO 13320-1. In various implementations, any one or more of these parameters can be pre-programmed into the instrument itself.

[0036] In other implementations, various droplet size measurement techniques can be used. The most common method is dynamic light scattering (DLS), also known as photon correlation spectroscopy (PCS). It is frequently used in colloid science, nanotechnology, and biophysics. The principle of DLS is based on the Brownian motion of particles suspended in a liquid medium. In DLS, the intensity fluctuations detected by a photodetector are analyzed using autocorrelation techniques. Autocorrelation measures the correlation between intensity fluctuations at different time intervals, calculated by analyzing the rate of scattered light intensity fluctuations. The autocorrelation function provides information about the rate of particle motion (Brownian motion) in the sample. From this information, the particle diffusion coefficient can be determined. Furthermore, the droplet size distribution can be calculated using the Stokes-Einstein equation (which correlates the diffusion coefficient with the droplet size). Static multiple light scattering (SMLS), also known as static light scattering (SLS), is another technique used for droplet size measurement. Unlike dynamic light scattering (DLS), which analyzes scattered light intensity fluctuations caused by Brownian motion, SMLS relies on measuring the intensity of scattered light at a fixed angle. SMLS operates in the Fraunhofer scattering region, where the scattering angle is sufficiently large that the scattering pattern can be approximated by a simple scattering equation known as the Fraunhofer equation, which correlates the intensity of scattered light with the droplet size and concentration. Based on backscattering intensity measurements, the average equivalent particle diameter can be calculated using the following formula:

[0037] in: I BS Backscattered light intensity; g Asymmetric factor; Q e Extinction efficiency factor; Volume fraction; D : average equivalent particle diameter; and α and β: coefficients related to the geometry of the optical devices in the instrument (angles, beam size, glass cell, etc.) and embedded in the instrument software based on the instrument settings. In various implementations, the stability of emulsions over time was evaluated using TurbiScan Lab and its software provided by Formulaction (address: 3-5 Rue Paule Raymondis), particularly the measurement of emulsion droplet size, which was performed according to ISO TS 21357:2022 “Nanotechnology—Evaluation of the average size of nano-objects in liquid dispersions by static multiple light scattering (SMLS). For more information, see also Mengual, O., Meunier, G., Cayré, I., Puech, K., and Snabre, P. (1999). “TURBISCAN MA 2000: multiple light scattering measurement for concentrated emulsion and suspension instability analysis”, Talanta, 50(2), 445-456, which is expressly incorporated herein by reference for various non-limiting implementations.

[0038] The detailed experimental procedures for each implementation scheme are as follows: 1) Add the prepared emulsion containing all key components to the TurbiScan vial provided by the instrument company. Special care must be taken when adding the sample to avoid leaving any cavities or air bubbles. Furthermore, the emulsion should not leave any stains on the glass surface of the vial where no sample is placed. Over time, these stains may drip into the sample body, thus interfering with the integrity of the original emulsion conditions.

[0039] 2) Once prepared, the sample should be aged at the required aging temperature for at least 12 hours before the initial scan. For samples aged at 45°C, they should be completely cooled to 22°C before scanning.

[0040] 3) After the initial scan, return the sample to the target temperature conditions, i.e., 22°C or 45°C. Periodically remove the sample from the aging conditions. For samples aged at 45°C, readjust to 22°C and then scan again using TurbiScan. Add the new traces to the original file and compare them with the original scan traces.

[0041] 4) Due to the opacity of emulsions, backscattered traces are used to monitor the stability properties of the emulsion system. In addition to changes in droplet size over time, potential buoyancy or aging progression is closely monitored. Typically, the standard is: if any point on the backscattered trace shows a relative change of no more than 20% relative to the original backscattered trace within a specific duration (e.g., approximately 4 weeks), the sample is considered stable under the specified aging conditions for 4 weeks. Otherwise, the sample is considered unstable for the specified duration.

[0042] In various embodiments, (I) the oil phase comprises an additive selected from glyceryl monostearate, fatty alcohols, and combinations thereof. The fatty alcohol is not particularly limited and can be any fatty alcohol known in the art. For example, the fatty alcohol can be straight-chain or branched and contains about 6 to about 20, about 8 to about 18, about 10 to about 16, or about 12 to about 14 carbon atoms. The fatty alcohol can be alkoxylated (e.g., ethoxylated) or non-alkoxylated. If alkoxylated, the molar number of the olefin oxide (e.g., ethylene oxide) used is not limited, and can be, for example, about 0.5 to about 20, about 0.5 to about 10, about 1 to about 10, about 1 to about 5, about 5 to about 10, etc. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​above and those between the values ​​above, are expressly considered for use herein. In other embodiments, the oil phase, and optionally the entire emulsion, may be free of fatty acids and / or surfactants. Aqueous phase

[0043] The aqueous phase may be or may contain water. For example, the aqueous phase may be about 100% water, or it may contain water and one or more co-solvents. Some non-limiting examples of suitable co-solvents are ethanol, methanol, isopropanol, glycerol, propylene glycol, or acetone, or mixtures thereof. In one embodiment, the aqueous phase is a mixture of water and one or more of ethanol, methanol, isopropanol, glycerol, glycols (such as propylene glycol), or acetone. A specific weight percentage of water and the one or more co-solvents may be any value between 0.5 and 99.5% chosen by those skilled in the art. Typically, based on the total weight of the emulsion, the aqueous phase is present in an amount of about 30 to about 94.5%, about 35 to about 90%, about 40 to about 85%, about 45 to about 80%, about 50 to about 75%, about 55 to about 70%, or about 60 to about 65% by weight of active ingredient. As is known in the art, water is 100% active ingredient. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​above and those between the values ​​above, are expressly considered to be used herein. polymer components

[0044] The emulsion further provides (III) a polymer component, which is present in an amount of about 0.5 to about 10% by weight of active ingredient, based on the total weight of the emulsion. In various embodiments, the polymer component is present in amounts of about 1 to about 9.5, about 1.5 to about 9, about 2 to about 8.5, about 2.5 to about 8, about 3 to about 7.5, about 3.5 to about 7, about 4 to about 6.5, about 4.5 to about 6, or about 5 to about 5.5% by weight of active ingredient, based on the total weight of the emulsion. In other embodiments, the polymer component is present in amounts of about 1 to about 7, about 1.5 to about 6.5, about 2 to about 6, about 2.5 to about 5.5, about 3 to about 5, about 3.5 to about 4.5, or about 4 to about 4.5% by weight of active ingredient, based on the total weight of the emulsion. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​above and values ​​between the values ​​above, are expressly intended to be used herein.

[0045] The (III) polymer component may be present in the (I) oil phase, in the (II) aqueous phase, simultaneously in the (I) oil phase and the (II) aqueous phase, or between the (I) oil phase and the (II) aqueous phase. (A) Starch component

[0046] The polymer component itself includes (A) a starch component, which is present in an amount of about 15 to about 45% by weight of active ingredient based on the total weight of the polymer component. In various embodiments, the starch component is present in an amount of about 20 to about 40, about 20 to about 35, about 25 to about 35, or about 30 to about 35% by weight of active ingredient based on the total weight of the polymer component. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​above and values ​​between the values ​​above, are expressly intended to be used herein.

[0047] The starch component comprises hydrophobic amphoteric starch.

[0048] In one embodiment, the hydrophobically modified starch has the following structure: ; Where R 1 It is C3 to C 19 Branched or straight-chain alkyl or alkenyl groups, R 2 It is H or an alkyl group having 1 to 10 carbons.

[0049] In various implementation schemes, R 1 It is a branched or straight-chain alkyl or alkenyl group having 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19 carbon atoms. In various non-limiting embodiments, all numerical values ​​and ranges, including those above and those between the above values, are expressly intended to be used herein.

[0050] In other implementations, R 2 It is H or an alkyl group having 1 to 10 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms). In various non-limiting embodiments, all numerical values ​​and ranges, including those above and those between the above values, are expressly intended to be used herein.

[0051] Furthermore, the term "Starch" represents amylose and / or amylopectin fraction or modified amylose and / or amylopectin fraction. Alternatively, the term may be described as representing amylose and / or amylopectin fraction or modified amylose and / or amylopectin fraction, wherein the hydrogen atom of the hydroxyl group of the dehydrated glucose unit of the amylose and / or amylopectin fraction or modified amylose and / or amylopectin fraction is substituted.

[0052] In various embodiments, the starch can be hydrophobically modified with an alkenyl succinic anhydride, which can be branched or unbranched. For example, the anhydride can be alternatively described as octenyl succinic anhydride (OSA). Alternative structures for OSA are provided in the art, such that the indicated double bonds can be located in other positions. All options of alkenyl succinic anhydride and OSA recognized in the art are hereby explicitly considered for use in various non-limiting embodiments.

[0053] The starch can be converted to amphoteric form by any reaction known in the art. For example, the starch can be converted to amphoteric form by reacting with 2-chloroethylaminodipropionic acid (EDPA). The reaction between starch and EDPA is typically carried out via etherification, in which the chloroethyl group of EDPA reacts with the hydroxyl group of starch to form an ether bond.

[0054] The starch can be further hydrophobically modified by reacting with alkenyl succinic anhydride (ASA), a reaction that introduces hydrophobic groups onto the starch surface. The reaction between starch and ASA is typically carried out via esterification, where the anhydride groups of ASA react with the hydroxyl groups of starch to form ester bonds. This reaction can be catalyzed by an acid (such as sulfuric acid or hydrochloric acid) or an enzyme (such as lipase or protease). During the reaction, the ASA molecule hydrolyzes to form an acid, which acts as a catalyst for the esterification reaction. The reaction can also be catalyzed by a base. In a typical base-catalyzed reaction, granular starch is treated with ASA in an aqueous slurry at a pH of 7 to 11 (more preferably, a pH of about 7.5 to 9). The hydrophobic alkyl or alkenyl groups on the ASA molecule are thus attached to the starch, making the modified starch more hydrophobic and less water-soluble than unmodified starch. The degree of modification, or the number of alkyl or alkenyl groups attached to the starch molecule, can be controlled by varying the reaction conditions, such as the amount of ASA, reaction time, and temperature. In one embodiment, the starch is reacted with octenyl succinic anhydride (OSA). In another embodiment, the starch is reacted with dodecenyl succinic anhydride (DDSA).

[0055] In an alternative embodiment, the hydrophobically modified starch can be one or more aliphatic or aromatic, saturated or unsaturated, linear, branched or cyclic C8-C. 30 Hydrophobic modification is performed on the hydrocarbon chain, particularly on hydrophobic groups containing 8 to 30 carbon atoms. In another embodiment, the hydrophobic substituents used may include C8-C64. 30 In another implementation, C8-C can be used. 22 Alkyl, alkenyl, aralkyl, or alkylaryl groups and mixtures thereof. In one embodiment, the hydrophobic substituent is C8-C. 22 For example, C8-C 12 Alkenyl chains, such as octenyl (unsaturated C8) and straight-chain or branched dodecenyl (unsaturated C8). 12 The hydrophobic group is derived from natural sources, including but not limited to tallow, beef tallow, soybean oil, coconut oil, and palm oil. The hydrophobic modifier can be attached to the starch matrix via ether, ester, or carbamate bonds. Ester bonds are preferred.

[0056] In one embodiment, the hydrophobically modified starch is wherein R 1 It is a C5 straight-chain alkyl group and R 2 Starch with H. This can be described as OSA-modified starch or octenyl succinic anhydride-modified starch.

[0057] In another embodiment, the hydrophobically modified starch is wherein R 1 It is a C9 straight-chain alkyl group and R 2 The starch is H. In another embodiment, the hydrophobically modified starch is wherein R is...1 It is a C9 branched alkyl group and R 2 Starch with H. Since DDSA can be linear or branched, these can be described as DDSA-modified amphoteric starch or dodecenyl succinic anhydride-modified amphoteric starch.

[0058] The starch can be derived from a variety of sources, including plants, animals, and microorganisms. In various embodiments, the starch is derived from corn, wheat, rice, or combinations thereof. In other embodiments, the starch is derived from potatoes, cassava, tapioca, or combinations thereof. In other embodiments, the starch is derived from peas, legumes (such as soybeans), lentils, or combinations thereof. In other embodiments, the starch is derived from bone marrow and / or animal tissue. In other embodiments, the starch is derived from a microbial fermentation process. Any combination of the above can be used.

[0059] The starch disclosed herein can be of any type. Starch is a complex carbohydrate composed of two types of glucose polymers: amylose and amylopectin. Amylose is a linear polymer composed of glucose units linked by α-1,4-glycosidic bonds. This gives amylose a helical structure, which is stabilized by intermolecular hydrogen bonds. The degree of polymerization of amylose can vary depending on the source, but typically varies between hundreds and thousands of glucose units. Amylopectin is a branched polymer composed of glucose units linked by α-1,4-glycosidic bonds and α-1,6-glycosidic bonds. This branching gives amylopectin a highly branched structure, in which clusters of glucose units are linked by α-1,6-glycosidic bonds. The degree of branching of amylopectin can vary depending on the source, but typically there is one branch point every 20 to 30 glucose units. Both amylose and amylopectin are composed of glucose monomers linked by glycosidic bonds. A glycosidic bond is formed when the hydroxyl group of the first glucose unit reacts with the hydroxyl group of the second glucose unit in a condensation reaction, thereby forming an oxygen bridge between the two units. In all non-limiting embodiments, all numerical values ​​and ranges, including the values ​​mentioned above and those in between, are hereby explicitly considered for use.

[0060] Although not intended to be bound by any particular theory, it is believed that the starch component (A) acts as a polymeric surfactant due to its amphoteric properties, while the hydrophobic functional groups provide anchoring points on both the oil and water phases of the oil-water interface. Modified starch, due to the hydrophilicity of its charge and hydroxyl functional groups, and its high molecular weight (particularly from amylopectin) resulting in high hydrodynamic volume, acts as an energy barrier. Figure 1B As shown. Compared to small molecule surfactants, polymeric surfactants are believed to have the advantage of providing a higher energy barrier at longer oil droplet distances, resulting in a lower probability of oil droplet coalescence.

[0061] In various embodiments, the starch component (A) is gelatinized. The term "gelatinized starch" includes "pregelatinized starch," "prepasted starch," and "cold-water swollen starch." The term "gelatinized" starch refers to swollen starch granules that have lost their birefringence cross under polarized light. Gelatinized modified starch is soluble in cold water without cooking. In this context, "soluble" does not necessarily mean the formation of a true molecular solution, but also means the attainment of a colloidal dispersion. In one embodiment, the starch component (A) is completely gelatinized.

[0062] In one embodiment, the hydrophobically modified starch is hydrophobically modified amylopectin. In another embodiment, the hydrophobically modified starch is hydrophobically modified amylose. In yet another embodiment, the hydrophobically modified starch is a combination of hydrophobically modified amylose and hydrophobically modified amylopectin. (B) Non-starch polysaccharides

[0063] The polymer component further includes (B) a non-starch polysaccharide, which is present in an amount of about 0 to about 40% by weight of active ingredient, based on the total weight of the polymer component. In various embodiments, this amount is present in amounts of about 0 to about 35, about 0 to about 30, about 0 to about 25, about 0 to about 20, about 0 to about 15, about 0 to about 10, about 0 to about 5, about 5 to about 30, about 5 to about 25, about 5 to about 20, about 5 to about 15, about 5 to about 10, about 10 to about 30, about 10 to about 25, about 10 to about 20, about 10 to about 15, about 15 to about 30, or about 20 to about 25% by weight of active ingredient, based on the total weight of the polymer component. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​above and values ​​between the values ​​above, are expressly intended to be used herein.

[0064] Starch and starch derivatives are known to provide desired tactile qualities for personal care formulations. Traditionally, starch concentrations used in such formulations have been higher than about 3%, otherwise the starch may undergo a phenomenon known as “retrogradation” and precipitate from the formulation, which is undesirable. However, in one embodiment, where (III) the polymer component is present at an amount of about 3.5 to about 10% by weight of active ingredient based on the total weight of the emulsion, then (B) the non-starch polysaccharide is optionally absent, or present at an amount of less than about 0.5, 0.4, 0.3, 0.2, 0.1, 0.05, or 0.01% by weight of active ingredient (based on the total weight of the polymer component). In another embodiment, where (III) the polymer component is present at an amount of about 0.5 to less than about 3.5% by weight of active ingredient based on the total weight of the emulsion, and (B) the non-starch polysaccharide is present at an amount greater than zero% by weight. In all the various non-limiting embodiments, all numerical values ​​and ranges, including those above and those between the above values, are expressly considered for use herein.

[0065] As is known in the art, polysaccharides can form helical, linear fibrous, or branched structures. The conformation of polysaccharides can be broadly categorized into two general types—ordered and disordered conformations—determined by the regularity of their molecular structure. In aqueous solutions, most non-starch polysaccharides with heterogeneous structures exhibit disordered conformations, including random coils, rigid conformations, and spherical conformations. High-performance size exclusion chromatography (HPSEC) can be used to study the conformational properties of polysaccharides in aqueous solutions. By combining refractive index (RI) light scattering detectors (LALS and RALS) with an online viscometer, the relationship between Mw and intrinsic viscosity [η], as well as Rg, Rh, and Rg / Rh (ρ), can be obtained, where Rg is the radius of gyration and Rh is the hydrodynamic radius. Rg is a mathematically defined size describing the distribution of the center of mass in the molecule, while Rh is a phenomenological property of the molecule.

[0066] In various embodiments, the (B) non-starch polysaccharide has a coil size (Rh) of at least 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, or 1600 nanometers. Alternatively, the coil size can be about 400 to about 1600, about 450 to about 1550, about 500 to about 1500, about 550 to about 1450, about 600 to about 1400, about 650 to about 1350, about 700 to about 1300, about 750 to about 1250, about 800 to about 1200, about 850 to about 1150, about 900 to about 1100, about 950 to about 1050, or about 950 to about 1000 nanometers. In all non-limiting embodiments, all numerical values ​​and ranges, including those described above and those falling within the ranges described above, are expressly considered for use herein. Dynamic light scattering (DLS) is most commonly used to measure the hydrodynamic volume of non-starch polysaccharides. The principle of using DLS to measure the hydrodynamic volume of polymers involves measuring the Brownian motion of polymer molecules in solution. In some non-limiting embodiments, the coil size of non-starch polysaccharides is of importance as... Figure 1B As shown. When oil droplets and non-starch polysaccharides are co-dispersed in an aqueous system, their interactions with water are completely opposite in nature; the latter is compatible with water and forms a homogeneous solution. The former is immiscible with water, leading to the most famous Oswald ripening phenomenon. At the microscopic level, when two oil droplets approach each other due to van der Waals forces, when the distance between the oil droplets becomes slightly smaller than the average hydrodynamic volume size of the non-starch polysaccharide, polymer coiling will be pushed away from the inter-droplet region, resulting in a practically zero concentration of the non-starch polysaccharide. This demixing process creates an energy barrier when two oil droplets approach each other, commonly known as the depletion mechanism, which is thermodynamically unfavorable to the aggregation of the two oil droplets, as shown on the right side of the energy versus inter-droplet distance graph ( Figure 1B From simple geometric considerations, it is not difficult to deduce that the larger the hydrodynamic volume of non-starch polysaccharides, the farther the distance between oil droplets that form energy barriers, thus reducing the probability of aggregation.

[0067] The non-starch polysaccharide is not particularly limited and can be any non-starch polysaccharide known in the art. In one embodiment, the non-starch polysaccharide is xanthan gum. In another embodiment, the (B) non-starch polysaccharide is selected from xanthan gum, nonionic cellulose, ionic cellulose, and combinations thereof. In other embodiments, the (B) non-starch polysaccharide is selected from cellulose ethers, such as methyl ethyl hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, and combinations thereof. In other embodiments, it is contemplated that the cellulose may also be ionic.

[0068] In various embodiments, the non-starch polysaccharide is a cellulose ether. Cellulose is a polysaccharide composed of 1,4-dehydrated glucose units. Cellulose molecules in natural cellulose are insoluble in water. To make cellulose soluble, it is usually necessary to modify it into a cellulose derivative, such as hydroxyethyl cellulose (HEC), ethyl hydroxyethyl cellulose (EHEC), hydroxypropyl cellulose (HPC), hydroxybutyl methyl cellulose (HBMC), hydroxypropyl methyl cellulose (HPMC), methyl ethyl hydroxyethyl cellulose (MEHEC), and hydrophobically modified ethyl hydroxyethyl cellulose (HMEHEC). Carboxymethyl cellulose may also be used.

[0069] To prepare modified cellulose, the cellulose is typically subjected to an alkalization step, followed by reaction with ethylene oxide and ethane chloride to prepare EHEC, and with methyl chloroethane to prepare MEHEC. Each dehydrated glucose unit of cellulose has three hydroxyl groups available for reaction. The number of reacted hydroxyl groups in each dehydrated glucose unit is expressed as the degree of substitution (DS), ranging from 0 to 3. The molar degree of substitution of ethylene oxide (MSEO) is the average total number of ethylene oxide groups on each dehydrated glucose unit.

[0070] The cellulose ether can be derived from any cellulose source, including but not limited to hardwood pulp, softwood pulp, cotton (including cotton linters), bacterial cellulose, and regenerated cellulose.

[0071] In one embodiment, the cellulose ether is a nonionic cellulose ether. In another embodiment, the cellulose ether is a hydroxy(C1-C4)alkyl cellulose. Examples of nonionic cellulose ethers include methylcellulose, ethylcellulose, propylcellulose, butylcellulose, hydroxyethylcellulose, methylhydroxyethylcellulose, ethylhydroxyethylcellulose, methylethylhydroxyethylcellulose, propylhydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose, hydroxypropylpropylcellulose, methylhydroxypropylhydroxyethylcellulose, hydroxypropylcellulose, and mixtures thereof. In one embodiment, the cellulose ether may be selected from methylcellulose, ethylcellulose, ethylhydroxyethylcellulose, methylhydroxyethylcellulose, methylethylhydroxyethylcellulose, hydroxypropylmethylcellulose, and mixtures thereof.

[0072] In one embodiment, the cellulose ether is methyl ethyl hydroxyethyl cellulose, referred to herein as "MEHEC". In another embodiment, the cellulose ether is ethyl hydroxyethyl cellulose, referred herein as "EHEC". Nonionic cellulose ethers may be particularly useful for applications requiring good salt resistance.

[0073] In one embodiment, the cellulose ether is an anionic cellulose ether, particularly in formulations where high salt tolerance is not required. Examples of anionic cellulose ethers include carboxymethyl cellulose, hydroxyethyl carboxymethyl cellulose, hydroxypropyl carboxymethyl cellulose, sulfoethyl cellulose, hydroxyethyl sulfoethyl cellulose, hydroxypropyl sulfoethyl cellulose, and mixtures thereof.

[0074] The cellulose ether can be prepared according to conventional methods known to those skilled in the art. For example, alkali cellulose (activated cellulose) can be prepared by first photochemically oxidizing cellulose with alkali filaments, and then reacting it with alkali cellulose in one or more steps in the presence of an organic reaction medium (e.g., ethane chloride, acetone, alkyl-blocked mono- or poly(ethylene glycol), isopropanol, tert-butanol, ethers such as methyl tert-butyl ether, methyl sec-butyl ether, dimethoxyethane, or mixtures thereof) at a temperature of about 50 to about 120°C, using an appropriate amount of one or more etherifying agents selected from ethylene oxide, propylene oxide, butane oxide, chloromethane, ethane chloride, monochloroacetic acid (MCA), and MCA salts.

[0075] The cellulose ether may include one or more substituents on the cellulose chain.

[0076] In one embodiment, the cellulose ether is replaced with a hydroxyalkyl group (e.g., ethylene oxide, referred to as MSEO). In various embodiments, MSEO is at least 1.0, at least 1.5, at least 2.0, or at least 2.4. In various non-limiting embodiments, all numerical values ​​and ranges, including those mentioned above and those between them, are expressly intended to be used herein.

[0077] In other embodiments, the cellulose ether is methyl and / or ethyl substituted, wherein DS 乙基 and DS 甲基 The sum is at least 0.1, at least 0.2, at least 0.4, at least 0.6, or at least 0.8. In all non-limiting embodiments, all values ​​and ranges of values, including those mentioned above and those in between, are expressly intended to be used herein.

[0078] In one method of preparing alkyl-substituted cellulose ethers, cellulose is mercerized in one or more steps with an aqueous base in a total amount of about 0.8 to about 1.8 mol / mol sugar units; then the mercerized cellulose is reacted with ethylene oxide in a total amount of about 2.6 to about 5.5 mol / mol sugar units. The reaction product is then reacted with chloroethane (in a total amount of about 0.2 to about 1.5 mol / mol sugar units) to prepare EHEC, or with chloroethane and chloromethane (in a total amount of about 0.2 to about 1.5 mol / mol sugar units) to prepare MEHEC. These components are added to the mercerized cellulose in one or more steps and the reaction is carried out in the presence of an organic reaction medium at a temperature of about 50 to about 120°C. In one embodiment, the weight ratio of the reaction medium to cellulose is about 1:1 to about 10:1, and in another embodiment it is about 4:3 to about 3:1. In various non-limiting embodiments, all numerical values ​​and ranges, including those above and those between the above values, are expressly intended to be used herein.

[0079] In one embodiment, chloromethane or chloroethane can be used as both an etherifying agent and a reaction medium, in which case the required amount of chloromethane or chloroethane is already present in the reaction mixture, and no further addition of chloromethane or chloroethane is necessary. Alkylation can be adjusted by the source of cellulose, the amount of base used, the reaction temperature, and the reaction time. If desired, a portion of the base can be added later in the reaction to further activate the cellulose. The total degree of substitution of methyl and ethyl groups can be controlled by the amount of base used during the mercerizing process, as an equivalent amount of NaOH is consumed and sodium chloride is formed. However, due to side reactions, the yield of alkyl substitution is approximately 40% to approximately 60%. U.S. Patent No. 7,319,146 (the entire contents of which are incorporated herein by reference for various non-limiting embodiments) provides a general description of a method for manufacturing cellulose ether polymers. In various non-limiting embodiments, all numerical values ​​and ranges, including those above and those between the above values, are expressly considered to be used herein.

[0080] A method for producing a cellulose ether applicable to this document is disclosed in U.S. Publication No. 2009 / 0326217 (the entire contents of which are incorporated herein by reference for various non-limiting embodiments), wherein the cellulose ether is typically prepared in the presence of an ether solvent.

[0081] While not intended to be bound by any particular theory, (B) non-starch polysaccharides are believed to play multiple roles. For example, non-starch polysaccharides may inhibit starch retrogradation. It is well known that two starch molecules form a double helix due to intermolecular hydrogen bonds and the specific conformation of starch molecules. The same is true for cellulose molecules; although the intermolecular hydrogen bonds are the same, the ordered structure of cellulose is fundamentally very different from that of starch due to conformational differences. However, the identical conformation of two adjacent polysaccharide molecules allows them to form intermolecular hydrogen bonds, which can further develop into an ordered structure. If two polysaccharide molecules with different conformations approach each other, intermolecular hydrogen bonds will still form, but the likelihood of forming a large regional ordered structure is low. Non-polysaccharides can enhance the thickening effect of emulsion continuous phases. Non-starch polysaccharides, with their large hydrodynamic volume, can effectively thicken systems through strong hydrophilicity, high molecular weight, and relatively high glass transition temperature. (C) Cross-linked starch

[0082] The polymer component further comprises (C) cross-linked starch, which is present in an amount of about 3 to about 75% by weight of active ingredient, based on the total weight of the polymer component. In various embodiments, this amount is present in amounts of about 5 to about 75%, about 10 to about 75%, about 15 to about 75%, about 20 to about 75%, about 25 to about 70%, about 30 to about 70%, about 30 to about 65%, about 35 to about 60%, about 40 to about 55%, or about 45 to about 50% by weight of active ingredient, based on the total weight of the polymer component. In various non-limiting embodiments, all numerical values ​​and ranges, including those above and those between the above values, are expressly intended to be used herein.

[0083] The cross-linked starch may be any cross-linked starch known in the art or described herein, including cross-linked versions of the starches described above.

[0084] In various embodiments, the starch can be isolated from any plant starch source, including, for example, corn, wheat, rice, sorghum, peas, potatoes, cassava, sweet potatoes, and sago. In various embodiments, the starch contains greater than about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85% by weight of amylopectin. In one embodiment, the starch contains greater than about 90% by weight of amylopectin. In another embodiment, the starch contains greater than 95% by weight of amylopectin. In yet another embodiment, the starch contains greater than 97% by weight of amylopectin. This high amylopectin is conventionally referred to in the art as waxy starch, and there are several commercially available varieties of waxy starch. In one embodiment, the waxy starch is derived from corn, rice, potatoes, or cassava. In various non-limiting embodiments, all values ​​and ranges, including the values ​​mentioned above and values ​​between the values ​​mentioned above, are expressly intended to be used herein.

[0085] In various embodiments, the starch has a high molecular weight, defined as the molecular weight of naturally occurring starch that has not been intentionally degraded to a lower molecular weight. That is, while some degradation may occur during starch separation and during chemical processing and drying, high molecular weight starch is that which retains its natural molecular weight as much as possible. In another embodiment, the starch can be partially degraded in a controlled manner by methods known in the art, including but not limited to acid-catalyzed hydrolysis, enzymatic hydrolysis, and oxidative degradation. In cases where starch is intentionally partially degraded, the water flowability (WF) of the degraded starch will be less than 70, typically less than 60, or most commonly less than 45. In various non-limiting embodiments, all numerical values ​​and ranges, including those above and those between the above values, are expressly considered for use herein.

[0086] Crosslinking of starch chains can be achieved using suitable crosslinking agents, such as bifunctional compounds. For example, crosslinking can be achieved by reacting starch with epichlorohydrin. In one embodiment, the crosslinking method is phosphorylation, wherein starch reacts with phosphorus oxychloride, phosphorus pentoxide, and / or sodium tripolyphosphate, causing two starch chains to be crosslinked via anionic PO groups. The anionic nature of the crosslinking sites contributes to the emulsion stabilization of starch. In a further embodiment, the crosslinking method uses C4-C... 18 The alkane or olefinic dicarboxylic acid, or C4-C8 alkaneic dicarboxylic acid, or adipic acid. The alkane or olefinic dicarboxylic acid links two starch chains via ester bonds. It can be in linear or branched form. In a further embodiment, cross-linked starch is obtained, for example, by reacting starch with a mixed anhydride of dicarboxylic acid and acetic acid. The starch can be cross-linked with a cross-linking agent of about 15 ppm to about 400 ppm, typically about 50 to about 300 ppm in another embodiment, and more commonly about 100 ppm to about 200 ppm in yet another embodiment. In various non-limiting embodiments, all values ​​and ranges, including those above and those between the above values, are expressly intended to be used herein.

[0087] In a further aspect, the crosslinked starch is further modified by the addition of a C2-C5 hydroxyalkyl moiety. While not wishing to be bound by theory, it is believed that hydroxyl groups are attached to the starch backbone via alkyl groups having 2 to 5 carbon atoms, resulting in a suitable hydrophilic-lipophilic balance in the starch. The position of the hydroxyl group within the alkyl group is not critical and can be at the α to ω positions. The degree of substitution is the average number of OH groups substituted on each dehydrated glucose unit of the starch molecule. In one embodiment, the degree of substitution of hydroxyalkylation is about 0.08 to 0.3, and in another embodiment, it is about 0.15 to 0.25. The hydroxyalkylation of natural starch can be achieved by reacting natural starch with an olefinic oxygen having an appropriate number of carbon atoms. In one embodiment, hydroxyethylated and / or hydroxypropylated starch obtained by reacting starch with ethylene oxide or propylene oxide is used. The starch may also include more than one hydroxyl group per alkyl group. In one embodiment, the starch is crosslinked hydroxypropyl distarch phosphate or crosslinked acetylated distarch adipate. In all non-limiting embodiments, all numerical values ​​and ranges, including the values ​​mentioned above and those in between, are hereby explicitly considered for use.

[0088] The cross-linked starch can be hydrophobically modified or unmodified. For example, the cross-linked starch can be one or more aliphatic or aromatic, saturated or unsaturated, linear, branched or cyclic C8-C. 30 The hydrocarbon chain is substituted, particularly with a hydrophobic group containing 8 to 30 carbon atoms. In another embodiment, the hydrophobic substituent used may include C8-C64. 30 In another implementation, it is typically C8-C 22 Alkyl, alkenyl, aralkyl, or alkylaryl groups and mixtures thereof. In one embodiment, the hydrophobic substituent is C8-C. 22 Typically C8-C 12 Alkenyl chains, such as octenyl (unsaturated C8) and straight-chain or branched dodecenyl (unsaturated C8). 12 The hydrophobic group is derived from natural sources, including but not limited to tallow, beef tallow, soybean, coconut oil, and palm oil. In one embodiment, the hydrophobic substituent according to this disclosure is octenyl or dodecenyl. The hydrophobic modifier can be attached to the starch matrix via an ether bond, ester bond, or urethane bond. An ester bond is preferred. Exemplary modifiers include, but are not limited to, octenyl succinic anhydride and dodecenyl anhydride. The crosslinked starch may also be modified using any of the methods or compounds described in this disclosure.

[0089] In one embodiment, the cross-linked modified starch is gelatinized. The term "gelatinized starch" includes "pregelatinized starch," "pregelatinized slurry starch," and "cold water-swellable starch." The term "gelatinized" starch refers to swollen starch particles that have lost their birefringence cross under polarized light. Gelatinized modified starch is soluble in cold water without cooking. In this context, "soluble" does not necessarily mean the formation of a true molecular solution, but also means the attainment of a colloidal dispersion. In one embodiment, the cross-linked starch is fully gelatinized.

[0090] The cross-linked starch can be gelatinized by cooking in water at a temperature above the gelatinization temperature. Some non-limiting examples of gelatinization include: water bath cooking, steam jet cooking, jet cooking (pressure approximately 10 to approximately 150 PSI), and extrusion. The cross-linked starch can be cooked at various temperatures and concentrations. In various embodiments, the cross-linked starch is cooked at approximately 90°C to approximately 200°C. In another embodiment, the cross-linked starch is cooked at approximately 100°C to approximately 150°C. Depending on the cooking method, the limit for the starch concentration in the water may vary due to factors such as viscosity, heat transfer, and solution stability. In one embodiment, the cross-linked starch is cooked at a concentration of approximately 1 to approximately 40 wt%. In another embodiment, the cross-linked starch is cooked at a concentration of approximately 2 wt% to approximately 30 wt%. In yet another embodiment, the concentration is approximately 3 wt% to approximately 15 wt%. In all non-limiting embodiments, all values ​​and ranges, including the values ​​mentioned above and values ​​between the values ​​mentioned above, are explicitly considered to be used herein.

[0091] Processes commonly used to produce this type of gelatinized starch include drum drying, extrusion, and spray drying. Drum drying involves simultaneously cooking and drying a very high-viscosity semi-solid starch paste on heated drums. The dried film is peeled off the drums with a metal scraper and then ground. This process can be carried out to very high solids contents. Extrusion can also be used to simultaneously cook and dry the starch. This process utilizes the physical treatment of a starch / water mixture under high temperature and pressure to gelatinize the starch, which then expands upon exiting the nozzle with the sudden evaporation of water. The use of gelatinized cross-linked modified starch allows for the production of starch at ambient temperatures or temperatures far below those used in the production conditions of known starch-containing compositions. In one embodiment, the gelatinized cross-linked modified starch is typically produced by spray drying.

[0092] In one embodiment, the cross-linked starch has mostly intact starch granules. An aqueous dispersion of gelatinized cross-linked starch with a substantially intact granular structure has a more uniform and smoother texture than an aqueous dispersion of starch without a granular structure, the latter being obtained, for example, by drying a starch solution whose dispersion has a slightly gritty feel. For gelatinized starch with an intact granular structure, the natural internal structure of hydrogen bonds is disrupted, but the external shape or morphology is retained. U.S. Patent No. 4,280,851 (the entire contents of which are incorporated herein by reference for various non-limiting embodiments) describes a process for producing particularly suitable spray-dried gelatinized starch. An apparatus suitable for performing this process is described in U.S. Patent No. 4,600,472 (also the entire contents of which are incorporated herein by reference for various non-limiting embodiments). In this process, a mixture of granular starch or modified starch is cooked or gelatinized in an atomized state. The starch to be cooked is atomized through an atomizing opening into a nozzle device to form a relatively finely divided spray material. Furthermore, a heating medium is injected into the spray material through an opening in the nozzle device to heat the starch to the temperature required for gelatinization. A closed chamber surrounds the spray opening for atomizing and heating the medium and defines a vent opening positioned to allow the heated starch spray material to exit the chamber. The arrangement of the apparatus such that the time elapsed during the passage of the starch spray material through the chamber (i.e., from the atomization opening to the vent opening) defines the gelatinization time of the starch. The resulting spray-dried gelatinized starch comprises uniformly gelatinized starch particles in the form of concave spheres, most of which remain intact, unbroken, and swollen after rehydration. Nozzles suitable for producing such starch are also described in U.S. Patent No. 4,610,760 (the entire contents of which are incorporated herein by reference for various non-limiting embodiments).

[0093] For the production of suitable gelatinized or modified starch, the process of U.S. Patent No. 5,149,799 (the entire contents of which are incorporated herein by reference for various non-limiting embodiments) can also be used. In this process, starch is uniformly atomized and cooked in the presence of an aqueous medium via single-stage atomization. The atomization stage is carried out in an apparatus with an internally mixed dual-fluid spray drying nozzle and coupled with an apparatus for drying and cooking the atomized starch.

[0094] Spray-dried gelatinized or modified starches with suitable properties can also be produced through a continuous, coupled process of spray cooking and spray drying. The starch suspension is gelatinized in a direct steam-jet cooker at 138°C to 160°C. The starch suspension and steam stream are mixed in a cooking or boiling chamber. The latter's outlet is connected to a pneumatic spray nozzle or high-pressure nozzle located in a conventional spray dryer. The spray-cooked starch is guided to the spray nozzle under elevated temperature and pressure and can be atomized with cold air, hot air, or, typically, steam. After atomization, the hot spray-cooked starch solution is treated in the same manner as conventionally spray-dried starch. The drying process is fast enough to prevent starch molecules from aging during droplet cooling and drying. Spray-dried starch is an amorphous material (i.e., essentially non-crystalline), readily soluble in water, or colloidally dispersed.

[0095] In one embodiment, the cross-linked starch can be provided as a dry powder composition, which is reconstituted in an aqueous medium upon use.

[0096] In various embodiments, the cross-linked starches possess dermatologically desirable properties and tactile qualities. They increase the skin's water retention capacity and contribute to smooth and supple skin.

[0097] In other embodiments, the (C) cross-linked starch is hydroxypropyl starch phosphate. In one embodiment, the (C) cross-linked starch is hydroxypropyl starch phosphate derived from corn, potato, and / or cassava. In another embodiment, the (C) cross-linked starch is hydroxypropyl starch phosphate derived from corn.

[0098] Although any emulsion is thermodynamically unstable, efforts to improve emulsion stability focus on addressing the kinetics of this instability. When the dispersed phase size is small (e.g., at the micrometer scale), gravity acting on the oil droplets is largely masked by more significant intermolecular forces (essentially interfacial / surface forces). As the surface area to volume ratio gradually decreases (proportional to the ~1 power of the length dimension of the dispersed phase), gravity begins to become more significant when aggregation occurs. This leads to phenomena such as buoyancy or sedimentation, depending on the density difference between the dispersed and continuous phases in the emulsion system. One effective way to address the effects of gravity is to thicken the continuous phase, for example, by extending the molecular relaxation time of molecules dispersed / dissolved in the continuous phase. Cross-linked starch is believed to significantly increase the molecular weight, thereby increasing the viscosity of the continuous phase and mitigating the buoyancy / settling process as gravity becomes more significant with increasing dispersed phase size. See [link to relevant documentation]. Figure 1A . additive

[0099] The emulsion may contain one or more additives, or may not contain one or more additives, in one or more of the oil phase, aqueous phase, and / or polymer components. Such additives may include, but are not limited to, emollients, humectants, thickeners, surfactants, UV inhibitors, shaping polymers, pigments, dyes, colorants, alpha-hydroxy acids, aesthetic enhancers (such as starch), fragrances and perfumes, film-forming agents (waterproofing agents), preservatives, antifungal agents, antimicrobial agents, and other pharmaceuticals, preservatives, and solvents.

[0100] Useful surfactants include nonionic and amphoteric surfactants. Permissible nonionic surfactants include polyoxyethylene-, polyoxypropylene-, or polyglycerol-modified alcohols, alkylphenols, and fatty acids having a straight-chain fatty acid chain containing 8 to 22 carbon atoms (typically containing 2 to 30 moles of ethylene oxide), fatty acid amides, alkoxylated fatty alcohol amines, fatty acid esters, glycerides, alkoxylated fatty acid esters, dehydrated sorbitan esters, alkoxylated dehydrated sorbitan esters, alkylphenol alkoxylates, aromatic alkoxylates, and alcohol alkoxylates. Also used are copolymers of ethylene oxide and propylene oxide, condensates of ethylene oxide and propylene oxide with fatty alcohols, polyoxyethylene-modified fatty amides or amines, glycolamides, fatty acid glycol esters, oxyethylene- or nonoxyethylene-modified fatty acid dehydrated sorbitan esters, fatty acid sucrose esters, fatty acid polyethylene glycol esters, triphosphate esters, and fatty acid esters of glucose derivatives. In various non-limiting embodiments, all values ​​and ranges, including those listed above and those between the listed values, are expressly considered for use herein.

[0101] In other embodiments, the surfactant is bio-based. For example, the surfactant may be selected from phospholipids, lecithin, palmitoyl oligopeptides, glycolipids, sphingolipids, sophorolipids, sphingolipids, and combinations thereof.

[0102] The additive may also be or include fatty alcohols. The fatty alcohols may be or include behenol, C12-16 alcohol, cetearyl alcohol, cetyl alcohol, cinnamyl alcohol, citronellol, geraniol, linalool, octyldodecyl alcohol, PEG-10 rapeseed sterol, phenoxyethanol, retinol, stearyl alcohol, tocopherol, or combinations thereof.

[0103] In various embodiments, one or more components, compounds, methods, or compositions described in U.S. Patent No. 10,100,178, the entire contents of which are incorporated herein by reference for various non-limiting embodiments, may be used. Use of lotion

[0104] The emulsion may be a cosmetic or personal care composition, or may be used to form a cosmetic or personal care composition. In one embodiment, the emulsion is a personal care composition. Alternatively, the personal care composition is a skin care composition. In other embodiments, the personal care composition is a hair care or styling composition. The emulsion may be a styling composition, or may be used to form a styling composition selected from gels, mousses, hair oils, and hair waxes.

[0105] In another embodiment, the lotion may be a personal care composition selected from: skin care compositions, skin cleansing compositions, makeup, facial lotions, cream moisturizers, shower gels, body lotions, foot care products (such as foot creams), hand creams, lipsticks, lip glosses, lip liners, eyeshadows, gel eyeshadows, liquid eyeliners, eyeliner pencils, mascara, concealers, foundations, loose powders, liquid blushes, blushes, deodorants, shaving cream compositions, nail polish, nail polish remover, exfoliating agents, exfoliating creams, acne creams, acne scrubs, toothpaste, aftershave, cream depilatories, lotion depilatories, waxes. Hair removal agents, face masks made from clay materials, anti-aging products, shampoos, hair care products (such as conditioners), hair conditioning creams, styling gels, styling foams, hair mousses, hairsprays, setting sprays, blow-drying styling sprays, hair dyes and dyes, hair bleaching creams, hair straightening compositions, curl-activating gels, fragrant hair shine products (such as sunscreen sticks and sunscreens), soaps, hand sanitizers, hand sanitizer gels, antibacterial hand sanitizers, body scrubs, hand scrubs, bubble baths, bath oils, quick-drying hand sanitizers, baby lotions, diaper rash creams, wet wipes, baby bath washes, vitamin creams and combinations thereof.

[0106] Alternatively, the emulsion may be the cosmetic composition itself. In other embodiments, the emulsion is present in the cosmetic or personal care composition in an amount of about 1 to about 99.5%, about 5 to about 90%, about 10 to about 85%, about 15 to about 80%, about 20 to about 75%, about 25 to about 70%, about 30 to about 65%, about 35 to about 60%, about 40 to about 55%, or about 45 to about 50% by weight of active ingredient, based on the total weight of the cosmetic or personal care composition. In various non-limiting embodiments, all numerical values ​​and ranges, including the values ​​above and values ​​between the values ​​above, are expressly intended to be used herein.

[0107] Preservatives are commonly used in personal care formulations to provide long-term shelf stability, particularly microbial shelf-life stability. Suitable preservatives include, for example, methylparaben, propylparaben, butylparaben, DMDM ​​hydantoin, imidazolidinyl urea, glutaraldehyde, phenoxyethanol, benzalkonium chloride, methylammonium chloride, benzyl chloride, benzyl alcohol, chlorobenzyl alcohol, methylchloroisothiazolinone, methylisothiazolinone, sodium benzoate, chloroacetamide, iodopropynyl butylcarbamate, sodium mercaptopyridine, zinc mercaptopyridine, and other cosmetically acceptable preservatives known to those skilled in the art. Example

[0108] A first series of compositions (compositions 1-5) were prepared, as shown below. After formation, each composition was evaluated individually to determine viscosity, stability, and droplet size, also as shown below.

[0109]

[0110] The first hydrophobically modified starch and the second hydrophobically modified starch each have the following structures: ; Where R 1 It is C3 to C 19 Branched or straight-chain alkyl or alkenyl groups, R 2 It is H or an alkyl group having 1 to 10 carbons.

[0111] The cross-linked starch 1 is hydroxypropyl starch phosphate derived from corn.

[0112] The non-starch polysaccharide is commercially available xanthan gum, traded under the name Jungbunzlauer FNPC.

[0113] Viscosities at a shear rate of 6.31 / s were determined using an MCR 302 rheometer, manufactured by Anton Parr GmbH, located at Anton Paar Strasse 20, 8054, Graz, Austria. Samples aged at 45°C were cooled and conditioned at 22°C for 24 hours prior to measurement. Parallel plates with a diameter of 50 mm and a gap of 1 mm were used as the measuring element. Measurements were performed at 22°C. A shear scan test protocol was used, scanning shear rates from 0.1 / s to 1000 / s, with five measurement points taken at every ten-fold scan.

[0114] TurbiScan stability was determined using the method described above via TurbiScan Lab.

[0115] The droplet size was also determined by TurbiScan Lab using the method described above.

[0116] The term "stable" in relation to visual observation of stability refers to the absence of significant upward movement of the emulsion top due to the density difference between the oil and aqueous phases, and the absence of significant segregation of the water sample at the bottom or middle of the vial, whether due to oil droplet uplift or aging in these areas. The data above indicate that (A) hydrophobically modified starch and (C) cross-linked starch can be unexpectedly used to achieve long-term stability.

[0117] Another composition (composition 6) was also prepared, as shown below, and its rheological properties (G' and tanδ), droplet size and visual stability were evaluated, as shown below.

[0118]

[0119] The non-starch polysaccharide, hydrophobically modified starch 1, and cross-linked starch 1 are all the same as those described above.

[0120] G' and tanδ values ​​were determined using an MCR 302 rheometer, manufactured by Anton Parr GmbH, Anton PaarStrasse 20, 8054, Graz, Austria. Samples aged at 45°C were cooled and conditioned at 22°C for 24 hours before measurement. Parallel plates with a diameter of 50 mm and a gap of 1 mm were used as the measuring element. Measurements were performed at 22°C. An oscillation test protocol was used, applying oscillation frequencies from 0.1 Hz to 10 Hz to the emulsion samples, with five measurement points taken every tenfold scan. 0.1 Hz was chosen as the representative reading to assess the rheology at the slowest shear rate, crucial for understanding the long-term flow behavior required to overcome gravity. G' (in Pa) is the elastic modulus, indicating the strength of a viscoelastic material in suspending powder and indicating its ability to overcome gravity, in addition to viscosity. Tanδ is the ratio of viscous modulus to elastic modulus and is dimensionless. The lower the value, the stronger the suspending force. The maximum suspending force is 1.

[0121] The droplet size was determined using the method described above.

[0122] The term "stable" for visual observation stability is the same as above.

[0123] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that numerous variations exist. It should also be understood that the exemplary embodiments are merely illustrative and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiments. It should be understood that various changes can be made to the function and arrangement of the elements described in the exemplary embodiments without departing from the scope set forth in the appended claims.

Claims

1. An oil-in-water emulsion with long-term stability, comprising: I. An oil phase, based on the total weight of the emulsion, comprising about 5 to about 60% by weight of active ingredient, wherein the oil phase exists in the emulsion in the form of microdroplets; II. The aqueous phase, based on the total weight of the emulsion, contains approximately 30% to approximately 94.5% by weight of active ingredient; and III. The polymer component, based on the total weight of the emulsion, comprises approximately 0.5 to approximately 10% by weight of active ingredient and includes: (A) A starch component, based on the total weight of the polymer component (III), comprising about 15 to about 45% by weight of active ingredient, and including at least one hydrophobically modified starch having the following structure: ; wherein R 1 is C3 to C 19 branched or straight chain alkyl or alkenyl, R 2 is H or an alkyl group having 1 to 10 carbons, and Starch represents a linear and / or branched starch fraction; (B) Non-starch polysaccharides, based on the total weight of polymer components (III), comprising approximately 0 to approximately 40% by weight of active ingredient; and (C) Cross-linked starch, based on the total weight of the polymer component (III), comprising about 3 to about 75% by weight of active ingredient; The emulsion described therein exhibits stability for at least 4 weeks at room temperature.

2. The oil-in-water emulsion of claim 1, wherein R 1 is a C5 linear alkyl group, and R 2 is H.

3. The oil-in-water emulsion according to claim 2, wherein the hydrophobically modified starch is hydrophobically modified amylopectin.

4. The oil-in-water emulsion according to claim 2, wherein the hydrophobically modified starch is hydrophobically modified amylose.

5. The oil-in-water emulsion according to claim 2, wherein the hydrophobically modified starch is a combination of hydrophobically modified amylose and hydrophobically modified amylopectin.

6. The oil-in-water emulsion of claim 1, wherein R 1 is a C9 linear or branched alkyl group, and R 2 is H.

7. The oil-in-water emulsion according to claim 6, wherein the hydrophobically modified starch is hydrophobically modified amylopectin.

8. The oil-in-water emulsion according to claim 6, wherein the hydrophobically modified starch is hydrophobically modified amylose.

9. The oil-in-water emulsion according to claim 6, wherein the hydrophobically modified starch is a combination of hydrophobically modified amylose and hydrophobically modified amylopectin.

10. The oil-in-water emulsion according to any of the preceding claims, wherein the starch component (A) is present in an amount of about 20 to about 35% by weight of active ingredient based on the total weight of the polymer component (III).

11. The oil-in-water emulsion according to any of the preceding claims, wherein the (III) polymer component is present in an amount of about 3.5 to about 10% by weight of active ingredient based on the total weight of the emulsion, and the (B) non-starch polysaccharide is optional.

12. The oil-in-water emulsion according to any of the preceding claims, wherein, based on the total weight of the emulsion, the (III) polymer component is present in an amount of about 0.5 to less than about 3.5% by weight of active ingredient, and the (B) non-starch polysaccharide is present in an amount of greater than zero% by weight.

13. The oil-in-water emulsion according to any of the preceding claims, wherein the (B) non-starch polysaccharide is selected from xanthan gum, nonionic cellulose, and combinations thereof.

14. The oil-in-water emulsion according to any of the preceding claims, wherein the (B) non-starch polysaccharide is present in an amount of about 5 to about 40% by weight of active ingredient based on the total weight of the (III) polymer component.

15. The oil-in-water emulsion according to any of the preceding claims, wherein the (B) non-starch polysaccharide has a coil size of at least 400 nanometers.

16. The oil-in-water emulsion according to any of the preceding claims, wherein the (B) non-starch polysaccharide is selected from methyl ethyl hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, and combinations thereof.

17. The oil-in-water emulsion according to any of the preceding claims, wherein the (C) cross-linked starch is hydroxypropyl starch phosphate.

18. The oil-in-water emulsion according to any of the preceding claims, wherein the (C) cross-linked starch is a hydroxypropyl starch phosphate derived from corn, potato and / or cassava.

19. The oil-in-water emulsion according to any of the preceding claims, wherein the (C) cross-linked starch is hydroxypropyl starch phosphate derived from corn.

20. The oil-in-water emulsion according to any of the preceding claims, wherein the (C) crosslinked starch is present in an amount of about 30 to about 70% by weight of active ingredient based on the total weight of the (III) polymer component.

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