A novel and versatile biodegradable micropowder

Abstract

The present invention relates to a micropowder, preferably having an oil absorption capacity of at least 2.5 g / g, which is biodegradable. The present invention further relates to a biodegradable micropowder, preferably comprising bacterial cellulose particles, which have an average particle size of 1 μm to 1000 μm and an average crystallinity of 30% to 80%. The present invention also preferably relates to a method for producing a micropowder, which comprises the steps of producing bacterial cellulose from a bacterial culture such that the produced bacterial cellulose has an average crystallinity of 30% to 80%, milling the bacterial cellulose to form bacterial cellulose particles having an average particle size of 1 μm to 1000 μm, and drying the milled bacterial cellulose particles. The present invention also relates to a cosmetic or personal care product comprising the micropowder.

Description

[Technical Field]

[0001] The present invention relates to a micropowder, preferably having an oil absorption capacity of at least 2.5 g / g, which is biodegradable. The present invention further relates to a biodegradable micropowder, preferably comprising bacterial cellulose particles, which have an average particle size of 1 μm to 1000 μm and an average crystallinity of 30% to 80%. The present invention also preferably relates to a method for producing a micropowder, which comprises the steps of producing bacterial cellulose from a bacterial culture such that the produced bacterial cellulose has an average crystallinity of 30% to 80%, milling the bacterial cellulose to form bacterial cellulose particles having an average particle size of 1 μm to 1000 μm, and drying the milled bacterial cellulose particles. The present invention also relates to a cosmetic or personal care product comprising the micropowder. [Background technology]

[0002] The present invention is in the technical field of micropowders and microbeads, in particular biodegradable micropowders, more particularly biodegradable micropowders suitable for use as rheology modifiers, viscosity enhancers, texture enhancers, texturizing agents, sensory enhancers or opacifying agents, either as solids or with various organic and inorganic media.

[0003] The use of micropowders and microbeads to modify the aesthetic, sensory, rheological, hydrophobic, hydrophilic, oil absorption, UV absorption, or other functional properties of solid or liquid products is known. Such powders and microbeads are currently used in a variety of products, such as personal care, home care, dental care, pharmaceutical products, coatings, and paint formulations. They are typically made from non-biodegradable synthetic polymers, as well as minerals and metal oxides.

[0004] Examples of liquid products include sunscreens and foundation creams. Titanium dioxide (TiO2) particles, which contribute to opacity and sun-filtering properties, are often provided in powder form and suspended in the formulation to adjust its color and solar absorption. Such formulations are often stored for several months before use, during which time the suspended particles may settle, resulting in inconsistencies in the product's color and opacity. To avoid this, the suspended particles are milled to a very small diameter and combined with a rheology modifier that retards any settling. Furthermore, the formulation's adhesion to the skin and avoidance of unwanted wetness, stickiness, or tackiness depend on the formulation's absorption. Due to the low oil and water absorption of titanium dioxide particles, additional microbeads, for example made from talcum powder or plastic, may be added.

[0005] As an example of a solid product, a pressed cosmetic powder can be considered. Pressed cosmetic powders are often based on finely divided mineral materials such as talc, silica, or metals such as magnesium. In some cases, microbeads are also an important component of such products. Titanium dioxide particles and zinc oxide particles are common ingredients added to adjust the opacity of the product or to provide sufficient sun protection. Metal, mineral, or plastic powders are also often used to provide desired pigments to such pressed cosmetic powders. In addition to aesthetic qualities, there is currently high consumer demand for such products to provide a soft, non-sticky finish, fill pores, and / or remain comfortable on the skin for a long time, even when sebum is produced. These textural properties are usually provided by fine plastic powders containing materials such as polymethyl methacrylate or trimethylol hexyl lactone.

[0006] The main drawback of these known micropowders is their lack of biodegradability, which is currently a pressing environmental and public health issue. There is ample evidence that fish have ingested microplastics on the market. Such microplastics can rapidly travel through the human body, potentially crossing the blood-brain barrier and potentially causing neurological problems and affecting the human immune system. Therefore, there is an urgent need to develop biodegradable and biocompatible alternatives to the currently widely used existing powders.

[0007] Furthermore, in recent years, concerns have been raised regarding the safety of many micropowder components typically used in various consumer products. For example, talcum, a common ingredient in pressed powders, deodorants, and baby care products, is suspected of being carcinogenic due to its presence in tumors. Because talcum naturally occurs on the earth's surface in close proximity to other known carcinogenic minerals, such as asbestos, cross-contamination can occur during mining. This could lead to asbestos being introduced into the body as part of such talcum powders.

[0008] Deodorants also contain very fine particles of aluminum (10 μm–50 μm) or aluminum salts to alleviate dryness and provide antiperspirant benefits by blocking pores. Because of their small size, these particles are highly absorbed, easily dispersed during spraying, and undetectable to the user. However, their small size allows them to overcome tissue barriers and enter the human body. Recently, a link has been made between breast cancer and the use of aluminum-based deodorants. It is believed that fine aluminum particles enter lymph nodes, migrate to breast tissue, and cause an increase in tumors found near lymph nodes. Because the particles do not break down in the body, they can accumulate and pose a risk to surrounding tissues. Therefore, there is a need to replace these powders with safer, more biocompatible alternatives.

[0009] Furthermore, there has been a recent trend by consumers and regulatory agencies to replace synthetic ingredients in not only cosmetics but all consumer products with naturally derived raw materials or to develop formulations composed partially or entirely of natural ingredients. Thus, there is a need for viable alternatives that are not only biodegradable and safer than current options, but also meet consumer demands for product aesthetic quality, feel, and performance. In particular, there is a need for versatile biodegradable micropowders that can fulfill several powder-type functions, from opacity to oil absorption and soft texture.

[0010] The use of natural polymers to replace non-natural polymers in non-biodegradable powders has been explored. For example, U.S. Patent Publication No. 2007 / 0129998 teaches the use of modified xanthan gum and galactomannan as a dry powder blend for producing personal care products. While the powder blend was found to provide suitable thickening properties for lotions and other products, it could not compete with the versatile functionality of conventional microplastics. The application of dry powder blends in solid (as opposed to emulsions or liquid) end products has not been explored. Consumers currently have high expectations for cosmetics and personal care products applied to the skin. Ideally, these should have a soft, natural-looking texture without being dry, cakey, or flaky. Skin products can flake off if they do not adhere properly to the skin or if they are unable to absorb the layer of sebum that accumulates between the product and the skin. This is thought to be due to the limited absorption capacity of known biodegradable alternatives to metal and plastic microbeads. Therefore, there is a need for micropowders that are not only biodegradable but also provide a long-lasting, soft texture and matte appearance upon application.

[0011] Plant cellulose has also been explored as a potential alternative to synthetic, non-biodegradable powder materials. Cellulose is typically produced from wood pulp and is bound with components such as wax, lignin, pectin, and hemicellulose. These additional components and the chemical structure of plant cellulose limit its hydrophilicity and solubility in aqueous media. Therefore, producing smooth emulsions from plant cellulose presents challenges. Furthermore, its natural off-white color makes it undesirable for use in paints or white products, where metal oxides remain preferred. Furthermore, products containing plant cellulose-based powders have not yet been found to meet consumer demand for a soft texture and non-sticky feel.

[0012] Surface-modified bacterial cellulose has also been used outside of the consumer product field for its oil absorption capacity. For example, Patent Document 2 discloses a PTES (phenyltriethoxysilane) surface-modified bacterial cellulose aerogel oil-absorbing material used in oil spill cleanup. The gel is produced by disrupting bacterial cellulose film, mixing the disrupted film with deionized water, and freeze-drying it for 24 to 72 hours to form an aerogel. The aerogel is then functionally modified in ethanol to increase its hydrophobicity. This functional modification allegedly enables the achievement of a claimed oil absorption capacity of up to 50 g / g. While this demonstrates the existence of a natural-based material with high oil absorption properties, it does not offer an alternative to known micropowders and microbeads. Gels have a homogeneous structure that relies on a network effect formed between long fibers. Micropowders and microbeads, on the other hand, are preferably formed as discrete particles. Particle agglomeration is generally undesirable. In particular, for scrubbing agents and exfoliants, hardened, discrete particles are required to perform the scrubbing function.

[0013] The highly hydrophobic nature of aerogels and their modified chemical structure make them suitable for oil spills, but may not be suitable for use on skin, where chemical stability, non-stickiness, and non-greasy properties are desirable. In addition to these limitations, surface modification of cellulose with PTES makes the resulting gel petroleum-based, which means it is no longer biodegradable.

[0014] Patent Document 3 discloses another example of an oil-absorbing aerogel made from bacterial cellulose. This aerogel is formed by culturing a bacterial cellulose film, pulverizing the film, and mixing it with deionized water to form an aquagel, which is then freeze-dried to form the aerogel. The aerogel is produced in block sizes ranging from 1 cm to 50 cm. Aerogels are hydrophobic and oleophilic, allowing them to absorb oil spills in water. In particular, their hydrophobicity allows aerogels to selectively absorb oil spills in water, so that the pores within their fiber network are filled only with unwanted oil components.

[0015] Due to its gelling properties, aerogel is unsuitable for use as a biodegradable micropowder in most consumer products. This is because the individual blocks of aerogel swell and lose their distinct shape as they gradually form a colloidal network with the oily components of the formulation. In aqueous or emulsion-based formulations, aerogel, particularly due to its hydrophobic properties, can be poorly mixed with the formulation, causing phase separation. Therefore, bacterial cellulose aerogel is also unsuitable for producing micropowder for use in formulations.

[0016] Patent Document 4 discloses a further example of an oil-absorbing aerogel made from bacterial cellulose. It is produced in a similar manner, based on culturing a bacterial cellulose film, grinding the film, mixing it with deionized water to form an aquagel, and then freeze-drying the aquagel to form an aerogel. The aerogel is described as a highly porous, three-dimensional network structure that has a high affinity for oil and can be used for oil-water separation. Due to its gelling properties, this material would not be suitable for use as a micropowder in most consumer products. In particular, the gel did not meet the characteristics of a powder in terms of particle size and dispersibility in the formulation, and could not provide a texture suitable for scrubbing.

[0017] To avoid the inconveniences associated with transporting and handling bulky cellulose gels, Patent Document 5 discloses an alternative method for preparing bacterial cellulose as a powder that can be subsequently reconstituted as a gel. This powder can be added to food formulations as a thickener. Due to the dry conditions encountered during production, this powder has a loose fibrous structure that forms a gel when added to a fluid. Furthermore, this powder has low water and oil absorption due to its low porosity and density. Furthermore, its open fibrous structure can result in high swelling, reducing the particle size when added to liquid formulations, which can undesirably affect the flowability of the formulation. Therefore, there is a need for a highly absorbent biodegradable powder that does not tend to form a gel in liquid formulations.

[0018] Patent Document 6 discloses bacterial cellulose powder for use in cosmetics. This powder is intended as a substitute for microplastics in cosmetic formulations. To produce bacterial cellulose powder suitable for use in such cosmetic formulations, Patent Document 6 teaches that it is important to completely remove oil and moisture between the individual fibers of biocellulose to eliminate powder absorption. Therefore, bacterial cellulose has little or no absorption properties to maintain its particle size when used in liquid formulations. Because such powders are not absorbent, they cannot provide the soft, matte finish desired in many cosmetic products. Furthermore, the powders tend to be large in diameter and do not absorb oil, which can result in poor adhesion to the skin. Consequently, cosmetics produced using this powder tend to flake and are therefore of poor quality.

[0019] Microbeads for use on the skin should ideally be completely biodegradable and not accumulate in the body. They should also maintain their particle size in fluid suspension and have sufficient oil absorption. Therefore, there is a need for micropowder with materials and properties suitable for use in a variety of everyday consumer products.

[0020] There is a need for alternative micropowder that is versatile in its properties. Preferably, the micropowder is biodegradable and derived from renewable resources. The micropowder is preferably a good opacifier, is neutral in color, can provide advantageous rheological properties, and is biologically safe. It is particularly preferred that the micropowder does not pose a health risk to humans if it enters the food chain. To effectively replace synthetic powders used in cosmetics and personal care products, there is a need for biodegradable powders that provide a soft, non-sticky, non-greasy feel on the skin. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] U.S. Patent Application Publication No. 2011274629 [Patent Document 2] Chinese Patent Application Publication No. 103962105 [Patent Document 3] Chinese Patent Application Publication No. 103966700 [Patent Document 4] Chinese Patent Application Publication No. 104017233 [Patent Document 5] Chinese Patent Application Publication No. 10935407 [Patent Document 6] International Publication No. 2019004520 Summary of the Invention

[0022] The object of the present invention was to overcome the drawbacks of currently known micropowders and microbeads and their manufacturing methods.

[0023] This problem is solved by the features of the independent claims. Preferred embodiments of the invention are provided by the dependent claims.

[0024] In one embodiment, the present invention relates to a micropowder comprising bacterial cellulose particles, the micropowder having an oil absorption of at least 2.5 g / g and being biodegradable.

[0025] Bacterial cellulose has been found to be a surprisingly versatile and advantageous alternative to materials originally used to form powders as building blocks in many industries. In contrast to metals and synthetic polymers, bacterial cellulose is highly biodegradable. In particular, in powder form, bacterial cellulose could reach a 75% biodegradation level within 28 days. Bacterial cellulose powder could be completely biodegraded in 60 days. By providing bacterial cellulose as a micropowder by washing and grinding the harvested cellulose, suspending it in deionized water, oven-drying, spray-drying, treating it with supercritical CO2, or freeze-drying it to form a non-gelling micropowder, the micropowder possessed a high surface area-to-mass ratio and high porosity without the need for organic solvents. Furthermore, the micropowder maintained its particle size even when suspended in a liquid formulation. The surface of bacterial cellulose was sufficiently amphiphilic to be attacked and rapidly degraded by microorganisms.

[0026] These results demonstrate the enormous potential of the described bacterial cellulose-based micropowders to replace currently used metals, minerals, and microplastics. Due to its rapid biodegradability in nature, bacterial cellulose poses a much lower risk of entering the global food chain. In any case, bacterial cellulose is not only a naturally occurring material that is digested and safely eaten by many organisms, but it can also safely decompose in water, air, or soil, thereby mitigating concerns about the accumulation of microplastics in water bodies and the food chain. From an environmental perspective, milled and dried bacterial cellulose micropowders free of organic solvents are a much more attractive alternative to currently used powders.

[0027] In contrast to conventional powders, bacterial cellulose powder has also been found to be surprisingly biocompatible. In contrast to known powder additives such as talcum and aluminum, bacterial cellulose has not been associated with any health concerns. Rather, chemically similar plant cellulose is often safely ingested by humans in the form of dietary fiber. Plant cellulose has also been originally used in a variety of materials intended for contact with human skin, such as cotton fabrics, bandages, or traditional medicines and cosmetics based on herbs, plant roots, stems, leaves, etc. Therefore, it is a particularly safe material.

[0028] The use of bacterial cellulose rather than plant cellulose offers additional advantages. Bacterial cellulose does not contain waxes, lignin, pectin, and hemicellulose, which are commonly found in cellulose prepared from plant sources. By culturing in a controlled environment, the bacterial cellulose can be guaranteed to be extremely pure. This is particularly useful when the biodegradable powder of the present invention is used in food, pharmaceutical, or healthcare products.

[0029] Compared to plant cellulose, bacterial cellulose tends to have a more crystalline structure and can form characteristic ribbon-like microfibrils. In particular, the thin microfibrils of bacterial cellulose are significantly smaller than those of plant cellulose, resulting in bacterial cellulose-based micropowders that are much more porous when cultivated, milled, and dried using appropriate techniques. Advantageously, as described in more detail herein, porosity can increase the surface area and thus surface interactions of bacterial cellulose particles, leading to a variety of interesting effects. Furthermore, porosity can reduce the overall density of bacterial cellulose particles, making them particularly light. It has been found that porosity is influenced by the degree of crystallinity of bacterial cellulose. Because bacterial cellulose can achieve a much wider range of crystallinity, this can be tailored during the micropowder manufacturing process. Crystallinity levels between 30% and 80% have been found to result in high porosity and surface irregularities that increase the surface area of ​​bacterial cellulose particles, especially when dried. This can be further improved by adjusting the average particle size of the micropowder to maximize the surface area available for intermolecular interactions with surrounding media such as oil or water. The inventors have discovered that dried bacterial cellulose particles can act as an excellent thickener and rheology modifier due to their ability to be suspended in large quantities in a variety of fluid media, allowing for an extended shelf life of multiple emulsions and resulting in high user satisfaction.

[0030] Furthermore, as further described herein, it is believed that the increased porosity of bacterial cellulose particles may contribute to their surprisingly high oil absorption, especially when dried with hornification, e.g., by oven drying or spray drying. The oil absorption of the micropowder of the present invention is comparable to, and far exceeds, other highly absorbent powders. This has significant implications for the manufacture of various consumer products. One such implication is that current state-of-the-art microplastic, metal, and mineral powders can be replaced with the much safer, fully biodegradable powder of the present invention without sacrificing absorption functionality and without reducing consumer satisfaction. Surprisingly, the functionality of conventional powders can be dramatically improved.

[0031] In the case of cosmetics and personal care products, the high oil absorption of bacterial cellulose allowed products containing the powder of the present invention to absorb sebum from the skin in high volume and for a long period of time. Therefore, these products could be worn comfortably for a long time without feeling sticky, greasy, or cakey. The products could provide a very soft, matte appearance and texture that conceals unevenness and pores. Subjects also reported that such products left a pleasant, non-sticky, non-sticky after-feel.

[0032] In addition to the advantageous texture, the high oil absorption of bacterial cellulose particles allows for the production of products with high oil content without compromising stability, shelf life, or aesthetics. For example, scented or flavored essential oils, cocoa butter (cocoa oil), or other vegetable oils can be incorporated in larger amounts into the product, creating a very high-quality impression. Potential applications include cosmetics, personal care products, and food products.

[0033] Bacterial cellulose preferably comprises an ultrafine network of highly uniaxially oriented cellulose fibers. This type of 3D structure can result in particularly high crystallinity and advantageous physicochemical and mechanical properties, especially when fabricated into the micropowder described herein. This structure aids in the formation of a bacterial cellulose pellicle, preferably a sheet- or film-like layer of bacterial cellulose. The crystallinity of bacterial cellulose can impart rigidity to the microfibrils and can be used to tailor the mechanical properties of the resulting product. These properties include flexibility, elasticity, and tensile strength. Crystallinity also confers excellent thermal and chemical stability to bacterial cellulose particles. Therefore, bacterial cellulose is a particularly versatile material for use as a biodegradable powder.

[0034] In the sense of the present invention, a "micropowder" is preferably a material comprising particles, grains, or fragments. At least one spatial dimension of the particles, grains, or fragments is preferably in the micro range. Preferably, the average length, width, thickness, or diameter of the particles, grains, or fragments is less than 1000 μm. The micropowder is preferably dry and has a water content of less than 5 wt. %, preferably less than 1 wt. %, more preferably less than 0.5 wt. %. The micropowder preferably maintains its particle size in aqueous, oil-based, or emulsion fluid formulations. Furthermore, the average swelling of the micropowder in a fluid formulation is preferably less than 100% by volume, more preferably less than 70% by volume, even more preferably less than 50% by volume, and even more preferably less than 25% by volume, and the swelling is preferably proportional to the increased volume of the swollen particle divided by the original volume of the particle.

[0035] Micropowder is preferably distinguished from gel by its inability to swell in fluids and by its preferably high volumetric percentage of solid material. Thus, the particles of micropowder are preferably at least 5%, more preferably at least 10%, and even more preferably at least 15% solid by mass when stored in air under ambient conditions or suspended in a liquid formulation. Furthermore, micropowder is preferably not suitable for retaining fluids to form substantially homogeneous colloids. Formulations containing micropowder at concentrations of up to 5 wt. % and more preferably up to 10 wt. % in a continuous liquid phase are preferably characterized as liquids rather than as soft solids or semisolids.

[0036] On the other hand, as used herein, the term "gel" preferably refers to a substantially homogeneous material comprising a three-dimensional fiber or polymer network and a fluid dispersed therein, the fluid mass preferably being several times greater than the mass of the fiber or polymer network. The three-dimensional fiber or polymer network preferably traps and immobilizes fluids, particularly liquids, preventing their flow without imposing a minimum yield stress. The minimum yield stress of the gel is preferably at least 10 Pa, more preferably at least 50 Pa, even more preferably at least 100 Pa, even more preferably at least 200 Pa, and even more preferably at least 500 Pa. Gels are preferably soft solids or semi-solids, particularly because liquids are trapped within the fiber or polymer network. Preferably, the fluid mass of the gel is at least 5 times, more preferably at least 10 times, and even more preferably at least 20 times the mass of the fiber or polymer network.

[0037] The gelling material is preferably a solid material that swells when added to a liquid to form the loose fibers or polymer network required for the gel. The gelling material preferably swells at least twice its volume when added to a liquid, preferably at least five times, more preferably at least ten times, and even more preferably at least 20 times.

[0038] In the sense of the present invention, the micropowder is preferably not a gel or a gelling material.

[0039] In the sense of the present invention, "oil absorption" is preferably the measure of the mass of oil that can be bound to 1 gram of micropowder in grams.Oil absorption can be measured for any oil, and oil is preferably any non-polar substance that is liquid at 25°C and is mainly composed of hydrocarbons.Sunflower oil can be used as reference oil.Preferably, oil absorption is experimentally measured using ASTM D281-95 or its modified version.

[0040] In the sense of the present invention, "biodegradability" is preferably a measure of the length of time it takes a material to decompose after exposure to biological factors. Cellulose degradation preferably involves the breakdown of cellulose polymers into dimers or monomers. Biodegradability can be determined using an OxiTop measuring device. A known mass of the material to be tested can be exposed to microorganisms in a test bottle. The microorganisms can convert oxygen (O2) to carbon dioxide (CO2) during biodegradation of the test material. OxiTop™ is preferably a cap-type pressure gauge attached to the test bottle, which measures biochemical oxygen demand by detecting the degree to which the air pressure inside the bottle decreases. After sealing the test bottle with an OxiTop™ cap, the bottle can be incubated in a constant temperature bath (e.g., IN804, Yamato Scientific Co., Ltd., Japan). According to the OECD (Guideline for Testing Chemicals: Ready biodegradability (1992)) and CSCL (Guideline for the Chemical Substances Control Law: Microbial Degradation Testing of Chemical Substances (2018) (Japanese)) guidelines, a test chemical is considered to be completely degraded (the remaining 40% is assumed to have been assimilated by microorganisms) when the biochemical oxygen demand value during the test period reaches 60% of the theoretical oxygen demand of the test chemical (especially in the 301C or 301F test procedures).

[0041] In the sense of the present invention, "bacterial cellulose" is preferably cellulose synthesized by bacteria, also called "microbial cellulose" or "biocellulose". Bacterial cellulose is a polysaccharide chain containing several β(1→4)-linked D-glucose units. Its chemical structure is represented by the formula (CH 10 O5) nIn the sense of the present invention, bacterial cellulose may have a chemical structure that deviates from the above formula, especially in the case of functionalized bacterial cellulose. The bacteria used to synthesize bacterial cellulose may preferably belong to the genus Gluconacetobacter, Acetobacter, Aerobacter, Achromobacter, Azotobacter, Rhizobium, Lactobacillus, Agrobacterium, Pseudomonas, Alcaligenes, Salmonella or Sarcina. Suitable bacterial species known to those skilled in the art include, but are not limited to, Gluconacetobacter xylinus, Gluconacetobacter hansenii, Acetobacter xylinum, Acetobacter senegalensis, Acetobacter pasteurianum, Acetobacter rancens, Sarcina ventriculi, and Lactobacillus Mali. Co-cultures of two or more bacterial species may also be used. Bacterial cellulose can be cultured in a medium providing a carbon source, optionally a nitrogen source, and any additional macronutrients or micronutrients deemed appropriate. Examples of carbon sources include glucose, fructose, sucrose, maltose, xylose, mannitol, glycerol, and molasses. For bacterial culture, it may be preferable to use Hestrin-Schramm medium. Bacteria can be cultured in a static or agitated environment, and the culture time can vary between 30 and 300 hours.The bacterial cellulose is preferably produced in the form of one or more sheets (also called pellicles, films or membranes).

[0042] In a preferred embodiment of the present invention, the micropowder is up to 75% biodegradable within 35 days. Preferably, the micropowder is up to 75% biodegradable within 28 days. Unless otherwise specified, the percentage of biodegradability preferably refers to the w / w percentage of material that is degraded or assimilated by microorganisms.

[0043] By adjusting the biodegradability of the micropowder to 75% within 28 days, the micropowder is rapidly biodegraded, reducing the need for any special disposal measures to prevent the micropowder from entering drains or the food chain. This is particularly due to the micropowder's small particle size, high porosity, and high surface area-to-mass ratio, which increase contact with air and microorganisms. Products formulated using this micropowder can boast high biodegradability and environmental compatibility. Therefore, this micropowder fulfills a long-standing need in the market for a micropowder that can be disposed of like other consumer products without environmental concerns.

[0044] In further preferred embodiments of the present invention, the micropowder has an oil absorption capacity of at least 4 g / g, preferably at least 4.5 g / g, and even more preferably at least 5 g / g. By tailoring the properties of the bacterial cellulose particles to achieve these oil absorption capacities, the micropowder of the present invention can far exceed known micropowder capacities while remaining completely biodegradable and safe. Preferably, the micropowder exhibits these absorption capacities for a variety of oils, including, but not limited to, sunflower oil, vegetable oil, canola oil, olive oil, rapeseed oil, neem oil, glycerol, lavender, tea tree oil, essential oils, and jojoba oil.

[0045] Such oil absorption provides a highly sought-after property, particularly in the fields of cosmetics and personal care products. Products intended for use on the skin are highly sought after for providing a soft texture, particularly a "blurred" or "airbrushed" effect. This effect can be achieved by absorbing the sebum that forms underneath the product on the skin, preventing the product from peeling, cracking, or otherwise exhibiting inconsistencies in texture. Manufacturers of such products have actively used harmful and non-biodegradable micropowders in their products. The inventors have discovered that the micropowders of the present invention can be easily configured to achieve higher oil absorption than those achieved by known micropowders.

[0046] By way of example only, the micropowder of the present invention was able to absorb sunflower oil at a capacity of over 5 g / g. Under the same conditions, a micropowder made from kaolin, vinyl dimethicone crosspolymer, and PMMA (polymethyl methacrylate) could absorb less than 2 g / g of sunflower oil. The oil absorption capacity of the micropowder of the present invention was also able to far exceed that of talcum powder, which is approximately 1.5 g / g. Subjects treated with formulations containing the same amounts of the micropowder of the present invention and the aforementioned micropowder made from PMMA and silica reported much higher satisfaction with the formulation containing the micropowder of the present invention. In particular, they reported a high degree of softness during application and a soft feel after application. Subjects also reported that the formulation containing the micropowder of the present invention was much less sticky than the alternatives, leaving a much less sticky and less tacky feel after application. These results (described in more detail herein) demonstrate great potential for improving the quality of consumer products.

[0047] In further preferred embodiments of the present invention, the micropowder has an oil absorption of at least 7 g / g, at least 10 g / g, at least 12 g / g, at least 15 g / g, at least 20 g / g, at least 25 g / g or more.

[0048] In a further preferred embodiment of the present invention, the micropowder has an oil absorption relative to oleic acid of at least 2.5 g / g, preferably at least 3 g / g, more preferably at least 3.5 g / g, more preferably at least 4 g / g, preferably at least 4.5 g / g, more preferably at least 5 g / g, more preferably at least 5.5 g / g, more preferably at least 6 g / g, more preferably at least 6.5 g / g, more preferably at least 7 g / g, more preferably at least 7.5 g / g, more preferably at least 8 g / g, and even more preferably at least 10 g / g. The use of oleic acid as a reference material is particularly advantageous because it is a common reference material in the cosmetics and cosmeceutical industries, allowing for an apples-to-apples comparison of the oil absorption of different materials. Furthermore, oleic acid is a frequently used component in many cosmetics and personal care products, primarily acting as an emollient. Therefore, the high absorption of oleic acid allows for a higher usage rate of products containing oleic acid.

[0049] In a preferred embodiment of the present invention, the bacterial cellulose particles have an average particle size D50 of 1 μm to 1000 μm. However, it is even more preferable that the average particle size D50 of the bacterial cellulose particles be 1 μm to 500 μm, preferably 5 μm to 250 μm, more preferably 25 μm to 100 μm, and particularly preferably 30 μm to 75 μm. Furthermore, an average particle size of approximately 65 μm may be preferred. These preferred average diameters balance light particles and high dispersibility on the one hand with safety on the other. These particles disperse very easily, filling pores and sweat glands and concealing uneven skin texture. The high absorption and small particle size favor the micropowder's good adhesion to the skin and its high flexibility when the liquid formulation dries on the skin to leave a coating. Therefore, materials containing this powder could be easily used to cover skin surfaces of different shapes and movements without cracking or peeling. At particularly preferred particle sizes, bacterial cellulose micropowder is also particularly light-scattering, contributing to a soft, matte finish. The preferred diameter also proved optimal for providing high porosity with pore sizes in the mesoporous range, allowing rapid absorption of fluids by capillary action while maintaining the powder's particle size. This allowed for high and rapid absorption while avoiding particle swelling, making the powder particularly comfortable and stable when applied to the skin. At the same time, the risk of penetration of tissue barriers was reduced, making the micropowder particularly biocompatible.

[0050] In a further preferred embodiment of the present invention, the average particle size D of the bacterial cellulose particles 50 The particle size is between 8 μm and 65 μm. Cellulose particles of this size, as determined from experiments carried out by the inventors, exhibit particularly advantageous properties of absorption, adsorption, adhesion and light scattering.

[0051] In addition, the average particle size of bacterial cellulose particles, D 50The particle size may be preferably 200 μm to 1000 μm, preferably 400 μm to 1000 μm, even more preferably 500 μm to 1000 μm, and even more preferably 500 μm to 800 μm. At these particle sizes, the micropowder can be used in cleansing products, scrubs, and exfoliants, providing the desired coarse texture for these applications. At the same time, the micropowder is sufficiently light and easily dispersible. Even at these particle sizes, the micropowder of the present invention exhibited significantly better oil absorption than known micropowder. It was possible to achieve excellent cleansing effects while leaving the user's skin feeling soft after use.

[0052] In a further preferred embodiment of the present invention, at least 90% of the bacterial cellulose particles have a diameter of 500 μm or less, preferably 300 μm or less, and particularly preferably 200 μm or less. Such micropowder contains very fine particles with a sufficiently broad particle size distribution. A broad particle size distribution can contribute to providing the semi-matt or matte finish that we may desire, for example, in lipsticks and other cosmetics.

[0053] In a further preferred embodiment of the present invention, the average particle size D of the bacterial cellulose particles 50 is 40% or less, preferably 30% or less, and even more preferably 25% or less of the 90th percentile particle size D90 of the micropowder. Thus, the micropowder can have a wide particle size distribution. This can contribute to providing a much more matte finish in some products. It has also been found to be useful in providing smooth thickening and extension effects in mascara liquids.

[0054] In a further preferred embodiment of the present invention, the 90th percentile particle size D 90 The values ​​of are between 20 μm and 200 μm. Especially in combination with the mean diameters of 8 μm to 65 μm, the experimentally produced micropowders were suitable for a wide range of purposes, especially in cosmetic and cosmeceutical formulations.

[0055] The inventors have found that the size and crystallinity of bacterial cellulose particles constitute factors that can be advantageously used to achieve high rates of oil uptake. In this regard, the average particle size D of bacterial cellulose particles between 1 μm and 1000 μm is 50 And an average crystallinity of bacterial cellulose particles between 30% and 80% has proven to be particularly beneficial.

[0056] In a further preferred embodiment of the present invention, the average particle size D of the bacterial cellulose particles 50 The average crystallinity of bacterial cellulose particles is between 30% and 80%.

[0057] With an average diameter of 1 μm to 1000 μm, preferably 1 μm to 500 μm, more preferably 5 μm to 250 μm, more preferably 25 μm to 100 μm, and particularly preferably 30 μm to 75 μm, bacterial cellulose powders could perform a variety of functions. At these diameters, bacterial cellulose particles could be easily dispersed in suspension. Therefore, they could form stable creams, lotions, paints, and the like. At the same time, this bacterial cellulose powder was suitable for use in dry products such as loose or pressed cosmetic powders. This powder had excellent adhesion to the skin, resulting in a comfortable, non-sticky, non-greasy texture and a matte finish. It was also found to be highly suitable for filling pores, fine lines, and concealing uneven skin tone. These properties are highly sought after in the cosmetics sector.

[0058] Within the selected average diameter range, the bacterial cellulose powder had a very high surface area-to-mass ratio. This could be further enhanced by adjusting the crystallinity, and therefore the porosity, of the bacterial cellulose used. Therefore, the bacterial cellulose particles could be made very light with a large surface area that interacts with fluids, particularly through intermolecular forces. Therefore, the bacterial cellulose particles could be suspended in aqueous, inorganic, and organic media without settling. Emulsions and suspensions with long shelf lives could be produced. The high surface area-to-mass ratio provided by the selected average diameter range also contributed to increasing the water and oil absorption of the biodegradable powder.

[0059] An average crystallinity within a selected range of 30% to 80%, preferably 40% to 80%, more preferably 40% to 60%, particularly preferably 40% to 50%, and even more preferably about 45% worked synergistically with the selected average particle size to provide optimal material properties and oil absorption. At these crystallinities, the bacterial cellulose harvested from the pellicles contained a mixture of crystalline and amorphous phases. Without being limited by theory, the inventors hypothesized that the mixture of crystalline and amorphous phases resulted in the presence of more pores, especially at the interface between the phases. This allowed the bacterial cellulose material to be lighter and more porous.

[0060] High crystallinity increases the tendency of bacterial cellulose to keratinize during drying, which is believed to be due to the close packing of bacterial cellulose fibers. As a result, the produced micropowder is substantially solid, and fluid absorption occurs substantially on its surface and within its pores. This is substantially different from the absorption mechanism of gelled cellulose materials, in which fluid is trapped within a loose fibrous network. In particular, the high crystallinity of the bacterial cellulose of preferred embodiments of the present invention reduces swelling behavior when immersed in liquid. Therefore, the preferred crystallinity also allows the micropowder to maintain its granularity and small particle size, filling and smoothing pores and fine lines, and providing a scrubbing effect when desired.

[0061] The selected average degree of crystallinity also provides bacterial cellulose with higher stiffness, particularly compared to plant cellulose and bacterial cellulose with an inappropriately adjusted or selected crystallinity. When bacterial cellulose with a crystallinity of 30% to 80% was crushed or pulverized to a selected average particle size of 1 μm to 1000 μm, the resulting particles had a variety of irregular shapes, particularly polyhedral and plate-like shapes. The irregular shapes contributed to increasing the surface area-to-mass ratio of the particles, thereby increasing oil absorption.

[0062] Advantageously, the irregular shape resulting from the mixture of crystalline and amorphous phases in the particles further increased the light-scattering ability of the powder, allowing it to function as an excellent opacifier. When used in paints, makeup, or skin care products, this light-scattering property contributed to a desirable soft, matte finish.

[0063] The inventors have discovered that the ratio of crystalline to amorphous phases in bacterial cellulose can be finely tuned by selecting one or more appropriate bacterial species and adjusting the culture conditions. It was also found that the agitation speed, frequency, and duration of the culture, as well as aeration, play important roles. By combining this with a selected drying technique, the degree of crystallinity could be more precisely adjusted. By setting the degree of crystallinity within a specified range, the absorption and matting effects could be optimized.

[0064] "Particle size" in the sense of the present invention is preferably the diameter of a theoretical equivalent sphere occupying a volume equivalent to that occupied by the particle. The skilled person knows how to calculate or estimate the equivalent sphere.

[0065] In the sense of the present invention, "average particle size" is preferably the median diameter of a plurality of particles. Unless otherwise specified, this is preferably D 50 The mean particle size is the particle size at which the cumulative percentage of ordered particles reaches 50%. That is, the D of 500 μm 50The average particle size preferably means that 50% of the particles have a diameter greater than 500 μm and 50% of the particles have a diameter less than 500 μm. 50 The average particle size can be determined by microscopic image analysis, differential sieving, light scattering or another method. 50 The average particle size is determined by polarized intensity differential scattering, in particular using a ULM standard PIDS instrument.

[0066] In a further preferred embodiment of the present invention, the micropowder is produced by a method comprising milling bacterial cellulose pellicles and drying the milled bacterial cellulose. Initially forming bacterial cellulose particles by milling allows for the production of a homogenized mixture or powder. The mixture or powder may contain particles with irregular shapes and small particle sizes due to the breakage caused by the mill. The particle size can be further adjusted by drying.

[0067] In some embodiments, it may be preferable for the drying to be configured to cause keratinization of the bacterial cellulose.

[0068] In the sense of the present invention, "keratinization" is preferably a phenomenon that occurs in cellulose materials during drying or water removal, which causes the cellulose microfibrils to aggregate, increasing their density and strength. The hydrogen bonds formed between the aggregated microfibrils are preferably strong enough not to be broken by rewetting the cellulose. Therefore, keratinized bacterial cellulose does not substantially swell when immersed in a liquid formulation. Furthermore, entanglement of cellulose chains during drying may further contribute to keratinization. At the same time, keratinization blocks chemical groups on the cellulose chains, improving the hydrophobicity of the produced bacterial cellulose particles.

[0069] Hornification preferably reduces the swelling capacity and wet flexibility of bacterial cellulose (Wenxuan Mo, Kefu Chen, Xuan Yang, Fangong Kong, Jiangyan Liu, Bo Li, Elucidating the hornification mechanism of cellulosic fibers during the process of thermal drying, Carbohydrate Polymers, Volume 289, 2022, 119434, ISSN 0144-8617). Hornification is known to prevent a material from gelling (Minor, JL (1994). "Hornification, its origin and meaning," Progress in Paper Recycling 3(2), 93-95. DOI 10.1007 / s00226-003-0216-2). Therefore, it is preferred that hornified bacterial cellulose is not a gelling material. Furthermore, hornification can increase the degree of crystallinity of bacterial cellulose and therefore its mechanical strength (Newman, RH Carbon-13 NMR evidence for cocrystallization of cellulose as a mechanism for hornification of bleached kraft pulp. Cellulose 11, 45-52 (2004)).

[0070] Drying methods that can result in keratinization of bacterial cellulose include oven drying and spray drying. The presence and degree of keratinization depends not only on the drying method, but also on the drying temperature, drying time, and parameters (if any) used to agitate or aerate the dried material.

[0071] In a further embodiment of the present invention, the drying method may be preferably selected to induce and / or enhance keratinization. One example of such a method is oven drying. Surprisingly, it has been found that oven drying of a fluid suspension containing pulverized bacterial cellulose can increase the hydrophobicity of the bacterial cellulose particles, resulting in significantly higher oil absorption. The oil absorption of the micropowder produced by oven drying was higher than that produced by freeze drying. Preferably, the drying temperature is up to 250°C, preferably up to 160°C, preferably 150°C, more preferably up to 120°C, even more preferably up to 100°C, even more preferably up to 80°C, and even more preferably up to 40°C. At these temperatures, keratinization of the bacterial cellulose can be achieved without risk of thermal decomposition of the bacterial cellulose. The drying period can be adjusted so that substantially all of the moisture is removed from the bacterial cellulose. Oven drying is preferably carried out for 12 hours to 10 days, preferably 12 hours to 72 hours, and more preferably 20 hours to 28 hours.

[0072] During oven drying, the bacterial cellulose can be positioned horizontally or vertically. The drying temperature and drying time can be adjusted to improve the porosity of the bacterial cellulose micropowder. In general, it has been found that slow oven drying at a relatively low temperature achieves an optimal level of keratinization while also allowing pore formation by the escaping moisture.

[0073] In a further embodiment of the present invention, a microwave oven is used to dry the bacterial cellulose. Such a drying mechanism has been found to effectively increase keratinization in a homogeneous manner while being fast and energy efficient. Furthermore, the rapid boiling and draining of water in the bacterial cellulose mixture is believed to increase the porosity and / or stiffness of the cellulose.

[0074] In a further preferred embodiment of the present invention, spray drying is used to dry the fluid suspension containing the pulverized bacterial cellulose. Airflow in the spray drying process can reduce the keratinization of the bacterial cellulose fibers and loosen their packing. To counter this, higher temperatures are preferably used to dry the bacterial cellulose during spray drying. In particular, temperatures of at least 180°C, preferably at least 200°C, and more preferably at least 250°C or higher are preferred.

[0075] In a further preferred embodiment of the present invention, the micropowder has a particle size of at least 2 m 2 / g, preferably at least 5 m 2 / g, more preferably at least 10 m 2 / g, more preferably at least 20 m 2 / g, more preferably at least 25 m 2 / g, more preferably at least 30 m 2 / g, more preferably at least 35 m 2 / g, more preferably at least 40 m 2 / g, more preferably at least 50 m 2 / g, more preferably at least 60 m 2 / g, more preferably at least 70 m 2 / g, and even more preferably at least 80 m 2 / g. To limit flammability and reactivity, the surface area to mass ratio is less than 100 m 2 / g or less may be preferable.

[0076] The surface area-to-mass ratio not only increased dispersibility by increasing the intermolecular interactions between the micropowder and the medium carrying it, but also improved oil and water absorption. Furthermore, the surface area-to-mass ratio increased the bacterial cellulose particles' capacity to adsorb and desorb molecules and living cells, thereby accelerating the biodegradation of the micropowder. The surface area-to-mass ratio could be adjusted by setting the speed and / or duration of the bacterial cellulose milling process.

[0077] Furthermore, the surface area to mass ratio can be increased by subjecting bacterial cellulose to a process that increases the porosity of the material. The inventors have found that increasing the number of open and closed pores in bacterial cellulose particles can significantly increase the surface area to mass ratio, thereby significantly increasing oil absorption. It is particularly preferred that the bacterial cellulose particles are mesoporous.

[0078] An example of a process found to increase porosity was the cultivation process itself, particularly when agitation was applied to the culture medium. Using SEM scanning microscopy to examine the effect of different culture medium compositions on the morphology of synthetic cellulose, it has been shown that the nutrients contained in the microbial substrate can also affect the degree of porosity due to the density of the cellulose fiber network (Molina-Ramirez, C.; Castro, C.; Zuluaga, R.; Ganan, P. Physical Characterization of Bacterial Cellulose Produced by Komagataeibacter medellinensis Using Food Supply Chain Waste and Agricultural By-Products as Alternative Low-Cost Feedstocks. J. Polym. Environ. 2018, 26, 830-837). Furthermore, porosity could be increased by adjusting post-treatment processes such as the drying process (Tang, W.; Jia, S.; Jia, Y.; Yang, H. The influence of fermentation conditions and post-treatment methods on porosity of bacterial cellulose membrane. World J. Microbiol. Biotechnol. 2010, 26, 125-13131). For example, spray drying or oven drying can increase the number of pores in bacterial cellulose, with oven drying being found to be particularly preferable.

[0079] In a further preferred embodiment of the present invention, the bacterial cellulose particles have an average crystallinity of 40% to 80%, preferably 40% to 60%, and particularly preferably 40% to 50%. Surprisingly, it has been found that bacterial cellulose particles with such a crystallinity are particularly light and easily dispersible. At the same time, the particles have high porosity and a large specific surface area. The resulting micropowder achieves very high water and oil absorption.

[0080] Bacterial cellulose produced under static culture conditions typically takes the form of one or more hydrated pellicles containing an interconnected network of fibrils organized into numerous dense layers. The degree of crystallinity of cellulose and the mechanical properties it imparts to cellulose are key factors affecting the layered bacterial cellulose structure formed during biosynthesis (Ruan et al., 2016). There are various important parameters of the bacterial fermentation process that can be used to control the structural characteristics of the resulting cellulose fibers. The degree of crystallinity can depend on: (i) the method chosen to cultivate cellulose-synthesizing microorganisms (Czaja, W.; Romanovicz, D.; Brown, R. M. Structural investigations of microbial cellulose produced in stationary and agitated culture. Cellulose 2004, 11, 403-411), (ii) the type of carbon source and other components of the medium (Yim, SM; Song, JE; Kim, HR Production and characterization of bacterial cellulose fabrics by nitrogen sources of tea and carbon sources of sugar. Process Biochem. 2017, 59, 26-3) (Hestrin-Schramm medium was found to be suitable for providing a crystallinity of 30% to 80%), and (iii) The drying method used (Stanislawska, A.; Staroszczyk, H.; Szkodo, M. The effect of dehydration / rehydration of bacterial nanocellulose on its tensile strength and physicochemical properties. Carbohydr. Polym. 2020, 236, 1160235). The inventors have found that the degree of crystallinity of bacterial cellulose is slightly higher in the case of oven-based or spray-drying than in the case of drying by lyophilization or freeze-drying. Therefore, the above crystallinity can be achieved by adjusting these factors, with oven- or spray-drying being particularly preferred.

[0081] The degree of crystallinity of bacterial cellulose correlates with its degree of polymerization. In a preferred embodiment of the present invention, bacterial cellulose has a degree of polymerization of 1,000 to 20,000. In comparison, plant cellulose has a degree of polymerization of 10 to 100, and its range of physical properties is less versatile. Without being bound by any particular theory, it is believed that a higher degree of polymerization, i.e., the production of longer polymer chains, allows the chains to pack more densely in the culture and crystallize more easily. On the other hand, when the culture is stirred or agitated, the length and packing of the polymer chains are thought to be limited by the shear forces present in the fluid medium. As a result, the degree of polymerization and crystallization is lower.

[0082] In the sense of the present invention, the "degree of polymerization" is preferably the average number of monomer units in the chain of the polymer.

[0083] The degree of polymerization is also related to the porosity of bacterial cellulose particles. During the polymerization process of bacterial cellulose, various types of pores may be formed. These include open pores, closed pores, and closed pores.

[0084] In the sense of the present invention, a "through-hole" is preferably a channel that extends through the particle and that is open at two different ends, i.e. the through-hole is preferably accessible from two different openings in the surface of the bacterial cellulose particle.

[0085] In the sense of the present invention, a "closed pore" is preferably a channel that extends at least partially through the particle, the channel being open at only one end, i.e. preferably the closed pore is accessible only through a single opening in the surface of the bacterial cellulose particle.

[0086] In the sense of the present invention, "closed pores" are preferably channels that are encapsulated within the bacterial cellulose particle and are not accessible from any of its surfaces.

[0087] In the sense of the present invention, "mesopores" are preferably through-pores, open pores or closed pores with a diameter of between 1 nm and 50 nm.

[0088] The through-pores contribute significantly to the permeability of bacterial cellulose micropowder and therefore its water and oil absorption capacity. The large number of through-pores in bacterial cellulose particles can also increase the surface area to volume ratio and surface area to mass ratio of the particles, further increasing their absorption capacity.

[0089] The closed pores also contribute to increasing the surface area to volume ratio and surface area to mass ratio of the particles. Therefore, both the open pores and the closed pores could contribute to the absorption, adsorption, and desorption amounts of the micropowder. The biodegradability of the micropowder could also be improved by the presence of such pores.

[0090] Open and closed pores have been found to be particularly advantageous in the absorption of sebum from the skin. The heteroatoms (e.g., oxygen, carbonyl, sulfur, phosphorus, or nitrogen) that form the functional groups present in cellulose are highly electronegative and have an attractive force for long-chain fatty acids, esters, proteins, lipids, carbohydrates, or drug molecules. Molecular dynamics simulation studies have shown that the dry bacterial cellulose surface exhibits a ΔGb of -300 kcal / mol, which has been calculated for vegetable oils. ind It has been confirmed that bacterial cellulose has a high affinity for oils with high molecular weight. In particular, sebum, especially containing esters and fatty acids, is very easily attracted to and absorbed by these bacterial cellulose pores. A larger number of pores or a larger size distribution can improve the absorption capacity and fluid flow therethrough (Burggraaf, AJ & Cot, L. Fundamentals of inorganic membrane science and technology. 4, (Elsevier, 1996); Joghataei, M., Semnani, D., Salimpour, MR, Ashrafi, Z. & Khoeini, D. Comparison of heat transfer coefficient for different fabrics by vapor-compression system. Int. J. Eng. Technol. 5, 11-15 (2016)).

[0091] Closed pores do not directly contribute to the transport of mass through the undegraded particle, but can improve the strength and flexibility of bacterial cellulose while reducing its density.

[0092] It may be preferred that the bacterial cellulose particles have a high proportion of through pores, preferably at least 20%, at least 30% or at least 40% of the void volume of the particle is located in the through pores.

[0093] It may also be preferred that the bacterial cellulose particles have a high combined percentage of open and closed pores, with at least 50%, at least 60%, or at least 70% of the particle's void volume being located in closed and open pores, which may improve micropowder absorption and adsorption.

[0094] It may also be preferred that the bacterial cellulose particles have a high total proportion of mesopores, with at least 50%, at least 60% or at least 70% of the void volume of the particles being located in mesopores.

[0095] In a further preferred embodiment of the invention, the bacterial cellulose particles have a porosity of at least 3%, preferably at least 5%, more preferably at least 10%, and even more preferably at least 20%.

[0096] In a further preferred embodiment of the present invention, the micropowder has a porosity of at least 20%, preferably at least 30%, more preferably at least 40%, even more preferably at least 50%.

[0097] In the sense of the present invention, the "porosity" of a particle is preferably the ratio of the volume of voids to the particle. The "porosity" of a material such as a micropowder is preferably the ratio of the volume of voids to the material. Porosity is preferably expressed as a percentage. The percentage of porosity can be calculated using the formula % porosity = Vv / VT x 100, where Vv is the void volume and VT is the total volume.

[0098] The percentage of porosity and pore type distribution of bacterial cellulose depend on the density of the cellulose fiber network, which has been found to depend on the bacterial culture conditions and the drying technique used (Tang, W.; Jia, S.; Jia, Y.; Yang, H. The influence of fermentation conditions and post-treatment methods on the porosity of bacterial cellulose membrane. World J. Microbiol. Biotechnol. 2010, 26, 125-13131). SEM scanning microscopy was used to examine the morphology of bacterial cellulose grown in different medium compositions, and it was shown that the nutrients contained in the medium affected the degree of porosity (Molina-Ramirez, C.; Castro, C.; Zuluaga, R.; Ganan, P. Physical Characterization of Bacterial Cellulose Produced by Komagataeibacter medellinensis Using Food Supply Chain Waste and Agricultural By-Products as Alternative Low-Cost Feedstocks. J. Polym. Environ. 2018, 26, 830-837). Porosity could also be affected by agitation and aeration of the medium.

[0099] It has also been found that different drying techniques affect the porosity of bacterial cellulose particles (Bruno Thibault, Cristina Ratti, Seddik Khalloufi, A mathematical tool for estimating the efficiency of pore formation during dehydration, Journal of Food Engineering, Vol 323, 2022, 110981). For example, it has been found that reducing pressure during the freeze-drying process can increase the porosity of many organic materials (Vasiliki P. Oikonomopoulou, Magdalini K. Krokida, Vaios T. Karathanos, The influence of freeze-drying conditions on microstructural changes of food products, Procedia Food Science, Volume 1, 2011, Pages 647-654).

[0100] In a further preferred embodiment of the present invention, the bacterial cellulose particles are mesoporous with an average pore radius of 1 nm to 50 nm, preferably 10 nm to 30 nm, more preferably 5 nm to 20 nm, and even more preferably about 7 nm. Preferably, the surface area to mass ratio of the bacterial cellulose particles is less than 10 m 2 / g~100 m 2 / g, more preferably 10 m 2 / g~80 m 2 / g.

[0101] The surface area is preferably the interface through which a solid interacts with its surroundings, particularly liquids and gases. Surface area can be created by particle size reduction, e.g., grinding and milling, and by making the material porous. The surface area of ​​a solid material is typically determined by physical adsorption of a gas on the surface of the solid and calculating the amount of adsorbate gas corresponding to a monolayer on the surface. The results of such analysis are presented further herein.

[0102] In a further preferred embodiment of the present invention, the surface of the bacterial cellulose particles exhibits thread-like projections similar to microvilli. Such microvilli-like projections have been observed in bacterial cellulose particles produced by the preferred methods set forth herein. It may be preferred that at least 2%, more preferably at least 5%, more preferably at least 10%, and even more preferably at least 20% of the surface area of ​​the bacterial cellulose particles is covered with microvilli. This can be recognized and quantified by the distinct texture of the microvilli-covered areas, as shown herein with reference to scanning electron microscope images.

[0103] Without being bound by theory, these microvilli-like projections are believed to improve the oil and water uptake of bacterial cellulose particles by increasing their surface area-to-mass ratio. Molecular dynamics simulations, particularly in the dry form, indicate that bacterial cellulose fibers have a high affinity for saturated hydrocarbon molecules, which will be published elsewhere. Free binding energies of ΔGbind ranging from -50 kcal / mol to -300 kcal / mol have been calculated for common oils, such as glycerol and vegetable oil. By exploiting this property of bacterial cellulose microfibers, we believe that exposing such microprojections on the surface of bacterial cellulose particles could dramatically improve the oil uptake of the micropowder.

[0104] In the sense of the present invention, "microvilli" are preferably elongated protrusions from the surface of a bulk material, preferably comprising fibers aligned approximately parallel to the plane formed by the surface of the bulk material. The protrusions may, for example, exhibit a diameter significantly smaller than 1 μm, preferably smaller than 100 nm, and may have an aspect ratio greater than 5, preferably greater than 10.

[0105] In the sense of the present invention, a "particle" is preferably a discrete portion of material with clearly defined boundaries in all directions. Preferably, a particle has a mass of less than 1 gram and / or a maximum dimension of up to 5 mm, preferably up to 1000 μm. Particles are preferably distinguished from fibers in that their aspect ratio is less than 50:1, more preferably less than 20:1, even more preferably less than 10:1. In a further preferred embodiment of the present invention, the bacterial cellulose particles have an average aspect ratio of less than 10:1, preferably less than 5:1, more preferably less than 2:1.

[0106] In the sense of the present invention, the "aspect ratio" of a particle is preferably the ratio of its largest dimension to its smallest dimension. The aspect ratio may preferably be the Ferre aspect ratio, determined in relation to the Ferre diameter, particularly in the case of polyhedral, spherical, discoidal, plate-like, ellipsoidal or spherical particles. Preferably, the Ferre aspect ratio is the ratio of the largest Ferre diameter to the smallest Ferre diameter of a particle. The largest Ferre diameter is preferably the largest distance between two parallel tangents of the particle at any possible angle. The smallest Ferre diameter is preferably the smallest distance between two parallel tangents of the particle at any possible angle. The largest and smallest Ferre diameters can be determined microscopically and / or using computer-based analysis software.

[0107] At low aspect ratios, bacterial cellulose particles are preferably nearly spherical. Such particles have been found to be less likely to aggregate and form networks than needle- or rod-shaped particles. Therefore, the micropowders are more stable and have a longer shelf life, despite the presence of small amounts of residual moisture. Bacterial cellulose particles with low aspect ratios can be suspended to form stable suspensions without undesirable colloidal gel formation. Therefore, the ease of application of creams or lotions can be maintained.

[0108] The aspect ratio of the particles also affected light scattering properties. It was found that a lower aspect ratio scatters light to a lesser extent, leaving the product with a more lustrous appearance. This was particularly observed in micropowders with spherical particles.

[0109] In some preferred embodiments of the present invention, the bacterial cellulose particles are polyhedral in shape. Polyhedral particles have been found to have higher light scattering properties than spherical particles, allowing consumer products containing micropowder of this embodiment to leave a more matte finish. Furthermore, polyhedral particles have a greater surface area to mass ratio than spherical particles, which further contributes to the absorption of the micropowder.

[0110] In the sense of the present invention, a "polyhedral" particle shape is preferably a three-dimensional shape having a plurality of flat surfaces, with adjacent flat surfaces preferably at an angle to each other. Preferably, polyhedral particles have at least six flat surfaces, more preferably at least eight flat surfaces. It may be preferred that polyhedral particles have no more than 30 flat surfaces, preferably no more than 20 flat surfaces.

[0111] In some preferred embodiments of the present invention, the bacterial cellulose particles are plate-shaped. Plate-shaped particles can be very densely packed and therefore could be used to formulate products with high coverage, which can be particularly advantageous in paints and cosmetics.

[0112] In the sense of the present invention, the term "plate-like" preferably refers to a particle having two flat faces, which are preferably approximately parallel to each other.

[0113] In the sense of the present invention, a micropowder in which the particles have a particular shape is preferably a micropowder in which at least 50%, more preferably at least 60%, 70% or more of the particles have said shape.

[0114] In a further preferred embodiment of the present invention, the bacterial cellulose micropowder does not contain organic solvents, making the micropowder highly biocompatible and suitable for use on the skin. Because cellulose fibers are somewhat hydrophobic, volatile organic solvents such as ethanol and acetone are sometimes used as carriers during cellulose processing. By eliminating or avoiding these components, a much more skin-friendly micropowder can be produced without the risk of irritation. The manufacturing process for the micropowder can also be made safer and more environmentally friendly.

[0115] Preferably, the micropowder has a water content of less than 10 w / w%, preferably less than 7 w / w%, and particularly preferably less than 5 w / w%. Even more preferably, the water content is less than 0.5 w / w%. These low water contents resulted in higher stability and longer shelf life of the micropowder, preventing undesirable particle aggregation. Furthermore, the low water content improved the absorption capacity of the micropowder, especially the oil absorption capacity. As is well known, water and oil tend to be immiscible. The reduced water content improved the contact between the micropowder and oil. Since the pores and outer surface of the bacterial cellulose particles lacked adsorbed water, they instead attracted oil particles and held them together through intermolecular forces. Therefore, the resulting micropowder exhibited very high absorption capacity.

[0116] In a further preferred embodiment of the present invention, the bacterial cellulose particles are not functionalized. Non-functionalized bacterial cellulose particles are naturally hydrophobic to a certain extent, and therefore could attract oily components released from the skin. Non-functionalized bacterial cellulose particles have also been found to be particularly effective for use as micropowders in cleaning products, toothpastes, etc., due to their affinity for oils and proteins. Furthermore, such micropowders require fewer chemical processing steps and can be positioned as natural products.

[0117] In a further preferred embodiment of the present invention, the bacterial cellulose particles comprise functionalized cellulose, preferably by adding alkyl, acyl, ester, amine, carboxyl, carboxymethyl, phosphorus, and / or sulfur groups, preferably at the C6 position. Functionalization of bacterial cellulose particles can impart specific properties to the micropowder, such as hydrophobicity, polarity, amorphousness, and solubility in various media. For example, carboxylation at C6 can increase the polarity of bacterial cellulose and impart partial solubility in aqueous media. Therefore, the functionalized micropowder can act as a good rheological modifier in liquid products, providing a desirable shear-thinning effect. Shear-thinning is particularly useful in products that spread easily on a surface but remain stable thereafter. Examples of such products include wall paint, mayonnaise, ketchup, and skin creams.

[0118] In a further preferred embodiment of the present invention, the micropowder is configured as a pigment. It may be preferable to coat the bacterial cellulose particles of the micropowder with a dye. It may be preferable to functionalize the bacterial cellulose particles before coating them with the dye. For example, the bacterial cellulose particles can be carboxylated so that their surfaces have a negative surface charge. The bacterial cellulose particles can then be coated by adsorption of dye molecules with a positive surface charge. Alternatively, the bacterial cellulose particles may be functionalized to have a positive surface charge before they are coated with the dye with a negative surface charge. The dye may preferably be an organic dye. Such micropowder not only improves the texture and feel of consumer products, but also allows for fine-tuning of their shade. In particular, in cosmetic products such as foundation creams, a close match between the color of the product and the user's skin color is highly desirable. Such micropowder can provide this color-matching function while remaining safe and biodegradable.

[0119] In a further preferred embodiment of the present invention, the micropowder is configured as a carrier of pharmacologically active molecules. For example, the pharmacologically active molecules may include drug molecules, urea, lipids, or proteins. Preferably, the pharmacologically active molecules are adsorbed onto the surface of the bacterial cellulose particles. Such micropowder can be used in particularly safe and biocompatible medical products, such as medicated ointments.

[0120] In a further aspect, the present invention relates to a biodegradable powder comprising bacterial cellulose particles, the bacterial cellulose particles having an average particle size D 50 The average crystallinity of the bacterial cellulose particles is 1 μm to 1000 μm, preferably 1 μm to 500 μm, more preferably 5 μm to 250 μm, and even more preferably 25 μm to 100 μm, and the average crystallinity of the bacterial cellulose particles is 30% to 80%, preferably 40% to 60%. Surprisingly, it has been found that with this combination of parameters, the bacterial cellulose particles have a very high surface area to mass ratio, high porosity, and very high oil absorption. For example, an oil absorption of more than 5 g / g of sunflower oil at 25°C can be achieved.

[0121] In a second aspect, the present invention relates to a method for producing a micropowder, the method comprising the steps of: producing bacterial cellulose from a bacterial culture such that the produced bacterial cellulose has an average crystallinity of 30% to 80%; Bacterial cellulose was crushed to an average particle size D of 1 μm to 1000 μm. 50 forming bacterial cellulose particles having drying the comminuted bacterial cellulose particles; Includes:

[0122] By producing bacterial cellulose from a culture configured to yield an average crystallinity of 30% to 80%, the bacterial cellulose bulk material contains an appropriate mixture of crystalline and amorphous phases. The crystalline phase preferably contains regular cellulose chains, densely packed parallel to each other and connected by hydrogen bonds. However, the cellulose chains in the amorphous phase are preferably disordered and held together by weaker intermolecular forces. Because hydrogen bonds make the crystalline phase much stiffer than the amorphous phase, their disruption preferably results in the formation of flat surfaces rather than spherical or ellipsoidal surfaces. As a result, polyhedral or plate-like particles are preferred. These provide a large surface area-to-mass ratio and are highly light-scattering, allowing the micropowder to have a non-sticky feel and matte appearance. At the same time, the mixture of crystalline and amorphous phases can reduce the tightness of the packing of the cellulose microfibrils. This can result in higher porosity of the bacterial cellulose, increasing its oil absorption capacity.

[0123] By grinding bacterial cellulose to an average particle size of 1 μm to 1000 μm, a powder or suspension of bacterial cellulose particles can be obtained that has a very high surface area-to-mass ratio. Therefore, the particles are highly dispersible and form stable suspensions. Due to the high surface area-to-volume ratio, the particles also have higher oil and water absorption.

[0124] Drying the pulverized bacterial cellulose particles can release fluid from their pores, further increasing their porosity. The drying process further adjusts the shape, morphology, and surface energy of the bacterial cellulose particles. During the drying process, the micropowder can preferably acquire a shape that can vary from roughly spherical to spherical to a deformed disk shape. The deformed disk shape scatters light differently than a sphere, and the resulting light scattering can produce various results (e.g., a glossy appearance) that are relevant to some cosmetic applications.

[0125] It has been found that the drying process changes the surface energy of bacterial cellulose particles in a way that can improve formulations and sensory experiences. Generally, the surfaces of micropowder and microbeads must be modified to make them compatible with various cosmetic formulations. To assist cosmetic formulations, provide functional properties, and enhance aesthetic experiences, known starch and silica microbeads are usually subjected to various types of surface treatments. Surprisingly, it has been found that drying milled bacterial cellulose can improve their hydrophobicity and their affinity for oil, making them suitable for use in emulsions and oily creams. This micropowder also has a surprisingly high oil absorption capacity compared to known micropowder.

[0126] Furthermore, drying of milled bacterial cellulose results in a micropowder that is free of organic solvents, has a low moisture content and a long shelf life.

[0127] Preferably, the drying step is carried out under sterile conditions.

[0128] In the sense of the present invention, the average "crystallinity" of a material is preferably the proportion of the total volume of the material that is crystalline.

[0129] In the sense of the present invention, a "comminute" step is preferably a process of breaking down bulk material into particles, also referred to herein as crushing, milling, pulverizing or homogenizing. By way of example only, comminution may be carried out in a colloid mill.

[0130] In the sense of the present invention, a "drying" step is a process of separating water from a solution, suspension or water-containing solid, preferably by applying a change in temperature and / or pressure. Preferably, the temperature change comprises boiling, freezing and / or sublimation of water. Preferably, the pressure change comprises reducing the pressure in the system, in particular by using a vacuum to lower the boiling or sublimation point of water.

[0131] In a preferred embodiment of the present invention, the bacterial culture is subjected to stirring and / or agitation during the process of producing bacterial cellulose from the bacterial culture. Stirring of the bacterial cellulose culture has been found to limit the degree of crystallinity and could therefore be used to adjust the balance between the crystalline and amorphous phases. Stirring can be preferably carried out at a speed of 5 rpm to 250 rpm (revolutions per minute), more preferably 100 rpm to 200 rpm.

[0132] In a preferred embodiment of the present invention, the bacterial cellulose is washed before being milled. Washing can be carried out using deionized water.

[0133] In a further preferred embodiment of the invention, the bacterial cellulose is at least partially dried between production and grinding, the partial drying preferably being carried out in an atmosphere having a relative humidity of up to 85%, preferably up to 80%, and a temperature of 20°C to 40°C, preferably 25°C to 35°C, for a period of 3 to 10 days, preferably 5 to 9 days.

[0134] By at least partially drying the bacterial cellulose, the cultivation process could be terminated and the bacterial cellulose could be milled without the culture medium, improving the efficiency of the milling process.

[0135] In a further preferred embodiment of the present invention, bacterial cellulose is treated with liquefied gas, preferably liquid nitrogen, before being crushed. Treatment with liquefied gas can rapidly reduce the temperature of bacterial cellulose, increasing its brittleness and causing cracks in the crystalline structure, which is thought to increase the porosity and irregularity of the resulting bacterial cellulose particles. In particular, when crushing is performed within 30 minutes after treatment with liquefied gas, the bacterial cellulose particles have a polyhedral shape, which is advantageous for increasing the surface area-to-mass ratio of the micropowder.

[0136] The grinding step may preferably include multiple grinding cycles. The multiple grinding cycles may correspond to different degrees of coarseness so that the bacterial cellulose particle size is gradually reduced. This may allow the use of various grinders specialized for producing different particle sizes, improving the efficiency of the manufacturing process. The multiple grinding cycles may preferably be separated by treatment with liquefied gas.

[0137] In a further preferred embodiment of the present invention, the pulverized bacterial cellulose particles are dried by freeze-drying, oven-drying, spray-drying, treatment with supercritical CO2, or a combination thereof. These drying methods have been found to be particularly suitable for achieving a low moisture level in the bacterial cellulose and leaving the bacterial cellulose particles with an appropriate surface energy, resulting in their high oil absorption. Furthermore, methods such as spray-drying, or particularly preferably oven-drying, are preferably used to increase the keratinization of the bacterial cellulose. This allows for the desired porosity to be achieved while preventing the bacterial cellulose particles from swelling in the fluid formulation.

[0138] In a further preferred embodiment of the present invention, prior to drying, the ground bacterial cellulose particles are mixed with deionized water to form a suspension having a bacterial cellulose concentration in water of 0.5 w / w% to 5 w / w%, more preferably 1.0 w / w% to 3.5 w / w%.

[0139] By suspending pulverized bacterial cellulose in water, a suspension with high chemical purity could be formed without the use of organic solvents. The resulting micropowder was particularly safe and suitable for use on sensitive skin and in pharmaceutical products. Furthermore, the absence of trace salts in deionized water allowed the micropowder to maintain its low polarity and high oil affinity. At the selected concentration, the suspension was stable, preventing the aggregation of suspended particles. Therefore, the suspension was particularly suitable for atomization.

[0140] In a further preferred embodiment of the present invention, the suspension of bacterial cellulose in water is spray dried, the spray drying preferably comprising: atomizing a suspension of bacterial cellulose in water to form droplets suspended in a gas, the atomization preferably being assisted by the use of pressurized gas, particularly air or an inert gas, particularly preferably nitrogen; exposing the suspended droplets to a stream of heated air so as to reduce the water content of the droplets, the heated air preferably having a temperature of 80°C to 250°C, particularly preferably 150°C to 190°C, more preferably 170°C to 190°C; collecting the dried particles; Includes:

[0141] Spray drying of the suspension resulted in fine particles with controlled particle size distribution and high purity. The keratinization that occurred during the drying process at the preferred higher temperature further improved the chemical stability of the micropowder and its hydrophobicity, while maintaining open interstices in the bacterial cellulose for absorption and adsorption.

[0142] Spray drying is preferably carried out in a drying chamber. In some preferred embodiments of the present invention, spray drying is carried out by pumping the suspension into a drying chamber, pumping heated air into the drying chamber at a volumetric flow rate of 500 NL / h to 700 NL / h (standard liters per hour), and aspirating the air from the drying chamber.

[0143] The heated air entering the drying chamber preferably has a relative humidity of up to 30%, more preferably up to 20%. The aspirated air preferably has a relative humidity of 35% or greater. The air flow causes evaporation of water from the falling droplets, so that solid particles are formed during their downward trajectory through the drying chamber.

[0144] In a further preferred embodiment of the present invention, atomization of the suspension of bacterial cellulose in water is carried out using pressurized gas, in particular nitrogen gas. Using such atomization, very fine particles with an average diameter as small as 300 nm can be produced.

[0145] In a further preferred embodiment of the present invention, the dried particles are collected by an electrostatic particle separator. Depending on the functional groups present on their surface, the surface charge of bacterial cellulose particles can be positive or negative. The magnitude of the charge can depend on the particle size. Using an electrostatic particle separator, particles with a predetermined size range can be collected so that the micropowder has a finely controlled particle size distribution. The electrostatic particle separator can also be used to improve the yield of the drying process. Yields of up to 90% have been achieved when particles are collected by electrostatic particle separation, compared to yields of 60% to 70% using conventional methods.

[0146] In a further preferred embodiment of the present invention, the suspension of bacterial cellulose in water is oven dried. Preferably, the drying temperature is up to 250°C, preferably up to 160°C, preferably 150°C, more preferably up to 120°C, even more preferably up to 100°C, even more preferably up to 80°C, even more preferably up to 40°C. In a preferred embodiment, the suspension is placed in an oven dryer with circulating hot air, preferably at 80°C to 160°C, preferably 90°C to 120°C, for 12 to 72 hours, preferably 20 to 28 hours.

[0147] In a further preferred embodiment of the present invention, the suspension of bacterial cellulose in water is freeze-dried, the freeze-drying preferably comprising: freezing the suspension at a temperature of -10°C to -50°C, preferably -15°C to -25°C; reducing the pressure of the controlled atmosphere surrounding the frozen suspension to less than 50 mbar, preferably less than 1 mbar, more preferably less than 0.5 mbar, even more preferably less than 0.2 mbar, so that ice is sublimated from the frozen suspension and the resulting cake has a water content of less than 7 w / w%, preferably less than 5 w / w%, particularly preferably less than 1 w / w%; Includes:

[0148] Freeze-drying a suspension of bacterial cellulose in water was found to increase porosity and decrease crystallinity, and was therefore an advantageous method for tailoring the material properties of bacterial cellulose particles after cultivation.

[0149] In a further preferred embodiment of the present invention, the cake obtained from the freeze-drying process is further subjected to a grinding step, which preferably comprises crushing the cake into micropowder, in particular using a blend cutter.

[0150] In a further preferred embodiment of the present invention, the dried bacterial cellulose particles are separated by a particle separation module according to their particle size, so that the resulting micropowder has an average diameter D of 1 μm to 500 μm, preferably 5 μm to 250 μm, particularly preferably 25 μm to 100 μm. 50 wherein at least 90% of the bacterial cellulose particles have a diameter of 500 μm or less, preferably 300 μm or less, particularly preferably 200 μm or less.

[0151] The particle separation module can be used to fine-tune the average diameter and particle size distribution of the micropowder. At selected particle sizes, the micropowder exhibited highly sought-after absorption properties. These are believed to be due, at least in part, to the high surface area-to-mass ratio of the micropowder having the selected particle size. The texture and coverage of the micropowder have also been found to provide advantageous qualities, particularly in the cosmetics industry.

[0152] In a further preferred embodiment of the present invention, the particle separation module comprises: one or more sieve shakers, inertial separators, especially sedimenters; Centrifugal separators, especially cyclones, electrostatic separator, or a combination thereof, Equipped with.

[0153] In a further preferred embodiment of the present invention, all equipment is sterilized before use to produce micropowder.

[0154] The micropowder of the present invention can be preferably used in consumer product compositions, particularly cosmetics, personal care, food, cleaning products, paints, or coatings. Preferred examples of cosmetic and personal care products in which the micropowder can be used include creams, emulsions, foams, gels, lotions, milks, mousses, solutions, sticks, ointments, pastes, powders (loose or pressed), cream-to-cosmetic products, sprays, or suspensions. The cosmetic product can preferably be any color cosmetic used on the skin, hair, eyes, or lips, such as concealer sticks, foundations (wet or dry), stage makeup, mascara (cake or cream), eyeshadow (liquid, pomade, powder, stick, pressed, or cream), hair color, lipstick, lip gloss, kohl pencil, eyeliner, blush, eyebrow pencil, and cream powder. Other exemplary cosmetic compositions include nail enamel, skin glosser sticks, hairsprays, face powders, leg cosmetics, insect repellent lotions, nail enamel removers, perfumed lotions, and any type of shampoo (gel or liquid). Additionally, the micropowders can be used in shaving creams (aerosol, brushless, foaming concentrates), hair styling products, cologne sticks, colognes, cologne emollients, bubble baths, body lotions (moisturizing, cleansing, soothing, astringent), aftershave lotions, after-bath milks, and sunscreen lotions.

[0155] In a further aspect, the present invention relates to a cosmetic or personal care product comprising the micropowder of the present invention, which is preferably a skin care product, including for example an anti-aging product, a treatment product for oily and acne-prone skin, a face mask, a moisturizer, a butter cream, a lotion, a BB cream, a primer, a glow serum, a day cream, a night cream or a sunscreen, a color cosmetic product, including for example a foundation, a concealer, a loose or pressed powder, a mascara, a lipstick or a lip gloss, a hair care product, including for example a fluid shampoo, a dry shampoo, a shampoo bar, a hair mask, a hair conditioner or a hair styling product, or a toiletry product, including for example an antiperspirant, a deodorant or an oral care product.

[0156] The micropowder of the present invention has been found to surprisingly improve the performance, pH insensitivity, viscosity and appearance of the above mentioned products, especially cosmetic, cosmeceutical or personal care products such as BB creams, primers, glow serums, day creams, night creams or sunscreens.

[0157] For cosmetic or personal care products, it may be preferred that the micropowder is present in the formulation at a concentration of from 0.5 w / w% to 50 w / w%, more preferably from 0.5 w / w% to 30 w / w%.

[0158] Advantageously, the micropowder of the present invention can be used in various standard formulations for cosmetics or personal care products to improve product properties. In particular, the micropowder of the present invention can be used to replace known absorbent powders, texturizing agents, or sensory enhancers, such as synthetic polymer or mineral powders, while exhibiting substantially improved properties. The micropowder of the present invention can preferably be used to replace known absorbent powders in known formulations in similar or smaller amounts.

[0159] In a preferred embodiment of the present invention, the cosmetic or personal care product comprises a fluid formulation comprising 1 wt% to 50 wt% micropowder, 1 wt% to 90 wt% solvent, 1 wt% to 10 wt% humectant, 0.1 wt% to 10 wt% rheology modifier, 0.1 wt% to 30 wt% emollient, and 0.1 wt% to 30 wt% emulsifier. The formulation may preferably further comprise antioxidants, preservatives, fragrances, pigments, structuring agents, pH adjusters, stabilizers, binders, fillers, and / or surfactants.

[0160] In a further preferred embodiment of the present invention, the cosmetic or personal care product comprises a solid formulation comprising, in order, 1 w / w% to 50 w / w% of micropowder, 1 w / w% to 50 w / w% of binder, and 1 w / w% to 90 w / w% of filler. Optionally, the solid formulation may further comprise pigments, fragrances, surfactants, conditioning agents, emollients, structuring agents, lake dispersants, pearlizing agents, antioxidants and / or preservatives. In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lotion for use on the body or face. The lotion preferably comprises: 55 w / w% to 85 w / w% of a solvent; 1 w / w% to 10 w / w% of a wetting agent; 0.1 w / w% to 1 w / w% of a thickener; 0.5 w / w% to 5 w / w% of the micropowder of the present invention; 2 w / w% to 20 w / w% of an emollient, particularly one or more oils; 1 w / w% to 10 w / w% of an emulsifier; 0.1 w / w% to 3 w / w% of an antioxidant, in particular tocopherol; 0.1 w / w% to 3 w / w% of a preservative, in particular EUXYL PE 9010; 0.1 w / w% to 3 w / w% of fragrance, especially essential oils, wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0161] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lotion for use on the body or face. The lotion preferably has a composition of approximately 76 w / w% of a solvent, in particular water, 5 w / w% of a humectant, in particular glycerin, 0.2 w / w% of a thickener, in particular xanthan gum; 1.5 w / w% of the micropowder of the present invention; 10 w / w% of an emollient, particularly one or more oils; 5.5 w / w% emulsifier; 0.5 w / w% of an antioxidant, in particular tocopherol, 1 w / w% of a preservative, in particular EUXYL PE 9010; 0.25 w / w% of fragrance, especially essential oils; Includes:

[0162] The lotion preferably has a pH of approximately 6.9. Preferably, the lotion has a viscosity of approximately 24,600 cP, particularly measured at 26° C. 24 hours after preparation of the lotion. The viscosity of the lotion of the present invention was significantly higher than that of a lotion having the same formulation but using a synthetic petroleum-based polymer micropowder (17,866 cP) and a silica-based micropowder (18,567 cP) instead of the micropowder of the present invention.

[0163] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a mascara. The mascara preferably comprises: 1 w / w% to 7 w / w% of a wetting agent; 0.1 w / w% to 3 w / w% of a rheology modifier; 30 w / w% to 80 w / w% of a solvent; 3 w / w% to 30 w / w% pigment; 2 w / w% to 20 w / w% of a structuring agent; 2 w / w% to 20 w / w% of an emulsifier; 0.5 w / w% to 10 w / w% of the micropowder of the present invention; 0.5 w / w% to 3 w / w% of a preservative; 0.01 w / w% to 3 w / w% of an antioxidant, and optionally, pH adjusters, especially sodium hydroxide, wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0164] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a mascara. The mascara preferably has a viscosity of approximately: 3 w / w% of a humectant, in particular propylene glycol, 0.3 w / w% of a rheology modifier, in particular xanthan gum; 60 w / w% of a solvent, in particular water, 9 w / w% of a pigment, in particular a black pigment, 12 w / w% of a structuring agent, in particular 8 w / w% beeswax and 4 w / w% carnauba wax in the final product; 8 w / w% of emulsifiers, in particular 3 w / w% of cetearyl alcohol and 5 w / w% of stearic acid in the final product; 2 w / w% of the micropowder of the present invention, 1 w / w% of a preservative, in particular EUXYL PE 9010; 0.05 w / w% of an antioxidant, in particular tocopherol, and optionally pH adjusters, especially sodium hydroxide, Includes:

[0165] The mascara preferably has a pH of approximately 7 and a viscosity of approximately 434,000 cP, particularly measured at 25° C. 24 hours after preparation of the mascara. It has been found that micropowder can significantly improve the volumizing and lengthening effects of mascara. This is believed to be due, at least in part, to a broad particle size distribution.

[0166] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a loose powder. The loose powder preferably comprises: 5 w / w% to 40 w / w% pigment; 1 w / w% to 50 w / w% of the micropowder of the present invention; 5 w / w% to 35 w / w% of a binder; 5 w / w% to 25 w / w% of a filler, and optionally, 0.1 w / w% to 5 w / w% of a fragrance; wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0167] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a loose powder. The loose powder preferably has an average particle size of approximately: 10 w / w% to 30 w / w% of a pigment, in particular titanium dioxide; 20 w / w% to 50 w / w% of the micropowder of the present invention; 5 w / w% to 35 w / w% of a binder, in particular magnesium stearate; 5 w / w% to 25 w / w% of a filler, in particular talcum powder; 5 w / w% to 25 w / w% of a further pigment, and optionally 1 to 20 drops of fragrance, especially essential oils, Includes:

[0168] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a liquid foundation. The liquid foundation preferably comprises: 1 w / w% to 30 w / w% of an emulsifier; 1 w / w% to 20 w / w% of an emollient; 1 w / w% to 15 w / w% pigment; 0.05 w / w% to 5 w / w% of a thickener wax; 0.5 w / w% to 5 w / w% of a stabilizer; 1 w / w% to 10 w / w% of a wetting agent; 40 w / w% to 80 w / w% of a solvent; 0.5 w / w% to 25 w / w% of the micropowder of the present invention; 0.1 w / w% to 5 w / w% of an antioxidant; 0.5 w / w% to 3 w / w% of a preservative; wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0169] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a liquid foundation. The liquid foundation preferably has a viscosity of approximately: 15 w / w% of emulsifiers, in particular 4 w / w% of polyglyceryl-3-polyricionate (PGPR) and 8 w / w% of caprylic acid, 2 w / w% of cetearyl alcohol and 1 w / w% of Emulsan II for the final product, 10 w / w% of an emollient, in particular sunflower oil; 4.65 w / w% of pigments, in particular 0.35 w / w% of red pigment, 0.10 w / w% of black pigment, 0.70 w / w% of yellow pigment and 3.50 w / w% of titanium dioxide in the final product; 0.75 w / w% of a first thickener wax, in particular carnauba wax; 0.25 w / w% of a second thickener wax, in particular xanthan gum; 1.5 w / w% of a stabilizer, in particular magnesium sulfate; 3 w / w% of a humectant, in particular glycerin, 61 w / w% to 63 w / w% of a solvent, especially water, 1.5 w / w% of the micropowder of the present invention; 0.5 w / w% of an antioxidant, in particular tocopherol, 1 w / w% of a preservative, in particular EUXYL PE 9010; Includes:

[0170] The liquid foundation of the present invention may preferably have a pH of approximately 6.35 and a viscosity of 33,000 cP, particularly 24 hours after preparation at 26° C. In particular, the liquid foundation of the present invention has a significantly higher viscosity than liquid foundations that use synthetic petroleum-based polymer micropowder in place of the micropowder of the present invention.

[0171] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a buttercream. The buttercream preferably comprises: 40 w / w% to 80 w / w% of a solvent; 1 w / w% to 20 w / w% of a wetting agent; 0.1 w / w% to 20 w / w% of the micropowder of the present invention; 0 w / w% to 5 w / w% of a rheology modifier; 5 w / w% to 20 w / w% of an emulsifier; 5 w / w% to 30 w / w% of an emollient; 0.01 w / w% to 5 w / w% of a fragrance; 0.5 w / w% to 3 w / w% of an antioxidant, especially vitamin E; 0.01 w / w% to 3 w / w% of a preservative, in particular Biogard 221; wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0172] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a buttercream. The buttercream preferably has a viscosity of approximately: 61 w / w% to 64 w / w% of a solvent, especially water, 5 w / w% of a humectant, in particular glycerin, 0.2 w / w% to 1 w / w% of the micropowder of the present invention; 0 w / w% to 1 w / w% of a rheology modifier, in particular xanthan gum; 10 w / w% of emulsifiers, in particular 4 w / w% Emulsan II and 6 w / w% cetearyl alcohol based on the final product; 20 w / w% of an emollient, in particular sunflower oil; 1 w / w% of fragrance, especially essential oils, 0.5 w / w% of an antioxidant, in particular vitamin E, 0.2 w / w% of a preservative, in particular Biogard 221, Includes:

[0173] Preferably, the essential oils used include one or more of methyl glucose sesquistearate, lavender essential oil, orange essential oil, dehydroacetic acid and / or benzyl alcohol.

[0174] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lipstick. The lipstick preferably comprises: 5 w / w% to 50 w / w% of a structuring agent; 40 w / w% to 80 w / w% of an emollient; 1 w / w% to 20 w / w% of the micropowder of the present invention; 0.5 w / w% to 5 w / w% of a lake dispersant; 0.1 w / w% to 3 w / w% of a pearling agent; 1 w / w% to 15 w / w% of one or more pigments; 0.01 w / w% to 3 w / w% of an antioxidant; 0.01 w / w% to 3 w / w% of a preservative; wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0175] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lipstick. The lipstick preferably has a viscosity of approximately: 27.5 w / w% of structuring agents, in particular 11.5 w / w% of synthetic waxes, 2 w / w% of candelilla wax (euphorbia cerifera) and 14 w / w% of tricyclodecanemethyl isononanoate, based on the final product; 62 w / w% to 63 w / w% of an emollient, in particular 30.5 w / w% seed oil of the final product; 4 w / w% of the micropowder of the present invention, 2 w / w% of a lake dispersant, in particular hydrogenated polydecene and polyhydroxystearic acid, 0.7 w / w% of pearling agents, in particular mica and iron oxide, 6 w / w% to 7 w / w% of one or more pigments; 0.1 w / w% of an antioxidant, in particular tocopherol, 0.75 w / w% of preservatives, in particular caprylyl glycol and phenoxyethanol, Includes:

[0176] The micropowder of the present invention could be used to provide a matte or semi-matte lipstick with soft sensory properties.

[0177] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a hand cream. The hand cream preferably comprises: 40 w / w% to 80 w / w% of a solvent; 1 w / w% to 10 w / w% of a wetting agent; 0.1 w / w% to 3 w / w% of a thickener; 0.5 w / w% to 10 w / w% of the micropowder of the present invention; 3 w / w% to 10 w / w% of an emulsifier; 5 w / w% to 30 w / w% of an emollient; 0.1 w / w% to 10 w / w% of a fragrance; 0.1 w / w% to 3 w / w% of an antioxidant; 0.1 w / w% to 3 w / w% of a preservative; wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0178] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a hand cream. The hand cream preferably has a composition of approximately 69 w / w% to 72 w / w% of a solvent, especially water, 5 w / w% of a humectant, in particular glycerin, 0.2 w / w% of a thickener, in particular xanthan gum; 1 w / w% to 3 w / w% of the micropowder of the present invention; 6 w / w% of emulsifiers, in particular 1 w / w% of Emulsan II and 5 w / w% of cetearyl alcohol in the final product; 15 w / w% of an emollient, in particular sunflower oil; 1 w / w% of fragrance, especially essential oils, 0.5 w / w% of an antioxidant, in particular vitamin E, 0.2 w / w% of a preservative, in particular EUXYL PE 9010; Includes:

[0179] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lip balm. The lip balm preferably comprises: 40 w / w% to 80 w / w% of a solvent; 1 w / w% to 10 w / w% of a wetting agent; 1 w / w% to 10 w / w% of a rheology modifier; 1 w / w% to 20 w / w% of the micropowder of the present invention; 5 w / w% to 30 w / w% of an emulsifier; 1 w / w% to 10 w / w% pigment; 0.1 w / w% to 10 w / w% of the active ingredient; 1 w / w% to 30 w / w% of an emollient; 0.1 w / w% to 3 w / w% of a preservative; wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0180] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lip balm. The lip balm preferably has a viscosity of approximately: 66 w / w% to 67 w / w% of a solvent, especially water, 6 w / w% of a humectant, in particular glycerin, 2.5 w / w% of a rheology modifier, in particular tapioca starch; 1.5 w / w% of the micropowder of the present invention; 13 w / w% of emulsifiers, in particular 11 w / w% of cetearyl alcohol and 2 w / w% of glyceryl caprylate in the final product; 2 w / w% of pigments, in particular jojoba beads, 1.5 w / w% of active ingredients, in particular D-panthenol, 6.5 w / w% emollients, in particular 0.5 w / w% veganolin, 4 w / w% vegetable oil and 2 w / w% dedraflow 30 of the final product; 0.25 w / w% preservative; 0.2 w / w% tocopherol; Includes:

[0181] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a powder shampoo. The powder shampoo preferably comprises: 10 w / w% to 40 w / w% of a surfactant; 40 w / w% to 65 w / w% of a filler; 1 w / w% to 30 w / w% of the micropowder of the present invention; 1 w / w% to 10 w / w% of a texture enhancer other than micropowder; 1 w / w% to 7 w / w% of a conditioner agent; 0.1 w / w% to 3 w / w% of an emollient; 0.1 w / w% to 3 w / w% of a fragrance; wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0182] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a powder shampoo. The powder shampoo preferably has a composition of approximately 32 w / w% of surfactants, in particular 30 w / w% of sodium cocoyl isethionate and 2 w / w% of betaine in the final product; 55 w / w% to 56 w / w% of a filler, in particular tapioca starch; 5 w / w% of the micropowder of the present invention as a texture enhancer; 5 w / w% of a further texture enhancer, in particular isoamyl laurate, 2 w / w% of a conditioning agent, in particular hydrotriticum, 0.5 w / w% of an emollient, in particular jojoba oil; 0.4 w / w% of fragrance, in particular lavender oil, Includes:

[0183] A powder shampoo (also known as a dry shampoo) of the present invention was compared to a powder shampoo in which a synthetic petroleum-based polymer micropowder was used instead of the micropowder of the present invention. After using both powder shampoos, users reported a superior skin feel after using the powder shampoo of the present invention.

[0184] In a further preferred embodiment of the present invention, the cosmetic or personal care product is an anti-aging cream. The anti-aging cream preferably has a composition of approximately 40 w / w% to 80 w / w% of a first solvent, in particular water; 1 w / w% to 10 w / w% of a wetting agent; 0.1 w / w% to 5 w / w% of a rheology modifier; 0.01 w / w% to 2 w / w% of a complexing agent; 2 w / w% to 10 w / w% of an emulsifier; 5 w / w% to 30 w / w% of an emollient; 0.5 w / w% to 5 w / w% of a skin smoothing agent; 0.1 w / w% to 10 w / w% of a second solvent, in particular an organic solvent; 0.1 w / w% to 3 w / w% tocopherol; 0.5 w / w% to 10 w / w% of the micropowder of the present invention; 0.01 w / w% to 0.5 w / w% of a pH adjuster; Optionally, a fragrance; and wherein the w / w% fractions are based on the total weight of the lotion and the sum of the w / w% fractions is less than or equal to 100%.

[0185] In a further preferred embodiment of the present invention, the cosmetic or personal care product is an anti-aging cream. The anti-aging cream preferably has a composition of approximately 63 w / w% to 64 w / w% of a first solvent, in particular water; 3 w / w% of a wetting agent, in particular propanediol, 1.8 w / w% of a rheology modifier, in particular xanthan gum; 0.1 w / w% of a complexing agent, in particular an aqueous solution of sodium phytate and alcohol, 6 w / w% of emulsifiers, in particular 4 w / w% palmitic acid and 2 w / w% cetearyl alcohol relative to the final product; 20 wt. % emollients, in particular 3 wt. % shea butter, 2 wt. % squalane, 5 wt. % coco-caprylate and 5 wt. % ethylhexyl stearate for the final product, 1.5 w / w% of a skin smoothing agent, in particular dimethicone; 1 w / w% of a second solvent, in particular hexylene glycol; 1.2 w / w% tocopherol; 1 w / w% of the micropowder of the present invention; 0.02 w / w% pH adjuster, preferably containing aqueous sodium hydroxide at a concentration of up to 30 w / w%; Optionally, a fragrance; and Includes:

[0186] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a facial sunscreen. The facial sunscreen preferably has a composition of approximately: 50 w / w% to 60 w / w% of a solvent, especially water, 24 w / w% to 34 w / w% of an emulsifier or a mixture of emulsifiers; 3 w / w% to 12 w / w% of a pigment or a mixture of pigments; 0.1 w / w% to 1 w / w% of a humectant; 0.5 w / w% to 6 w / w% of an emollient; 0.1 w / w% to 5 w / w% of a rheology modifier; 0.05 w / w% to 0.3 w / w% of an antioxidant; 0.2 w / w% to 1.5 w / w% of a preservative; 0.5 w / w% to 1 w / w% of the micropowder of the present invention; Optionally, a fragrance (in sufficient quantity); wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0187] The facial sunscreen preferably has a pH of approximately 5.87 to 6. Preferably, the sunscreen has a viscosity of approximately 17,340 cP, particularly measured at 20°C 24 hours after preparation of the sunscreen. The viscosity of the sunscreen of the present invention, prepared according to the preferred formulation described above, was optimal for spreading and application to the skin. Furthermore, the sunscreen was comfortable, adhered well to the skin, and provided long-lasting wear. Due to the presence of micropowder, the sunscreen also had a substantially matte finish, which is particularly desirable for avoiding unwanted shine or the appearance of wetness on the skin. The sunscreen was also highly compatible with application over cosmetics or other skin-related products.

[0188] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a facial sunscreen. The facial sunscreen preferably has a composition of approximately: 56.25 w / w% of a solvent, in particular water, 28 w / w% of an emulsifier, preferably an emulsifier comprising approximately 3 w / w% polyglyceryl-3 polyricinoleate, 1 w / w% polyglyceryl-3 polyricinoleate, a mixture of polyglyceryl-4 oleate and propanediol, 8 w / w% isoamyl cocoate, 5 w / w% ethylhexyl palmitate, 7 w / w% decyl cocoate, and 4 w / w% diisostearoyl polyglyceryl-3 dimer dilinoleate; 8.15 w / w% of a pigment, preferably a mixture comprising titanium dioxide, aluminum hydroxide, sodium lauroyl glutamate, lysine and magnesium chloride, one or more iron oxides, sodium lauroyl glutamate, lysine and magnesium chloride; 0.5 w / w% of a moisturizer, preferably Cera Alba, 3.5 w / w% of an emollient, preferably an emollient comprising 0.5 w / w% hydrogenated castor oil and 3 w / w% glycerin; 0.25 w / w% of a rheology modifier, preferably xanthan gum; 0.1 w / w% of an antioxidant, preferably tocopherol; 0.75 w / w% preservatives, preferably including phenoxyethanol and ethylhexylglycerin; 0.75 w / w% of the micropowder of the present invention; Optionally, a fragrance (in sufficient quantity); wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0189] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a sebum control cream. The sebum control cream preferably has a composition of approximately 65 w / w% to 75 w / w% of a solvent, especially water, 2 w / w% to 8 w / w% of a wetting agent; 0.2 w / w% to 2 w / w% of a rheology modifier; 12 w / w% to 20 w / w% of an emulsifier or a mixture of emulsifiers; 1 w / w% to 7 w / w% of an emollient; 0.2 w / w% to 5 w / w% of an active ingredient or a mixture of active ingredients; 0.05 w / w% to 0.2 w / w% of an antioxidant; 0.2 w / w% to 1.5 w / w% of a preservative; 0.5 w / w% to 2 w / w% of the micropowder of the present invention; optionally a chelating agent; Optionally, 0.1 w / w% to 2 w / w% of a fragrance; wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0190] The sebum control cream preferably has a pH of approximately 6. Preferably, the sebum control cream has a viscosity of approximately 15,733 cP, particularly measured at 25°C 24 hours after preparation. The sebum control cream prepared using the preferred formulation described above has an ivory or light beige emulsion appearance, which is particularly attractive to consumers as a neutral color product that can be applied under or in combination with other product layers. The presence of micropowder acts synergistically with the presence of one or more active ingredients to reduce the appearance of oiliness on the skin by providing a matte finish, while also reducing sebum production for a long time. Therefore, customers who use the sebum control cream of the present invention can observe both short-term and long-term effects, resulting in increased product satisfaction.

[0191] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a sebum control cream. The sebum control cream preferably has a composition of approximately 69.2% of solvent, especially water, 5 w / w% of a wetting agent, preferably propanediol; 1 w / w% of a rheology modifier, preferably comprising a mixture of xanthan gum and gum arabic; 16 w / w% of an emulsifier, preferably comprising a mixture of ethylhexyl stearate, isoamyl laurate, cetearyl alcohol, glyceryl behenate, behenyl alcohol and lecithin; 4 w / w% of an emollient, preferably comprising a mixture of squalene, sodium acrylate copolymer and lecithin; 2 w / w% of active ingredient, preferably a mixture of propanediol, water and foams officinalis extract; 0.1 w / w% of an antioxidant, preferably tocopherol; 1 w / w% of a preservative, preferably a mixture of phenoxyethanol and ethylhexylglycerin; 1.5 w / w% of the micropowder of the present invention; 0.2 w / w of flavoring; wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0192] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a restoring night cream. The restoring night cream preferably has a composition of approximately: 50 w / w% to 60 w / w% of a solvent, especially water, 1 w / w% to 5 w / w% of a wetting agent; 0.01 w / w% to 0.2 w / w% of a chelating agent; 0.5 w / w% to 2.0 w / w% of a rheology modifier; 20 w / w% to 30 w / w% of an emulsifier or a mixture of emulsifiers; 8 w / w% to 14 w / w% of an emollient; 0.5 w / w% to 2 w / w% of active ingredients, especially antioxidant moisturizers; 0.05 w / w% to 0.2 w / w% of an antioxidant; 0.5 w / w% to 2 w / w% of a preservative; 0.5 w / w% to 3 w / w% of the micropowder of the present invention; Optionally, 0.05 w / w% to 0.5 w / w% of a fragrance; and wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0193] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a restoring night cream. The restoring night cream preferably has a composition of approximately: 56.7% solvent, especially water, 3 w / w% of a wetting agent, preferably propanediol; 0.1 w / w% of a chelating agent, in particular sodium phytate, alcohol and water; 1.5 w / w% of a rheology modifier, preferably comprising a mixture of xanthan gum, lecithin, sclerotium gum and pullulan; 24 w / w% emulsifier, preferably comprising a mixture of 8 w / w% isoamyl cocoate, 10 w / w% caprylic or capric triglyceride, 4 w / w% oleyl erucate and 2 w / w% pentaerythrityl distearate; 11 w / w% emollient, preferably a mixture of 1 w / w% dimethicone, 6 w / w% butyrospermum parkii (shea) butter, and 4 w / w% glyceryl behenate, behenyl alcohol, and lecithin; 1 w / w% of an active ingredient, preferably vaccinium macrocarpon (cranberry) fruit extract, 0.1 w / w% of an antioxidant, preferably tocopherol; 1 w / w% of a preservative, preferably a mixture of phenoxyethanol and ethylhexylglycerin; 1.5 w / w% of the micropowder of the present invention; 0.1 w / w of flavoring; wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0194] The restoring night cream preferably has a pH of approximately 6. Preferably, the restoring night cream has a viscosity of approximately 10516 cP, particularly measured at 25°C 24 hours after preparation of the restoring night cream. The restoring night cream prepared using the preferred formulation described above has an ivory or light beige emulsion appearance, which is particularly attractive to consumers. The cream adheres well to the skin and provides a comfortable, soft feel.

[0195] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a color correcting primer. The color correcting primer preferably has a viscosity of approximately: 65 w / w% to 75 w / w% of a solvent, especially water, 0.5 w / w% to 5 w / w% of a thickener; 0.1 w / w% to 5 w / w% of a pigment or combination of pigments; 7 w / w% to 20 w / w% of a humectant or combination of humectants; 3 w / w% to 8 w / w% of an emulsifier or a mixture of emulsifiers; 0.5 w / w% to 1.5 w / w% of a preservative; 1 w / w% to 3 w / w% of the micropowder of the present invention; Optionally, a stabilizer (in a sufficient amount), wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0196] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a color correcting primer. The color correcting primer preferably has a viscosity of approximately: 70.9 w / w% of a solvent, in particular water, 1 w / w% of a thickener, preferably sodium polyacrylate; 2.6 w / w% of a pigment or combination of pigments, preferably a mixture of titanium dioxide, mica, tin oxide and synthetic fluorphlogopite; 15 w / w% of a humectant, preferably propanediol and pentylene glycol; 7 w / w% of an emulsifier, preferably 2 w / w% sucrose laurate and 5 w / w% cococaprylate; 1 w / w% of a preservative, preferably a mixture of phenoxyethanol and ethylhexylglycerin; 1.5 w / w% of the micropowder of the present invention; Optionally, a stabilizer (in sufficient quantity), preferably a citric acid solution; wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0197] The color correcting primer preferably has a pH of approximately 6. Preferably, the color correcting primer has a viscosity of approximately 16,760 cP, particularly measured at 25° C. 24 hours after preparation of the color correcting primer. The primer prepared using the preferred formulation described above had the appearance of a pink pearlescent cream and allowed for consistent application to the skin.

[0198] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a BB (blemish balm) cream. The BB cream preferably has a composition of approximately: 65 w / w% to 75 w / w% of a solvent, especially water, 2 w / w% to 7 w / w% of a wetting agent; 0.05 w / w% to 2 w / w% of a chelating agent; 0.5 w / w% to 2 w / w% of a rheology modifier; 10 w / w% to 20 w / w% of an emulsifier or a combination of emulsifiers; 2 w / w% to 5 w / w% of a complexing agent or combination of complexing agents; 3 w / w% to 8 w / w% of a pigment or combination of pigments; 0.05 w / w% to 0.2 w / w% of an antioxidant; 0.5 w / w% to 2 w / w% of a preservative; 0.01 w / w% to 0.1 w / w% of a stabilizer; 0.25 w / w% to 1.5 w / w% of the micropowder of the present invention; Optionally, a fragrance (in sufficient quantity); wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0199] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a BB (blemish balm) cream. The BB cream preferably has a composition of approximately: 69.29 w / w% of a solvent, in particular water, 4 w / w% of a wetting agent, preferably propanediol; 0.1 w / w% of a chelating agent, preferably tetrasodium glutamate diacetate; 1 w / w% of a rheology modifier, preferably lysolecithin, sclerotium gum, xanthan gum and pullulan; 15 w / w% emulsifier, preferably comprising 3 w / w% cococaprylate, 5 w / w% diethylhexyl sebacate and 7 w / w% caprylic or capric triglyceride; 3.5 w / w% complexing agent, preferably comprising arachidyl alcohol, behenyl alcohol and arachidyl glucoside; 5.23 w / w% pigment or combination of pigments, preferably comprising titanium dioxide, aluminum hydroxide, sodium lauroyl glutamate, lysine, magnesium chloride, and iron oxide; 0.1 w / w% of an antioxidant, preferably tocopherol; 1 w / w% of a preservative, preferably a combination of phenoxyethanol and ethylhexylglycerin; 0.03 w / w% of a stabilizer, preferably an aqueous solution of citric acid (50% solution); 0.75 w / w% of the micropowder of the present invention; Optionally, a fragrance (in sufficient quantity); wherein the w / w% fractions are based on the total weight of the cosmetic or personal care product and the sum of the w / w% fractions is less than or equal to 100%.

[0200] BB cream preferably has a pH of about 5.7.Preferably, BB cream has a viscosity of approximately 2324 cP, particularly measured at 25°C after 24 hours of preparation of BB cream.BB cream has the appearance of a colored fluid emulsion, and is particularly suitable for use as BB cream.In particular, BB cream can be made to be particularly translucent, soft, and oil-absorbing, and is particularly suitable for meeting the needs of users.

[0201] The product of the present invention and its formulations have been subjected to extensive testing. It has been found that the broad particle size distribution, irregular shape of the bacterial cellulose particles, and high oil and water absorption contribute to improved sensory properties and user satisfaction of the product. In particular, the product has been found to have excellent mattifying properties.

[0202] Due to its high mattifying effect, the micropowder can partially or completely replace talcum powder in formulations, making them safer and more satisfying for users. The products were also found to provide greater softness, less tackiness, and less stickiness compared to identical products containing conventional micropowder instead of the micropowder of the present invention in their formulations. The micropowder could be used as a gentle peeling agent that clumps with rubbing. It was also found to be suitable for use in both hot and cold products, from cosmetics to cleansing products used in warm water. The biocompatibility and sustainability of all products were improved by the use of the micropowder of the present invention.

[0203] Terms such as substantially, approximately, about, approximately, nearly, etc. preferably describe a tolerance range of less than ±20%, preferably less than ±10%, particularly preferably less than ±5%, in particular less than ±1%, and include the exact value.

[0204] A person of average skill in the art will recognize that the technical features, definitions and advantages of the preferred embodiments of the micropowder according to the present invention also apply to the method for producing the micropowder according to the present invention, to the product comprising the micropowder according to the present invention, and vice versa.

[0205] Detailed Description of the Invention and Examples It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the claims of the present invention define the scope of the invention, and that methods and apparatuses that fall within the scope of these claims and their equivalents be covered thereby.

[0206] Without intending to be limiting, the invention will now be explained in more detail with reference to exemplary embodiments and the following drawings, in which: [Brief explanation of the drawings]

[0207] [Figure 1] 1A-1C are magnified views of a first sample of micropowder according to a preferred embodiment of the present invention taken using SEM microscopy at increasing zoom levels. 2 cm (scale) = 100 μm. [Figure 2] 1A-1C are magnified views of a first sample of micropowder according to a preferred embodiment of the present invention taken using SEM microscopy at increasing zoom levels. 2 cm (scale) = 30 μm (100x zoom). [Figure 3] 1A-1C are magnified views of a first sample of micropowder according to a preferred embodiment of the present invention taken using SEM microscopy at increasing zoom levels. 2 cm (scale) = 10 μm (1000x zoom). [Figure 4] 1A-1C are magnified views of a first sample of micropowder according to a preferred embodiment of the present invention taken using SEM microscopy at increasing zoom levels: 2 cm (scale) = 1 μm (10000x zoom); [Figure 5] 1A and 1B are enlarged views of a second sample of micropowder according to a further preferred embodiment of the present invention, taken using SEM microscopy, at 1 cm (scale) = 30 μm (100x zoom). [Figure 6] 1A and 1B are enlarged views of a second sample of micropowder according to a further preferred embodiment of the present invention, taken using SEM microscopy, at 1 cm (scale) = 1 μm (10000x zoom). [Figure 7] FIG. 1 is a schematic representation of the types of pores present in the particles of a micropowder sample. [Figure 8] 1 is a photographic image of a micropowder of a preferred embodiment of the present invention. [Figure 9]FIG. 1 shows the degradation of a micropowder of a preferred embodiment of the present invention, demonstrating greater than 75% biodegradation in 28 days. [Figure 10] FIG. 1 shows the oil uptake of a micropowder of a preferred embodiment of the present invention and a series of prior art micropowder for a series of different oils. [Figure 11] FIG. 1 shows the oil absorption of a number of micropowders (the micropowders having different average particle sizes) according to various preferred embodiments of the present invention. [Figure 12] FIG. 1 shows the results of an X-ray diffraction analysis of a micropowder of a preferred embodiment. [Figure 13] FIG. 1 shows the particle size distribution of the micropowder of a preferred embodiment. [Figure 14] FIG. 1 shows the results of volumetric gas sorption analysis of the micropowder of the preferred embodiment. [Figure 15] Scanning electron microscope image of plant cellulose powder at 10,000x magnification (scale 1 cm = 1 μm). [Figure 16] 1 is a scanning electron microscope image (1 cm (scale) = 1 μm) at 10,000x magnification of bacterial cellulose micropowder according to a first preferred embodiment of the present invention. [Figure 17] 1 is a scanning electron microscope image (1 cm (scale) = 1 μm) at 10,000x magnification of bacterial cellulose micropowder according to a further preferred embodiment of the present invention. [Figure 18] FIG. 1 shows the oil uptake of a micropowder of a preferred embodiment of the present invention and a series of prior art micropowder with respect to oleic acid. DETAILED DESCRIPTION OF THE INVENTION

[0208] The figures show the results of various tests performed on micropowder samples according to a preferred embodiment of the present invention. The micropowder was formed from numerous bacterial cellulose pellicles harvested from a culture. After washing, the pellicles were dried at 30°C under 80% relative humidity for one week. The dried pellicles were treated with nitrogen, crushed, and milled. The milling process included cutting, coarse milling, and fine milling. The fine-milled bacterial cellulose was then mixed with deionized water and stirred to form a suspension with a bacterial cellulose concentration of approximately 2 wt%. The suspension was then pumped into a sprayer, atomized, and spray-dried. High-purity nitrogen gas was used to atomize the suspension. Spray drying was performed in a B-290 Buchi spray dryer, and the dried micropowder was then pumped into a cyclone and collected. Spray drying was performed at a temperature of approximately 200°C to ensure keratinization of the bacterial cellulose.

[0209] The micropowder was then analyzed by scanning electron microscopy. A Gemini SEM 300 (Zeiss) instrument with an accelerating voltage of 0.02 kV to 30 kV and a resolution of 0.8 nm (at 15 kV) was used. High-resolution images of the micropowder were obtained using magnifications up to 2,000,000x. SEM images were obtained using an InLens detector at an accelerating voltage of 2 kV and a probe current of 80 pA. A small amount of micropowder was applied onto aluminum stubs with carbon tape using a spatula. To reduce charging effects, a thin Cu foil was applied to the end of each Al stub. Excess powder was blown off using air. The sample was coated with gold using a Polaron SC7640 sputter. A coating sequence lasting 40 s at 20 mA was used. Image analysis was performed using image processing software (Olympus GmbH, Germany) to assist in determining particle size and its distribution.

[0210] The results of the first sample at different magnifications are shown in Figures 1 to 4. As shown in Figure 1, the bacterial cellulose particles had irregular morphologies, including polyhedral and plate-like particles. The particle surfaces were uneven, increasing the surface area and light diffusion properties.

[0211] In Figure 2, various cracks and defects can be seen on the surface of the polyhedral particles. Adsorption studies were used to confirm that these are evidence of the presence of layers and mesopores in the bacterial cellulose particles. As shown further below, the adsorption analysis showed characteristics of Type III and Type V isotherms.

[0212] Figure 3 shows a further magnified image of the micropowder of the first sample, where the irregularities in particle shape, their layered structure, and surface roughness are even more visible. From this figure, it is clear that the bacterial cellulose particles of the micropowder have a larger surface area to mass ratio than conventional microbeads, which have relatively regular spherical particles.

[0213] Figure 4 shows a further magnified image of the micropowder of the first sample, where one can observe the non-smooth, fibrous surface quality, which further increases the surface area of ​​the particles, thereby improving their absorption and adsorption qualities.

[0214] Figure 5 shows a magnified image of the micropowder of the second sample. Plate-like layered particles can be observed. These can be densely packed to provide high coverage and can scatter light to provide a matte finish.

[0215] The surface quality of these particles is shown in a further magnified image in Figure 6 (which contains the maximum magnification of the SEM microscopy image reproduced herein). In this image, it can be observed that even seemingly smooth portions of the bacterial cellulose particles exhibit microvilli. These are visible as lines across the surface of the particle and are formed by cellulose fibers. The presence of microvilli on the surface of bacterial cellulose particles dramatically increases their surface area-to-volume ratio, improving their absorption properties. Furthermore, the overlapping and layered arrangement of cellulose fibers results in a large proportion of open and closed pores in the bacterial cellulose particles with openings on the particle surface. This further increases the absorption and adsorption capacity of the micropowder, contributing to the surprisingly high performance of the micropowder of the present invention compared to the prior art.

[0216] Microvilli can also be observed on the surface of bacterial cellulose particles shown in the scanning electron microscope images of Figures 16 and 17, which show bacterial cellulose particles formed in samples of further preferred embodiments of the micropowder of the present invention. The analyzed particles contained pores and a dense, solid fibrous structure in their core, while the surfaces of the particles had a looser fibrous structure, and their surface area was substantially increased.

[0217] The surface quality of particles formed according to the present invention can be visually compared with particles produced by other methods to confirm the presence or absence of microvilli on the particle surface. For example, Figure 15 shows the surface of a particle of a powder formed from plant cellulose at the same magnification as Figure 17. The scanning electron microscope image of the plant cellulose particle in Figure 15 is provided solely for comparison. Here, it can be seen that the surface is substantially flat and free of loose, protruding fibers. Therefore, the absence of microvilli in the particle surface structure can be confirmed by microscopic analysis.

[0218] Figure 7 shows a schematic representation of the different types of pores found in bacterial cellulose particles. A through pore (1) is a channel that runs between two openings on the surface of the bacterial cellulose particle. A closed pore (3) is a channel with only a single opening on the surface of the bacterial cellulose, while a closed pore (2) is a void completely surrounded by the bacterial cellulose. Tests have shown that the bacterial cellulose particles in the micropowder have a high percentage of through pores, which is believed to improve the oil absorption of the micropowder.

[0219] Figure 8 shows a photographic image of the micropowder. As can be seen, the micropowder has a neutral white color and is highly light-scattering. Note that other samples, depending on their manufacturing method, had a range of colors including white, off-white, pearl white, cream, brown, yellow, light or dark yellow, dark brown, or wood, without the use of pigments or bleaching agents. The neutral color and optical properties of the micropowder made it highly versatile for use as an opacifier or pigment in consumer products.

[0220] Figure 9 shows the results of biodegradation tests performed on samples of micropowder according to a preferred embodiment (shown in the SEM and photographic images above). An OxiTop™ device (WTW, Germany) was used to allow microorganisms in the test bottles to convert oxygen to carbon dioxide (CO2) during the biodegradation of the samples. The OxiTop™ is a cap-type pressure gauge attached to the test bottle, which measures biochemical oxygen demand by simply detecting the degree to which the air pressure inside the bottle decreases, without generating oxygen. After sealing the test bottle with the OxiTop™ cap, the bottle was incubated in a constant temperature bath (IN804, Yamato Scientific Co., Ltd., Japan). According to the OECD (Guideline for Testing Chemicals: Ready biodegradability (1992)) and CSCL (Guideline for the Chemical Substances Control Law: Microbial Degradation Testing of Chemical Substances (2018) (Japanese)) guidelines, a sample is considered to be completely degraded when its biochemical oxygen demand (BOD) value during the test period reaches 60% of the sample's theoretical oxygen demand (ThOD) (the remaining 40% is assumed to be assimilated by microorganisms). This sample achieved 75% biodegradability within 28 days.

[0221] FIG. 10 shows the results of oil absorption tests of a sample of a micropowder of the preferred embodiment and various different micropowder samples of the prior art. Oil absorption was tested according to the ASTM D281-95 method known to those skilled in the art. The results showed that the sample micropowder was able to absorb jojoba oil at a rate of approximately 5 g / g, while the absorption rates of sunflower oil and orange and grapefruit essential oils were all above 5 g / g. These results were more than twice the performance of the most commonly used prior art micropowder. As can be seen from the graph, the closest performance was provided by microcrystalline cellulose particles derived from plant cellulose. Due to their different material properties, their oil absorption was approximately 2 g / g for sunflower oil under the same conditions. This was less than 40% of the absorption of the micropowder produced according to the present invention.

[0222] The oil absorption performance of the micropowder of the present invention even surpassed that of metal and plastic micropowder. Combined with the biodegradability performance demonstrated above, it is clear that the micropowder of the present invention can replace environmentally problematic prior art micropowder without sacrificing consumer satisfaction.

[0223] Further analytical results of the samples used are shown in Table 1 below.

[0224] Table 1: Analysis of micropowder according to a preferred embodiment of the present invention [Table 1] a Monochromatic breath test (WTW OxiTop™ Control measurement system), b Dual Circuit Diffractometer (D 50 00, Bruker-AXS), c ULM standard PIDS, d KERN DAB 200-3 (moisture meter), e Modified ASTM D2819-5 method, f Dynamic vapor sorption, 20°C, 76% humidity g BET nitrogen adsorption isotherm, h GPC, 8% LiCl in DMAc, FM A (0.5% LiCl in DMAc).

[0225] FIG. 11 shows a number of micropowders (micropowders of various average diameters D 50 The oil absorption of the samples was tested according to ASTM D281-95 under the same conditions. It can be seen that for all the tested samples, despite their different particle sizes, the oil absorption was high and even exceeded that of the prior art micropowder shown in the previous figure.

[0226] Furthermore, Figure 11 shows that for all oils, the smaller the particle size, the higher the oil absorption. There is a strong correlation between absorption and average particle size, especially for vegetable oils. Therefore, particle size can be used to tailor this property of the micropowder, for example, by adjusting the milling speed and / or duration.

[0227] Figure 18 shows a comparison of the oil absorption relative to oleic acid for a number of micropowders produced according to the present invention and prior art micropowders. Oleic acid is often used as an ingredient in the cosmetics and cosmeceutical industries and serves as a standard reference oil for measuring oil absorption in this context. Micropowders with different particle sizes were produced from bacterial cellulose according to the present invention. The first sample, "Micropowder-67_Or," had an average particle size of 67 μm; the second sample, "Micropowder-204_FW," had an average particle size of 204 μm; the third sample, "Micropowder-106_FW," had an average particle size of 106 μm; the fourth sample, "Micropowder-8_HK," had an average particle size of 8 μm; and the fifth sample, "Micropowder-400_FW," had an average particle size of 400 μm. Other micropowders tested included polyvinyl dimethicone microplastic, microcrystalline cellulose, kaolin, PMMA cosmetic beads (specifically, "Covabeads"), talcum, and potato starch. The oil absorption of the samples was tested according to ASTM D281-95 under the same conditions. The prior art micropowder tested achieved a maximum oleic acid absorption of 2.27 g / g. Meanwhile, all prior art micropowder samples were able to achieve an absorption of at least 2.65 g / g, with the most absorbent sample having an absorption of 5.64 g, more than double the absorption capacity of the best prior art micropowder studied here.

[0228] Figure 12 shows the results of an X-ray diffraction analysis of a micropowder sample of the preferred embodiment (the properties of which are also listed in Table 1 above). X-ray diffraction analysis was performed using a dual-circuit diffractometer (D5000, Bruker-AXS), a Ge(111) primary beam monochromator, a wavelength of Cu-Kα1; λ = 0.15406 nm, a scintillation counter, and operation (standard): symmetric transmission. The sample was rotated to analyze the diffraction angle from 5° to 80° (2θ) in steps of 0.02° at 0.2 seconds per step. Prior to analysis, the sample was ground with ethanol, dispersed on a zero-background silicon sample holder, and placed under a lamp to evaporate the ethanol. The results were used to determine the crystallinity of the micropowder.

[0229] Figure 13 shows the results of particle size distribution analysis of a micropowder sample of the preferred embodiment. Particle size distribution was measured using laser diffraction with a Mastersizer 3000 (Malvern Panalytical, Ltd, Malvern, UK) using the dry method with the Aero S accessory. Light scattering data converted to particle size distribution was analyzed using the Mie scattering model, using a non-spherical particle type and MgCCb as the material (i.e., MgCCb settings of refractive index (1.717) and adsorption index (0.01)). Before adding the sample to the instrument, the sample container was thoroughly mixed to ensure good sample collection. Several grams of powder were used for each measurement, and the measurement time was set to 10 to 30 seconds. The lower and upper obscuration limits were set to 0.5%, 5%, and the air pressure was set to 1.5 bar. The feed rate was constantly adjusted during the measurement to maintain obscuration between 0.5% and 5%. All measurements were averaged and performed at least five times. The sample had an average particle size D of 64.7 μm as shown in Table 1. 50 It was found to have excellent oil absorption, water absorption, matte finish, and pore coverage while being safe and biocompatible.

[0230] Figure 14 shows the results of volumetric gas sorption analysis performed on a sample of micropowder. This was used to perform a Brunauer-Emmett-Teller (BET) analysis of the surface area to mass ratio of the micropowder to draw conclusions about its porosity. The test involved nitrogen gas adsorption in a liquid nitrogen bath at 77 K. Measurements were performed on a Belsorp Max II surface area and porosity analyzer. Prior to analysis, the sample was degassed in a FlowPrep060 sample degassing system at 105 °C under a stream of nitrogen gas for 12 hours. The surface area was determined by using the well-recognized BET equation and was therefore calculated from the nitrogen sorption isotherm (Brunauer et al., JACS, 60, 1938, 309-319).

[0231] The data indicate that the analyzed micropowder corresponds to a Type V isotherm and is therefore mesoporous. Type V isotherms are generally found in flat, homogeneous adsorbents. The initial path of this isotherm is similar to that of Type III. In this case, the adsorbate preferentially interacts with the monolayer rather than the adsorbent surface due to the low heat of adsorption compared to the heat of liquefaction. On the other hand, a high-affinity isotherm is typical of very strong adsorption interactions.

[0232] Adsorption data showed an average surface area to mass ratio, S, of 7.8 m / g for the sample. BET was calculated as 42.1 m 2 / g of mesoporous particles with average surface area to mass ratio S Meso and an average pore radius r of 5.6 nm pore was calculated.

[0233] Table 2 shows the results of user testing of various formulations applied to the skin.

[0234] Table 2 - Sensory evaluation results of micropowder [Table 2]

[0235] The micropowder was tested in the form of a lotion having the formulation shown in Table 3 below. 70 μL of the lotion was applied to the back of the user's hand and spread eight times with three fingers of the other hand. Users were instructed to rate the sensation upon application for softness and stickiness. The scale used was 0-10, with 0 representing no softness and no stickiness and 10 representing very softness and very stickiness, respectively.

[0236] The feel of the micropowder was tested using a lotion with the formulation shown above. 70 μL of the lotion was applied to the back of the user's hand and spread 20 times with three fingers of the other hand. The user was instructed to rate the feel after one minute. A scale of 0 to 10 was used to evaluate the stickiness of the feel, with 0 representing no stickiness and 10 representing very high stickiness. Stickiness was tested by gently tapping the back of the lotioned hand with the other hand.

[0237] The softness sensation was tested by the user stroking the back of the hand using a scale ranging from 0 representing no softness to 10 representing very high softness.

[0238] Sticky sensation was tested by having the user run their index finger and thumb over the back of the lotioned hand, using a scale of 0 to 10, with 0 representing no stickiness and 10 representing a very high degree of stickiness.

[0239] Compared with formulations containing polymethyl methacrylate or silica micropowder, users reported a softer feel both during and after application of the formulation containing the bacterial cellulose micropowder of the present invention. Users also reported less tackiness and stickiness. A semi-matt appearance could be observed when using the micropowder of the preferred embodiment. This is believed to be due to the high surface area-to-volume ratio, high porosity, and irregular shape of the bacterial cellulose particles, which result in high oil absorption. Furthermore, the particle size distribution was found to provide good coverage when used in foundations, and to provide volume and length to eyelashes when used in mascaras. Therefore, the present micropowder shows great potential as a replacement for current state-of-the-art micropowder.

[0240] Additionally, the inventors investigated the properties of the bacterial cellulose micropowder of the present invention in comparison with a plant cellulose-based powder. Micropowder samples were prepared from bacterial cellulose cultured according to a preferred embodiment of the present invention, which is also shown enlarged in Figure 17. Additionally, plant cellulose micropowder samples were provided for comparison. The samples were compared visually and quantitatively analyzed. The comparative results are shown in Table 3 below.

[0241] Table 3 - Analysis results of micropowders derived from plant cellulose and bacterial cellulose according to a preferred embodiment of the present invention [Table 3]

[0242] From Figure 17 it can be deduced that the bacterial cellulose micropowder produced using the teachings of the present invention has a significant microvilli coverage on its surface.

[0243] The collected data further indicates that the micropowder samples produced according to the present invention had a much higher void volume as well as much higher porosity, particularly mesoporosity, compared to plant cellulose. In particular, a BJH (Barrett-Joyner-Halenda) analysis of porosity showed that the bacterial cellulose micropowder of the preferred embodiment of the present invention had approximately 2.4 times higher mesoporosity than the plant cellulose powder used for comparison.

[0244] Surprisingly, the oil adsorption capacity of bacterial cellulose micropowder produced according to the present invention significantly exceeds that of plant cellulose, with the adsorption capacity being at least twice as high.

[0245] Micropowders have proven particularly advantageous for use in cosmetics or personal care products. Without intending to be limiting, the following cosmetic formulations shown in Tables 4 to 13 illustrate the possible applications and extraordinary potential of the micropowders of the present invention in improving the properties of the respective products.

[0246] Table 4 - Comparison of exemplary formulations of body or face lotions containing the micropowder of the present invention as a sensory enhancer with equivalent formulations using other powders [Table 4]

[0247] Table 5 - Exemplary formulations of mascaras containing micropowder of the present invention [Table 5]

[0248] Table 6 - Exemplary formulations and comparisons of four loose powders containing micropowder of the present invention [Table 6]

[0249] Table 7 - Exemplary formulations of liquid foundations containing micropowder of the present invention and comparison with liquid foundations containing different powders [Table 7]

[0250] Table 8 - Exemplary formulations of Examples 12-18 and comparison of various buttercream formulations with and without micropowder of the present invention [Table 8]

[0251] Table 9 - Exemplary formulations of lipsticks containing micropowder of the present invention [Table 9]

[0252] Table 10 - Exemplary formulations and comparisons of hand creams with and without micropowder of the present invention [Table 10]

[0253] Table 11 - Exemplary formulations of lip balms containing micropowder of the present invention [Table 11]

[0254] Table 12 - Exemplary formulations of powder shampoos containing micropowder of the present invention and comparison with powder shampoos containing synthetic powders [Table 12]

[0255] Table 13 - Exemplary formulations of anti-aging creams containing micropowder of the present invention Example 28 [Table 13]

[0256] Table 14 - Exemplary formulations of facial sunscreens containing micropowder of the present invention Example 29 [Table 14]

[0257] Table 15 - Exemplary formulation of sebum control cream containing micropowder of the present invention Example 30 [Table 15]

[0258] Table 16 - Exemplary formulation of a restoring night cream containing micropowder of the present invention Example 31 [Table 16]

[0259] Table 17 - Exemplary Formulations of Color Correcting Primers Containing Micropowder of the Invention Example 32 [Table 17]

[0260] Table 18 - Exemplary Formulations of BB Creams Containing Micropowder of the Present Invention Example 33 [Table 18] [Explanation of symbols]

[0261] Drawing translation Figure 9 Degradation (% ThOD) Degradation (% ThOD) Time (days) Figure 10 Sunflower oil Jojoba oil Orange / grapefruit essential oil Oil absorption (g / g) Micropowder (Bacterial Cellulose) Cellulose Powder (Spent Coffee) Microcrystalline cellulose Cellulose Powder (Potato Peel) Cellulose Powder (Spent tea) Vinyl dimethicone crosspolymer Polymethylmethacrylate (PMMA) Tapioca starch Kaolin Talkum powder Calcium Carbonate Micropowder / Microbeads Figure 11 Oil absorption (g / g) Particle size (um) Vegetable Oil Sunflower oil Jojoba oil Essential Oil (GF / Orange) Figure 12 Micropowder Normal Intensity Figure 13 Volume Density (%) Cumulative Volume (%) Cumulative Volume (%) Particle Diameter Class (μm) Figure 18 Oleic Acid, Absorption Capacity (g / g) Micropowder Polyvinyl dimethicone... Polyvinyl dimethicone... Microcrystalline cellulose Kaolin Talkum talcum Potato Starch

Claims

1. 1. A micropowder comprising bacterial cellulose particles, characterized in that the micropowder has an oil absorption of at least 2.5 g / g and is biodegradable.

2. 10. The micropowder of claim 1, wherein the micropowder is biodegraded by up to 75% within 35 days, or within 28 days.

3. 3. Micropowder according to claim 1 or 2, characterized in that the micropowder has an oil absorption of at least 4 g / g, or at least 4.5 g / g, or at least 5 g / g.

4. The average particle size D of the bacterial cellulose particles 50 The micropowder according to any one of claims 1 to 3, characterized in that the diameter of the bacterial cellulose particles is 1 μm to 1000 μm, and the average crystallinity of the bacterial cellulose particles is 30% to 80%. (Multi-Multi)

5. The micropowder according to any one of claims 1 to 4, characterized in that the micropowder is produced by a method comprising grinding bacterial cellulose from a culture and drying the ground bacterial cellulose, the drying being configured to induce keratinization of the bacterial cellulose. (Multi-Multi)

6. The average particle size D of the bacterial cellulose particles 50 The micropowder according to any one of claims 1 to 5, wherein the average aspect ratio of the bacterial cellulose particles is between 1 μm and 500 μm, or between 5 μm and 250 μm, or between 25 μm and 100 μm, and the bacterial cellulose particles have an average aspect ratio of between 10:1 and 1:10, or between 5:1 and 1:5, or between 2:1 and 1:

2. (Multi-Multi)

7. The micropowder according to any one of claims 1 to 6, wherein the bacterial cellulose particles have an average crystallinity of 40% to 80%, or 40% to 60%, or 40% to 50%. (Multi-Multi)

8. The bacterial cellulose particles are mesoporous with an average pore radius of 1 nm to 50 nm, or 5 nm to 20 nm, or 7 nm, and the surface area to mass ratio of the bacterial cellulose particles is 10 m or 10 m 2 / g~100m 2 / g, or 10 m 2 / g~80 m 2 The micropowder according to any one of claims 1 to 7, characterized in that the micropowder has a molecular weight of 1 / g (multi-multi).

9. The following steps: producing bacterial cellulose from a bacterial culture such that the produced bacterial cellulose has an average crystallinity of 30% to 80%; milling the bacterial cellulose to form bacterial cellulose particles having an average particle size of 1 μm to 1000 μm; drying the comminuted bacterial cellulose particles; The method for producing micropowder according to any one of claims 1 to 8, comprising: (Multi-Multi)

10. 10. The method of claim 9, wherein the bacterial cellulose is at least partially dried between its production and grinding, the partial drying being carried out in an atmosphere having a relative humidity of up to 85%, or up to 80%, and a temperature of 20°C to 40°C, or 25°C to 35°C, for 3 to 10 days, or 5 to 9 days.

11. 11. The method according to claim 9 or 10, characterized in that the bacterial cellulose is treated with liquefied gas or liquid nitrogen before being crushed.

12. The method according to any one of claims 9 to 11, characterized in that before drying, the pulverized bacterial cellulose particles are mixed with deionized water to form a suspension having a concentration of bacterial cellulose in water of 0.5 w / w% to 5 w / w%, or of 1.0 w / w% to 3.5 w / w%. (Multi-Multi)

13. The suspension of bacterial cellulose in water is spray dried, the spray drying comprising: atomizing the suspension of bacterial cellulose in water to form droplets suspended in a gas, said atomization being assisted by the use of pressurized gas, air or an inert gas, or nitrogen; exposing the suspended droplets to a stream of heated air such that the moisture content of the droplets is reduced, the heated air having a temperature of between 80°C and 250°C, or between 150°C and 190°C; collecting the dried particles; 13. The method of claim 12, comprising:

14. freeze-drying the suspension of bacterial cellulose in water, said freeze-drying comprising: freezing the suspension at a temperature between -10°C and -50°C, or between 15°C and -25°C; reducing the pressure of the controlled atmosphere surrounding the frozen suspension to less than 50 mbar, or less than 1 mbar, or less than 0.5 mbar, so that ice is sublimated from the frozen suspension and the resulting cake has a water content of less than 7 w / w%, or less than 5 w / w%, or less than 1 w / w%; The method according to any one of claims 9 to 13, characterized in that it comprises: (multi-multi)

15. A cosmetic or personal care product comprising the micropowder of any one of claims 1 to 8, wherein the cosmetic or personal care product is an anti-aging product, a treatment product for oily and acne-prone skin, a face mask, a moisturizer, a butter cream, a lotion, a foundation, a concealer, a loose or pressed powder, a mascara, a lipstick, a lip gloss, a fluid shampoo, a dry shampoo, a shampoo bar, a hair mask, a hair conditioner, a hair styling product, an antiperspirant, a deodorant, or an oral care product. (Multi-Multi)

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