Stabilized vitamin a

Abstract

The present invention relates to the field of nutraceuticals, in particular to the field of animal nutrition and animal feed. Specifically, the present invention relates to a composition comprising droplets of a vitamin A compound in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets of the vitamin A compound exhibit a droplet size D[4,3] in the range of 0.4 to 1 µm. Further, the invention contemplates a method for manufacturing the composition, and a feed additive comprising the composition.

Description

[0001] 240920W001

[0002] Stabilized Vitamin A

[0003] The present invention relates to the field of animal nutrition and animal feed. Specifically, the present invention relates to a composition comprising droplets of a vitamin A compound in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets of the vitamin A compound exhibit a droplet size D[4,3] in the range of 0.4 to 1 pm. Further, the invention contemplates a method for manufacturing the composition, and a feed additive comprising the composition.

[0004] Vitamins including fat-soluble vitamins, such as vitamin A, vitamin E and vitamin K are essential nutrients for many species and hence represent important ingredients in human and animal nutrition. Vitamins are often very sensitive to oxidation and therefore require specific formulations to ensure stability, maintain high activity and offer miscibility with further feed or food ingredients and a high shelf life of feeds or feed additives comprising the same. Providing stable formulations of fat-soluble vitamins like vitamin A is particularly challenging, as they are usually sensitive to oxidation and do not dissolve in water.

[0005] WO 2021 / 069752 and WO 2022 / 078924 disclose a feed additive comprising at least a fat-soluble vitamin in a polysaccharide matrix, and to a process for its manufacture. The polysaccharide matrix comprises lignosulfonate and a hexose-dimer, -oligomer or -polymer.

[0006] US 5,668,183 is concerned with water dispersible preparations of fat-soluble vitamins and a process for their manufacture. The preparations contain a water-soluble or water-dispersible lignin derivative as the matrix component and fat-soluble substances, especially the fat-soluble vitamins A, D, E and K, carotenoids.

[0007] Despite a variety of water-dispersible formulations comprising fat-soluble vitamins that already exists, there is still a need of improving their stability and for providing and maintaining high vitamin concentration and activity. In particular, there is still a need for formulations that ensure high stability of fat-soluble vitamins for a prolonged period of time, such as several weeks.

[0008] Moreover, there is a need for providing a feed additive that is free of animal derived products, i.e. no compounds from animal sources such as e.g. gelatin are used.

[0009] The problem to be solved may be seen as the provision of means and methods for complying with the aforementioned needs. This problem is addressed by the products and methods with 240920W001

[0010] - 2 - the features of the independent claims. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims as well as throughout the specification.

[0011] Thus, the present invention relates to a composition comprising droplets of a vitamin A compound in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets of the vitamin A compound exhibit a droplet size D[4,3] in the range of 0.4 to 1 pm.

[0012] Advantageously, the compositions comprising small sized droplets of vitamin A and a high amount of lignosulfonate, in particular calcium lignosulfonate, show excellent stability. In particular, the compositions have a desirable effect on the stability of the vitamin A compound over time. Moreover, the use of gelatin in the composition can be avoided allowing entry into halaldemanding markets. A further advantage can be seen in that the compositions are derived from non-animal renewable sources.

[0013] Further, the invention contemplates a method for manufacturing the composition, and a feed additive comprising the composition.

[0014] It is to be understood that as used in the specification and in the claims, “a” or “an” can mean one or more, depending upon the context in which it is used. Thus, for example, reference to “a cell” can mean that at least one cell can be utilized.

[0015] As used herein, the terms “have”, “comprise” or “include” or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situation in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions “A has B”, “A comprises B” and “A includes B” may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements. As noted above, the terms “comprising”, “having”, “including” as used herein shall not be understood in a limiting sense. The terms rather indicate that more than the actual items referred to may be present, e.g., if it refers to a method comprising certain steps, the presence of further steps shall not be excluded. However, the terms also encompass embodiments where only the items referred to are present, i.e. they have a limiting meaning in the sense of “consisting of”. 240920W001

[0016] - 3 -

[0017] Further, it shall be noted that the terms “at least one”, “one or more” or similar expressions indicating that a feature or element may be present once or more than once typically are used only once when introducing the respective feature or element. In most cases, when referring to the respective feature or element, the expressions “at least one” or “one or more” are not repeated, non-withstanding the fact that the respective feature or element may be present once or more than once.

[0018] The term “about” as used herein means that with respect to any number recited after said term an interval accuracy exists within in which a technical effect can be achieved. Accordingly, about as referred to herein, preferably, refers to the precise numerical value or a range around said precise numerical value of ±20 %, preferably ±15 %, more preferably ±10 %, or even more preferably ±5 %.

[0019] Further, as used herein, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically", “typically”, and “more typically” or similar terms are used in conjunction with optional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative features. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features, without any restriction regarding alternative embodiments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.

[0020] The composition according to the invention comprises droplets of a vitamin A compound. The term ’’vitamin A compound” as used herein refers to vitamin A and isomers thereof as well as chemically related compounds, including retinoids and retinoic acids, retinyl esters and derivatives thereof. In line with the invention, the term may typically relate to a compound selected from the group consisting of retinol, retinyl esters, retinal, retinoids including synthetic retinoids, derivatives thereof, and mixtures thereof; preferably the vitamin A compound is vitamin A acetate and / or vitamin A palmitate, more preferably the vitamin A compound is vitamin A acetate.

[0021] The vitamin A compound is present in the composition according to the invention as droplets that exhibit a droplet size D[4,3] in the range of 0,4 pm to 1 pm. The vitamin A compound is hence typically a lipophilic liquid also referred to as oil. Said liquid may preferably comprise an antioxidant for preventing or reducing oxidation of the vitamin A compound. Particularly, suitable 240920W001

[0022] - 4 - antioxidants in line with the present invention are selected from the group consisting of bu- tylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tocopherol, ascorbic acid, ascorbate, salicylic acid, and derivatives or mixtures thereof. The term “derivatives” of said antioxidants typically refers to esters and salts of tocopherol, ascorbic acid, ascorbate and salicylic acid, more typically acetates thereof.

[0023] Typically, the antioxidant is mixed with the Vitamin A compound prior to forming the droplets. More typically, the antioxidant present in an amount of at least 6 wt.-%, even more typically in an amount of 6 to 12 wt.-% based on the total weight of the dry matter of the composition.

[0024] The composition is specifically an emulsion wherein the droplets of the vitamin A compound form the dispersed phase. More specifically, the dispersed phase consists of droplets of the vitamin A compound, or of droplets of the vitamin A compound and an antioxidant. The term “dispersed phase” is used herein to describe the discontinuous phase of the emulsion, typically the lipophilic phase. In contrast, the continuous phase of the emulsion in line with the present invention typically refers to the aqueous phase.

[0025] The term “droplet” used herein refers to any kind and form of small liquid drop, in particular of a hydrophobic liquid, with a droplet size D[4,3] in the pm range or below. In line with the present invention the droplet may be a droplet of a hydrophobic liquid form of a vitamin A compound such as the Vitamin A compounds referred to elsewhere herein, in particular of vitamin A acetate or vitamin A palmitate.

[0026] Typically, the droplets of vitamin A, optionally the droplets further comprising an antioxidant, form upon addition of the vitamin A compound or the mixture of vitamin A and antioxidant into the aqueous solution of the lignosulfonate as described elsewhere herein in further detail.

[0027] The droplets exhibit a droplet size D[4,3] in the range of 0,4 pm to 1 pm. The droplet size can be determined by static light scattering, in particular with a Malvern Mastersizer 3000 (Malvern Panalytical, Worcester, UK) and the following parameters: Dispersant Refractive Index: 1 ,330; Particle Refractive Index: 1 ,456; Particle Absorption Index: 0,010; Scattering Model: Mie ; Analysis Model: universal.

[0028] The droplet size D[4,3] of the droplets of the vitamin A compound may be below 0.9 pm, preferably below 0.8 pm, even more preferably below 0,7 pm, still more preferably the size D[4,3] of said droplets may be between 0.4 pm and 0.7 pm. The droplet size D[4,3] of the droplets of the vitamin A compound, is still more preferably in the range of 0.5 pm to 0.7 pm; even more preferably in the range of 0.55 pm to 0.6 pm. 240920W001

[0029] - 5 -

[0030] Specifically, the size distribution of the droplets of vitamin A compound is uniform. More specifically the size distribution of the droplets of vitamin A compound is monomodal; even more specifically the size distribution of the droplets D[4,3] has a monomodal peak around 0.3 pm to 1.0 pm. It is to be understood that in line with the present invention, an uniform distribution of droplet size refers to a single peak, i.e. is a monomodal distribution. More typically, it is to be understood that in line with the invention, the droplet size distribution is narrow. In other words, the droplet size distribution may have a width of droplet size in the range of at most 1.8 pm more typically of at most 1.5 pm, at most 1.3 pm, at most 1.2 pm or at most 1.1 pm.

[0031] Moreover, in line with the invention, the uniformity of the droplet size distribution is lower than 0.6, more preferably lower than 0.5, even more preferably lower than 0.4. In a particularly preferred embodiment, the droplet size distribution has a width of 1.11 pm and a uniformity of 0.34.

[0032] Without wishing to be bound by theory, the droplet size and / or droplet size distribution are regarded by the present inventors to positively influence the stability of the composition and allow for excellent shelf life of the composition and formulation, i.e. in particular said droplet size and / or droplet size distribution surprisingly appear to stabilize the vitamin A compound.

[0033] The droplet size distribution can be determined by static light scattering, in particular with a Malvern Mastersizer 3000 (Malvern Panalytical, Worcester, UK). The settings are as specified herein above in the context of particle size determination.

[0034] Preferably, the composition according to the invention, in particular the emulsion, has a dynamic viscosity of at least 80 mPas, more preferably a dynamic viscosity of at least 100 mPas, 120 mPas, 140 mPas or at least 145 mPas; more preferably as determined by using a suitable rheometer, or viscometer, in particular a shear velocity viscometer, such as Physic Rheolab MC1 (Anton Paar GmbH; Germany). A typical application is operating the analysis tool Rheoplus / 32 V3.40 by Anton Paar; more typically using the following settings: MC1 + SN253758; System Z3 DIN (25mm) d=1 mm. Even more preferably, the composition according to the invention, in particular the emulsion, has a dynamic viscosity of less than 170 mPas, less than 160 mPas or less than 155 mPas.

[0035] The composition according to the invention further comprises an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition.

[0036] The term “lignosulfonate” as used herein typically refers to a sulfonated lignin derived compound. Typically, a lignosulfonate is a water soluble anionic polyelectrolyte polymer that is in 240920W001

[0037] - 6 - particular derived as byproducts from the production of wood pulp. More particularly, lignosulfonates are compounds lignin derived from the treatment of wood, specifically chopped wood, for example wood chips, with solutions of sulfite and / or bisulfite. In line with the composition and the method of the present invention, the lignosulfonate is preferably Ca-lignosulfonate.

[0038] Examples of a typical lignosulfonate include sodium lignosulfonate, ammonium lignosulfonate, magnesium and calcium lignosulfonate as well as any of their mixtures. In line with the present invention, the lignosulfonate is preferably calcium lignosulfonate (Ca-lignosulfonate). More typically, the lignosulfonate is a Ca-lignosulfonate with an average molecular weight between 5000 and 30’000 Daltons. Typically, the average molecular weight may be determined as known in the art, in particular by size exclusion chromatography. Calcium lignosulfonate is commercially available for example from Borregaard Industries Limited, Norway under the tradenames Borre- bright CY22P, Borresperse Na220 and Borrement CA120; wherein Borrement CA120 is especially preferred.

[0039] The aqueous solution comprises, preferably consist of, lignosulfonate in an amount of at least 40 wt.-% based on the total weight of the dry matter of the composition. Typically, the aqueous solution is water, more typically de-ionized water. The aqueous solution of lignosulfonate may be prepared by adding the lignosulfonate to water, typically accompanied by mixing or stirring for a time suitable to achieve dissolving of the lignosulfonate. More typically, the temperature and the / or the pH may be adjusted as described elsewhere herein.

[0040] In line with the invention, the composition may have a pH in the rage of 3 to 8. The pH may be adjusted as known in the art.

[0041] The invention further contemplates a method for manufacturing the composition according to the invention comprising at least the following steps: a) providing an aqueous solution of at least 40 wt.-% lignosulfonate based on the total weight of dry matter of the composition; b) providing a vitamin A compound, optionally mixed with an antioxidant; c) transferring the vitamin A compound into the aqueous solution, thereby obtaining an emulsion; d) homogenizing the emulsion to obtain droplets of the vitamin A compound with a droplet size D[4,3] below 1 pm; and e) obtaining the composition.

[0042] The term “total weight of dry matter” generally refers to the total weight of all components, i.e. the sum of the weights of the components, comprised in the matter at issue except water. In the present invention the “total weight dry matter of the composition” hence includes all components comprised in the composition except water. Typically, the sum of the weights of the components of the composition according to the invention hence includes the weight of the vitamin A compound, the weight of the optionally present antioxidant, and the weight of the lignosulfonate. 240920W001

[0043] - 7 -

[0044] The total weights of the dry matter can be determined as known in the art. Typically, the total weights of the dry matter is determined experimentally. In particular, a fixed amount of sample is weighed and then dried for at least 4 hours, or overnight, in a suitable oven, such as a vacuum drying oven at 70°C to 150°C, typically, at 80 °C to 140 °C, more typically at 130 °C. More typically the drying is performed until weight consistency is reached. The weight is typically determined using a high precision scale. Said dry matter analysis may be performed using suitable commercially available devices combining a drying unit and a weighing unit, for example a moisture analyzer HR73 as commercially available from Mettler-Toledo GmbH (Germany). The weight remaining after the drying step is the dry matter of the sample.

[0045] Said dry matter may be regarded as being equivalent to the total solids content of the composition including the vitamin A compound. Typically, the solids content in the composition, or the emulsion, is at least 50 wt.-%, preferably at least 55 % wt.-%, more preferably at least 57 wt.-%. Said high solids content, i.e. of at least 50 wt.-%,is advantageous as it allows higher amounts of the vitamin A compound to be included. Moreover, it was surprisingly found in the experiments underlying the invention that said high solids content could support the formation of smaller oil droplet size. The maximum solids content in the composition typically does not exceed 70 wt.- %, more typically does not exceed 65 wt.-%, even more typically it does not exceed 60 wt.-%.

[0046] The composition according to the invention specifically is an oil in water emulsion. Said emulsion may be obtained by adding the vitamin A compound into the aqueous solution of the lignosulfonate. The vitamin A compounds is preferably transferred into the aqueous solution by means of dripping or pouring as described elsewhere herein. More specifically, the dispersed phase of the emulsion comprises, preferably consists of, the droplets of the vitamin A compound and optionally mixed with an antioxidant; and even more specifically, the continuous phase of the emulsion comprises, preferably consists of an aqueous solution of lignosulfonate.

[0047] Preferably, the aqueous solution consists of at least 20 wt.-% of lignosulfonate in water, more preferably of at least 30 wt.-%, even more preferably of at least 40 wt.-% of lignosulfonate in water; still more preferably of at least 50 wt.-% of lignosulfonate in water, still even more preferably of about 60 wt.-% of lignosulfonate in water.

[0048] Typically, the composition consists of the droplets of the vitamin A compound in said aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition. 240920W001

[0049] - 8 -

[0050] More typically, the composition consists of droplets of a vitamin A compound and an antioxidant in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets exhibit a droplet size D[4,3] in the range of 0.4 to 1 pm.

[0051] Even more typically, the composition comprises the vitamin A compound in an amount of at least 30 wt.-%, preferably at least 35 wt.-% more preferably, at least 40 wt.-% based on the total weight of dry matter of the composition.

[0052] A preferred composition in line with the present invention comprises, preferably consists of, 40 to 60 wt.-% of lignosulfonate and 40 to 60 wt.-% of the vitamin A compound and optionally 6 to 12 wt.-% of an antioxidant, all wt.-% based on the total weight of dry matter of the composition.

[0053] Typically, the composition according to the invention is free of hexose-dimers, modified hexosedimers, hexose-oligomers, modified hexose-oligomers, hexose-polymers, modified hexose-poly- mers, such as dextrins or modified starches; more typically the said hexose dimers, hexose-oligomers, and hexose-polymers are absent from the composition, i.e. their amount is less than 1 wt.-%, less than 0.1 wt.-%, less than 0.01 wt.-%, less than 0.001 wt.-%, less than 0.0001 wt.-% based on the total weight of dry matter of the composition; or even more typically, their amount is below the limit of detection.

[0054] The present invention further contemplates a method for manufacturing the composition according to the invention comprising the following steps: a) providing an aqueous solution of at least 20 wt.-% lignosulfonate in water b) providing a vitamin A compound, optionally mixed with an antioxidant; c) transferring the vitamin A compound into the aqueous solution, thereby obtaining an emulsion; d) homogenizing the emulsion to obtain droplets of the vitamin A compound with a droplet size D[4,3] below 1 pm; and e) obtaining the composition.

[0055] Preferably, providing the aqueous solution in step a) comprises dissolving the lignosulfonate by stirring for a sufficient time at an elevated temperature, in particular in a suitable aqueous solvent, more preferably step a) is performed at a temperature in the range of 50 to 70 °C; even more preferably for at least several minutes. Typically, the suitable solvent is water or a waterbased buffer solution, more typically deionized water. The stirring may specifically be performed using a blade stirrer. To enable dissolving of the lignosulfonate, heating the suitable solvent to a 240920W001

[0056] - 9 - suitable temperature, such as a temperature in the range of 50 to 70 °C may be advantageous.

[0057] More particular, said temperature range may be 55°C to 65°C.

[0058] Furthermore, providing the vitamin A compound in step b) of the method for manufacturing the composition according to the invention may comprise heating a vitamin A compound, preferably vitamin A acetate, to a temperature above 60 °C. However, the temperature should not exceed 80 °C in order to avoid undesired decomposition or inactivation of the vitamin A compound.

[0059] The heating may be achieved by any means known in the art, typically, a heater, and be accompanied by stirring the heated solutions or liquid compounds.

[0060] Hence, providing the vitamin A compound in step b) of the method for manufacturing the composition according to the invention may comprise heating a vitamin A compound to 70 °C or above, more preferably to about 75 °C.

[0061] Further, step b) of providing the vitamin A compound may comprise adding an antioxidant to the vitamin A compound and mixing the same; preferably the antioxidant is selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tocopherol, ascorbic acid, ascorbate, salicylic acid, derivatives and mixtures thereof. The term “derivatives” of said antioxidants typically refers to esters and salts of tocopherol, ascorbic acid, ascorbate and salicylic acid more typically acetates thereof.

[0062] Typically, the antioxidant, such as BHT, is added in an amount of 6 to 12 wt.% based on the total weight of dry matter of the composition.

[0063] In the method for manufacturing the composition according to the invention the vitamin A compound, optionally mixed with an antioxidant, is transferred to the aqueous solution of the lignosulfonate thereby obtaining an emulsion, typically an oil in water emulsion. Said transferring in step c) may involve pouring or dripping the vitamin A compound into the aqueous solution of the lignosulfonate. Typically, step c) further comprises stirring the resulting mixture for at least several minutes to obtain an emulsion.

[0064] The method for manufacturing the composition according to the invention further comprises a step d) of homogenizing the emulsion; said homogenization typically results in droplets of the vitamin A compound with a droplet size D[4,3] below 1 pm, preferably below 0.9 pm. Said droplet size can be determined as described elsewhere herein in more detail. 240920W001

[0065] - 10 -

[0066] Preferably, said step d) of homogenizing the emulsion comprises shear mixing the emulsion; preferably high shear mixing, such as at a velocity of at least 8000 U / rnin. Even more preferably, the velocity of the shear mixing does not exceed 15000 U / rnin; still more preferably, the velocity, i.e. the rotational speed, is chosen depending on the rotor size, i.e. diameter of the rotor and / or the device used. Typically, said homogenizing in step d) is performed to ensure the desired droplet size of size D[4,3] below 1 pm, preferably below 0.9 pm. Typically, said step d) of homogenizing the emulsion comprises simultaneously maintaining the temperature of the emulsion at about 60°C.

[0067] The term “high shear mixing” a used herein specifically refers to dispersing or emulsifying a compound, such as a vitamin A compound, into a main continuous liquid phase, such as an aqueous solution of lignosulfonate. More specifically, high shear mixing is performed by using a high-speed rotor or a rotating impeller that may create flow and shear in the continuous phase, such as a rotor-stator system. Rotor-stator systems are known in the art and commercially available for example from IKA-Werke GmbH & Co. KG (Staufen, Germany) or Charles Ross and Son Company (Hauppauge, NY, USA).

[0068] Furthermore, the composition or the emulsion according to the invention may have a dynamic viscosity of at least 80 mPas, preferably as determined by means and methods known in the art and outlined elsewhere herein. More preferably, the dynamic viscosity is at least 100 mPas, at least 120 mPas or at least 140 mPas. Typically, the dynamic viscosity does not exceed 180 mPas.

[0069] The method for manufacturing the composition according to the invention further comprises a step d) of obtaining the composition; typically obtaining a composition, wherein the droplets of the vitamin A compound in the composition exhibit a droplet size D[4,3] in the range of 0.4 pm to 1 pm.

[0070] Moreover, the present invention relates to a method for producing a feed additive comprising the composition according to the invention, said method for producing a feed additive comprises at least one step of drying the composition. Said drying step may be performed as known in the art. Typically, said drying involves spray drying; bed granulation, powder-catch techniques or the like, preferably said drying is performed in the presence of a powder-coating agent. In line with the present invention, in said drying step, the composition, in particular the emulsion, may be heated to above 50 °C, preferably to a temperature around 60 °C and sprayed into a spray tower filled with the powder coating agent. More preferably, said spraying is performed at a pressure of at least 5 bar, more preferably a pressure between 8 and 12 bar. More preferably, 240920W001

[0071] - 11 - said spraying further comprises a drying step in in a fluid bed dryer, typically at room temperature, e.g. 25 °C. Hence, the method for producing a feed additive according to the invention may comprise spray drying the composition in a spray dryer, typically followed by further drying the composition in a fluid bed dryer.

[0072] In particular, the method for producing a feed additive may comprise the steps according to the method for manufacturing the composition according to the invention and at least one step of drying the composition.

[0073] By said one or more drying steps, typically a dried powder is obtained. Hence, the method for producing a feed additive may further comprise a step of obtaining a dried powder.

[0074] According to the invention, the powder coating agent may be a hydrophilic compound; such as silica or starch. Typically, the powder coating agent is present in an amount of 1 wt.-% to 7 wt.- %, more typically in an amount of 3 wt.-% to 5 wt.-% based on the dry matter of the dried powder.

[0075] Moreover, the present invention relates to a feed additive comprising, preferably consisting of, the dried powder obtained by or obtainable by the method producing the feed additive according the invention. Preferably, the residual water content of the feed additive, in particular of the dried powder is below 6 wt.-%, preferably the residual water content is between 1 and 5 wt.-%. Said residual water content may be determined by similar means as the dry matter. Said determination may involve drying a sample of the dried powder at a suitable temperature until weight consistency is reached and therefrom deducing the amount of water that has evaporated from the sample. Further details for determining the dry matter are described elsewhere herein.. In particular, the weight can typically be determined using a high precision scale as known in the art or a combined drying and weighing device such as a moisture analyzer described elsewhere herein.

[0076] Further, the invention contemplates a feed comprising the feed additive as described elsewhere herein. Moreover, it contemplates the use of the feed or feed additive according to the invention in an animal feed, in particular in a feed for ruminants, pigs, horses, rabbits, dogs, cats, mink, foxes, poultry, and in aquaculture for vitamin A supplementation.

[0077] Advantageously, it has been found in the experiments underlying the present invention that a high amount of lignosulfonate in the composition as specified herein, in combination with the small droplet size in particular exhibiting a narrow droplet size distribution and more particularly a monomodal distribution scheme increases the stability of the vitamin A in the composition. 240920W001

[0078] - 12 -

[0079] This is specifically advantageous as the use of gelatin in the composition can be avoided thereby costs can be reduced. Further, the composition being gelatin free can be used in mus- limic, halal demanding countries.

[0080] The explanations and interpretations of the terms made above apply mutatis mutandis to the embodiments described herein below.

[0081] Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged. Therein, the respective optional features may be realized in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restricted by the preferred embodiments

[0082] The following embodiments are preferred embodiments of the method of the invention:

[0083] 1. A composition comprising droplets of a vitamin A compound in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets of the vitamin A compound exhibit a droplet size D[4,3] in the range of 0.4 pm to 1 pm.

[0084] 2. The composition according to embodiment 1, wherein the composition is an oil in water emulsion.

[0085] 3. The composition according to embodiment 2, wherein the dispersed phase of the emulsion comprises, preferably consists of, the droplets of the vitamin A compound and optionally mixed with an antioxidant; and wherein the continuous phase of the emulsion comprises, preferably consists of an aqueous solution of lignosulfonate.

[0086] 4. The composition according to any of the preceding embodiments, further comprising an antioxidant in the droplets.

[0087] 5. The composition according to the preceding embodiment, wherein the antioxidant is selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tocopherol, ascorbic acid, ascorbate, salicylic acid, and derivatives or mixtures thereof.

[0088] 6. The composition according to any of the preceding embodiments, wherein the aqueous solution consists of at least 20 wt.-% of lignosulfonate in water.

[0089] 7. The composition according to any of the preceding embodiments, wherein the lignosulfonate is a Ca-lignosulfonate. 240920W001

[0090] - 13 -

[0091] 8. The composition according to any of the preceding embodiments, wherein the average molecular weight of the Ca-lignosulfonate is between 5000 and 30’000 Dalton.

[0092] 9. The composition according to any of the preceding embodiments, wherein the vitamin A compound is a compound selected from the group consisting of retinol, retinyl esters, retinal, retinoids including synthetic retinoids, and mixtures thereof; preferably vitamin A acetate and vitamin-A palmitate.

[0093] 10. The composition according to any of the preceding embodiments, wherein the solids content in the composition, preferably in the emulsion, is at least 50 wt.-%.

[0094] 11. The composition according to any of the preceding embodiments, wherein the size distribution of the droplets of the vitamin A compound is uniform, preferably mono- modal; more preferably wherein the size distribution of the droplets D[4,3] has a mon- omodal peak around of 0.3 pm to 1.0 pm.

[0095] 12. The composition according to any of the preceding embodiments, wherein the droplet size D[4,3] of the droplets of the vitamin A compound is below 1 pm, preferably below 0.9 pm, more preferably below 0.8 pm, even more preferably below 0,7 pm, still more preferably between 0,4 pm and 0.7 pm, still even more preferably between 0,5 pm and 0.7 pm.

[0096] 13. The composition according to the preceding embodiment, wherein the droplet size D[4,3] of the droplets of the vitamin A compound in the emulsion is determined by static light scattering with a Malvern Mastersizer 3000.

[0097] 14. The composition according to any of the preceding embodiments, wherein the composition, preferably the emulsion, has a dynamic viscosity of at least 80 mPas, specifically as determined by a viscometer, more specifically a using a shear velocity viscometer, still more specifically, by operating the analysis tool Rheoplus / 32 V3.40 by: Anton Paar (Anton Paar GmbH; Germany); even more specifically using the following settings: MC1 + SN253758; System Z3 DIN (25mm) d=1 mm.

[0098] 15. The composition according to any of the preceding embodiments, wherein the composition consists of said droplets of the vitamin A compound in said aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition. 240920W001

[0099] - 14 -

[0100] 16. The composition according to any of the preceding composition embodiments, wherein the composition consists of droplets of the vitamin A compound and an antioxidant in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets exhibit a droplet size D[4,3] in the range of 0.4 to 1 pm.

[0101] 17. The composition according to any of the preceding embodiments, wherein the composition comprises the vitamin A compound in an amount of at least 30 wt.-%, preferably at least 35 wt.-% more preferably, at least 40 wt.-% based on the total weight of dry matter of the composition.

[0102] 18. The composition according to any of the preceding embodiments, wherein the composition has a pH in the rage of 3 to 8.

[0103] 19. A method for manufacturing the composition according to any of the preceding embodiments, comprising the following steps: a) providing an aqueous solution of at least 20 wt.-% lignosulfonate in water; b) providing a vitamin A compound, optionally mixed with an antioxidant; c) transferring the vitamin A compound into the aqueous solution, thereby obtaining an emulsion; d) homogenizing the emulsion; preferably to obtain droplets of the vitamin A compound with a droplet size D[4,3] below 1 pm; and e) obtaining the composition.

[0104] 20. The method according to embodiment 19, wherein step e) of obtaining the composition comprises obtaining a composition wherein the droplets of the vitamin A compound in the composition exhibit a droplet size D[4,3] in the range of 0.4 pm to 1 pm.

[0105] 21. The method according to embodiment 19 or 20, wherein the lignosulfonate is Ca-lig- nosulfonate.

[0106] 22. The method according to any of embodiments 19 to 21 , wherein providing the aqueous solution in step a) comprises dissolving the lignosulfonate by stirring for a sufficient time at an elevated temperature, preferably at a temperature in the range of 50 to 70 °C; more preferably for at least several minutes.

[0107] 23. The method according to any of embodiments 19 to 22, wherein providing the vitamin A compound comprises heating a vitamin A compound , preferably vitamin A acetate, to a temperature above 60 °C. 240920W001

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[0109] 24. The method according to any of embodiments 19 to 23, wherein providing the vitamin A compound comprises heating a vitamin A compound to 70 °C or above, more preferably to about 75 °C.

[0110] 25. The method according to any of embodiments 19 to 23, wherein the step b) of providing the vitamin A compound comprises adding an antioxidant to the vitamin A compound and mixing the same; preferably the antioxidant is selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tocopherol, ascorbic acid, ascorbate, salicylic acid, and derivatives or mixtures thereof.

[0111] 26. The method according to the preceding embodiment, wherein the antioxidant, such as BHT, is added in an amount of 6 to 12 wt.% based on the total weight of dry matter of the composition.

[0112] 27. The method according to any of embodiments 19 to 26, wherein step c) comprises stirring the resulting mixture for at least several minutes to obtain an emulsion.

[0113] 28. The method according to any of embodiments 19 to 27, wherein step d) of homogenizing the emulsion comprises shear mixing the emulsion at at least 8000 ll / rnin, preferably simultaneously maintaining the temperature of the emulsion at about 60°C.

[0114] 29. A method for producing a feed additive comprising the composition according to any of embodiments 1 to 18, comprising at least one step of drying the composition; typically thereby obtaining a dried powder.

[0115] 30. The method according to embodiment 29, wherein the drying involves spray drying; bed granulation, powder-catch techniques or the like, preferably in the presence of a powder-coating agent.

[0116] 31 . The method according to embodiment 29 or 30, wherein the powder coating agent is silica or starch.

[0117] 32. A dried powder obtained by or obtainable by the method according to any of embodiments 29 to 31 .

[0118] 33. A feed additive comprising, preferably consisting of, the dried powder of claim 32.

[0119] 34. The feed additive according to the preceding embodiment or the dried powder according to claim 32, wherein the residual water content of the dried powder is below 6 wt.- %, preferably the residual water content is between 1 and 5 wt.-%.

[0120] 35. A feed comprising the feed additive according to the preceding two embodiments. 240920W001

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[0122] 36. Use of the feed or feed additive according to the preceding three embodiments in an animal feed, in particular in a feed for vitamin A supplementation in ruminants, pigs, horses, rabbits, dogs, cats, mink, foxes, poultry, and / or aquaculture.

[0123] FIGURES

[0124] Fig. 1 depicts the relative retention value of several exemplary premixes, left bar Ca lignosulfonate, right bar Na lignosulfonate.

[0125] Fig. 2 depicts the relative retention value of retention of several exemplary premixes with varying oil droplet sizes depending on solids content; solids content from left to right: 50 %, 54 %, 55 %, 58 %.

[0126] Fig. 3 depicts the relative volume density in [%] for the droplet size distribution of premixes having different solids content. Fig. 3A 54 % solid matter content; Fig. 3B 55 % solid matter content; Fig. 30 58 % solid matter content.

[0127] EXAMPLES

[0128] Example 1 - Preparation of the aqueous solution of the lignosulfonate

[0129] 663 g of demineralized / de-ionized water at a temperature of 60 °C were provided in a 2 L four- neck glass flask. 499.2 g of calcium lignosulfonate (Borrement CA120, Borregaard, Norway) or sodium lignosulfonate (Borrresperse NA220, Borregaard, Norway) were added and stirred using a blade stirrer at 300 to 600 rpm for 30 minutes at 60 °C. Further, aqueous solutions of lignosulfonate were prepared by varying the amount of added water as indicated in Table 1 below.

[0130] Example 2 - Preparation of the vitamin A compound

[0131] 430 g of vitamin A acetate, 2.7 Mio IE, were provided in a 600 mL beaker at 75 °C. The vitamin A acetate was completely dissolved. Then 93.6 g of BHT was added at 75 °C and dissolved.

[0132] Example 3 - Preparation of the emulsion 240920W001

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[0134] The vitamin A compound as prepared in example 2 was added to the four-neck glass flask containing one of the solutions of Ca lignosulfonate as prepared in example 1 and stirred for 5 to 10 minutes at 600 to 800 rpm. The resulting emulsions were cooled and homogenized at 8000 rpm in an Ultra Turrax (I KA, Germany). After 5 minutes of homogenizing, the droplets in the emulsion with a solid matter content of 58% (58.37 %) exhibited a droplet size D[4,3] of 0.9 pm; after 20 minutes the final droplet size in the emulsion was D[4,3] 0.57 pm. The solids content for the different emulsions was between 50 % and 58 % (58.37 %) as determined using a moisture analyzer HR73 from Mettler-Toledo GmbH (Germany) and according to the manufacturer’s instructions. The droplet size of the different emulsions as well as the width and uniformity is shown in Table 1 below. The viscosity was determined by using a Physic Rheolab MC1 viscometer, Anton Paar GmbH; Germany. The analysis tool Rheoplus / 32 V3.40 (Anton Paar GmbH, Germany) was used with the following settings: MC1 + SN253758; System Z3 DIN (25mm) d=1 mm. The viscosity at 60 °C was 148 MPas for the emulsion with a solid matter content of 58.37 %.

[0135] Table 1 shows emulsions / premixes prepared as outlined above with different solid matter contents.

[0136] Table 1

[0137] Example 4- Spray formulation

[0138] The emulsion obtained in example 3 was sprayed into a spray tower filled with a powder coating agent at a temperature of 60 °C and a pressure of 10 bar using an high pressure autoclave. The product was dried in a fluid bed at room temperature. The resulting dried powder (spray formulation) was used for further analysis and applications. Retention was measured as retained vitamin A in a stress premix test, as disclosed e.g. in WO 2017 / 162413 A1 , using high performance liquid chromatography (HPLC) analysis. A 100 mg sample of the dried spray formulation was carefully mixed by hand with 4 g of a test composition consisting of 60% of wheat semolina bran, 30% of choline chloride supported at 50% on silica, and 10% of trace element mixture. The trace element mixture consisted of 46% of FeSO4x7H2O, 38% of CUSO4X5H2O, 12% of 240920W001

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[0140] ZnO, and 4% of MnO. The resulting premix was stored in a climate chamber for a period of 4 weeks at 40°C , 70 % humidity and standard pressure. The vitamin A content of the premix was determined before the beginning of storage and after the end of storage. The vitamin A content was determined in accordance with Regulation (EC) No. 152 / 2009, Annex IV, Part A. The ratio between the vitamin A contents in the premix after and before storage was used to calculate the retention. Retention results are depicted in Fig. 1 and Fig. 2.

Claims

240920W001- 19 -Claims1. A composition comprising droplets of a vitamin A compound in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets of the vitamin A compound exhibit a droplet size D[4,3] in the range of 0.4 pm to 1 pm.

2. The composition according to claim 1, wherein the composition is an oil in water emulsion, preferably wherein the dispersed phase of the emulsion comprises, more preferably consists of, the droplets of the vitamin A compound optionally mixed with an antioxidant; and wherein the continuous phase of the emulsion comprises, even more preferably consists of, an aqueous solution of lignosulfonate.

3. The composition according to the preceding claim, wherein the antioxidant is selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tocopherol, ascorbic acid, ascorbate, salicylic acid, and derivatives or mixtures thereof.

4. The composition according to any of the preceding claims, wherein the lignosulfonate is a Ca-lignosulfonate, preferably wherein the average molecular weight of the Ca-lig- nosulfonate is between 5000 and 30.000 Dalton.

5. The composition according to any of the preceding claims, wherein the vitamin A compound is a compound selected from the group consisting of retinol, retinyl esters, retinal, retinoids including synthetic retinoids, and mixtures thereof; preferably selected from vitamin A acetate and vitamin-A palmitate or mixtures thereof.

6. The composition according to any of the preceding claims, wherein the solids content in the composition, preferably in the emulsion, is at least 50 wt.-%.

7. The composition according to any of the preceding claims, wherein the size distribution of the droplets of the vitamin A compound is uniform, preferably monomodal; more preferably wherein the size distribution of the droplets D [4,3] has a monomodal peak around of 0.3 pm to 1.0 pm; more preferably wherein the droplet size D[4,3] of the droplets of the vitamin A compound is below 0.9 pm, still more preferably below 0.8 pm, even more preferably below 0,7 pm, still more preferably between 0,4 pm and 0.7 pm, still more preferably between 0,5 pm and 0.7 pm; still even more preferably wherein the droplet size D[4,3] of the droplets of the vitamin A compound in the emulsion is determined by static light scattering with a Malvern Mastersizer 3000.240920W001- 20 -8. The composition according to any of the preceding claims, wherein the composition consists of droplets of a vitamin A compound and an antioxidant in an aqueous solution of at least 40 wt.-% of lignosulfonate based on the total weight of dry matter of the composition, wherein the droplets exhibit a droplet size D[4,3] in the range of 0.4 pm to 1 pm.

9. A method for manufacturing the composition according to any of the preceding claims, comprising the following steps: a) providing an aqueous solution of at least 20 wt.-% lignosulfonate in water; b) providing a vitamin A compound, optionally mixed with an antioxidant c) transferring the vitamin A compound into the aqueous solution, thereby obtaining an emulsion; d) homogenizing the emulsion; and e) obtaining the composition, typically wherein the droplets of the vitamin A compound in the composition exhibit a droplet size D[4,3] in the range of 0.4 pm to 1 pm.

10. The method according to claim 9, wherein providing the aqueous solution in step a) comprises dissolving the lignosulfonate by stirring for a sufficient time at an elevated temperature, preferably at a temperature in the range of 50 to 70 °C; more preferably for at least several minutes.11 . The method according to any of claims 9 or 10, wherein providing the vitamin A compound comprises heating the vitamin A compound, preferably vitamin A acetate, to a temperature above 60 °C.

12. The method according to any of claims 9 to 11 , wherein step c) comprises stirring the resulting mixture for at least several minutes to obtain an emulsion.

13. The method according to any of claims 9 to 12, wherein step d) of homogenizing the emulsion comprises shear mixing the emulsion, preferably high shear mixing the emulsion.

14. The method according to any of claims 9 to 12, wherein step d) of homogenizing the emulsion comprises simultaneously maintaining the temperature of the emulsion at about 60°C.

15. A method for producing a feed additive comprising the composition according to any of claims 1 to 8, comprising at least one step of drying the composition, typically thereby obtaining a dried powder.

16. A dried powder obtained by or obtainable by the method according to claim 14.

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