Synthesis method

Abstract

The present invention provides a method for synthesizing dicholine succinate (DISU) and a DISU formulation that is slightly hygroscopic or non-hygroscopic. The DISU formulation of the present invention is suitable as a food or nutritional supplement.

Description

Technical Field

[0001] The present invention relates to a method for synthesizing dicolin succinate, and foods and dietary supplements containing dicolin succinate obtained by the method.

Background Art

[0002] Choline is an essential nutrient naturally contained in some foods and available as a dietary supplement. Choline is a source of methyl groups required for many steps in metabolism. The body requires choline to synthesize phosphatidylcholine and sphingomyelin, two major phospholipids essential for cell membranes. In addition, choline is required to produce acetylcholine, a neurotransmitter important for memory, mood, muscle control, and other brain and nervous system functions. Choline also plays an important role in gene expression, cell membrane signaling, lipid transport and metabolism, and regulation of early brain development.

[0003] Choline has been shown to be a potent sensitizer of the insulin receptor in nerve cells in the form of a salt of succinic acid (dicolin succinate or DISU) (Non-Patent Document 1). Furthermore, a composition of dicolin succinate and nicotinamide is synergistically effective in increasing the levels of both NAD, ATP, and phosphocreatine in brain cells (Patent Document 1). Recently, DISU has been reported to be a potent enhancer of skeletal muscle function (Patent Document 2), and DISU has been shown to be the most potent in supporting one-carbon metabolism in humans compared to two other choline salts, choline bitartrate and choline chloride (Patent Document 3).

[0004] Supplementation of choline to foods has been proven to be beneficial to the health of both humans and breeding mammals. The production of several choline salts suitable as dietary supplements, such as choline chloride, choline bitartrate, or choline citrate / dihydrogen choline citrate, is well established, and dietary supplements containing these salts are commercially available.

[0005] Methods for preparing crystalline DISU on a laboratory scale are described in Patent Documents 4 and 5. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2019002858 [Patent Document 2] International Publication No. 2022254185 [Patent Document 3] International Publication No. 2023026043 [Patent Document 4] International Publication No. 2001076583 [Patent Document 5] International Publication No. 2009022933 [Non-patent literature]

[0007] [Non-Patent Document 1] Storozhevykh T., et al (2008) BCM Neurocsi. doi:10.1186 / 1471-2202-8-84 [Overview of the Initiative]

[0008] A method for producing the dicolin salt (DISU) of succinic acid, To obtain a solution of choline in water or in a water-miscible organic solvent selected from methanol, ethanol, 1-propanol, or 2-propanol, Furthermore, the choline solution contains one or more o-ethoxylated choline derivatives, and the amount of the one or more ethoxylated choline derivatives exceeds 0.3% by weight. Treating the choline solution with activated carbon (AC), The weight ratio of AC to Colin is approximately 100-1:1-100. Adding succinic acid or succinate to a choline solution and reacting the succinate anion with the choline cation at ambient temperature for at least 10 minutes, thereby producing DISU dissolved in water or a water-miscible organic solvent, The molar ratio of choline to succinic acid is approximately 2:1, preferably approximately 2:1.01 to approximately 2:1.1. Includes, The manufactured DISU solution is At least 40% by weight of DISU, preferably 50% by weight of DISU, and One or more o-ethoxylated choline derivatives in a maximum of 0.3% by weight, preferably less than 0.3% by weight. A method that includes [a specific component].

[0009] A second aspect of the present invention relates to a liquid formulation comprising at least 40% by weight of DISU, preferably at least 50% by weight of DISU, and one or more o-ethoxylated choline derivatives in a maximum of 0.3% by weight, preferably less than 0.3% by weight.

[0010] A third aspect of the present invention relates to a solid formulation comprising DISU and a hygroscopicity control agent (HCA), wherein the weight / weight ratio of DISU:HCA is 1:3 to 1:10, and the formulation contains one or more o-ethoxylated choline derivatives in a maximum of 0.3% by weight, preferably less than 0.3% by weight. [Modes for carrying out the invention]

[0011] The present invention provides a simple, robust, industrially scalable, and environmentally friendly method for the synthesis of dicholine succinate (DISU) and the preparation of non-hygroscopic DISU concentrates, the method comprising reacting choline (base or salt) with succinic acid (acid or salt), preferably in water, to obtain a DISU material containing at least 40% by weight of DISU and up to 0.3% by weight of an o-ethoxylated choline derivative.

[0012] The synthesis of DISU has been previously described. Patent Document 4 describes a method comprising the reaction of choline hydroxide (in methanol solution) with succinic acid and the crystallization of DISU from the reaction medium by using tert-butanol. Another previously described method (Patent Document 5) includes a series of steps for obtaining crystalline DISU. Both methods use crystallization from organic solvents as a means to obtain DISU of a purity suitable for pharmaceutical use. However, the final product, crystalline DISU, is not a stable formulation because it is highly hygroscopic, and therefore the crystalline DISU material requires specific handling and storage conditions to avoid uncontrolled water accumulation. Consequently, the described methods and the DISU products obtained by these methods are not readily applicable to large-scale industrial production of the compound and long-term shelf storage, and in addition, they have the disadvantage of being environmentally unfriendly due to the use of large amounts of organic solvents.

[0013] The present invention overcomes the drawbacks of the aforementioned method and provides a simple method for producing food-grade dicolin succinate (DISU). The method includes reacting choline cation ("choline") with divalent succinate anion ("succinic acid") in water or a water-miscible organic solvent selected from methanol, ethanol, 1-propanol or 2-propanol, with water being the preferred reaction medium, thereby obtaining a concentrated DISU solution with a DISU content of at least 40% by weight, preferably approximately 50% by weight or more. The DISU solution of the present invention has a purity comparable to crystalline DISU because the amount of impurities such as trimethylamine (TMA), ethylene oxide (EO), and their derivatives is very small. In particular, the amount of o-ethoxylated by-products of choline synthesis from TMA and EO is very small. These o-ethoxylated by-products represent the residual complexity (RC) of the choline product of the reaction between TMA and EO. The term "residual complexity" (RC) process in the context of the present invention means the subtle but important convolution of the major chemical species in the material derived from a biochemical or synthetic reaction mixture (see go.uic.edu / residualcomplexity). The RC compounds contained in choline hydroxide produced from TMA and EO are formed first through the reaction between choline and EO, and then through the further reaction between the obtained choline-EO derivative and EO, as shown below.

Chemical formula

[0014] The reaction continues and several structurally similar RC compounds can be produced. Thus, the final choline hydroxide product obtained following the reaction between TMA and EO may contain a pool of structurally related o-ethoxylated choline derivatives (RC compounds) including one or more of the compounds shown below.

Chemical formula

[0015] Typically, these by-products are present in amounts significantly exceeding 0.3% by weight in the choline hydroxide solution and are often typically from approximately 3% to approximately 10% - 15% by weight. Since these by-products are undesirable in food, they must be removed from the initial choline solution used in the DISU synthesis process of the present invention or from the final DISU product.

[0016] Methods for reducing the amount of these by-products in the choline hydroxide obtained by the above reaction are described in the prior art. Most of these methods use either a lower reaction temperature in the reaction between TMA and EO and / or a reduced amount of EO relative to the amount of TMA used in the synthesis (WO 2013098575). However, the efficiency of this method is not sufficient, and if a food-grade quality choline product is desired, the resulting choline hydroxide requires further treatment to remove these by-products. Another method previously described is to prepare choline hydroxide from choline chloride, where choline chloride is purified using a weakly acidic cation resin (US Pat. No. 3,522,296). This process seems to be more efficient but is quite complex and time-consuming. Furthermore, another method for obtaining high-purity choline hydroxide is to prepare it from other choline salts obtained by crystallization. However, this method is too complex and too costly to be considered suitable for industrial production of food-grade choline salts such as DISU and other choline derivatives.

[0017] The present invention provides an alternative method for producing DISU containing up to approximately 0.3% by weight, preferably less than 0.3% by weight, for example, approximately 0.05% to 0.1% by weight, preferably less than that, for example, 0.015% to 0.035% by weight, of RC compounds for choline hydroxide synthesis (i.e., o-ethoxylated choline derivatives such as one or more compounds of (1), (2), and (3)), and also containing, if any, only very small amounts, TMA and EO, or their derivatives such as dioxane or ethylene glycol. Surprisingly, the inventors have found that treating a choline solution containing the aforementioned o-ethoxylated choline derivatives (RC compounds) with activated carbon at an activated carbon / carbon to choline weight ratio of 100 to 1:1 to 100 is very effective in removing these compounds. Preferably, at least 1 part by weight of activated carbon (AC) is used to treat 10 parts by weight of choline (i.e., 1:10 wt / g AC to choline, i.e., 1 g of AC to treat 10 g of choline, e.g., 1:5 wt / g or 1:3 wt / g AC to choline). However, the relative amount of AC used for treatment may vary in different embodiments. In different embodiments, the preferred wt / g ratio of AC to choline may be in the range of 1 to 50:1 wt / g. In other preferred embodiments, the ratio may be in the range of 50 to 100:1 wt / g. In other preferred embodiments, the ratio of AC to choline may be 1:1 to 50 or 1:50 to 100 wt / g. The amount of AC used to efficiently remove the above impurities from the choline material will depend on the amount of these compounds (o-ethoxylated choline derivatives) present in the choline material. The amount of RC compound in the choline solution can be determined by any preferred method of the prior art, for example, the method described in Achanta, PC, et al. (2022) J Pharm Biomed Anal., 214: 114709; doi: 10.1016 / j.jpba.2022.114709. All values ​​within the indicated range are understood to be within the scope of the present invention.AC (also referred herein as “activated carbon”) treatment significantly reduces the amount of o-ethoxylated choline by-products (also referred herein as “o-ethoxylated impurities”) to less than one-tenth, e.g., less than one-hundredth, e.g., less than one-three-hundredth to one-thousandth, providing choline hydroxide containing up to 0.3% by weight of these by-products. This simple yet remarkable approach solves the problem of reducing the amount of undesirable RC products, e.g., o-ethoxylated choline derivatives, present in the starting choline material in the DISU produced from this choline material, without applying any other steps typically used to obtain high-purity DISU, such as crystallization. Nevertheless, the method allows for the crystallization of DISU from the produced DISU material, if desired, for other purposes, e.g., to obtain a non-hygroscopic solid formulation of DISU as described herein.

[0018] The methods described herein can also be advantageously used in the production of other choline salts widely used as dietary supplements, such as choline chloride, choline bitartrate, citric acid / choline dihydrogen citrate, etc.

[0019] Aspects and embodiments of the present invention are described below and illustrated by non-limiting examples. All terms and definitions presented throughout this specification relate to all aspects and embodiments of the present invention unless otherwise specified. Values ​​defined by a range are understood to include all individual values ​​within that range.

[0020] The terms "approximately" and "about" mean a deviation of only 0.01% to 10%, for example, 0.5% to 5%, from the given value.

[0021] In this context, the terms "less" and "below" are synonyms.

[0022] In this context, the term "at most" refers to all values ​​smaller than the given value.

[0023] The term "choline" ("choline cation") refers to the chemical formula C5H 14 NO + This refers to a compound having CAS number 62-49-7. In different embodiments of the present invention, choline may be in the form of a base, i.e., choline hydroxide, or in the form of a salt, such as choline chloride, (bi)choline carbonate, etc.

[0024] In this context, the term "succinate" refers to the divalent anion of succinic acid (CAS number 110-15-6).

[0025] The terms "dicholine succinate," "choline succinate (2:1)," and "DISU" are interchangeable, and formula (I) (CAS number 109438-15-5): [ka] It means the molecule.

[0026] The term "DISU material" refers to a composition containing a certain amount of the DISU compound as described above, for example, a solution of DISU in an aqueous or water-miscible solvent medium, wet crystalline DISU, DISU, and a hygroscopicity control additive (HCA). The term "humidity hygroscopicity additive / agent" refers to a hygroscopic material that helps maintain a dry state. In the context of this invention, the HCA compound is a desiccant.

[0027] The term "molar ratio" refers to the relative amount of molecules in a compound. For example, in dicholine succinate, the molar ratio of choline to succinate is 2:1.

[0028] The term "water-miscible organic solvent" means that the solvent can be mixed with water in any ratio without separation of the two phases. The term "aqueous solution" or "water solution" means water containing one or more dissolved molecules, such as choline hydroxide.

[0029] The term "activated carbon (AC)" (as used herein interchangeably with "activated carbon") means a carbonaceous adsorbent synthesized from carbonaceous materials having a high carbon content, low ash content, and considerable volatile matter by physical, chemical, or a combination of both treatments.

[0030] The term "v / v" means volume versus volume and is used in this context to describe the ratio between two liquids. The term "weight %" is interchangeable with "weight / weight" and means the mass / weight fraction of the compound of interest in a composition.

[0031] The term "derivative" refers to a compound that is derived from a similar compound through a chemical reaction.

[0032] The term "by-product" refers to a secondary product derived from a production process, manufacturing process, or chemical reaction.

[0033] The term "impurity" refers to a limited amount of chemical substances in a liquid, gas, or solid. These differ from the chemical composition of the material or compound.

[0034] The term "decomposition products" refers to chemical substances resulting from the partial or chemical breakdown of a substance.

[0035] The present invention preferably relates to food-grade purity of DISU. In the context of the present invention, the term “food-grade purity” means that the DISU obtained by the process described herein contains impurities / by-products / decomposition products such as trimethylamine (TMA), ethylene oxide (EO), ethylene glycol, glycol, chloroethanol, and dioxane in amounts of approximately 500 ppm or less (i.e., 0.05 wt%), preferably about 200 ppm to 500 ppm or less, for example, about 50 ppm to 200 ppm, about 10 ppm to 50 ppm or less, for example, about 1 ppm to 5 ppm or less. The term “ppm” or “parts per million” usually refers to a unit used to describe a very small concentration of a substance, for example, the concentration in a mixture of different substances. 1 ppm is equal to 1 milli to other units such as milligrams per liter of solution, milligrams per kilogram, etc. The latter impurities are typically choline synthesized from TMA and ethylene oxide and are often present in the compound. According to the present invention, these impurities should be removed (partially or completely) from choline as the initial material for DISU synthesis before synthesis, or from DISU obtained after synthesis from choline containing these impurities. In a preferred embodiment, the impurities are removed (completely or partially) from choline intended as the initial material for DISU synthesis. Some impurities, such as TMA or EO, ​​can be removed from an aqueous choline solution, for example, by distilling the solution under vacuum using a nitrogen sweep at a pressure of 20 mmHg and a pot temperature of about 38°C. Water may be added to the distillation pot as needed to maintain the initial volume. Distillation is continued until the TMA level in the pot liquid is reduced to less than 15 ppm, preferably less than 10 ppm, for example, about 5 ppm. Alternatively, impurities, particularly uncharged or negatively charged molecules, can be removed by treating the choline solution with an ion exchanger, such as a cation exchanger, preferably a weakly acidic cation exchanger, as described, for example, in U.S. Patent No. 3,522,396.Passing the solution over a weakly acidic cationic resin has the advantage of purifying choline by removing amineralized impurities, including volatile amines such as monomethylamine, dimethylamine, and trimethylamine, as well as fixed amines such as the amines formed by the first two o-ethoxylations mentioned above. All of these amines are considerably more hydrophobic and weakly basic than choline. By passing an excess solution over the cationic resin, the initially fixed amines are gradually replaced by choline, which has a greater affinity for the resin, and the amines migrate into the effluent. In addition, uncharged impurities should also be removed in this pass. Furthermore, the present invention provides a method for removing other organic impurities, such as o-ethoxylated choline byproducts (RC compounds), from choline produced via the reaction of TMA and EO, where the choline solution is treated with AC. AC efficiently adsorbs these impurities, significantly reducing their amount in the choline material intended for the synthesis of DISU to a desired maximum of 0.3 wt%. The AC treatment can be performed before or after treatment with a weakly cationic resin and / or distillation. In a preferred embodiment, the o-ethoxylated compound is removed by treating the choline hydroxide solution with AC, following the step of removing TMA and EO by distillation as described above in one or repeated treatments, as further described in the specification.

[0036] The term "aqueous medium" means an aqueous solution of water or one or more chemical substances.

[0037] In the context of the present invention, the term “water miscible solvent” means an organic solvent that can be mixed with water to form a homogeneous mixture (i.e., without substantial phase separation), for example, in one embodiment of the present invention, an alcohol containing one to three carbon atoms, such as methanol, ethanol, propanol (including 2-propanol and 1-propanol), or in another embodiment of the present invention, acetone.

[0038] A first aspect of the present invention is a method for producing the dicolin salt (DISU) of succinic acid, To obtain a solution of choline in water or in a water-miscible organic solvent selected from methanol, ethanol, 1-propanol, or 2-propanol, Furthermore, the choline solution contains one or more o-ethoxylated choline derivatives, and the amount of the one or more ethoxylated choline derivatives exceeds 0.3% by weight. Treating the choline solution with activated carbon (AC), The weight ratio of AC to choline is 100 to 1:1 to 100, and preferably the weight / weight ratio of AC to choline is 50 to 1:1 to 50, for example, 10 to 1:1 to 10. Adding succinic acid or succinate to a choline solution and reacting the succinate anion with the choline cation at ambient temperature for at least 10 minutes, thereby producing DISU dissolved in water or a water-miscible organic solvent, The molar ratio of choline to succinic acid is approximately 2:1, for example, approximately 2:1.01 to approximately 2:1.1. Includes, The present invention relates to a method for producing a solution of DISU containing at least 40% by weight, preferably about 50% by weight of DISU, and a maximum of 0.3% by weight, preferably less than 0.3% by weight, for example about 0.2% by weight, for example 0.05% to 0.15% by weight or less, for example about 0.015% to 0.035% by weight of one or more of the above o-ethoxylated choline derivatives.

[0039] According to the present invention, reducing the amount of one or more o-ethoxylated choline derivatives, particularly monoethoxylated, diethoxylated, and triethoxylated choline, involves treating a choline solution, preferably a solution treated by distillation to remove residual TMA and EO, with activated carbon (AC). In different embodiments, AC can be used in any form: powder, granules, or in cartridge form. AC is commercially available from several manufacturers. Preferably, AC is used in cartridge form. The amount of AC used for treatment is at least 1 part by weight per 10 parts by weight of choline (i.e., 1:10 by weight / weight, 1 g of AC for treatment of 10 g of choline, for example, 1:5 by weight / weight or 1:3 by weight / weight). In some embodiments, the AC treatment of the choline solution may be repeated as many times as necessary to obtain a final choline solution in which the amount of these byproducts is at most 0.3% by weight, preferably less than 0.3% by weight, for example less than 0.2% by weight, for example about 0.05% to 0.15% by weight, for example about 0.015% to 0.035% by weight. According to the present invention, the AC treatment reduces the amount of these impurities in the final choline solution (i.e., the solution used for DISU synthesis) to at least 1 / 10 to 1 / 100, for example 1 / 100 to 1 / 500, or 1 / 500 to 1 / 1000.

[0040] Preferably, prior to treatment with AC, the choline solution is distilled under vacuum using a nitrogen sweep at a pressure of 20 mmHg and a pot temperature of about 38°C to remove TMA and EO.

[0041] In one preferred embodiment, the choline solution is a solution of choline hydroxide in water. However, embodiments in which choline hydroxide is dissolved in a water-miscible solvent are also within the scope of the present invention. Preferred water-miscible solvents of the present invention include methanol, ethanol, and 1-propanol or 2-propanol, or mixtures thereof. In embodiments in which choline hydroxide is dissolved in a water-miscible solvent, the DISU solution obtained by synthesis is a solution of DISU in the corresponding water-miscible solvent, with a DISU content of at least 50% by weight. These embodiments of the DISU solution may have advantages when a non-hygroscopic solid formulation of DISU is to be prepared. Organic solvent-based DISU solutions can facilitate the dissolution of hygroscopicity control additives (HCAs) in these solutions and the drying of the prepared blend to obtain a solid formulation of DISU, such as those described below herein.

[0042] Embodiments of the present invention also include the use of a choline solution, such as a solution of choline salt in water or in a water-miscible solvent selected from methanol, ethanol, 1-propanol, 2-propanol, or mixtures thereof. In these embodiments, the method of the present invention is Adding a base to a choline salt solution to obtain a solution containing choline hydroxide and the salt, Add succinic acid to a solution of choline hydroxide and its salt, and react the succinate anion with the choline cation at ambient temperature for at least 10 minutes to form DISU. The molar ratio of choline cation to succinate anion is approximately 2:1, for example, approximately 2:1.01 to approximately 2:1.1. Removing salt from the DISU solution, Includes.

[0043] The preferred choline salts of the present invention are choline bicarbonate, choline chloride, or choline carbonate. These choline salts are commercially available. The base used to convert the choline salt to choline hydroxide is preferably an inorganic base, such as sodium hydroxide, potassium hydroxide, or ammonium hydroxide. In a preferred embodiment, the salt obtained by this conversion is sodium carbonate or potassium carbonate, or sodium chloride or potassium chloride, wherein the choline solution is choline bicarbonate / choline carbonate or choline chloride, respectively, and the base is sodium hydroxide or potassium hydroxide. The salt is ammonium carbonate, wherein the choline solution is choline bicarbonate / choline carbonate, and the base is ammonium hydroxide. The resulting salt is an undesirable byproduct of the described reaction and should be removed from the choline hydroxide solution before or after the reaction with succinic acid. Since salts such as sodium carbonate or potassium carbonate, or sodium chloride or potassium chloride are insoluble in organic solvents, it may be advantageous to add an organic solvent to the reaction mixture of choline hydroxide and succinic acid to precipitate the salt. Therefore, in one preferred embodiment, the succinic acid added to the choline hydroxide solution is a solution of succinic acid in ethanol, methanol, or 1-propanol or 2-propanol. In another preferred embodiment, the choline solution is a solution of a choline salt such as choline chloride or (bi)choline carbonate in methanol, ethanol, or 1-propanol or 2-propanol, and the added succinic acid is an aqueous solution of succinic acid or crystalline succinic acid. The precipitated salt can be easily removed from the reaction medium by filtration. In one preferred embodiment, the choline salt is a solution of (bi)choline carbonate in water, and the base is ammonium hydroxide. The by-product salt obtained in this embodiment, ammonium carbonate, may be removed by heating the solution containing it to approximately 55°C. In one embodiment, ammonium carbonate is removed from the choline hydroxide solution before the addition of succinic acid, and in another embodiment, ammonium carbonate is removed from the reaction mixture containing DISU.

[0044] According to the present invention, the obtained DISU material contains at least 40% by weight of DISU, preferably about 50% by weight of DISU. The DISU material can be concentrated, for example, by vacuum evaporation, to a maximum of about 70% by weight of DISU, for example, about 69% by weight of DISU (corresponding to DISU octahydrate, i.e., DISU with 8 molecules of water) or about 72% by weight of DISU (corresponding to DISU heptahydrate, i.e., DISU with 7 molecules of water). This concentrated DISU material corresponds to DISU octahydrate, which is a very stable formulation, i.e., it has a shelf life of at least 6 months without significant change in composition under high humidity and ambient temperature conditions of 25°C to 40°C. The 40% to 70% by weight DISU solution produced according to the present invention is slightly hygroscopic, meaning that the weight increase of the DISU material maintained at 25°C ± 1°C and 80% ± 2% relative humidity (RH) for 24 hours is at most 2% (weight / weight), preferably about 1.5%, for example about 1% or less, for example about 0.2% to 0.5% (weight / weight).

[0045] In one embodiment, the liquid content in the obtained DISU material can be reduced by DISU precipitation. Preferably, the DISU precipitate is Add at least 2 volumes of acetone to the DISU solution and incubate the mixture at 10°C to 15°C for 3 to 6 hours. Collecting the DISU precipitate using Nucche filtration, The DISU precipitate collected by the Nucche filter is dried, It is obtained by [method].

[0046] According to the present invention, the dried DISU material is preferably used in the preparation of a non-hygroscopic dried formulation of DISU. This preparation is typically carried out by, Dissolving dried DISU in an organic solvent, preferably methanol, ethanol, 1-propanol, 2-propanol, or a mixture thereof, Mixing the DISU solution with one or more hygroscopic control agents (HCAs), The solvent is removed by drying the mixture, thereby obtaining a non-hygroscopic solid formulation of DISU. Includes.

[0047] According to the present invention, one or more HCAs are preferably selected from microcrystalline cellulose, ethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, ethylmethylcellulose, or mixtures thereof.

[0048] Typically, DISU is mixed with HCA at a DISU:HCA weight / weight ratio of 1:3 to 1:8, preferably about 1:3 to 1:4.

[0049] Accordingly, one aspect of the present invention is a slightly hygroscopic or non-hygroscopic formulation of the DISU material obtained by the method of the present invention. In a preferred embodiment, the slightly hygroscopic formulation of DISU is approximately 30% by weight of water or a water-miscible organic solvent selected from methanol, ethanol, or 1-propanol or 2-propanol. In a preferred embodiment, the non-hygroscopic solid formulation of DISU contains DISU and HCA in a weight / weight ratio of DISU to HCA of about 1:3 to about 1:8, preferably about 1:3 to 1:4 by weight / weight. HCA is preferably one or more compounds selected from microcrystalline cellulose, ethylcellulose, hydroxypropyl, or mixtures thereof.

[0050] Further embodiments of the above method and the composition of the present invention are described below.

[0051] The synthesis of DISU is typically carried out in a medium containing approximately 2 moles of choline (i.e., choline cations) and approximately 1 mole of succinic acid (i.e., divalent succinate anions), where the molar ratio of choline to succinic acid in the reaction mixture is approximately 1.9 to 2:1 to 1.1, for example, 2:1, 1.95:1, 2:1.01, etc. Preferably, succinic acid (divalent succinate anions) is present in the reaction medium in a molar excess relative to the molar amount of choline cations to ensure the formation of dicolin succinate and avoid the formation of monocholine succinate.

[0052] The reaction between succinic acid and choline typically takes at least 10 minutes at ambient temperature, but if necessary for manufacturing purposes, the reaction time may be extended to a longer period. Extending the reaction time does not lead to the formation of undesirable byproducts.

[0053] The initial compounds of the reaction are a solution of choline hydroxide or a solution of choline salt and succinic acid, and the reaction is preferably carried out in an aqueous medium. In another preferred embodiment, succinic acid is preferably used in its crystalline form, and choline hydroxide / salt is used as an alcoholic solution, such as methanol, ethanol, or 2-propanol. Crystalline succinic acid and aqueous and alcoholic solutions of choline are both commercially available. Preferably, the commercially available compounds used in the reaction are of food-grade purity. Alternatively, the choline hydroxide solution can be purified before the reaction using the method described above.

[0054] Therefore, in one embodiment, the method for synthesizing DISU according to the present invention is To provide an aqueous solution of choline hydroxide and crystalline succinic acid, Optionally, purify the choline hydroxide solution to food-grade quality, The mixture of choline hydroxide and succinic acid contains approximately 2 moles of choline and approximately 1 mole of succinic acid, preferably 1.01 to 1.1 moles of succinic acid per mole of choline, by adding succinic acid to the solution of choline hydroxide, thereby reacting the choline with succinic acid to obtain a solution of DISU in water. Includes.

[0055] In another embodiment, the initial choline hydroxide solution is in methanol, ethanol, or 1-propanol or 2-propanol, and the method for synthesizing DISU according to the present invention is To provide a solution of choline hydroxide in methanol, ethanol, or 1-propanol or 2-propanol, or a mixture thereof, and crystalline succinic acid, Optionally, the choline hydroxide solution may be purified to food-grade quality as described above. The succinic acid is added to a solution of choline hydroxide so that the mixture of choline hydroxide and succinic acid contains approximately 2 moles of choline and approximately 1 mole of succinic acid, preferably 1.01 to 1.1 moles of succinic acid per mole of choline, thereby reacting the choline with the succinic acid to obtain a solution of DISU in methanol, ethanol, 1-propanol, or 2-propanol, or a mixture thereof. Includes.

[0056] In one embodiment, the method for synthesizing DISU according to the present invention includes providing a solution of choline hydroxide containing less than 0.3% by weight of an o-ethoxylated choline derivative for further use in the DISU synthesis process. Such a solution of choline hydroxide is provided according to the present invention by treating a solution of choline hydroxide containing more than 0.3% by weight of an o-ethoxylated choline derivative with AC as described above, or alternatively, by reacting an alcoholic solution of food-grade choline chloride, such as a 2-propanol solution or aqueous solution, with sodium hydroxide. Therefore, in this embodiment, the method of the present invention is To provide a solution of choline chloride in methanol, ethanol, 1-propanol, or 2-propanol, The process involves adding sodium hydroxide to a solution of choline chloride, thereby obtaining a solution of choline hydroxide in 2-propanol and a precipitate of sodium chloride. The removal of sodium chloride precipitate from a choline hydroxide solution, The succinic acid is added to a solution of choline hydroxide so that the mixture of choline hydroxide and succinic acid contains approximately 2 moles of choline and approximately 1 mole of succinic acid, thereby reacting the choline with the succinic acid to obtain a solution of DISU in 2-propanol. Includes.

[0057] Food-grade choline chloride is commercially available and usually does not require further purification. However, if necessary, choline chloride can be purified using a weakly acidic cation exchanger and treated with AC (as described above).

[0058] Choline chloride dissolved in water or alcohol, preferably 2-propanol, is converted to choline hydroxide by adding an equimolar amount of sodium hydroxide, thereby providing a solution of choline hydroxide in water or alcohol.

[0059] The reaction between choline chloride and sodium hydroxide can be carried out at or near room temperature. However, in some embodiments, the reaction can also be carried out at 25°C to 50°C. The reaction time is typically about 3 to 6 hours.

[0060] The sodium chloride precipitate formed by the reaction between choline chloride and sodium hydroxide in a 2-propanol or aqueous medium is removed from the reaction medium containing choline hydroxide before the choline hydroxide solution proceeds to a further step, namely the step of reacting choline with succinic acid.

[0061] To remove the sodium chloride precipitate formed in the 2-propanol reaction medium, the reaction medium, containing the suspension of dissolved choline hydroxide and sodium chloride precipitate, may be subjected to filtration, centrifugation, or another preferred procedure for separating the precipitated material from the liquid medium. In a preferred embodiment, the solution is filtered using a Nutche filtration. Following filtration, the liquid phase that has passed through the filter containing choline hydroxide is collected and proceeds to the synthesis step of DISU in the reaction of choline with succinic acid. The precipitated sodium chloride material may be further washed with 2-propanol to extract any remaining choline hydroxide, which is then combined with the main fraction collected following filtration.

[0062] To remove sodium chloride from an aqueous reaction medium in which both choline hydroxide and sodium chloride are dissolved, an excess amount of a solvent in which sodium chloride is insoluble and choline hydroxide is soluble is added to the reaction medium. Preferably, the solvent is 2-propanol. Preferably, the aqueous reaction medium is treated to reduce its water content before the addition of 2-propanol, for example, by air-drying, vacuum-drying, water evaporation, nanofiltration, reverse osmosis, spray-drying, freeze-drying, or other methods suitable for the purpose. Typically, about 7 to 10 volumes of 2-propanol are added to 1 volume of aqueous solution to precipitate the dissolved sodium chloride. In addition to desalting the aqueous reaction medium with 2-propanol, other desalting methods known in the art can be applied.

[0063] In the next step of the process, succinic acid is added to the filtered solution of choline hydroxide. The succinic acid used in DISU synthesis may be a crystalline material or a succinic acid solution, preferably a solution in 2-propanol. Typically, succinic acid in solid form is added to the solution in an amount that achieves a choline-to-succinic acid molar ratio of about 2:1.

[0064] Typically, in all the embodiments of the method of the present invention described above, the reaction of choline with succinic acid is carried out at room temperature (i.e., approximately 19°C to 25°C) under constant stirring for approximately 10 to 60 minutes to 2 to 3 hours. However, the reaction can also be carried out at other temperatures, and both temperatures below and above the indicated temperatures can be applied (for example, any temperature in the range of 10°C to 50°C can be used). The yield of DISU obtained from the reaction is usually approximately 100%.

[0065] In a preferred embodiment, both of the above methods may further include a step of reducing the content of the reaction medium (i.e., DISU solvent) in the obtained DISU material. The reduction in one embodiment can be achieved by obtaining solid DISU, such as crystalline or amorphous solid DISU, or by obtaining a concentrated solution of DISU. Preferably, the concentrated solution of DISU is a slightly hygroscopic aqueous solution of DISU.

[0066] The term "slightly hygroscopic solution" means a solution that does not absorb a significant amount of water from the surrounding environment, where "significant amount" means the amount of water absorbed that increases the mass of a sample of the compound by no more than 2% after being stored for 24 hours at approximately 80% relative humidity and approximately 25°C. In this context, the term "concentrated solution" means an aqueous solution containing more than 40% by weight of DISU, preferably more than 50% by weight of DISU, preferably 55% to 68% by weight of DISU, for example, approximately 70% by weight of DISU, for example, 69% by weight of DISU, or 72% by weight of DISU. The concentrated DISU solution according to the present invention is a slightly hygroscopic solution.

[0067] A procedure for obtaining an aqueous, slightly hygroscopic DISU solution, i.e., a solution containing more than 40% by weight of DISU, preferably at least 50% by weight, for example 55% to 68% by weight of DISU, for example about 70% by weight of DISU, for example 69% by weight of DISU, or 72% by weight of DISU, may include one or more water reduction steps, for example, by using air drying, vacuum drying, water evaporation, nanofiltration, reverse osmosis, spray drying, freeze-drying, or other methods suitable for the purpose of the DISU solution. In one embodiment, a slightly hygroscopic concentrated aqueous DISU solution can be obtained from crystalline DISU. Crystalline DISU can be obtained from either an aqueous or alcoholic solution of DISU, preferably from an alcoholic DISU solution, preferably from an alcoholic DISU solution containing 2-propanol, by mixing the DISU solution with acetone.

[0068] DISU synthesized by any embodiment of the above method can optionally be precipitated from the reaction medium in crystalline form by mixing the reaction medium with acetone. Preferably, the reaction medium containing dissolved DISU is concentrated (5 to 20 times) before being mixed with a precipitant, preferably acetone. Excess solvent can be removed by any preferred method, such as evaporation. The 5 to 20 times concentrated DISU solution is then mixed with an equal volume of acetone, preferably about 2 to 10 volumes, and maintained with stirring at a temperature of about 10°C to 15°C for 2 to 3 hours. Preferably, DISU is precipitated from an alcohol solution, such as 2-propanol or a mixture of 2-propanol with methanol, ethanol, or 1-propanol.

[0069] When a DISU solution is mixed with chilled acetone, crystalline DISU is obtained suspended in the reaction mixture. The suspension of crystalline DISU is first subjected to filtration to collect the solid. Preferably, the solid material is collected using Nutsche filtration. The term "Nutsche filtration" refers to a batch filtration technique that uses vacuum and / or pressure in a closed container ("Nutsche filter"). Pressure / vacuum is used in combination with a filter plate fitted with appropriate filter media, forcing the liquid to pass through the media to form a solid bed often called a "cake".

[0070] The DISU cake is then dried to remove the liquid. The dried DISU cake can optionally be repeatedly washed with cold acetone and dried again.

[0071] Crystalline DISU is highly hygroscopic and must be stored under non-humid conditions. The dried DISU material collected from the Nucche filter must be immediately sealed in a sealed container. If long-term storage of DISU is required, crystalline DISU should preferably be formulated as heptahydrate or octahydrate DISU (i.e., a formulation containing one DISU molecule and seven or eight water molecules), which corresponds to a liquid composition of DISU containing approximately 70% by weight of DISU and 30% by weight of water. Concentrates can be prepared by adding an amount of water to the dried crystalline DISU to create a solution with the desired wt% of DISU directly in the Nucche filter.

[0072] Alternatively, according to the present invention, the obtained crystalline DISU can be mixed with a compound that can control the hygroscopicity of DISU in a solid mixture form. For example, dry crystalline DISU can be dissolved in alcohol, preferably anhydrous ethanol, and mixed with a powder or alcohol solution of microcrystalline cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, ethyl methylcellulose, or a mixture thereof, and then dried. The resulting dried formulation has much lower hygroscopicity and can be transported and stored without special precautions regarding ambient humidity. In a preferred embodiment, crystalline DISU is formulated in a mixture of microcrystalline cellulose and hydroxypropyl cellulose (or hydroxypropyl methylcellulose) in a w / w ratio of 1:3 to 6:0.3 to 0.4 (wherein DISU:microcrystalline cellulose:hydroxypropyl cellulose (or hydroxypropyl methylcellulose)). The dried powder containing the mixture of DISU and cellulose derivatives may optionally further contain succinic acid in an amount that stabilizes DISU in the formulation, and silica in an amount that provides further control of the hygroscopicity of the composition. Typically, the amount of succinic acid added to the composition is about 2.5% of the DISU amount, and the amount of silica added is about 7% to 10% of the DISU amount.

[0073] The solid-state dry formulations of DISU of the present invention (as described above) are substantially non-hygroscopic; that is, a dry material stored at 80% relative humidity and 25°C for 24 hours will only increase in mass by 0% to 0.012% w / w or less. All components of these compositions are non-toxic and approved as food additives by the EFSA and FDA, so the compositions can be easily sealed in edible capsules (e.g., gelatin or hydroxypropyl methylcellulose (HPMC)) and sold as DISU dietary supplements. Such encapsulation of the described solid formulations of DISU further reduces the risk of moisture absorption by DISU without reducing its bioavailability. Non-limiting examples of such solid formulations of DISU are described in the examples.

[0074] A solution and reaction medium containing choline hydroxide, choline chloride or other choline salts, succinic acid, and DISU can be treated with AC as many times as necessary to obtain the desired DISU material containing up to 0.3% by weight of an o-ethoxylated choline derivative. [Examples]

[0075] The following examples are for illustrative purposes only and do not limit the scope of the present invention in any way.

[0076] Example 1. Process for producing DISU from choline chloride and succinic acid in a reaction medium containing 2-propanol 2-propanol was added to a jacketed reactor equipped with a temperature control system and a stirrer. The temperature was set to 25°C to 50°C, and when the temperature reached 40±1°C, choline chloride (food grade) was added. The mixture was kept stirred until the choline chloride was completely dissolved. Sodium hydroxide was then added, and the mixture was kept stirred at a temperature of 25°C to 50°C for 6 hours. After the holding time was complete, the reaction mass was filtered through a monoplate filter. The sodium chloride precipitate was pressed and rinsed with 2-propanol. The filtrate was transferred to a jacketed reactor equipped with a temperature control system and a stirrer.

[0077] The filtrate from the previous step was heated to 25°C-50°C. Crystalline succinic acid was added (approximately a 1:2 molar ratio of succinic acid to choline), completely dissolved, and the mixture was maintained under stirring for 3 hours. After the holding time was complete, the solution was filtered through an activated carbon filter cartridge.

[0078] The filtered solution was concentrated to its residual volume (by evaporation in a vacuum) and transferred to a reactor containing approximately 3 volumes of acetone (pre-cooled to 10°C-15°C). The distilled 2-propanol was transferred to a collection container. The reaction mixture was maintained under stirring at a temperature of 10°C-15°C for 3 hours.

[0079] The formed precipitate was filtered through a Nütsche filter, pressed, and rinsed with a 2-propanol:acetone (1:2) mixture. A wet precipitate with residual solvent was obtained. Both the mother liquor and the rinse liquid were collected in a collection container. Crude DISU was formed.

[0080] DISU was dissolved in a Nutsche filter containing a wet precipitate of DISU. The solution of DISU in 2-propanol was transferred to a reactor containing acetone pre-cooled to approximately 10°C. The reaction mixture was kept agitated for 3 hours while maintaining the temperature within the range of 10°C to 15°C. The formed precipitate was filtered through the Nutsche filter, pressed, and rinsed with a 2-propanol / acetone mixture (1:2). A wet precipitate of DISU with residual solvent was obtained. Both the mother liquor and rinse liquid were collected in collection containers. The filtered cake was then dried under vacuum and a nitrogen atmosphere. Purified DISU was formed.

[0081] After the drying process is complete, the dried DISU precipitate on the Nucche filter is dissolved in purified water to obtain the target DISU content (at least 50% by weight), or formulated as described in Example 4. Analysis of the sample by HPLC and Q-NMR revealed no detection of o-ethoxylated choline impurities.

[0082] Example 2. Process for producing DISU from choline hydroxide and succinic acid in an aqueous medium. An aqueous solution of non-food grade choline hydroxide (45% to 55% choline) was distilled under vacuum using a nitrogen sweep at a pressure of 20 mmHg and a pot temperature of approximately 38°C. Following distillation, the solution was treated with powdered activated carbon (AC) (10% by weight, stirred at ambient temperature for 1 hour), filtered, and the filtrate was heated to 20°C to 50°C. Crystalline succinic acid was added (approximately a 1:2 molar ratio of succinic acid to choline), and the mixture was maintained under stirring for 15 minutes until all succinic acid was dissolved. After the holding time was complete, the solution was filtered through an AC filter cartridge, and samples of the filtered solution were taken for analysis by HPLC and Q-NMR. Analysis showed that the sample contained approximately 50% DISU and approximately 0.1% o-ethoxylated choline derivatives, and no TMA was detected. The amount of o-ethoxylated choline derivatives in the DISU sample was reduced to approximately 1 / 100th of their amount in the initial aqueous solution of choline hydroxide, and TMA was completely removed by AC treatment.

[0083] The prepared 50% by weight DISU solution was stored in a sealed container at room temperature, or used as described below for the preparation of DISU octahydrate material (60% to 70% by weight DISU solution) or a non-hygroscopic solid formulation of DISU (see Example 4).

[0084] The filtered 50 wt% DISU solution was then concentrated to its residual volume (by evaporation in a vacuum), mixed with 2-propanol (1 v / v), and transferred to a reactor containing acetone (3-5 v / v, pre-cooled to 10°C-15°C). The reaction mixture was maintained under stirring at approximately 10°C for 3 hours.

[0085] The formed precipitate was filtered through a Nütsche filter, pressed, and rinsed with a 2-propanol:acetone mixture (1:2 v / v). A wet precipitate of DISU containing residual solvent was obtained. Both the mother liquor and the rinse liquid were collected in a collection container.

[0086] DISU was suspended in a Nutsche filter containing a wet precipitate of crude DISU by adding 2-propanol. The DISU solution suspension in 2-propanol was transferred to a reactor containing acetone (1:2 v / v) pre-cooled to 10°C to 15°C. The reaction mixture was kept agitated for 3 hours while maintaining the temperature within the range of 10°C to 15°C. The formed precipitate was filtered through the Nutsche filter, pressed, and washed with the 2-propanol / acetone mixture. The wet precipitate of DISU containing residual solvent was then rinsed. After the drying process was complete, the dried DISU precipitate on the Nutsche filter was dissolved in purified water to the target DISU content (to at least 50% by weight) or formulated as described in Example 4. Analysis of the DISU samples showed that the amount of o-ethoxylated choline derivative had further decreased to approximately 0.03% to 0.05% by weight.

[0087] Example 3. Process for producing DISU from choline hydroxide and succinic acid in a reaction medium containing ethanol or methanol. A solution of non-food grade choline hydroxide (approximately 50% by weight) in ethanol (or methanol) was heated to 25°C to 50°C. Crystalline succinic acid was added (succinic acid:choline molar ratio of approximately 1.01 to 1.1:2). Optionally, the solvent was evaporated to concentrate the choline solution to the residual volume, and 2-propanol was added to prepare a choline hydroxide solution in 2-propanol. Then, crystalline succinic acid was added to the prepared choline hydroxide solution. The succinic acid was dissolved in the choline hydroxide solution, and the mixture was maintained under stirring for 3 hours. After the holding time was complete, the solution was filtered through an activated carbon filter cartridge.

[0088] The filtered solution was concentrated to its residual volume (by evaporation in a vacuum) and transferred to a reactor containing 2 to 10 volumes of acetone, pre-cooled to 10°C to 15°C. The reaction mixture was maintained under stirring at 10°C to 15°C for 3 hours.

[0089] The formed precipitate was filtered through a Nutsche filter, pressed, and rinsed with a 2-propanol:acetone mixture. A wet precipitate with residual solvent was obtained. Both the mother liquor and rinse liquid were collected in a collection container. Crude DISU was formed. 2-propanol was added to the Nutsche filter containing the wet precipitate of DISU, and the DISU suspension in 2-propanol was transferred to a reactor containing acetone pre-cooled to 10°C-15°C. The reaction mixture was kept agitated for 3 hours while maintaining the temperature within the range of 10°C-15°C. The formed precipitate was filtered through a Nutsche filter, pressed, and rinsed with a 2-propanol / acetone mixture (1:2). A wet precipitate with residual solvent was obtained. Both the mother liquor and rinse liquid were collected in a collection container. The filtered cake was then dried under vacuum and a nitrogen atmosphere. Purified DISU was formed.

[0090] After the drying process was completed, the dried DISU precipitate on the Nucche filter was dissolved in purified water to obtain the target DISU content (at least 50% by weight), or formulated as described in Example 4. Analysis of the 50% by weight DISU solution by HPLC and Q-NMR revealed no detection of o-ethoxylated choline derivatives.

[0091] Example 4. Preparation of slightly hygroscopic and non-hygroscopic formulations of DISU 4.1. Water concentrate of DISU After the final drying step of the DISU cake in the Nucche filter (obtained as described in Examples 1 to 3) is completed, purified water is added to the dried precipitate until the target DISU content (72% by weight DISU) is reached. The hygroscopicity of the DISU material was measured after storage in an incubator at 80% relative humidity and 25°C for 24 hours. The formulation showed a mass increase of approximately 1.8%. Therefore, the 72% by weight DISU concentrate is slightly hygroscopic.

[0092] 4.2. Solid Dosage Forms of DISU Dried DISU precipitate (obtained as described in Examples 1 to 3) was dissolved in anhydrous ethanol (2.5 to 3 weight equivalents of DISU), and the DISU solution was mixed with crystalline succinic acid (0.02 to 0.03 weight equivalents of DISU), hydroxypropyl cellulose (2.5 to 3.5 weight equivalents of DISU), microcrystalline cellulose (7 to 10 weight equivalents of DISU), and silica (0.1 to 0.2 weight equivalents of DISU). The mixture was air-dried to obtain a solid formulation of DISU.

[0093] The hygroscopicity of the DISU solid formulation was evaluated after storage in an incubator at 25°C with 80% relative humidity for 24 hours. The formulation did not show any increase in mass.

Claims

1. A method for producing dicholine salt (DISU) of succinic acid, To obtain a solution of choline in water or in a water-miscible organic solvent selected from methanol, ethanol, 1-propanol, or 2-propanol, Furthermore, the choline solution contains one or more o-ethoxylated choline derivatives, and the amount of the one or more ethoxylated choline derivatives exceeds 0.3% by weight; The choline solution is treated with activated carbon (AC), The weight ratio of AC to koline is 100 to 1:1 to 100; Add succinic acid or succinate to the choline solution, react the succinic acid with choline at ambient temperature for at least 10 minutes, thereby producing DISU dissolved in water or the water-miscible organic solvent. The molar ratio of choline to succinic acid is approximately 2:1, preferably approximately 2:1.01 to approximately 2:1.

1. Includes, The solution of the manufactured DISU is At least 40% by weight of DISU, preferably 50% by weight of DISU, and A maximum of 0.3% by weight of one or more of the above o-ethoxylated choline derivatives, A method that includes [a specific component].

2. The method according to claim 1, wherein the weight ratio of AC to choline is 10 to 1:1 to 10.

3. The method according to claim 1 or 2, wherein the choline solution is a solution of choline hydroxide in water or the water-miscible solvent.

4. The choline solution is a solution of a choline salt in water or the water-miscible solvent, and the method is The choline salt solution is treated with activated carbon (AC), The weight ratio of AC to koline is 100 to 1:1 to 100; The base is added to the choline salt solution to obtain a solution containing choline hydroxide and by-product salts, Add succinic acid to the solution of choline hydroxide and salt, and react the succinic acid with choline at ambient temperature for at least 10 minutes to form DISU. The molar ratio of choline to succinic acid is 2:1.01 to 2:1.

1. To remove the by-product salt from the DISU solution, The method according to claim 1 or 2, including the method described in claim 1 or 2.

5. The method according to claim 4, wherein the choline salt is selected from choline chloride, choline bicarbonate, or choline carbonate.

6. The method according to claim 4 or 5, wherein the base is selected from sodium hydroxide, potassium hydroxide, or ammonium hydroxide.

7. The method according to any one of claims 1 to 6, further comprising the step of obtaining a DISU material in which the liquid content has been reduced.

8. The method according to claim 7, wherein the DISU material with reduced liquid content is a DISU solution containing at least 50% by weight of DISU, preferably about 60% to 70% by weight of DISU.

9. The method according to claim 7, wherein the DISU material with reduced liquid content is a DISU precipitate.

10. The DISU precipitate is A DISU precipitate is obtained by mixing at least 2 volumes of acetone with the DISU solution containing at least 50% by weight of DISU, and incubating the mixture at 10°C to 15°C for 3 to 6 hours. The DISU precipitate is collected using Nütsch filtration, The DISU precipitate collected by the Nucche filter is dried, The method according to claim 9, obtained by...

11. The method according to claim 10, further comprising dissolving the dried DISU precipitate in water to prepare a liquid formulation of DISU containing approximately 70% by weight of DISU.

12. The dried DISU precipitate is dissolved in a water-miscible solvent, preferably methanol, ethanol, 1-propanol, or 2-propanol, or a mixture thereof. The DISU solution is mixed with one or more hygroscopicity control additives (HCAs), The solvent is removed by drying the mixture, thereby obtaining a non-hygroscopic solid formulation of DISU. The method according to claim 10, further comprising:

13. The method according to claim 12, wherein the one or more HCAs are selected from microcrystalline cellulose, ethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, ethylmethylcellulose, or a mixture thereof.

14. The method according to claim 12 or 13, wherein DISU is mixed with HCA in a DISU:HCA weight / weight ratio of 1:3 to 1:

10.

15. A liquid formulation comprising at least 40% by weight of DISU, preferably at least 50% by weight of DISU, and up to 0.3% by weight of one or more o-ethoxylated choline derivatives.

16. The liquid formulation according to claim 15, comprising approximately 70% by weight of DISU.

17. The liquid formulation according to claim 16, wherein the liquid formulation is DISU octahydrate.

18. The liquid formulation according to claim 16, wherein the liquid formulation is DISU heptahydrate.

19. The liquid formulation according to any one of claims 15 to 17, wherein the mass of the formulation increases by up to 2% after being stored for 24 hours at 80% relative humidity and 25°C.

20. A solid formulation comprising a DISU and a hygroscopicity control agent (HCA), wherein the weight / weight ratio of DISU:HCA is 1:3 to 1:10, and the formulation contains up to 0.3% by weight of one or more o-ethoxylated choline derivatives.

21. The solid formulation according to claim 19, wherein the HCA is selected from microcrystalline cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, ethyl methylcellulose, or a mixture thereof.

22. The solid formulation according to claim 19 or 20, wherein the mass of the formulation increases by up to 0.012% after being stored for 24 hours at 80% relative humidity and 25°C.

23. The formulation according to any one of claims 15 to 21, wherein the DISU material is obtained by the method described in any one of claims 1 to 14.

Images