EP4362697A1

EP4362697A1 - Carnitine formulation

Info

Publication number: EP4362697A1
Application number: EP22731705.4A
Authority: EP
Inventors: Heiko DIETZ; Niclas GENTHE
Original assignee: Kaesler Nutrition GmbH
Current assignee: Kaesler Nutrition GmbH
Priority date: 2021-06-07
Filing date: 2022-06-07
Publication date: 2024-05-08
Also published as: WO2022258631A1

Abstract

The invention relates to a carnitine formulation, comprising carnitine or a derivative thereof; and a stabilizer selected from an inorganic salt, a C₁-C₃ carboxylic acid or a salt thereof, and combinations thereof.

Description

Title: Carnitine formulation

The invention relates to a carnitine formulation, a premix formulation comprising a carnitine formulation, a food product comprising a carnitine formulation and methods of preparing said carnitine formulation, premix formulation and food product.

L-carnitine, also referred to as ‘vitamin BT’ is a quaternary ammonium compound that naturally occurs in raw materials of both vegetable and animal origin. In living cells, L-carnitine plays an essential role in the metabolism of fatty acids by facilitating the transport of activated fatty acid (acyl-CoA) from the cytosol to the mitochondria, where the fatty acids undergo b-oxidation under formation of ATP, as source of energy.

Although most species are capable of synthesizing L-carnitine, e.g. humans are capable of synthesizing L-carnitine from the amino acids lysine and methionine, supplementation of L-carnitine has been linked to many positive health effects in animals, including humans. For example, supplementation of carnitine or derivatives thereof has been reported to boost metabolism of fatty acids, and to have a beneficial effect on the cardiovascular, muscular and nervous system of animals (Wang et al., 2018. Life Sci 194: 88-97; Karlic et al., 2014. Nutrition 20: 809-715; Onofrj et al., 2013. Expert Rev Neurother 13: 925-936).

Therefore, in agriculture, it is recommended to supplement animals with L- carnitine, in particular during reproduction, at young age, or during periods of rapid growth. Furthermore, L-carnitine maybe supplemented to the diet of humans that aim to increase metabolism of fat, or to boost their health.

However, carnitine is highly hygroscopic, thereby rendering compositions comprising carnitine typically sticky. This property makes the use of carnitine compositions, e.g. in agricultural settings more difficult, because during administration, carnitine may adhere to the surface of pipes, containers, cribs and the like. This leads to both loss of valuable carnitine composition, and to clogging of pipes and wearing of equipment. In addition, the hygroscopic nature of carnitine may complicate packaging and proportioning of carnitine, for example when preparing a composition comprising other relevant nutrients, such as essential vitamins and minerals.

Furthermore, carnitine is unstable, in particular at elevated temperatures that are typically required to load it on a suitable carrier. During decomposition of carnitine, ammonia is released, which has an unpleasant smell and is corrosive, thus providing a health risk to those working with it.

Accordingly, there is a need for a carnitine formulation that is less hygroscopic, that has increased flowability and/or increased stability, compared to known carnitine formulations.

It was found that in the presence of a stabilizer one or more of the drawbacks of the prior art has been overcome.

Accordingly, the invention relates to a carnitine formulation, comprising carnitine or a derivative thereof and a stabilizer selected from an inorganic salt, a Ci-Ce carboxylic acid or a salt thereof, and combinations thereof.

Figures

Figure 1: Solubility of L-carnitine in water at different temperatures.

Figure 2: Hardness (N) of carnitine formulations according to the invention compared to a control carnitine formulation (L-carnitine in absence of stabilizer) at room temperature.

Figure 3: Hardness (N) of several carnitine formulations according to the invention, compared to other carnitine formulations.

Figure 4: Recovery level carnitine formulation according to the invention compared to a control carnitine formulation (L-carnitine in absence of stabilizer) after incubation at 80 °C for 24 h.

Figure 5: Shear cell measurement of precipitated silicon dioxide (carrier) loaded with a carnitine formulation according to the invention and with a control carnitine formulation (L-carnitine in absence of stabilizer), compared to a control (free carrier) and reference carnitine formulation (Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd). In addition anticaking was added directly after loading (process I) or after cooling down (process II).

Figure 6: Shear cell measurement of a carnitine formulation according to the invention, compared to other carnitine formulations and a control (free carrier). Figure 7: Flow function of a carnitine formulation according to the invention, compared to a control (free carrier), a control carnitine formulation (L-carnitine in absence of stabilizer) and a reference carnitine formulation (Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd).

Figure 8: Recovery level after ruminal in-vitro digestibility of a carnitine formulation according to the invention coated with saturated palm and rapeseed oil, compared to an uncoated carnitine formulation according to the invention.

Figure 9: Recovery level of L-carnitine from a pellet comprising a carnitine formulation according to the invention (stripes) compared to a pellet comprising a reference carnitine formulation (black).

Detailed description

The term ‘or’ as used herein is defined as ‘and/or’ unless specified otherwise.

The term ‘a’ or ‘an’ as used herein is defined as “at least one” unless specified otherwise.

When referring to a noun ( e.g . a compound, an additive, etc.) in the singular, the plural is meant to be included.

The term ‘essentially free’ is generally used herein to indicate that a substance is not present (below the detection limit achievable with analytical technology as available on the effective filing date) or present in such a low amount that it does not significantly affect the property of the product that is essentially free of said substance.

In the context of this application, the term ‘about’ means generally a deviation of 15 % or less from the given value, in particular a deviation of 10% or less, more in particular a deviation of 5%, 4%, 3%, 2%, 1%, 0.5% or less.

A “liquid medium” as used herein, refers to any medium that is substantially liquid at a suitable application temperature, typically between about 50 and about 95 °C. A liquid medium is capable of dissolving, at the application temperature, at least 50 wt.% of carnitine or a derivative thereof, based on the total weight of a carnitine formulation according to the invention. Particularly suitable is a liquid medium of which dietary intake by animals, including humans at concentrations of typically up to 15 wt.%, based on the total weight of a carnitine formulation according to the invention, comprising a carrier, is not advised against by common health authorities such as the Food and Drug Administration (FDA) and/or the European Food Safety Authority (EFSA). Examples of liquid media include water and aqueous solutions, including aqueous buffer solutions.

In the context of the present application a “food product” refers to any product that is edible for animals, including humans, meaning that dietary intake is not advised against by common health authorities, for example the FDA and/or the EFSA.

A salt is defined as a compound that is formed by chemical combination of an acid and a base, or through neutralization. Salts may be formed when the ions are joined together by an ionic bond. A salt may dissociate into ions (other than H⁺ or OH ) when dissolved in a solvent such as water. An “inorganic salt” is generally understood in the art to refer to a salt that does not comprise a C-H bond in its scaffold. Examples of inorganic salts include sodium chloride, ammonium sulphate, potassium phosphate and the like.

A “Cx-Cy carboxylic acid”, such as C₁-C₃ carboxylic acid, is generally understood in the art to refer to a molecule comprising at least one carboxylic acid (COOH) moiety. The terms “C_x” and “C_y” refer to the total number (x or y) of carbon atoms in the molecule. An example of a C2 carboxylic acid is acetic acid (CH₃COOH).

As used herein, “a salt of a C_x-C_y carboxylic acid” refers to a C_x-C_y carboxylic acid, wherein the acidic hydrogen present in at least one COOH moiety of a C_x-C_y carboxylic acid is replaced by a positively charged ion such as a sodium ion, a potassium ion or an ammonium ion, that forms an ionic bond with a negatively charged carboxylate (COO ) moiety. Examples of salts of a C2 carboxylic acid include sodium acetate and sodium diacetate.

Carnitine formulation

Several compositions comprising carnitine are described in the art that aim to improve flowability of carnitine compositions. WO 2011/069654 describes an L- carnitine granulate which essentially consists of a silica carrier coated with carnitine and optionally an anticaking agent. This L-carnitine granulate is described to have better flowability, compared to a commercially available L- carnitine composition as reflected by a lower HAUSNER ratio, as determinable according to DIN ISO 4324, of 1.18 compared to 1.41 for the commercially available L-carnitine composition. The HAUSNER ratio refers to a value determined with the formula wherein, pris the trapped bulk density of the powder and ρ B is the freely settled bulk density of the powder.

However, the L-carnitine granulate of WO 2011/069654 lacks sufficient flowability, thereby hampering its use in many agricultural or nutritional applications. In addition, the granulate suffers from poor stability, in particular at temperatures exceeding 50 °C, required during manufacturing.

It was realized that the presence of a stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₃ carboxylic acid or a salt thereof and combinations thereof, allows reduction of the amount of liquid medium, preferably water, in a carnitine formulation according to the invention, facilitates precipitation of carnitine from the liquid medium and/or increases the stability of carnitine, in particular the stability in solution and at elevated temperature.

Furthermore, it was found that the hardness of a carnitine formulation according to the invention, is significantly increased compared to a control carnitine composition wherein no stabilizer is present. An increased hardness advantageously contributes to improved stability and/or flowability of said carnitine formulation, compared to known carnitine compositions, when formulated with a suitable carrier. Improved stability and/or improved flowability of the carnitine formulation significantly improves the ease of handling in agricultural, nutritional and/or pharmaceutical applications. The improved stability and/or flowability of a carnitine formulation according to the invention may be advantageous both at the site of manufacturing of a carnitine formulation, as well as at the site of processing a carnitine formulation into an intermediate or an end product, such as a premix formulation or a food product. At such sites, typically harsh conditions, such as elevated temperature or pressure, may be applied to the product which may result in degradation of carnitine in a carnitine formulation, a premix formulation or a food product if a stabilizer is absent.

Accordingly, the invention relates to a carnitine formulation, comprising

- carnitine or a derivative thereof; and

- a stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, and combinations thereof.

The carnitine formulation according to the invention comprises carnitine or a derivative thereof. Preferably, the carnitine formulation according to the invention comprises carnitine. Carnitine is also known under the chemical name 3-hydroxy- 4-(trimethylammonio)butanoate and comprises the chemical structure: (CH₃)₃N⁺CH₂CH(OH)CH₂COO.

Carnitine as present in a carnitine formulation according to the invention may be carnitine in free form, also referred to as zwitterionic carnitine or inner salt of carnitine, or a salt of carnitine. Examples of carnitine salts suitable for preparing a carnitine formulation according to the invention are chloride salts, sulphate salts and nitrate salts. Preferably, carnitine used for the formulation according to the invention is carnitine in its free form. Carnitine is a chiral molecule by virtue of the presence of an asymmetric carbon (C-3), which bears as substituents a hydrogen, a hydroxy group, a trimethylamino methyl group, and a carboxymethyl group. Consequently, there are two possible absolute configurations around the C-3, resulting in two enantiomers, i.e. L-carnitine and D-carnitine. Herein, L-carnitine causes levorotation (also referred to as left-handed or counter clockwise rotation) of a plane of polarized light, while the other optical isomer causes dextrorotation (right-handed or clockwise rotation) and is designated as the D-isomer of carnitine. DL-carnitine is a racemic mixture of the stereoisomers of carnitine.

L-carnitine is the enantiomer that is bioactive in animals and therefore frequently applied in agricultural or nutritional applications. Therefore, the carnitine as present in a carnitine formulation according to the invention preferably comprises L-carnitine, in particular the inner salt of L-carnitine, also known as (3i?)-3-hydroxy-4-trimethylazaniumylbutanoaat. The carnitine as present in a carnitine formulation according to the invention is preferably L-carnitine, in particular the inner salt of L-carnitine.

Any source of carnitine may be used for the preparation of the carnitine formulation according to the invention. Accordingly, a commercially available source of L-carnitine may be used such as, for example, L-carnitine base from Lonza Group Ltd (Basel, Switzerland), from Northeast Pharmaceutical group Co. Ltd. (Shenyang, China, from HuangGang HuaYan Pharmaceutical Co. Ltd. (Sanlifam Town, China), from Kaiyuan Hengtai Chemical Co. (Kaiyuan City, China), and from Liaoning Koncepnutra Co. (Liaoning, China).

Alternatively or additionally, carnitine in a carnitine formulation according to the invention may be chemically or enzymatically synthesized. A number of chemical methods for the synthesis of DL-carnitine are known. For example, US 3,135, 788 is directed to the preparation of DL-carnitine hydrochloride wherein epichlorohydrin is first treated with trimethylamine to provide l-chloro-2-hydroxy- 4- (trimethylammonio)butane, following by displacement of chloride with cyanide to obtain the corresponding cyano-compound. Subsequently, said cyano-compound may be hydrolysed with acid to yield DL-carnitine.

In addition, methods to prepare optically pure L-carnitine are described, for example in US 5,473,104, wherein a two-step process is used starting from (S)- 3- hydroxybutyrolactone. In a first step, the hydroxyl group of (S)- 3- hydroxybutyrolactone is activated using a triflate, followed by nucleophilic addition of trimethylamine to form L-carnitine.

Alternatively or additionally, carnitine may be isolated from raw material comprising carnitine. For example, carnitine, in particular L-carnitine may be isolated from animal products such as (red) meat, fish, poultry and dairy products such as milk.

Optionally, a carnitine formulation according to the invention may comprise a derivative of carnitine, such as acetyl-carnitine, propionyl-carnitine or isovaleryl- carnitine, preferably a bioactive derivative of carnitine, such as acetyl-L-carnitine. Acetyl- L-carnitine is also known under the chemical name (R )-3-acetyloxy-4- trimethylammonio-butanoate.

A bioactive carnitine derivative, preferably acetyl-L-carnitine, may be hydrolyzed in the body by esterases into L-carnitine, and thus has simil r beneficial health effects in animals, including human as L-carnitine and is therefore also beneficially supplemented to an animals’ diet. Any source of a derivative of carnitine, preferably acetyl-L-carnitine may be used for the preparation of the carnitine formulation according to the invention. Alternatively or additionally, a derivative of carnitine, preferably acetyl-L- carnitine in the carnitine formulation according to the invention may be may be chemically or enzymatically synthesized or isolated from raw material comprising said derivative of carnitine using any suitable method known in the art. In a carnitine formulation according to the invention, carnitine or a derivative thereof, preferably L-carnitine is typically present in an amount of about 50 wt.% to about 85 wt.%, preferably about 60 wt.% to about 82 wt.%, more preferably about 70 wt.% to about 80 wt.%, in particular around 76.5 wt.% of the total weight of the carnitine formulation.

A carnitine formulation according to the invention further comprises a stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, and combinations thereof.

It was found that in presence of a stabilizer as defined herein the amount of liquid medium, preferably water, in a carnitine formulation according to the invention may be reduced.

Generally, the amount of liquid medium, preferably water required to dissolve a specific amount of carnitine, preferably L-carnitine, may be reduced by at least 1%, preferably at least 3%, in particular at least 5%, compared to the amount of liquid medium, preferably water required to solubilize the same amount of carnitine in the same liquid medium, preferably water, in absence of a stabilizer as defined herein. Preferably, the amount of liquid medium preferably water required to dissolve carnitine, preferably L-carnitine, was reduced by about 1-10%, more preferably about 2-9%, about 3-7.5%, in particular about 4-6% such as about 4.5%, compared to a control carnitine formulation, preferably comprising L- carnitine, in the absence of a stabilizer as defined herein at substantially the same conditions. It is advantageous to achieve a lower liquid medium, preferably water content in a carnitine formulation according to the invention, because this requires the use of less liquid medium, preferably water to prepare a carnitine formulation according to the invention, whereas the content of carnitine, preferably L-carnitine, may remain the same. Using less liquid medium, such as water is advantageous for environmental purposes.

Furthermore, the stabilizer as defined herein was typically found to have a beneficial effect on the crystallization rate of carnitine, preferably L-carnitine, from a liquid medium, preferably water. By increasing the crystallization rate, the efficiency of the process is further enhanced, because carnitine, for example L- carnitine, is kept in solution for a shorter period of time. Furthermore, it was found that an increased crystallization rate beneficially increases the hardness of the solid carnitine formulation.

Preferably, the presence of a stabilizer as defined herein was found to increase the rate of crystallization from a liquid medium, by at least 1%, compared to the crystallization rate of carnitine in absence of a stabilizer, more preferably by at least 3%, by at least 5%, at least 10%. Preferably, the crystallization rate of carnitine, preferably L-carnitine, in water is increased by about 1-10%, more preferably about 2-9%, about 3-8%, in particular about 5-7%. Said crystallization rate was typically determined by visually monitoring the formation of solids precipitating from a liquid medium in a carnitine formulation according to the invention, compared to a control formulation comprising carnitine, but essentially free of a stabilizer, at the same conditions. Herein, both the time when the carnitine formulation started to precipitate, and the time wherein precipitation of the carnitine formulation was substantially finished, was monitored. Typically, a carnitine formulation according to the invention both started to precipitate faster than a carnitine formulation wherein no stabilizer was present, and precipitation was finished faster compared to a carnitine formulation wherein no stabilizer was present. Advantageously, the carnitine formulation according to the invention, in solid form, was found to exhibit an increased hardness, compared to a control carnitine composition wherein the stabilizer is not present. Typically, increased hardness of a carnitine formulation according to the invention, indicates that said carnitine formulation is less sticky compared to a control carnitine formulation lacking a stabilizer. Lower stickiness of a carnitine formulation according to the invention beneficially facilitates handling of said carnitine formulation during use thereof. As the skilled person will appreciate, handling of a carnitine formulation according to the invention may occur at any production or manufacturing site, e.g. at a production facility where a carnitine formulation according to the invention is produced, or at a facility where a carnitine formulation according to the invention is manufactured into an intermediate product, such as a premix formulation, or into an end product, such as a food product, including animal feed.

Therefore, the invention preferably relates to a carnitine formulation, wherein the carnitine formulation is a solid having a hardness of at least about 12 N, preferably at least about 15 N, in particular at least about 20 N, or at least about 30 N as determinable with a TA.HDplusC Texture Analyser (Stable Micro Systems Ltd., Godaiming, United Kingdom). A carnitine formulation according to the invention may be in liquid or in solid form. Typically, a carnitine formulation according to the invention comprising for example 70 wt.% of carnitine or a derivative thereof based on the total weight of the carnitine formulation, is in liquid form at a temperature of about 60 °C or higher, preferably about 70 °C or higher, more preferably about 80 °C or higher. At such temperatures, carnitine or a derivative thereof was found to be highly soluble in suitable liquid media, such as water.

Typically, the carnitine formulation according to the invention, comprising for example 70 wt.% of carnitine or a derivative thereof, based on the total weight of the composition, is in solid form at a temperature of about 55 °C or lower, preferably about 50 °C or lower, in particular about 40 °C or lower, or around 25 °C or lower. At such temperatures, solubility of carnitine or a derivative thereof in a suitable liquid medium such as water was found to be insufficient.

In a carnitine formulation according to the invention, the stabilizer is preferably present in an amount of about 1 to about 12 wt.%, based on the total weight of the carnitine formulation, preferably about 2 to about 10 wt.%, more preferably about 2.5 to about 8 wt.% of stabilizer, preferably about 2.99 to about 5 wt.% of stabilizer, based on the total weight of the carnitine formulation.

In an aspect, the stabilizer is preferably an inorganic salt. The inorganic salt in the carnitine formulation according to the invention should be soluble in the liquid medium it is dissolved in during the preparation of the carnitine formulation according to the invention. Preferably, the inorganic salt is water-soluble. In particular, the solubility of the inorganic salt in water at 20 °C as present in a carnitine formulation according to the invention should be at least 10 g of inorganic salt per 100 g of water, preferably at least 20 g of inorganic salt per 100 g of water, at least 30 g per 100 g of water, at least 35 g per 100 g of water, at least 40 g per 100 g water, at least 45 g per 100 g of water, at least 50 g per 100 g of water at least 55 g per 100 g water, at least 60 g per 100 g water, at least 65 g per 100 g water, at least 70 g per 100 g water, at least 72 g per 100 g water, at least 74 g per 100 g of water.

Preferably, the solubility of the inorganic salt in a carnitine formulation according to the invention should be at most 100 g per 100 g of water at 20 °C, at most 90 g per 100 g of water, at most 85 g per 100 g of water, at most 80 g per 100 g of water, at most 75 g per 100 g of water. In particular, the solubility of the inorganic salt in water at 20 °C should be about between 10 g to about 75 g per 100 g of water, more preferably between about 30 g to about 70 g per 100 g of water.

Examples of suitable inorganic salt present in the carnitine formulation according to the invention include water-soluble chloride salts and water-soluble sulphate salts. Examples include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, ammonium chloride, ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate and combinations thereof.

Preferably, the inorganic salt is a sulphate or a phosphate salt, more preferably selected from the group consisting of ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate and combinations thereof. Alternatively or additionally, said inorganic salt may comprise sodium chloride.

Preferably, an inorganic salt may be used according to the invention, that may also function as a buffering system, preferably a buffering system that buffers the pH between 2 and 7, preferably between 3 and 6, in particular between 4 and 5. In a carnitine formulation according to the invention, an inorganic salt capable of buffering a solution at a pH between 2 and 7 may increase to the stability of carnitine or a derivative thereof.

Without wishing to be bound by theory, it is believed that inorganic salts increase the ionic strength of an aqueous solution thereby aiding carnitine or a derivative thereof to dissolve in a liquid medium, such as water. The inorganic salt, in the carnitine formulation according to the invention, was further found to beneficially improve the rate of crystallization, thereby improving the efficiency of the method of preparation of a carnitine formulation according to the invention. Further, inorganic salts in a carnitine formulation according to the invention, advantageously improve the hardness of a solid carnitine formulation according to the invention. Without wishing to be bound by theory, it is believed that inorganic salts may assist in binding water in the form of a hydrate in the carnitine formulation according to the invention. When water is present in bound form, there is usually less water present in fluid form. Water in fluid form typically has a negative impact on the hardness of a solid carnitine formulation according to the invention.

Alternatively or additionally, the stabilizer may be a C₁-C₆ carboxylic acid or a salt thereof. Preferably, the stabilizer is a C₁-C₄ carboxylic acid or a salt thereof, more preferably a C₁-C₃ carboxylic acid or a salt thereof, even more preferably a C₁- C₂ carboxylic acid or a salt thereof.

It was found that a carnitine formulation comprising a C₁-C₆ carboxylic acid or a salt thereof stabilizes carnitine, preferably L-carnitine, in particular at elevated temperature, such as a temperature of 60 °C or more. In solution, carnitine, in particular L-carnitine, is particularly prone to degradation, which is characterized by the formation of ammonia and the coloration of the solution (formation of a brownish/reddish color).

Without wishing to be bound by theory, it is believed that C₁-C₆ carboxylic acid or a salt thereof stabilizes carnitine in solution, at least partly, by means of acidification of the solution. Said C₁-C₆ carboxylic acid or salt thereof, may further act as a scavenger to collect degradation products formed during decomposition of carnitine or a derivative thereof, and preventing these degradation products to participate in a reaction underlying decomposition of carnitine. Further said C₁-C₆ carboxylic acid or salt thereof may form a complex with carnitine or a derivative thereof, thereby shielding carnitine from undergoing a decomposition reaction.

Preferably, the pH of the carnitine formulation according to the invention, comprising a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₄ carboxylic acid or a salt thereof, more preferably a C₁-C₃ carboxylic acid or salt thereof has a pH of 7 or less, preferably a pH of 6.5 or less, more preferably a pH of 6.0 or less, a pH of 5.5 or less, a pH of 5.0 or less. In particular said pH is between 2.0 and 7.0, preferably between 3.0 and 6.0, more preferably between 4.0 and 5.0.

The carnitine formulation according to the invention, comprising a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₄ carboxylic acid or a salt thereof, more preferably a C₁-C₃ carboxylic acid or salt thereof, exhibits no substantial degradation of carnitine, preferably L-carnitine, at a temperature of at least 80 °C during a time interval of 24 hours or more.

Preferably, the content of carnitine or a derivative thereof in a carnitine formulation according to the invention, is about 5 % higher, more preferably about 10 % higher than a carnitine solution (free of stabilizer) after 24 h at 80 °C due to degradation of carnitine or derivative thereof in absence of a stabilizer over time at 80 °C, at a substantially identical starting concentration of carnitine or a derivative thereof. Preferably, the rate of degradation of carnitine or a derivative thereof in a carnitine formulation according to the invention comprising a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₄ carboxylic acid or a salt thereof, more preferably a C₁-C₃ carboxylic acid or a salt thereof, at 80 °C is less than 5% per 24 h, more preferably less than 3% per 24 h, in particular less than 1% per 24 h.

The rate of degradation may be obtained by determining the concentration of carnitine or derivative thereof, preferably L-carnitine, at a defined starting time (t=0), and after a specified time period, for example 24 h (t=24) after the starting time under the same conditions. The ratio between the concentration of carnitine or derivative thereof at t=0 and the concentration of carnitine or derivative thereof at t=24 may be determined to obtain the rate of degradation over said specified time period.

The concentration of carnitine or a derivative thereof may be determined using any suitable method known in the art, for example using an enzymatic method, or by using high-performance liquid chromatography (HPLC) or by mass spectrometry (MS) such as, for example, Liquid Chromatography Triple Quadrupole Mass Spectrometry (LC-MS/MS).

The C₁-C₆ carboxylic acid or salt thereof in a carnitine formulation according to the invention preferably comprises at least one carboxylic acid or carboxylate group, but may optionally comprise more than one carboxylic acid group, such as two or three carboxylic acid groups. Preferably, the C₁-C₆ carboxylic acid or salt thereof is a mono carboxylic acid, more preferably a C₁-C₃ mono carboxylic acid or a salt thereof, even more preferably a C₁-C₂ mono carboxylic acid or a salt thereof.

A C₁-C₆ carboxylic acid or salt thereof, preferably a C₁-C₃ carboxylic acid or salt thereof in a carnitine formulation according to the invention preferably is a linear carboxylic acid, and/or may comprise one or more substituents. A substituent is any group other than hydrogen attached to the backbone of the C₁-C₆ carboxylic acid. Examples of substituents are hydroxyl- groups (OH), carboxylic acid groups (COOH), amines (NH₂), including secondary and tertiary amines (NHCH₃), amides (NHCO), ketones (CO), sulphates (SO3), thiols (SH), methanethiols (SMet), sulfonates, sulphonamides, halides and the like. Preferably, a C₁-C₆ carboxylic acid or salt thereof, preferably a C₁-C₆ mono carboxylic acid or salt thereof, in a carnitine formulation according to the invention does not comprise a substituent, in particular does not comprise a hydroxyl group. Even more preferably, the C₁-C₆ carboxylic acid or salt thereof is an unsubstituted C₁-C₄ carboxylic acid, preferably an unsubstituted C₁-C₄ mono carboxylic acid or salt thereof, an unsubstituted C₁-C₃ carboxylic acid or salt thereof, preferably an unsubstituted C₁-C₃ mono carboxylic acid or salt thereof, even more preferably an unsubstituted C₁-C₂ carboxylic acid or salt thereof, in particular an unsubstituted C₁-C₂ mono carboxylic acid or salt thereof.

The C₁-C₆ carboxylic acid or salt thereof in a carnitine formulation according to the invention may be a saturated C₁-C₆ carboxylic acid or salt thereof or may comprise one or more double or triple bonds. Preferably the C₁-C₆ carboxylic acid or salt thereof is a saturated C₁-C₆ carboxylic acid or salt thereof, more preferably a saturated C₁-C₄ carboxylic acid or salt thereof, in particular a saturated C₁-C₄ mono carboxylic acid, even more preferably a saturated C₁-C₃ carboxylic acid or salt thereof, in particular a saturated C₁-C₃ mono carboxylic acid or salt thereof, most preferably a saturated C₁-C₂ carboxylic acid or salt thereof, in particular a saturated C₁-C₂ mono carboxylic acid or salt thereof.

A C₁-C₆ carboxylic acid or salt thereof, preferably a C₁-C₃ carboxylic acid or salt thereof that is used as a stabilizer in a carnitine formulation according to the invention should be soluble in the liquid medium it is dissolved in. Preferably, the C₁-C₆ carboxylic acid or salt thereof, more preferably a C₁-C₃ carboxylic acid or salt thereof, is water-soluble. In particular, the solubility of a C₁-C₆ carboxylic acid or salt thereof in water at 20 °C as present in a carnitine formulation according to the invention should be at least 10 g of C₁-C₆ carboxylic acid or salt thereof per 100 g of water, preferably at least 15 g per 100g of water, more preferably at least 20 g perlOO g of water, at least 25 g per 100 g of water, at least 30 g per 100 g of water, at least 35 g per 100 g of water.

Examples of a C₁-C₆ carboxylic acid or salt thereof in the carnitine formulation according to the invention include oxalic acid, propionic acid, lactic acid, malic acid, citric acid, acetic acid, formic acid or salts thereof. Preferably, the C₁-C₆ carboxylic acid or salt thereof is not tartrate or fumarate. Alternatively or additionally, the C₁-C₆ carboxylic acid or salt thereof may be an amino acid, such as Met, Lys or a combination thereof.

Preferably, the C₁-C₆ carboxylic acid or salt thereof in a carnitine formulation according to the invention is a salt of a C₁-C₆ carboxylic acid, preferably a salt of a C₁-C₄ carboxylic acid, more preferably a salt of a C₁-C₃ carboxylic acid even more preferably a salt of a C₁-C₂ carboxylic acid.

Most preferably, the C₁-C₆ carboxylic acid or salt thereof in a carnitine formulation according to the invention is an unsaturated, unsubstituted, mono C₁- C₆ carboxylic acid or salt thereof, preferably an unsaturated, unsubstituted, mono

C₁-C₄ carboxylic acid or salt thereof, even more preferably an unsaturated, unsubstituted, mono C₁-C₃ carboxylic acid or salt thereof, in particular an unsaturated, unsubstituted, mono C₁-C₂ carboxylic acid or salt thereof.

Therefore, the carnitine formulation according to the invention, preferably comprises a salt of a C₁-C₄ carboxylic acid, preferably a salt of a C₁-C₃ carboxylic acid, in particular a salt of a C₁-C₂ carboxylic acid selected from the group consisting of an acetate salt, such as a monoacetate salt or a diacetate salt, a formate salt, such as a monoformate salt, a diformate salt, or combinations thereof.

Good results have been obtained with a carnitine formulation according to the invention comprising different salts of C₁-C₄ carboxylic acids, preferably C₁-C₃ carboxylic acids, more preferably C₁-C₂ carboxylic acids such as ammonium formate, potassium diformate, sodium diformate, ammonium acetate, sodium diacetate and potassium diacetate. A carnitine formulation according to the invention comprising a formate, diformate, acetate and/or diacetate salt was found to exhibit good stability and/or good hardness.

Excellent results were obtained with a carnitine formulation comprising carnitine or a derivative thereof, preferably L-carnitine, and sodium diacetate or ammonium acetate. Such a carnitine formulation advantageously exhibits a hardness of at least about 20 N, preferably at least about 25 N, in particular at least about 30 N as determinable with a TA.HDplusC Texture Analyser.

A carnitine formulation according to the invention further comprises a liquid medium, such as water. Preferably, a carnitine formulation according to the invention comprises, based on the total weight of the carnitine formulation, at least

13.5 wt.% of a liquid medium, preferably water, preferably at least 15 wt.%, more preferably at least 18.5 wt.% of a liquid medium, preferably water.

Preferably, a carnitine formulation according to the invention comprises, based on the total weight of a carnitine formulation, at most 22.5 wt.% of a liquid medium, preferably water, preferably at most 21.5 wt.%, more preferably at most

20.5 wt.% of a liquid medium, preferably water. Typically, a carnitine formulation according to the invention comprises between 13 wt.% and 25 wt.% of water, preferably between 15 wt.% and 22.5 wt.%, in particular between 18.5 wt.% and 20.5 wt.% of water.

It was further realized that a carnitine formulation according to the invention may be advantageously formulated with a suitable carrier, in particular a carrier suitable for agricultural applications. This allows the formation of a carnitine formulation in powder form, which facilitates handling of the composition in agricultural and nutritional applications.

The invention therefore further relates to a carnitine formulation, comprising a carrier, preferably a carrier comprising silica. Said carnitine formulation preferably comprises granules. Preferably, said granules have a mass median diameter (also referred to as d50) of between about 50 μm and about 600 μm, preferably between about 150 μm and about 300 μm. The mass median diameter (d50) can be determined according to ISO 13320:2020. It was found that the flow ability of the carnitine formulation according to the invention, when loaded onto a carrier, does not significantly alter the flow ability of the carrier. The flowability of the carnitine formulation may be determined using any suitable method known in the art. Particularly, the flowability of the carnitine formulation is determinable with a shear cell measurement. In a shear cell measurement, a solid is packed in a cylinder and put under stress. Upon release of the stress, the normal stress (s) and shear stress (t) are recorded (Wang et al. 2016. Powder Technology 294: 105-112)

At a normal stress, when applying an axial force of about 4 kPa, a carnitine formulation according to the invention, comprising a carrier, preferably has a shear stress that is at least about 50% lower than a comparable carnitine formulation that is essentially free of a stabilizer as defined herein, i.e. essentially comprising carnitine and a carrier, such as Carniking™ of Lonza Group. Preferably, the carnitine formulation according to the invention has a shear stress at normal stress of 4 kPa that is at least about 30% lower, at least about 20% lower, at least about 10% lower than a comparable carnitine formulation that is essentially free of a stabilizer as defined herein, such as Carniking™ of Lonza Group.

Further, at a normal stress of 4 kPa, a carnitine formulation according to the invention, comprising a carrier, preferably has a shear stress that is preferably at most 5% higher than said carrier (that is essentially free of the carnitine formulation according to the invention). Preferably, at normal stress of 4 kPa, a carnitine formulation according to the invention, comprising a carrier, has a shear stress that is at most 4% higher, at most 3% higher, at most 2% higher, at most 1% higher, most preferably essentially the same as the shear stress at normal stress of 4 kPa of the same carrier that is essentially free of a carnitine formulation according to the invention.

It was furthermore surprisingly found that a carnitine formulation according to the invention had comparable shear stress at normal stress as a reference carnitine formulation that was subjected to extensive drying. This is advantageous, because a carnitine formulation may be obtained with comparable flowability, but without requiring the use of extensive drying, which is energy intensive and costly, and thus undesired.

Therefore, at a normal stress of 4 kPa, a carnitine formulation according to the invention, comprising a carrier, preferably has a shear stress that is preferably at most 5% higher than a reference carnitine formulation sold under the name “Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd. Preferably, at normal stress of 4 kPa, a carnitine formulation according to the invention, comprising a carrier, has a shear stress that is at most 4% higher, at most 3% higher, at most 2% higher, at most 1% higher, most preferably essentially the same as the shear stress at normal stress of 4 kPa of a reference carnitine formulation sold under the name “Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd.

Said reference carnitine formulation “levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd is an extensively dried carnitine formulation, comprising 48-52 wt.% L-carnitine and 10 wt.% of water or less, preferably 9 wt.% or less, more preferably between about 5 and about 8 wt.% of water, based on the total weight of the carnitine formulation, as determinable with a Karl Fischer titration (ISO 760:1978).

The shear stress at normal stress of a carnitine formulation according to the invention may further be described in terms of flow function. A flow function is a parameter used to rank flowability of powders, wherein values below 4 denote poor flow and values above 10, indicate good flow. The flow function is the relationship between the major consolidation pressure (sΐ) and the unconfined yield strength (δc) of a powder, and may be derived from the normal stress (δ) to shear stress (τ) plot.

Mohr stress circles may be fitted to the s,t plot, to derive the major principle stress or consolidation stress (δ1) and the unconfined yield strength (δc), respectively the upper and lower values on the a- axis, where the Mohr stress circles intersect the horizontal axis (δ). Herein, the ratio between sΐ and ac quantifies the flow function of a powder (Schulze, 2008. Flow properties of bulk solids. In: Powders and Bulk Solids. Springer, Berlin, Heidelberg).

A carnitine formulation according to the invention preferably has a flow function of at least 15, more preferably at least 20, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, in particular at least 60.

A carnitine formulation according to the invention preferably has a flow function of in the range of between about 25 and about 120, more preferably in the range of between about 40 and about 90, in particular between about 50 and about 70.

Preferably the flow function of a carnitine formulation according to the invention is less than 10% lower than the flow function of the carrier essentially free of L-carnitine and stabilizer, more preferably less than 5% lower, less than 3% lower, in particular essentially the same or higher than the flow function of the same carrier which is essentially free of L-carnitine and stabilizer. For example, the flow function of a carnitine formulation according to the invention is preferably about 5% higher than the flow function of the carrier, more preferably about 10% higher, about 20%, about 30% higher than the flow function of the carrier.

Preferably the flow function of a carnitine formulation according to the invention is less than 20% lower than the flow function of “Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd, more preferably less than 15% lower, less than 10% lower, less than 5% lower, in particular essentially the same or higher than the flow function of “Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd. For example, the flow function of a carnitine formulation according to the invention is preferably about 5% higher than the flow function of

“Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd, more preferably about 10% higher, about 20%, about 30% higher than the flow function of “Levocarnitine 50%” of Northeast Pharmaceutical Group Co. Ltd. A carnitine formulation comprising a carrier with a shear cell stress at normal stress as defined herein above, advantageously has a good shelf life. In particular, the shelf life of a carnitine formulation according to the invention is at least 1 week, at least 1 month, at least 6 months, at least 12 months, preferably at least 16 months, more preferably at least 18 months, in particular at least 24 months, when stored dry, at room temperature and atmospheric pressure. Advantageously, the carnitine formulation according to the invention has a better shelf life compared to a carnitine composition that is essentially free of a stabilizer, preferably about 10% better, about 20% better, about 30% better, in particular about 50% better compared to a carnitine composition wherein no stabilizer is present, stored at essentially the same conditions.

The carrier in a carnitine formulation according to the invention should have a good absorption capacity and high chemical compatibility with a carnitine formulation according to the invention.

The absorption capacity of a solid is also reflected in the surface area of the carrier. Typically, components with high surface area have a high capacity of absorbing liquids Preferably, the carrier has a surface area of at least 100 m2/g, more preferably at least 200 m2/g, more preferably at least 300 m2/g. In particular, the surface area of the carrier is between 100 and 1000 m2/g, more preferably between 150 and 750 m2/g, in particular between 200 and 500 m2/g as determined by BET analysis (also known in the art as Brunauer, Emmett and Tellers analysis theory). Using BET analysis, the surface area of the carrier may be determined by physical adsorption of nitrogen (N2) gas on the surface of the carrier, which is a solid. The value of the BET analysis is expressed as m² per gram of solid carrier material (ISO 5794-1).

The carrier in a carnitine formulation according to the invention preferably has a good capacity of liquid absorbance. Preferably, the carrier has a di-(2- ethylhexyl) adipate (DOA) absorption number of at least 210 ml per 100 g, preferably at least 220 ml per 100 g, at least 230 ml per 100g, preferably at least 240 ml per 100g, in particular at least 250 ml per 100 g as determinable with ISO 19246:2016.

At most, the DOA absorption number is 300 ml per 100 g, preferably at most 280 ml per 100g, more preferably at most 260 ml per 100 g as determinable with ISO 19246:2016. Preferably, the DOA absorption number of the carrier is between 210-250 ml per 100 gas determinable with ISO 19246:2016.

Examples of suitable carriers include carriers comprising silica, such as silicon dioxide, and natural carriers, preferably vermiculite, perlite and natural fibers or derivative thereof, including hemicellulose, pomace and grain by-products.

Preferably, a carnitine formulation according to the invention comprises silicon dioxide. Preferably a carrier comprising silicon dioxide comprises at least 90 wt.% of silicon dioxide, more preferably at least 95 wt.% of silicon dioxide, in particular at least 98 wt.% of silicon dioxide, based on the total weight of the carrier.

The carrier comprising silica as present in a carnitine formulation according to the invention, is preferably a microparticulate silica carrier.

The mass median diameter (also referred to as d50) of the carrier in the carnitine formulation according to the invention is preferably at least 100 μm, preferably at least 200 μm, more preferably at least 250 μm, in particular about 300 μm. The d50 of the carrier, preferably silicon dioxide, is preferably between about 100 μm and about 380 μm, more preferably between about 150 μm and about 350 μm, more preferably between about 250 μm and about 325 μm. The mass median diameter (d50 μm) of the carrier can be determined according to ISO 13320:2009.

A carnitine formulation according to the invention, comprising a carrier and preferably comprising L-carnitine, preferably comprises about 30 wt.% to about 60 wt.% of carnitine, preferably about 40 wt.% to about 55 wt.% of carnitine, around 45 wt.% to about 53 wt.% of carnitine, in particular about 50 wt.% of carnitine, based on the total weight of the carnitine formulation.

A carnitine formulation according to the invention, comprising a carrier, preferably about 1 wt.% to about 10 wt.% of stabilizer as defined herein, preferably about 2 wt.% to about 8 wt.%, about 2.5 wt.% to about 5 wt.%, in particular about 2.95 wt.% to about 3.5 wt.% of stabilizer as defined herein, based on the total weight of the carnitine formulation.

A carnitine formulation according to the invention, preferably comprises about 20 wt.% to about 70 wt.% of carrier, preferably silicon dioxide, preferably about 25 wt.% to about 50 wt.% of carrier, preferably silicon dioxide, preferably about 30 wt.% to about 60 wt.% of carrier, in particular about 33 wt.% of carrier, based on the total weight of the carnitine formulation.

A carnitine formulation according to the invention may further comprise about 4 to about 25 wt.% of water, preferably between 8 and 20, in particular between 10 and 18 wt.% of water.

A carnitine formulation according to the invention, preferably further comprises an anticaking agent. An anticaking agent is a compound that prevents the carnitine formulation from forming caking together, thereby forming aggregates. Hence, addition of an anticaking agent further improves the flowability of the carnitine formulation.

Examples of suitable anticaking agents include silicon dioxide, or natural anticaking agents such as gluten, talcum, lime, corn flour, diatomite, or natural fibers or derivatives thereof such as hemicellulose, pomance and grain by-products, and mixtures thereof. The mass median diameter (also referred to as d50) of the anticaking agent as present in a carnitine formulation according to the invention is preferably less than 150 μm, preferably less than 125 μm, more preferably less than 100 μm. The d50 of the anticaking agent, preferably silicon dioxide, is preferably between about 5 μm and about 150 μm, more preferably between about 50 μm and about 125 μm, more preferably between about 75 μm and about 110 μm. The mass median diameter (d50) can be determined according to ISO 13320:2020.

Preferably, the anticaking agent in a carnitine formulation according to the invention has a mass median diameter that is at least a factor 2 smaller than the a mass median diameter of the carrier, more preferably at least a factor 3 smaller than the a mass median diameter of the carrier, more preferably at least a factor 4 smaller than the mass median diameter of the carrier, in particular at least a factor 5 smaller than the mass median diameter of the carrier.

A carnitine formulation according to the invention, preferably comprises about 0.25 wt.% to about 5 wt.% of anticaking agent, preferably about 0.5 wt.% to about 4 wt.% of anticaking agent, preferably about 0.75 wt.% to about 3 wt.% of anticaking agent, in particular about 1 wt.% to about 2 wt.% of carrier, based on the total weight of the carnitine formulation.

In a specific embodiment, a carnitine formulation according to the invention comprises, based on the total weight of the composition: - between about 45 wt.% and about 55 wt.% of carnitine or derivative thereof, preferably L-carnitine;

- between about 2.5 wt.% to about 3.5 wt.% of stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, and combinations thereof, preferably a C₁-C₄ carboxylic acid or salt thereof, even more preferably a C₁-C₃ carboxylic acid or salt thereof;

- between about 30 wt.% to about 35 wt.% of a carrier, preferably silicon dioxide, more preferably silicon dioxide with a d50 of between about 250 μm and about 325 μm; and - between about 0.5 to about 1.5 wt.% of an anticaking agent, preferably silicon dioxide having a d50 of between 75 μm and 125 μm.

In a specific embodiment, the carnitine formulation according to the invention is at least partly coated with one or more saturated fatty acids. Such a carnitine formulation has increased rumen stability, and is therefore particularly suitable for administration to ruminants.

As is known, ruminants are animals that have a stomach comprising four compartments, i.e. the rumen, reticulum, omasum and abomasum. Feed ingested by ruminants first enters the rumen, followed by the reticulum, where the feed is subjected to microbial fermentation. The fermented food is subsequently transferred to the omasum, before the residue from the omassum enters the abomasum, comparable to the monogastric stomach in non-ruminants. The digested feed then proceeds to the intestines, wherein digestion and absorption of nutrients occur. Hence, coating of the carnitine formulation with a component that is not essentially digestible by microbes present in the rumen and reticulum is important, because in absence of such coating, the carnitine formulation will be at least partly degraded before it reaches the intestines of the ruminant.

A carnitine formulation according to the invention, which is at least partly coated with one or more saturated fatty acids, is particularly suitable for use in ruminants such as bovines, goats and sheep, preferably in cows.

Preferably, a carnitine formulation according to the invention is at least partly coated with one or more saturated C₁₂-C₂₀ saturated fatty acids, more preferably saturated C₁₄-C₂₀ fatty acids, in particular saturated C₁₆-C₁₈ fatty acids. Said saturated C₁₂-C₂₀ fatty acid may be any type of saturated fatty acid known in the art, e.g. plant -based fatty acids, animal derived fatty acids, synthetic fatty acids, natural fatty acids or oils, or hydrogenated fatty acids or oils, or a combination thereof. Examples of suitable C₁₂-C₂₀ saturated fatty acids include hydrogenated C_12-

C₂₀ fatty acids, such as hydrogenated rapeseed oil, hydrogenated palm oil, hydrogenated palm kernel oil, hydrogenated peanut oil, hydrogenated corn oil, hydrogenated olive oil, hydrogenated linseed oil, hydrogenated safflower oil, hydrogenated soy oil, hydrogenated sunflower oil, saturated lard, and combinations thereof.

Preferably, said C₁₂-C₂₀ saturated fatty acids have a melting temperature or end value of a melting range of less than 90 °C, more preferably less than 80 °C, less than 75 °C, less than 70 °C, in particular less than 60 °C.

Preferably, said C₁₂-C₂₀ saturated fatty acids have a melting temperature or starting value of a melting range of more than 30 °C, more preferably more than 35 °C, more than 40 °C, more than 45 °C, in particular more than 50 °C.

In particular the melting value or range is between 30 °C and 90 °C, preferably between 35 °C and 85 °C, more preferably between 40 °C and 80 °C, in particular between 50 °C and 65 °C. In this temperature range, the C₁₂-C₂₀ saturated fatty acids are substantially solid at the temperature of administration (typically room temperature), which makes the coated carnitine formulation robust and prevents wearing off of the coating from the solid carnitine formulation. Further, the coating is advantageously applied in fluid form, to ease the coating process and to allow applying the coating homogenously. Excellent results have been obtained with a combination of hydrogenated palm oil and hydrogenated rapeseed oil.

Preferably, a carnitine formulation according to the invention, which is is at least partly coated with one or more saturated fatty acids, comprises at least about 40 wt.% of one or more saturated fatty acids, based on the total weight of the carnitine formulation, preferably at least 50 wt.% of one or more saturated fatty acids, more preferably at least 60 wt.% of one or more saturated fatty acids, in particular at least 70 wt. of one or more saturated fatty acids.

Preferably, a carnitine formulation according to the invention, which is is at least partly coated with one or more saturated fatty acids, comprises at most about 90 wt.% of one or more saturated fatty acids, based on the total weight of the carnitine formulation, preferably at most 85 wt.% of one or more saturated fatty acids, more preferably at most 80 wt.% of one or more saturated fatty acids, in particular at most 75 wt. of one or more saturated fatty acids, based on the total weight of the carnitine formulation.

Preferably, a carnitine formulation according to the invention, which is at least partly coated with one or more saturated fatty acids, comprises about 40 to about 80 wt.% of one or more saturated fatty acids, preferably about 50 to about 75 wt.% of one or more saturated fatty acids, more preferably about 60 to about 70 wt.% of or more saturated fatty acids, based on the total weight of the coated carnitine formulation.

In a specific embodiment, an at least partly coated carnitine formulation according to the invention, comprises, based on the total weight of the at least partly coated carnitine formulation: - between about 16 wt.% and about 22 wt.% of carnitine or derivative thereof, preferably L-carnitine;

- between about 0.9 wt.% to about 1.4 wt.% of stabilizer selected from an inorganic salt, a Ci-Ce carboxylic acid or a salt thereof, and combinations thereof, preferably

C₁-C₄ carboxylic acid or salt thereof, more preferably a C₁-C₃ carboxylic acid or salt thereof;

- between about 10 wt.% to about 14 wt.% of carrier, preferably silicon dioxide, more preferably silicon dioxide with a d50 of between about 250 μm and about 325 μm; and

- between about 0.2 to about 0.6 wt.% of anticaking agent, preferably silicon dioxide having a d50 of between 75 μm and 125 μm.

- between about 60 to about 65 wt.% of one or more saturated fatty acids, preferably one or more saturated C₁₂-C₂₀ fatty acids.

A carnitine formulation according to the invention is particularly suitable as food supplement to a food product. Said carnitine formulation may advantageously already be administered with other nutrients that are beneficial for animals including humans, such as essential minerals and/or essential vitamins. The invention therefore furthermore relates to a premix formulation, comprising a carnitine formulation according to the invention and one or more minerals and/or vitamins. Examples of minerals suitable for addition to the premix formulation are sodium, chloride, potassium, calcium, phosphorus, magnesium, sulfur, iron, zinc, iodine, selenium, copper, manganese, fluoride, chromium and/or molybdenum.

Examples of essential vitamins suitable for addition to a premix formulation are vitamin A, vitamin B1 (thiamin), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6, vitamin B8 (biotin), vitamin B9, vitamin BIO (factor R), vitamin Bll (folate), vitamin B12, vitamin C, vitamin D, vitamin E and or vitamin K.

The invention further relates to a food product, preferably animal feed, comprising the carnitine formulation according to the invention or the premix formulation according to the invention and one or more of a carbohydrate, a fat, and proteinaceous matter.

Any fat that is edible by animals including humans is suitable for use in the food product according to the invention. Such fats include animal fat, such as lard or butter, or a vegetable oil. Said fat may comprise saturated fatty acids, unsaturated fatty acids and polyunsaturated fatty acids and combinations thereof.

Examples of vegetable oils include rapeseed oil, sunflower oil, corn oil, soybean oil, coconut oil, palm oil, palm kernel oil, linseed oil, safflower oil, peanut oil, and olive oil. The fat may further comprise one or more of an omega-3-fatty acid, such as eicosapentaenoic acid, docosahexaenoic acid and docosapentaenoic acid.

Any carbohydrate that is edible by animals including humans is suitable for use in the food product according to the invention, including digestible and indigestible carbohydrates. Any proteinaceous matter that is edible by animals including humans is suitable for use in a food product according to the invention. For example, a protein or any part of a protein, such as non-hydrolyzed protein, native protein, hydrolyzed protein, peptides, such as oligopeptides, i.e. peptide comprising two to fifty amino acids, and free amino acids of any source may be used in the food product according to the invention. The total content of proteinaceous matter of a food product according to the invention is determinable with the Kjehldahl method as known in the art. Said food product may be formulated in any form or shape, for example as a solid, such as in pellet form, tablet form, capsule form, powder form, or fluid form such as a gel, a suspension, or a drink. Methods

The invention further relates to a method for producing a carnitine formulation according to the invention, comprising

- preparing a mixture of carnitine or a derivative thereof, a stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, and combinations thereof and optionally a carrier in a liquid medium at a temperature of between about 50 and about 95 °C; and

- cooling the mixture of carnitine, stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, and combinations thereof and optionally the carrier to form a solid carnitine formulation. Preferably, the stabilizer is a C₁-C₆ carboxylic acid or a salt thereof, more preferably a C₁-C₄ carboxylic acid or salt thereof, even more preferably a C₁-C₃ carboxylic acid or a salt thereof, such as a C₁-C₂ carboxylic acid or a salt thereof selected from the group consisting of an acetate salt, a diacetate salt, a formate salt, a diformate salt and combinations thereof, even more preferably sodium diacetate, ammonium acetate or a combination thereof.

Alternatively or additionally, the stabilizer is an inorganic salt, more preferably an inorganic salt selected from the group consisting of a chloride salt, a phosphate salt and a sulphate salt, even more preferably sodium chloride, ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof.

The mixture of carnitine or derivative thereof and stabilizer in a liquid medium is prepared at a temperature of at least 50 °C, preferably at least 55 °C, at least 60 °C, at least 65 °C, at least 70 °C or at least 75 °C. At higher temperature, carnitine or a derivative thereof, in particular L-carnitine has a higher solubility in the liquid medium, which allows to prepare a carnitine formulation with a higher carnitine content, or higher loading of carnitine or a derivative thereof on a suitable carrier.

The mixture of carnitine or derivative thereof and stabilizer in a liquid medium is prepared at a temperature of less 95 °C, preferably less than 90 °C, more preferably less than 85 °C. At these temperatures, the solubility of carnitine or the derivative thereof in the liquid medium is sufficient, whilst the method is still energy-efficient, i.e. no energy is wasted by unnecessarily increasing the temperature of the liquid medium further. Therefore, the mixture of carnitine or derivative thereof and stabilizer as defined herein in a liquid medium is prepared at a temperature of between about 50 °C and about 95 °C, preferably between about 60 °C and about 90 °C, more preferably between about 65 °C and about 85 °C, in particular between about 70 °C and about 80 °C. According to the method of the invention, said carnitine or derivative thereof and stabilizer as defined herein may be mixed with a liquid medium at a temperature below about 50 °C, such as at room temperature and subsequently heated to the temperature of about 50 and about 95 °C to obtain a solution of carnitine or derivative thereof and a stabilizer. Alternatively, said liquid medium may be provided at between about 50 and about 95 °C and subsequently said carnitine or derivative thereof and stabilizer as defined herein may be added thereto to provide a solution of carnitine or derivative thereof and stabilizer as defined herein.

A liquid medium suitable for use in the method according to the invention may be any liquid medium that is suitable of dissolving carnitine or a carrier thereof. Said liquid medium preferably is not substantially toxic to animals. Examples of suitable liquid media suitable for use in a method according to the invention include water and aqueous solutions, such as a mixture of water and a water-miscible co-solvent, for example a mixture of alcohol and water, in particular a mixture of water and ethanol. If an aqueous solution comprising water and a co solvent is used as liquid medium in a carnitine formulation according to the invention, preferably said mixture comprises about 2 to 50 wt.% of co-solvent, more preferably about 5 to about 30 wt.%, in particular about 10 to about 20 wt.% of co solvent, based on the total weight of the liquid medium. Preferably, a liquid medium suitable for use in the method according to the invention comprises water. Said aqueous solution may comprise a buffer, preferably a buffer with a pH in the range of about 2 to about 6, more preferably about 3 to about 5, in particular about 4 to about 4.5. Suitable buffers include an acetate buffer, a citrate buffer or a glycine buffer. In a method according to the invention, preferably a carrier is provided to a mixture of carnitine or the derivative thereof and a stabilizer as defined herein.

Said mixture of carnitine or derivative thereof, stabilizer and carrier may be prepared using any method known in the art. Preferably, first a solution of carnitine or derivative and stabilizer is prepared in a liquid medium at a temperature of between about 50 and about 95 °C, followed by the addition of said solution of carnitine or derivative and stabilizer to the carrier. This order of addition is advantageous, because it may be ensured that all carnitine or derivative thereof and stabilizer have been solubilized before addition of the solution to a carrier. Solubilization of carnitine and stabilizer is important, in order to allow efficient adsorption of the components onto the carrier. Furthermore, addition of a solution of carnitine or derivative thereof and stabilizer to a carrier ensures proper absorption of said solution onto the carrier.

Alternatively, said carrier may be added to a solution of carnitine or derivative thereof and stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₃ carboxylic acid or a salt thereof, and combinations thereof. Preferably, the carrier is added batch- wise, e.g. in portions of about 0.05-0.2 kg of carrier, into a solution of carnitine or derivative thereof and stabilizer to allow proper mixing of the carrier through the solution. In a method according to the invention, said mixture of carnitine or a derivative thereof, stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₃ carboxylic acid or a salt thereof, and combinations thereof and optionally carrier may be subjected to one or more treatment steps prior to cooling the mixture. For example, if a solution of carnitine or derivative thereof and stabilizer is prepared, said solution may be filtered to reduce insoluble particles, such as dust or insolubilized carnitine, or insolubilized stabilizer.

Alternatively or additionally, the pH of a mixture or solution of carnitine or a derivative thereof and stabilizer selected from an inorganic salt, a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₃ carboxylic acid or a salt thereof and combinations thereof and optionally carrier may be altered, for example to a pH of between 2.0 and 7.0, preferably between 3.0 and 6.0, more preferably between 4.0 and 5.0. The mixture of carnitine or the derivative thereof, the stabilizer and optionally the carrier is preferably prepared under agitation. Preferably, said mixture is stirred at a speed of between 5 Hz and between 60 Hz in a mixer, such as a ploughshare mixer.

According to a method of the invention, the mixture of carnitine or the derivative thereof, stabilizer as defined herein and, optionally, carrier is allowed to cool to form a solid carnitine formulation. Said mixture maybe allowed to cool, i.e. by taking away the heating means, or cooling may be enhanced, e.g. by lowering the temperature to below 25 °C. For example, the mixture may be cooled by placing it in a fridge or freezer, or by blowing cool air over the mixture to enhance the cooling process.

Optionally, a mixture of carnitine or derivative thereof, stabilizer as defined herein and, optionally, carrier may be subjected to a step of spray drying to advantageously obtain a solid carnitine formulation in powder form. Any methods for spray drying known in the art is suitable therefore.

The obtained solid carnitine formulation maybe used directly, without further purification, e.g. as food supplement. The solid formulation may be stored for a period of time, for example for a period of 1 week, 1 month, 6 months or at least 12 months, preferably at least 16 months, more preferably at least 18 months or at least 24 months, without losing more than 10 wt.% of the L-carnitine content due to degradation. Preferably, without losing more than 5 wt.%, more than 4 wt.%, more than 3 wt.%, more than 2 wt.%, more than 1 wt.%, without losing essentially any L-carnitine of the carnitine formulation, based on the total weight of the carnitine formulation.

Advantageously, no substantial drying of the solid formulation obtained in the method according to the invention is required. Omission of a drying step saves the use of energy and equipment required to decrease the water content of a solid carnitine formulation.

The method according to the invention, further preferably comprises a step of providing an anticaking agent to a mixture of carnitine or derivative thereof, stabilizer as defined herein and optionally carrier or a step of mixing an anticaking agent with the solid carnitine formulation. The presence of an anticaking agent in the solid carnitine formulation advantageously avoids the formation of aggregates in the solid carnitine formulation, thereby further improving the flowability of the carnitine formulation.

The anticaking agent may be provided to a mixture of carnitine or derivative thereof, stabilizer and optionally carrier, prior to cooling said mixture to obtain a solid carnitine formulation. Alternatively, the anticaking agent may be mixed with a solidified carnitine formulation after cooling of the mixture comprising carnitine or a derivative thereof, stabilizer and carrier. In both cases, the flowability of the obtained solid carnitine formulation may be significantly improved.

The invention further relates to a method for preparing an at least partly coated carnitine formulation according to the invention, comprising providing a solid carnitine formulation as provided herein, preferably without anticaking agent, and at least partly coating said carnitine formulation with one or more saturated C₁₂-C₂₀ fatty acids to obtain an at least partly coated carnitine formulation.

Coating of said solid carnitine formulation preferably takes place at a temperature of between 30 °C and 90 °C, more preferably between 40 °C and 80 °C, in particular around between 50 °C and 70 °C. Such a temperature typically ensures that the one or more saturated C₁₂-C₂₀ fatty acids are in fluid form and may be applied to a solid carnitine formulation. Said one or more saturated C₁₂-C₂₀ fatty acids are preferably substantially homogenously applied to a solid carnitine formulation.

Said at least partly coated carnitine formulation is preferably mixed with an anticaking agent. Addition of an anticaking agent advantageously improves the flowability of the at least partly coated carnitine formulation, as provided herein above. In said method, the flowability of the at least partly coated carnitine formulation is efficiently improved if said anticaking agent is added after coating of the solid carnitine formulation. Anticaking agent that is added before coating, is mainly captured inside the saturated C₁₂-C₂₀ fatty acid coating and hence less effective in improving flowability.

The invention further relates to a method for preparing a food product according to the invention, comprising providing a carnitine formulation according to the invention or a premix formulation according to the invention and mixing said carnitine formulation with one or more of a carbohydrate, a fat or proteinaceous matter.

Mixing of said carnitine formulation with said one or more of a carbohydrate, a fat or proteinaceous matter may be performed using any method in the art, such as by whisking, beating or stirring.

Optionally, said method further comprises a step of moulding, shaping, pressing or extruding the mixture of carnitine formulation and one or more of a carbohydrate, a fat and proteinaceous matter into a desired form. Preferably, said mixture comprising carnitine formulation and one or more of a carbohydrate, a fat and proteinaceous matter is pressed or extruded to form a pellet or tablet.

Preferably, said moulding, shaping, pressing or extruding occurs at an elevated temperature, such as a temperature of above 50 °C, more preferably above 60 °C, above 70 °C, above 80 °C, above 90 °C, most preferably above 100 °C. In particular, said moulding, shaping or pressing occurs at a temperature between 40 °C and 150 °C, more preferably between 60 and 140 °C, even more preferably between 100 and 130 °C.

Preferably, said pressing or extruding occurs at a pressure of at least 2 bar, more preferably at least 5 bar, at least 7 bar, at least 9 bar, at least 10 bar. In particular, said pressing occurs at a pressure of between 5 and 20 bar, such as around 10 bar.

The invention further relates to a method for feeding an animal, comprising providing a food product or carnitine formulation according to the invention and administering said food product to an animal in need thereof.

The food product may be administered to any animal that benefits from administration of the carnitine formulation. Preferably, the food product or carnitine formulation is administered to livestock, such as cattle, goat, sheep, lamb, pig and horse, or to poultry, such as chicken, turkey, pheasant and fowl. Said food product or carnitine formulation according to the invention may further be administered to domestic animals such as cat, dog, rabbit, guinea pig, hamster or rat, or to wild animals such as deer, haze or wild boar.

The invention further relates to the use of a C₁-C₆ carboxylic acid or a salt thereof, preferably a C₁-C₄ carboxylic acid or salt thereof, more preferably a C₁-C₃ carboxylic acid or a salt thereof in improving the stability of a carnitine formulation and/or improving the flowability of a carnitine formulation. As the skilled person will appreciate, said use encompasses both the improvement of stability and/or flowability of a carnitine formulation as such, as well as the improvement of stability and/or flowability of a product comprising said carnitine formulation. Examples include a premix formulation comprising a carnitine formulation according to the invention and a food product, such as animal feed, comprising a carnitine formulation according to the invention.

Preferably, said C₁-C₃ carboxylic acid or a salt thereof is sodium diacetate, ammonium acetate or a combination thereof.

The invention further relates to the use of an inorganic salt for improving the stability of a carnitine formulation and/or for improving the flowability of a carnitine formulation. Preferably, said inorganic salt is selected from the group consisting of a chloride salt, a phosphate salt and a sulphate salt, more preferably said inorganic salt is sodium chloride, ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof. The invention further relates to the non-medical use of a carnitine formulation or a food product according to the invention to enhance the metabolism of fatty acids in an animal including human in need thereof.

Said food product or carnitine formulation according to the invention is preferably administered to a healthy human, preferably a healthy human of 12 years or more, more preferably of 15 years or more, in particular of 18 years or more, for cosmetic or nutritional purposes, e.g. to improve shape of the body or to increase nutrient intake. For example, said human may be an athlete or worker performing intense labour that may benefit from an increased intake of carnitine or a derivative thereof, preferably from increased L-carnitine intake (Karlic et al, 2014. Nutrition, 20(7-8): 809-715). Preferably, said human is not obese, or anorexic.

The food product or carnitine formulation according to the invention may further be administered to humans at risk of becoming carnitine-deficient. For example humans having a vegetarian or vegan diet may become carnitine, specifically L- carnitine deficient, because L-carnitine and the L-carnitine precursors methionine and lysine are less abundant in plant-based food.

Alternatively, said food product or carnitine formulation according to the invention may be administered to humans of the age of 10 or less, preferably 8 or less, 6 or less, 4 or less, 2 or less, in particular 1 year or less. In particular, said food product or carnitine formulation according to the invention may be administered to an infant, preferably an infant of the age of between 1 and 24 months, preferably between 3 and 18 months, in particular between 6 and 12 months. Newborn babies do not (sufficiently) synthesize L-carnitine in the body and therefore benefit from supplementation with L-carnitine (Crill, et al. 2007. Nutr Clin Pract 22: 204-213).

The invention further relates to a carnitine formulation or food product for use in a method of treating a medical condition associated with deficiency of carnitine or a derivative thereof, in particular L-carnitine.

Examples of medical conditions associated with deficiency of carnitine or a derivative thereof, include metabolic disorders, cardiovascular disease, mood disorders, such as depression, Alzheimer’s disease, or fatigue.

The human may be a human suffering from a metabolic disorder. Said metabolic disorder may be a disorder leading to insufficient L-carnitine production in the body, thereby hampering metabolism of fatty acids into energy. This may lead to fatigue, tiredness, depression and the like. Evidence suggests that intake of L-carnitine has a beneficial effect in treatment of subjects suffering from chronic fatigue syndrome (Pliopys et al. 1997. Neuropsychobiology 35: 16-23).

The carnitine formulation or food product according to the invention may be for use in treating Alzheimer’s disease. Preferably, said carnitine formulation comprises acetyl-L-carnitine. Evidence suggests that intake of acetyl-L-carnitine is advantageous in slowing down dementia in Alzheimer’s patients (Spagnoli, et al., 1991. Neurology, 41: 1726-32; Bownman et al., 1992. Nutrition Reviews 50: 142- 144).

Preferably, a carnitine formulation or food product according to the invention is for use in treating an elderly human, i.e. a human having an age of 50 or more, preferably 60 or more, 65 or more, 70 or more, in particular 75 or more.

The invention further relates to a method of treating a human suffering from a condition associated with carnitine deficiency, preferably suffering from Alzheimer’s disease, fatigue, depression or a metabolic disorder. The invention further relates to a use of a carnitine formulation according to the invention in the manufacturing of a medicament for treating a condition associated with carnitine deficiency, preferably for treating Alzheimer’s disease, fatigue, depression or a metabolic disorder. For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

The invention is illustrated by the following nondimiting examples.

Examples

Example 1 : Solubility of carnitine

60 g of L-carnitine and 40 g of water were provided into a locked glass vessel. Then the mixture was heated to 60 °C. When L-carnitine was completely dissolved, an additional 2,5 g of L-carnitine was added to the solution. This step was repeated until the solution was saturated and no additional L-carnitine could be dissolved. Then, the temperature was raised, with increments of 2 °C, until max. 84 °C, until the solution was completely clear again and all L-carnitine had dissolved. At 78 °C, a total amount of 155 g carnitine was dissolved into 40 g of water, to give a solution of 79.49 wt.% L-carnitine (Figure 1). At higher temperature, no more L-carnitine could be dissolved.

Example 2: Characteristics of stabilizers 76.5 g of L-carnitine, 23.5 - x g of water and x g (1 to 10 g) stabilizer (Table 1) were provided into a locked glass vessel. The mixture was heated up to 80 °C until a solution was obtained.

The solution was cooled down to 25 °C to obtain a solid complex of L-carnitine and stabilizer.

The crystallization process was determined in terms of solubility, coloring of the solution and rate of crystallization, as shown in Table 1. Table 1. Properties of L-carnitine solution with different stabilizers. Water reduction (- <1% / 0 1-5 % / + >5%); Coloring reaction ( - faster / 0 equal / + slower ); Crystallization ( - slower or no / 0 equal / + faster ); Hardness ( - softer / 0 equal /

+ harder )

The reduction of water in carnitine formulations comprising L-carnitine and stabilizer in water was determined for all mixtures of L-carnitine and stabilizer in water.

For all stabilizers, except for citric acid, the content of water in the carnitine formulation could be reduced or kept the same, compared to a control formulation comprising L-carnitine, but essentially free of stabilizer. In presence of a stabilizer, less water was required to dissolve the same amount of L-carnitine (76.5 wt.% based on the total weight of the carnitine formulation). (Table 1).

Coloring of the solution of L-carnitine and stabilizer was determined by visually detecting occurrence of browning of the solution over time and comparing to an L- carnitine solution in absence of stabilizer (control). When browning occurred at a later time point, or was absent, compared to the control formulation comprising L- carnitine in water, but in absence of a stabilizer, a (+) was assigned. When browning occurred faster than in the control, a (-) was assigned.

As can be derived from Table 1, C₁-C₆ carboxylic acids or salts thereof had a positive effect on browning of an L-carnitine solution. Typically, no browning or slower browning was observed for mixtures of L-carnitine and C₁-C₆ carboxylic acids or salts thereof compared to the control. In contrast, polyols and inorganic salts did not decrease the rate of browning.

Furthermore, the rate of crystallization of the solutions of L-carnitine and stabilizers were monitored. As can be derived from Table 1, polyols, inorganic acids and salts of C₁-C₆ carboxylic acids increased the rate of crystallization, compared to the control carnitine formulation (L-carnitine in absence of stabilizer), whereas only the C₁-C₆ carboxylic acids propionic acid and citric acid improved the crystallization rate.

In addition, hardness of the solid carnitine formulations of L-carnitine and stabilizers were determined, by visual inspection and manual inspection of the solids by trained personal. As can be derived from Table 1, inorganic acids and salts of C₁-C₆ carboxylic acids increased the hardness of the solid carnitine formulation, compared to the control carnitine formulation (L-carnitine in absence of stabilizer), whereas polyols were not capable of improving the hardness of the solids comprising L-carnitine.

Fxamnle 3: Texture measurement Solids obtained in Example 1 were prepared at least in quadruple samples and then measured with a TA.HDplusC Texture Analyser (Stable Micro Systems) according to the manufacturer’s instructions. The results are shown in Figures 2 and 3. As can be derived from Figure 2, all salts of C₁-C₆ carboxylic acids increased the hardness of the carnitine formulation according to the invention. The best results were obtained with 5 wt.% of sodium diacetate or ammonium acetate, based on the total weight of the carnitine formulation. To the contrary, carnitine formulations comprising L-carnitine and sorbitol or glucose did not increase the hardness of the carnitine formulation, compared to a control carnitine formulation, comprising only L-carnitine and essentially free of stabilizer (Figure 3). Fxamnle 4: Temperature stress

Coloring of a carnitine formulation comprising 5 wt.% of sodium diacetate was determined. A solution of L-carnitine (76.5 g), sodium diacetate (5 g) in water (18.5 g) at 80 °C was kept for 24 h. After 24 h, the content of L-carnitine was determined and compared to the control. The L-carnitine content in the carnitine formulation comprising sodium diacetate had not changed over time, which indicates that no degradation had occurred during 24 h at 80 °C. To the contrary, in the control sample (no sodium diacetate), the L-carnitine content was decreased by 10% due to degradation of L-carnitine to form ammonia. The results are visualized in Figure 4.

Fxamnle 5: Shear cell measurement

1.95 kg of liquid carnitine formulation comprising 5.0 wt.% sodium diacetate, 1.95 kg of L-carnitine solution (no sodium diacetate or other stabilizer), 1.95 kg of liquid carnitine formulation comprising 5.0 wt.% glucose and 1.95 kg of liquid carnitine formulation comprising 5.0 wt.% sorbitol were prepared at 80 °C.

Each solution was mixed with 1.02 kg carrier (precipitated silicon dioxide; d50 around 300 μm) in a preheated ploughshare mixer (MIX S.r.L). The mixer-shell was heated to 50 °C to simulate greater production volumes with poorer heat dissipation. The speed was set at 8 Hz until all carrier was filled. Then the speed was increased to 30 Hz and the carnitine formulation was poured into the mixer during 5 minutes. The speed was then further increased to 60 Hz for 6 minutes.

For process I: 0.03 kg anticaking agent (precipitated silicon dioxide; d50 around 100 μm) was added to the liquid carnitine formulation (comprising sodium acetate) and to L-carnitine solution (no stabilizer). The suspensions were mixed for 2 minutes at 50 Hz, and subsequently allowed to cool down to room temperature to obtain a solid carnitine formulation and a solid comprising L-carnitine and carrier. For process II: The liquid carnitine formulation was cooled down to room temperature to obtain a solid carnitine formulation. Subsequently, 0.03 kg anticaking agent (precipitated silicon dioxide; d50 around 100 μm) was added to the cooled mixture. The shear stress of the solids obtained with process I (and process II were analyzed using a Powder Rheometer FT4 (Freemann technology) and compared to the shear stress of the carrier at the same normal stress (precipitated silicon dioxide; d50 around 300 μm) and the shear stress of a reference carnitine formulation (“Levocarnitine 50%” of North East Pharmaceutical Co. Ltd.)

Shear cell 9 kPa“ was used according to the manufacturer’s instructions using a 25 mm vessel to determine the shear stress of the solids at normal stress of up to 9 kPa. The results are shown in Figure 5.

In addition, the flow function was determined for the carnitine formulation prepared according to process II and compared to the flow function of the carrier, a control carnitine formulation comprising carrier and L-carnitine, and essentially free of stabilizer, and the reference product “Levocarnitine 50%). The results are shown in Figure 6.

As can be derived from Figure 5, the carnitine formulations according to the invention, comprising sodium diacetate as stabilizer showed similar shear stress at normal stress compared to the carrier without carnitine formulation. These results indicates that the presence of the carnitine formulation does not substantially modify the flowability of the carrier.

To the contrary, a carnitine formulation comprising L-carnitine and carrier (in absence of stabilizer) had a higher shear stress at the same normal stress, indicating that the product was less flowable than a carnitine formulation according to the invention.

Similarly, as can be derived from Figure 6, a carnitine formulation comprising glucose or sorbitol exhibited a higher shear stress at normal stress than a carnitine formulation according to the invention, indicating a lower flowability than the carnitine formulation according to the invention.

Further, as can be derived from Figure 5, a carnitine formulation according to the invention exhibited similar shear stress at normal stress as the reference carnitine formulation “Levocarnitine 50%” of Northeast Pharmaceutical Group, which has been subjected to a step of drying.

These results are also confirmed by the flow function of each composition. A carnitine formulation according to the invention has a flow function of about 70, indicating free flowing. As can be derived from Figure 7, the flow function of a carnitine formulation comprising carrier and L-carnitine was significantly lower than the flow function of a carnitine formulation according to the invention. Further, the flow function of a carnitine formulation according to the invention was comparable to the flow function of the same carrier, essentially free of L-carnitine and stabilizer, or the reference product.

Accordingly, it follows from Figures 5 and 7 that a carnitine formulation according to the invention comprises similar shear stress at normal stress as the reference formulation “Levocarnitine 50%”, without requiring extensive drying of said carnitine formulation.

Fxarrmfe 6: Rumen stability

1.00 kg of a carnitine formulation comprising sodium diacetate as prepared using process I (see example 5) was coated with 1.67 kg hydrogenated fat (palm/rapeseed oil, melting point 61°C) in a fluidized bed system (Glatt 3 ProCell Lab System, bottom spray, Wurster process) at a supply air temperature of 45 °C, a volume flow of ~ 140 m³/h, a fat temperature 90°C and spray rate (4.4 g/min to 10 g/min).

The ruminal in-vitro digestibility of the carnitine formulation coated with hydrogenated fat was determined using ANKOM Daisy II Incubator according to manufacturer’s instructions, using rumen inoculum. The results are shown in Figure 8.

As can be derived from Figure 8, the carnitine formulation coated with hydrogenated fat exhibited a recovery rate of approximately 90 % of the total carnitine formulation. The uncoated carnitine formulation only showed around 35 %, which correlate with the content of solid material (silicon dioxide) in the sample. This indicate that the majority of the L-carnitine was digested by the microbes present in the rumen. Example 7: Pellet stability

A first dog food mixture was prepared by mixing 5 kg premium model dog food (ingredients: potato flakes 49.3 wt.%, poultry greaves 32.7 wt.%, poultry fat 7.8 wt.%, pea protein 6.0 wt.%, calcium carbonate 2.2 wt.%, disodium phosphate 1 wt.%, L- carnitine 1.0 wt.%) at 29 Hz for 2 minutes in a mixer (MIX S.r.l N-MXCM0012) while adding an antioxidant formulation comprising 0.1 g of Butylated hydroxytoluene (BHT) and 0.1 g of Butylhydroxyanisol (BHA) in 0.8 g of rapeseed oil and 380 g poultry fat over a gravimetic nozzle. The mixer was then ramped to 45 Hz for 3.5 minutes.

A second dog food mixture was prepared by mixing 5 kg vegan model dog food (ingredients: pea protein 53.1 wt.%, potato flakes 30.7 wt.%, rapeseed oil 9.6 wt.%, cellulose 1.4 wt. %, calcium carbonate 2.2 wt.%, L-carnitine 2.0 wt.%, disodium phosphate 1 wt.%) at 29 Hz for 2 minutes in a mixer (MIX S.r.l N-MXCM0012) while adding an antioxidant formulation comprising 0.25 g of BHT and 0.25 g of BHA in 477 g of rapeseed oil over a gravimetic nozzle. The mixer was then ramped to 45 Hz for 3.5 minutes. Subsequently, 100 g of a carnitine formulation according to the invention comprising - based on the total weight of the carnitine formulation - 5 wt.% of sodium acetate as prepared using process II as described in Example 5 or 100 g of Levocarnitine 50 % North East (reference) was added to the dog food mixtures. As a second reference product, a pellet was prepared lacking an additional carnitine formulation. This reference product thus only contains the L-carnitine already present in the premium model or vegan model dog food.

In the next step the dog food mixtures were pelletized using a twin-shaft hot extruder (Biihler DNDL-44) using the following settings: Toque 6 %, speed 55 rpm, cutter speed 22 rμm, water addition approximately 3 kg/h, pressure 10 bar, zone temperature 100 to 130 °C. The pellets were subsequently dried in a convection oven (Stikken MIWE roll-in e+) at 90 °C for 15 minutes to reach a final residual humidity of 4%. 1 g of pellets was subsequently grinded and the ground pellet was extracted with 20 mL of acetonitrile/water 2:8. The content of L-carnitine in the soluble fraction was determined using LC-MS/MS. The results are shown in Figure 9. It can be derived from Figure 9 that from a pellet comprising a carnitine formulation according to the invention, approximately 6 to 8% more of L-carnitine was recovered from the pellet compared to the pellet comprising a reference carnitine formulation lacking a stabilizer. In addition, from the reference pellet, lacking additional carnitine, no L-carnitine could be recovered, because the amount of L-carnitine still present appeared to be below the detection limit (>0.05%). These results indicate a higher stability of L-carnitine when present as a carnitine formulation according to the invention and hence lower degradation during the preparation of the pellet. This experiment shows that the improved stability of a carnitine formulation according to the invention is also beneficial during manufacturing of the carnitine formulation into an end product, such as a pellet of dog food.

Claims

1. A carnitine formulation, comprising

- carnitine or a derivative thereof; and

- a stabilizer selected from an inorganic salt, a C₁-C₃ carboxylic acid or a salt thereof, and combinations thereof.

2. The carnitine formulation according to claim 1, wherein the stabilizer is a C₁- C₃ carboxylic acid or a salt thereof.

3. The carnitine formulation according to claim 1 or 2, wherein the C₁-C₃ carboxylic acid or salt thereof is selected from the group consisting of an acetate salt, a diacetate salt, a formate salt, a diformate salt and combinations thereof.

4. The carnitine formulation according to any one of claims 1-3, wherein the C₁- C₃ carboxylic acid or salt thereof is sodium diacetate, ammonium acetate or a combination thereof.

5. The carnitine formulation according to claim 1, wherein the stabilizer is an inorganic salt.

6. The carnitine formulation according to claim 5, wherein the inorganic salt is selected from the group consisting of a chloride salt, a phosphate salt and a sulphate salt.

7. The carnitine formulation according to claim 6, wherein the inorganic salt is sodium chloride, ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof.

8. The carnitine formulation according to claim 6 or 7, wherein the inorganic salt is ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof.

9. The carnitine formulation according to any one of the preceding claims, wherein the carnitine formulation is a solid having a hardness of at least about 12 N, preferably at least about 15 N, in particular at least about 20 N as determinable with a TA.HDplusC Texture Analyser.

10. The carnitine formulation according to any one of the preceding claims, further comprising a carrier, preferably wherein the carrier comprises silica, most preferably silicon dioxide.

11. The carnitine formulation according to claim 10, further comprising an anticaking agent.

12. The carnitine formulation according to claim 9 or 11, wherein the carnitine formulation comprises granules.

13. The carnitine formulation according to any one of claims 9 to 12, wherein the flow function is at least 25, more preferably at least 50.

14. The carnitine formulation according to any one of claims 8 to 13, wherein the carnitine formulation is at least partly coated with one or more saturated fatty acids, preferably one or more saturated C₁₂-C₂₀ fatty acids.

15. A premix formulation, comprising the carnitine formulation according to any one of the preceding claims and one or more minerals and/or vitamins.

16. A food product, preferably animal feed, comprising the carnitine formulation according to any one of claims 1 to 14, or the premix formulation according to claim 15, and one or more of a carbohydrate, a fat, and proteinaceous matter.

17. The food product according to claim 16, wherein the food product is formulated as a pellet.

18. A method for producing a carnitine formulation according to any one of claims 9 to 13, comprising a) preparing a mixture of carnitine, a stabilizer selected from an inorganic salt, a C₁-C₃ carboxylic acid or a salt thereof, and combinations thereof and optionally a carrier in a liquid medium at a temperature of about 50-95 °C, preferably about between 75-85 °C; and b) cooling said mixture of carnitine, stabilizer and optionally the carrier to form a solid carnitine formulation.

19. The method according to claim 18, wherein the stabilizer is a C₁-C₃ carboxylic acid or a salt thereof.

20. The method according to claim 19, wherein the C₁-C₃ carboxylic acid or salt thereof is selected from the group consisting of an acetate salt, a diacetate salt, a formate salt, a diformate salt and combinations thereof.

21. The method according to claim 20, wherein the C₁-C₃ carboxylic acid or salt thereof is sodium diacetate, ammonium acetate or a combination thereof.

22. The method according to claim 18, wherein the stabilizer is an inorganic salt.

23. The method according to claim 22, wherein the inorganic salt is selected from the group consisting of a chloride salt, a phosphate salt and a sulphate salt.

24. The method according to claim 23, wherein the inorganic salt is sodium chloride, ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof.

25. The method according to claim 22 or 23, wherein the inorganic salt is ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof.

26. The method according to any one of claims, further comprising providing an anticaking agent to the mixture of carnitine, the stabilizer and optionally the carrier obtained in step a) or by mixing an anticaking agent with the solid carnitine formulation obtained in step b).

27. A method for preparing a food product according to claim 16, comprising providing the carnitine formulation according to any one of claims 1 to 14, or the premix formulation according to claim 15, and mixing said carnitine formulation with one or more of a carbohydrate, a fat or proteinaceous matter.

28. A method for feeding an animal, comprising providing a food product according to claim 16 and administering said food product to an animal in need thereof.

29. Use of a C₁-C₃ carboxylic acid or a salt thereof for improving the stability of a carnitine formulation and/or for improving the flowability of a carnitine formulation.

30. Use according to claim 29, wherein the C₁-C₃ carboxylic acid or a salt thereof is sodium diacetate, ammonium acetate or a combination thereof.

31. Use of an inorganic salt for improving the stability of a carnitine formulation and/or for improving the flowability of a carnitine formulation.

32. Use according to claim 31, wherein the inorganic salt is selected from the group consisting of a chloride salt, a phosphate salt and a sulphate salt.

33. Use according to claim 32, wherein the inorganic salt is sodium chloride, ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof.

34. Use according to claim 32 or 33, wherein the inorganic salt is ammonium sulphate, hydrogen phosphate, sodium phosphate, potassium phosphate or a combinations thereof.

35. The carnitine formulation according to any one of claims 1 to 14, the premix formulation according to claim 15 or the food product according to claim 16 or 17 for use in a method of treatment by therapy.

36. The carnitine formulation, the premix formulation or the food product for use according to claim 35, comprising treatment of deficiency of carnitine or a derivative thereof in a subject in need thereof.

37. The carnitine formulation, the premix formulation or the food product for use according to claim 35 or claim 36, comprising treatment of a metabolic disorder, a cardiovascular disease, a mood disorder, Alzheimer’s disease, or fatigue

38. Non-medical use of the carnitine formulation according to any one of claims 1 to 14, the premix formulation according to claim 15 or the food product according to claim 16 or 17 in enhancing the metabolism of fatty acids in an animal.