EP1677622A1 - Veterinary method for administering a vitamin e derivative and formulation - Google Patents

Abstract

The invention relates to a non-therapeutic, veterinary method, comprising orally administering a stable vitamin E derivative to a monogastric animal, alone or in admixture with an additive and/or food, said derivative being hydrolysable into the assimilable form of the vitamin E and administered to said animal in the presence of at least one food emulsifier, selected from the non-ethoxylated esters of sorbitol and fatty acids. Said invention also relates to a formulation which comprises a stable vitamin E derivative and the at least one food emulsifier and the use of a food emulsifier in animal nutrition.

Description

 ZOOTECHNICAL PROCESS FOR THE ADMINISTRATION OF A VITAMIN E DERIVATIVE AND FORMULATION

The present invention relates generally to the administration of vitamin E to monogastric farm animals, such as pigs and poultry, but also fish and shrimp. Vitamin E, or d-α-tocopherol, exists in nature mainly in vegetable oils; it is obtained after various synthetic routes in the racemic form of d, l-α-tocopherol (abbreviated as Toi). Vitamin E is, in its native state, an oily, lipophilic liquid, miscible in all proportions in any hydrophobic or lipid phase. It is extremely unstable, and easily oxidizable, and, in the oxidized state, it loses most of its biological activity. Its bioavailability in animals does not exceed 50% when it is administered orally, because, rapidly oxidized, it is mainly absorbed in an oxidized, inactive form. Also, when administered orally, vitamin E is administered in the form of a more stable derivative, generally chosen from esters, for example acetate, and vitamin E salts. 'prior art closest to the invention and the problems encountered by this prior art, and to present the invention, a definition of bioavailability as understood in the following description is given below. The bioavailability of vitamin E or a derivative of vitamin E is represented by the concentration of vitamin E released in the blood, compared to the concentration of vitamin E present in the ration of the animal, or compared to the concentration expressed in vitamin E equivalent of the vitamin E derivative introduced into the animal's ration when a vitamin derivative is administered. This representation of the bioavailability of vitamin E therefore takes into account the absorption of vitamin E or the vitamin E derivative in the intestine during the digestive transit. According to T. Julianto et al., International Journal of Pharmaceutics, 200 (2000) pp 53-57, the authors prepared a solution of vitamin E in palm oil, emulsified in a mixture of emulsifiers, then after dilution in water, they examined the bioavailability of vitamin E in such a solution, in humans, and compared it to that of a vitamin E intake in the form of capsules. We learn that the bioavailability of vitamin E is three times greater when vitamin E is provided in the solution described above. Given the instability of vitamin E in non-esterified form, such a solution cannot find applications in a food supplement. Various animal food supplements are known, in particular marketed by the Applicant, in which vitamin E is administered in the form of vitamin E acetate, or d, l-α-tocopheryl acetate (Tac), on various supports such as example adsorption on silica, or different physical forms, for example oil in water emulsion. Since the publication of HE Gallo-Torres, Lipids (1,970) Vol. 5, N ° 4, pp 379-384, we know that Tac is not assimilated directly, in humans or animals, but that it is in fact hydrolyzed to vitamin E, in the gastrointestinal tract , under the action of pancreatic enzymes called cholesterol-ester-hydrolases (abbreviated CEH), vitamin E is finally absorbed from the intestinal wall. However, Tac has limited bioavailability, for example at best 40%, regardless of the animal considered. The object of the present invention is therefore to improve the bioavailability of derivatives of vitamin E, and in particular of Tac. It has been discovered, completely surprisingly, that the presence of a particular emulsifier makes it possible to significantly increase the bioavailability of a vitamin E derivative, said derivative being hydrolyzable to the assimilable form of vitamin E. This emulsifier is edible and is chosen from non-ethoxylated esters of sorbitol and fatty acids. According to the Russian patent, SU-1 676 572, a composition is known comprising vitamin E acetate, a polyethoxylated emulsifier and ethanol. It is added to poultry beverages in a proportion that ensures daily absorption of vitamin E of the order of 3 mg over specified periods of time. The authors observe an assimilability of vitamin E, a survival rate and a weight gain of poultry a little higher than those obtained with conventional compositions. The problem of bioavailability of vitamin E in farm animals by administration in their ration remains due to the too low levels obtained with the known compositions. The Applicant has demonstrated a substantially greater effect of an emulsifier of the invention on the bioavailability of vitamin E of a composition of the invention, in particular compared to a polyethoxylated emulsifier. It further discovered that said emulsifier promotes hydrolysis of the vitamin E derivative in its assimilable form, in the gastrointestinal tract, this phenomenon favorably influencing the release of bioavailable vitamin E. The invention is described below in more detail and its advantages will be illustrated in examples, in particular comparative examples. According to a preferred variant of the invention, the emulsifier is chosen from esters of long chain fatty acids, for example those having a hydrocarbon chain, saturated or unsaturated, of at least 11 carbon atoms. Thus, a first object of the invention is thus a zootechnical process, which makes it possible to administer to monogastric farm animals, a formulation of a vitamin E derivative, in which at the same time, vitamin E is protected up to 'until it reaches its place of absorption, and it is bioavailable in high proportion. The method according to the invention is a non-therapeutic method, consisting in administering orally to monogastric farm animals, a stable derivative of vitamin E, alone or as a mixture with an additive and / or a food, said derivative being hydrolyzable to the assimilable form of vitamin E, in the presence of at least one food emulsifier chosen from non-ethoxylated esters of sorbitol and of fatty acids. By fatty acid according to the invention is preferably meant a monocarboxylic acid comprising a hydrocarbon chain with n carbon atoms, n being an integer varying from 0 to 30, said chain being saturated or unsaturated. According to a more advantageous variant, the fatty acids according to the invention have a hydrocarbon chain, saturated or unsaturated, of at least 11 carbon atoms. According to the process of the invention, the vitamin E derivative and the emulsifier can be administered to the animal, concomitantly or sequentially, for example the emulsifier being supplied to the animal before the vitamin E derivative. Thus, the vitamin E derivative and / or the emulsifier or emulsifiers can be mixed with the food. The invention also relates to a food formulation for animal nutrition allowing in particular the implementation of the above process, which comprises a stable derivative of vitamin E, said derivative being hydrolyzable to the assimilable form of vitamin E, and at least a food emulsifier chosen from non-ethoxylated esters of sorbitol and fatty acids. According to a variant of the invention, it is preferable to use two food emulsifiers corresponding to the definition above. A formulation of the invention preferably satisfies at least one of the characteristics described below. The weight ratio of the emulsifier, or emulsifiers, to the vitamin derivative can vary from 10/1 to 1/200, advantageously it is between 1/5 and 1/100. The vitamin E derivative is preferably a vitamin E ester, in particular vitamin E acetate. A preferred emulsifier is a sorbitol ester chosen from monolaurate (MLS), monopalmitate (MPS), monostearate (MSS) , monooleate (MOS) and tristearate. Monoleate is preferred. As the examples below will demonstrate, an advantageous formulation according to the invention comprises vitamin E acetate and at least one emulsifier chosen from sorbitol monolaurate and sorbitol monooleate. Another object of the invention is the use of a food emulsifier chosen from non-ethoxylated esters of sorbitol and of fatty acids, for preparing a food formulation for animal nutrition based on a vitamin E derivative, said fatty acids advantageously meeting the above definition. Yet another object of the invention is the use of a food emulsifier described above, for increasing the bioavailability of vitamin E in a monogastric animal, said derivative being hydrolysable into the assimilable form of vitamin E The examples below illustrate the influence of an emulsifier of the invention on the bioavailability of a vitamin E derivative, its greater effect in comparison with known emulsifiers and its influence on the hydrolysis of the vitamin E derivative, in support of the drawings in which: Figure 1 is a graph representing the equivalent quantity of vitamin E fixed by a cell culture, in nmoles / cm ² , as a function of the quantity of incubated Tac, in nmoles / cm ² , said Tac being incubated without MOS (empty columns) and with 0.05% MOS (hatched columns). Figures 2 and 3 are graphs representing the equivalent amount of fixed vitamin E corresponding to retinyl acetate (Rac, an internal reference) in black columns, Tac in hatched columns and d, l-α-tocopherol in empty columns, depending on the absence or the presence and nature of the emulsifier incubated with Tac. According to Figure 2, the emulsifier / vitamin E equivalent ratio is 6, according to Figure 3, this ratio is 1. FIG. 4 represents the rate of hydrolysis from Tac to Toi as a function of the incubation time under the conditions described in Example 5, 5.2). FIG. 5 represents the rate of hydrolysis from Tac to Toi as a function of the incubation time under the conditions described in Example 5, 5.1).

Example 1 Influence of Emulsifiers on the Absorption of Vitamin E Acetate (Tac) in an In Vitro Cell System By In Vitro Tests on an Appropriate Cell Model, the Quantity of Tac, Expressed in Vitamin E Equivalents, is Measured , fixed by the cell, by incubation of a corresponding cell culture, on the one hand in the presence of Tac alone, and on the other hand in the presence of Tac with one or more food emulsifiers according to the invention. The selected cell model is a parental line called CaCo-2, available or accessible under the reference HTB-37 from the American Type Culture Collection (ATCC). According to this test, a cell culture of the previously identified line is incubated for 3 hours, in the presence of micelles consisting of a suspension of Tac in water. The amount of micelles introduced into the cell culture is measured in nmoles / cm ² of Tac and varies from 4 to 60 nmoles / cm ² . For each concentration of Tac thus introduced into the cell culture, the amount of Tac fixed by the cell culture is measured, expressed in equivalent of vitamin E in nmoles / cm ² , on the one hand without emulsifier introduced into said culture, and of on the other hand with an amount of 0.05% (m / v) of the emulsifier MOS (sorbitan monooleate), this percentage being obtained by dividing the mass of the emulsifier introduced into the culture relative to the volume of micelles introduced into the same culture. The graph shown in Figure 1 represents the amount of fixed Tac expressed in equivalent of vitamin E in nmoles / cm ² , compared to the amount of incubated Tac, expressed in nmoles / cm ² , the empty columns referring to the micelles introduced without MOS , and the hatched columns referring to the micelles introduced with 0.05% MOS. It is noted that the higher the amount of Tac incubated, the greater the amount of corresponding vitamin E equivalent, until observing in the last test, a fixation of Tac by the cells six times greater when using the emulsifier. MOS.

Example 2 Influence of Emulsifiers on the Absorption of Vitamin E Acetate (Tac) and of Vitamin E in an In Vitro Cell System

2. 1) Experimental protocol: Absorption tests are carried out with the same cell line as that described above, by incubating the cells for 3 hours, in a physiological medium close to the intestinal medium, containing the cholesterol ester hydrolase (CEH ), the pancreatic enzyme hydrolyzing Tac to vitamin E in animals, and sodium taurocholate which represents bile salts. This medium is in the form of an oil-in-water emulsion, in the form of micelles and is commercially identified under the reference M20. It is in this medium that the Tac and possibly the emulsifier tested are placed. The concentration of vitamin E equivalent introduced into each well, in the form of Tac, is 1566 μM. For each test, three boxes of six wells are used

(representing for each well an area of 9.6 cm ² ) containing the aforementioned medium with respectively different emulsifiers. Each experiment is therefore carried out three times.

2.2) Weight ratio of the emulsifier added to the Tac (in vitamin E equivalent) of M 20 = approximately 6: According to the present test, the concentration of the emulsifier introduced into the M20 medium is 0.05%, expressed in mass of emulsifier (s) by volume of M20, which corresponds approximately to a weight ratio of the emulsifier added to the Tac of M20 of approximately 6. Six experiments are carried out, each being repeated three times, with a protocol comprising three incubation hours, as follows: 1) M20 alone, at a rate of 2 mM M20 per well; Tac is therefore alone without an emulsifier; 2) M20 + MLS emulsifier (sorbitan monolaurate) 3) M20 + MPS emulsifier (sorbitan monopalmitate) 4) M20 + MLSE emulsifier (polyoxyethylated sorbitan monolaurate) 5) M20 + a mixture of 1,56 μM Tac and 1,56 μM of d, l-α-tocopherol, 6) An internal reference, called Rac (retinyl acetate), to verify the analysis. The graph according to Figure 2 represents, for each test, and expressed in nmoles of vitamin E equivalent fixed per well: the amount of Rac, shown in black column, - the amount of Tac fixed by the cells, shown in the columns hatched, and the amount of vitamin E, obtained by hydrolysis and then fixed, shown in the empty columns. As demonstrated by tests 2) and 3), the amount of vitamin E absorbed by the cell culture is increased by approximately 50%, compared to that absorbed from M20 alone. On the contrary, it is observed with test 4) in comparison with test 1) without emulsifier, that the emulsifier MLSE, corresponding to emulsifier 2) (MLS) ethoxylated, tends to prevent the absorption of Tac and vitamin E. Unexpectedly, it is found that the ethoxylation of the emulsifier inhibits the favorable influence of an emulsifier of the invention on the absorption of Tac and of vitamin E. 2.3) Weight ratio of the emulsifier added to Tac (in vitamin E equivalent) of M 20 = approximately 1: According to the present test, the concentration of the emulsifier introduced into the M20 medium is 0.01%, expressed in mass of emulsifier (s) relative to the volume of M20, which corresponds approximately to a weight ratio of the emulsifier added to the Tac of M20 of approximately 1. Six experiments are carried out, each being repeated three times, with a protocol comprising three hours of incubation, as follows: 1) M20 alone, at a rate of 2 mM M20 per well; it is therefore sodium taurocholate and Tac alone 2) M20 + MLS emulsifier (sorbitan monolaurate) 3) M20 + MPS emulsifier (sorbitan monopalmitate) 4) M20 + MLS emulsifier and MPS emulsifier 5) M20 + MOS emulsifier (sorbitan monooleate) 6) The internal reference, called Rac, to verify the analysis. The graph according to FIG. 3 represents, for each test, and expressed in nmoles of vitamin E equivalent fixed by well: - the amount of Rac, shown in black column, - the amount of Tac fixed by the cells, shown in the hatched columns, and - the amount of vitamin E, obtained by hydrolysis and then fixed, shown in the empty columns. Even in a ratio of the emulsifier to the amount of lower Tac (relative to 2.2)), the influence of an emulsifier of the invention on the absorption of Tac or vitamin E is observed.

Example 3: Comparison between the influence of the emulsifiers of the invention and the corresponding ethoxylated emulsifiers on the absorption of Tac and vitamin E, in a cellular system in vitro 3. 1) Experimental protocol: The general experimental conditions of the protocol described in Example 2, 2.1) are identical, only the surface of the wells and the concentration of Tac introduced into the M20 medium differ. The surface of the wells is 6.5 cm ² and the concentration of Tac is 23.7 μM / cm ² .

3.2) MLS, MPS and MLSE comparison: Four experiments are carried out, each being repeated three times, with a protocol comprising an hour of incubation at 37 ° C., as follows: 1) M20 alone, at a rate of 2 mM; Tac is therefore alone without an emulsifier; 2) M20 + MLS emulsifier (sorbitan monolaurate) 3) M20 + MPS emulsifier (sorbitan monopalmitate) 4) M20 + MLSE (ethoxylated sorbitan monolaurate) For each of the tests 2), 3) and 4), the weight ratio of the emulsifier added to Tac (equivalent to vitamin E) is 1: 6.9. The results obtained are presented in Table 1 below:

Table 1

In support of these results, it can be seen that the emulsifiers of the invention make it possible to increase the absorption of You and Tac in vitamin E equivalent, by a factor of 1, 9 for MLS and by a factor 1, 78 for MPS, compared to test 1) control without emulsifier. On the other hand, it is observed that the ethoxylated emulsifier (MLSE) reduced the absorption of vitamin E by a factor of 0.76 compared to test 1).

3.3) MLS, MPS and M OSE comparison: Four experiments are carried out, each being repeated three times, with a protocol comprising an hour of incubation at 37 ° C., as follows: 1) M20 alone; Tac is therefore alone without an emulsifier; 2) M20 + MLS emulsifier (sorbitan monolaurate) 3) M20 + MPS emulsifier (sorbitan monopalmitate) 4) M20 + MOSE (ethoxylated sorbitan monooleate) For each of the tests 2), 3) and 4), the weight ratio of the emulsifier added to Tac (equivalent to vitamin E) is 1: 6.9. The results obtained are presented in Table 2 below: Table 2

In support of these results, it is once again noted that the emulsifiers of the invention make it possible to significantly increase the absorption of You and Tac in vitamin E equivalent, ie by a factor 1, 92 for MLS and a factor of 1, 81 for MPS, compared to test 1) control without emulsifier. We also observe that the ethoxylated emulsifier (MOSE) slightly increased the absorption of vitamin E compared to test 1).

Example 4 Influence of an Emulsifier of the Invention on the Release of Tac from its Support According to the present example, the effect of an emulsifier of the invention, MOS (sorbitan monooleate), is tested on the release of Tac fixed on silica. To this end, Tac is available on a silica support in a weight ratio of 1: 1 for the test without emulsifier, and Tac + emulsifier (MOS) on silica in a weight ratio of 50: 5: 45. 10 g of Tac (optionally + MOS) on silica above (i.e. a final concentration of Tac of 10 mM) for 2.5 hours, with stirring, at 38 ° C, under different pH conditions, in the following solutions : Either 35 mM phosphate, pH 6.5, NaCI 0.15 mM Or HCI / glycine 35 mM, pH 2.5 The results are given in Table 3 below:

Table 3

At pH 2.5, the addition of MOS increased the release of Tac with respect to its support (silica) by a factor of 1.18, ie by more than 18%. At pH 6.5, this increase is 1.21 (more than 21%). Example 5 Influence of an Emulsifier of the Invention on the Hydrolysis of Tac in You, in Vitro

5. 1) Influence of MOS According to the present example, the effect of an emulsifier of the invention, MOS (sorbitan monooleate), is tested on the hydrolysis of Tac to Toi. For this purpose, Tac is available for the test without emulsifier, and Tac + MOS in a weight ratio of 10: 1. 0.5 g of Tac (optionally + MOS) is incubated, ie a final concentration of Tac of 10 mM for 16 hours, with stirring, at 38 ° C, in the following solution: 35 mM phosphate, pH 6.5, NaCl 0.15 mM, pancreatin in a pancreatin: Tac weight ratio of 2: 1, bile salts in a bile salt: Tac weight ratio of 5: 1. Pancreatin is a pancreatic extract comprising in particular the cholesterol ester hydrolase and the bile salts include activators of the CEH. At different incubation times under the aforementioned conditions, the rate of release of vitamin E is measured relative to the amount of initial Tac. The curves in FIG. 5 represent the rate of hydrolysis expressed as a concentration in% (w / w) of You in the solution, as a function of the incubation time. It can be seen that the MOS (I) increased the hydrolysis rate of Tac to Toi by 22% (calculated by the ratio of the slopes of the hydrolysis curves) compared to the test without emulsifier ().

5.2) Influence of MOS as a function of the bile acid concentration of the incubation solution According to the present test, the effect of an emulsifier of the invention, MOS (sorbitan monooleate), is tested on the hydrolysis of Tac in you. For this purpose, Tac is available for the test without emulsifier, and Tac + MOS in a weight ratio of 1 0: 1. 4 mg of Tac (optionally + MOS) are incubated, ie a final concentration of 8.45 μM Tac for 3 hours, with stirring, at 37 ° C., in the following solution: Phosphate 35 mM, pH 6.5, NaCl 0.1, 5 mM, pancreatin 2 mg or a pancreatin: Tac weight ratio of 1: 2, bile salts in variable concentrations. The following tests are carried out: 1) Tac without emulsifier, with bile salts at 10 mM 2) Tac + MOS, with bile salts at 10 mM 3) Tac without emulsifier, with bile salts at 20 mM 4) Tac + MOS bile at 20 mM 5) Tac without emulsifier, with bile salt at 50 mM 6) Tac + MOS, with bile salt at 50 mM Before incubation and after 1 hour and 3 hours respectively of incubation under the above conditions, the rate is measured of vitamin E release compared to the initial amount of Tac. The graph in FIG. 4 represents, for each test, the rate of hydrolysis expressed as a concentration in% (w / w) of You in the solution. We again note that the MOS strongly increases the rate of hydrolysis from Tac to Toi, activating the CEH. This increase depends on the bile salt concentration: it is indeed doubled for a bile salt concentration of 50 mM, multiplied by 4, 1 for a concentration of 20 mM and multiplied by 4.7 for a concentration of 10 mM.

Example 6: Influence of an emulsifier of the invention on the bioavailability of vitamin E from Tac measured by the cumulative influence of the emulsifier on the release of Tac from its support and of the hydrolysis of Tac released in You. According to the present example, the effect of an emulsifier of the invention, MOS (sorbitan monooleate), is tested. To this end, Tac is available on a silica support in a weight ratio of 1: 1 for the test without emulsifier, and Tac + emulsifier (MOS) on silica in a weight ratio of 50: 5: 45. 8 mg of Tac (optionally + MOS) on the above silica (i.e. a final concentration of Tac of 16.9 μM) for 3 hours, with stirring, at 37 ° C., in the following solutions: 35 mM phosphate, pH 6.5, NaCl 0.1, 5 mM, pancreatin (2 mg) and bile salts (20 mM). Before incubation and after 1 hour and 3 hours respectively of incubation under the aforementioned conditions, the concentration of vitamin E in the solution is measured, relative to the amount of initial Tac. The results obtained in Table 4 below are obtained:

Table 4

The addition of MOS improves the bioavailability of Tac estimated by the efficiency of the release of Tac from its silica support and the efficiency of the hydrolysis of Tac in You. This increase reaches more

90% after 3 hours of incubation resulting from increased release and accelerated hydrolysis. Example 7 Influence of the emulsifiers on the excretion of vitamin E in caecectomized roosters Two series of tests were carried out on caecectomized roosters. A first series included 32 roosters, the second included 51 roosters. They were fed in "wet gavage" with a food incorporating Tac (vitamin E acetate) or Tac associated with one or two food emulsifiers according to the invention, in different proportions. The Tac or the associated Tac were formulated in gelatin capsules, which were obtained by depositing, using a pipette, a predetermined amount of Tac or associated Tac in a half-shell of a capsule, then closing. of the capsule with the other half-shell. 48 hours after taking food, in a bowl, the feces are collected and the excretion of the vitamin in these materials is determined. To this end, the vitamin E is extracted with a solvent for vitamin E, hexane for example, then the amount extracted is determined by HPLC chromatography. The proportion of digested vitamin E is deducted from the excreted proportion. 7. 1) First series

Table 5

It is observed that according to the method of the invention, the digestibility of vitamin E can increase up to 31% compared to the control.

7.2) Second series

Table 6

As in the first series, an increased digestibility of vitamin E is observed when vitamin E is administered according to the invention. This increase can reach 40.5% of the digestibility obtained with Tac alone. Example 8: Influence of emulsifiers on the hydrolysis of derivatives of vitamin E 8. 1) The conditions under which the tests are carried out are as follows Cell model: CaCo 2 cells Surface of the wells: 6.5 cm ² Quantity of Tac: 67 nmol / cm ² Solution used: Micelle M40 according to Mathias et al.

(Mathias, PM, Harries, JT, Muller, DPR (1,981): Optimization and validation of assays to estimate pancreatic ester activity using well-characterized micellar solutions of cholesteryl oleate and tocopheryl acetate. Journal of Lipid Research 22, 1 77-1 84), associated with 1.34 nmol / cm ² of cholesterol ester hydrolase (EC 3.1 .1 .1 3) Treatments: A: Without emulsifier B: With emulsifier (mixture MLS + MSS; ratio 1/1), ratio Tac / 100/1 C emulsifier: With emulsifier (MPS + MOS mixture; 1/1 ratio), Tac / 100/1 emulsifier ratio Incubation time: 1 hour at 37 ° C Analysis: Analysis of Tac in the medium to calculate the rate of hydrolysis The results are presented in Table 7 below:

Table 7

It appears from this table that the presence of emulsifiers has doubled the hydrolysis of Tac. The emulsifiers according to the invention improved the hydrolysis conditions for the cholesterol ester hydrolase. 8.2) The conditions under which the tests are carried out are the following Cell model: CaCo-2 cells Surface of the wells: 4.2 cm ² Quantity of Tac: 67 nmol / cm ² Solution used: Micelle M 40 according to Mathias et al. Treatments: A: Without emulsifier B: With emulsifier (MPS + MOS mixture; ratio 1/1), Tac / emulsifier ratio 100/1 Incubation time: 2 hours at 37 ° C Analyzes: Tac analysis in the medium above cells to calculate the hydrolysis rate The results are presented in Table 8 below:

Table 8

The presence of emulsifiers improved the hydrolysis of Tac by 44%. As in 8.1), the emulsifiers improved the hydrolysis conditions for the cholesterol ester hydrolase.

Claims

1) Zootechnical, non-therapeutic process, consisting in administering orally to monogastric farm animals, a stable derivative of vitamin E, alone or in mixture with an additive and / or a food, said derivative being hydrolysable in the assimilable form of vitamin E, characterized in that said vitamin E derivative is administered to animals, in the presence of at least one food emulsifier chosen from non-ethoxylated esters of sorbitol and of fatty acids. 2) Method according to claim 1, characterized in that the vitamin E derivative and said emulsifier at least are administered to animals, concomitantly. 3) Method according to claim 1, characterized in that said emulsifier is administered to animals before the vitamin E derivative is administered to animals. 4) Method according to claim 2 or 3, characterized in that the vitamin E derivative and / or said emulsifier at least are mixed with the food. 5) Process according to any one of claims 1 to 4, characterized in that said at least one emulsifier is chosen by the esters of sorbitol and of fatty acids having a hydrocarbon chain, saturated or unsaturated, of at least 1 1 atoms of carbon. 6) Food formulation for animal nutrition comprising a stable derivative of vitamin E, said derivative being hydrolyzable to the assimilable form of vitamin E, characterized in that it further comprises at least one food emulsifier chosen from non-ethoxylated esters sorbitol. 7) Formulation according to claim 6, characterized in that it comprises two food emulsifiers chosen from non-ethoxylated esters of sorbitol and fatty acids. 8) Formulation according to claim 6 or 7, characterized in that the weight ratio of the emulsifier, or emulsifiers, to the vitamin derivative varies from 10/1 to 1/200. 9) Formulation according to claim 8, characterized in that the weight ratio of the emulsifier, or emulsifiers, to the vitamin E derivative, is between 1/5 and 1/1 00. 10) Formulation according to any one of claims 6 to 9, characterized in that said at least one emulsifier is chosen by sorbitol and fatty acid esters having a hydrocarbon chain, saturated or unsaturated, of at least 11 carbon atoms. 1 1) Formulation according to any one of claims 6 to 1 0, characterized in that the vitamin E derivative is a vitamin E ester. 1 2) Formulation according to claim 1 1, characterized in that the vitamin E derivative is vitamin E acetate. 1 3) Formulation according to any one of claims 6 to 1 2, characterized in that said at least one emulsifier is a sorbitol ester chosen from monolaurate, monopalmitate, monostearate, monooleate and tristearate. 14) Formulation according to any one of claims 6 to 1 3, characterized in that it comprises vitamin E acetate and at least one emulsifier chosen from sorbitol monolaurate and sorbitol monooleate. 1 5) Use of a food emulsifier chosen from non-ethoxylated esters of sorbitol and fatty acids, for preparing a food formulation for animal nutrition, based on a derivative of vitamin E. 1 6) Use of a food emulsifier chosen from non-ethoxylated esters of sorbitol and fatty acids, in combination with a stable vitamin E derivative, to increase the bioavailability of vitamin E in a monogastric animal, said derivative being hydrolyzable in the form assimilable of vitamin E.