STABILIZATION OF VITAMIN A IN A NUTRITIONAL SOLUTION

Abstract

The invention relates to a medical product for preventing or correcting vitamin A deficiency in a patient comprising a lipid emulsion in a flexible container, the lipid emulsion comprising (a) vitamin A in the lipid phase of the lipid emulsion, (b) optionally additionally vitamin D, vitamin E and/or vitamin K in the lipid phase of the lipid emulsion, and (c) no more than 1.5 ppm dissolved oxygen (DO), (d) wherein the pH of the lipid emulsion is from 5 to 9.

Claims

1. A medical product for preventing or correcting vitamin A deficiency in a patient comprising a lipid emulsion in a flexible container, the lipid emulsion comprising: a. vitamin A in the lipid phase of the lipid emulsion, b. optionally additionally vitamin D, vitamin E and/or vitamin K in the lipid phase of the lipid emulsion, and c. no more than 1.5 ppm dissolved oxygen (DO), d. wherein the pH of the lipid emulsion is from 5 to 9.

2. The medical product according to claim 1, wherein the vitamin A is present in form of retinyl palmitate, retinyl acetate, retinal, retinol and/or retinoic acid.

3. The medical product according to claim 1, wherein the lipid emulsion comprises as a lipid component a low peroxide level oil.

4. The medical product according to claim 1, wherein the lipid emulsion comprises as a lipid component an oil with a peroxide value of no more than 5 milliequivalents (mEq) O.sub.2/kg.

5. The medical product according to claim 1, wherein the lipid emulsion has a lipid concentration of 2-40%.

6. The medical product according to claim 1, wherein the lipid emulsion comprises an antioxidant agent.

7. The medical product according to claim 1, wherein the medicinal product comprises 2000-4000 International Units (IU) vitamin A.

8. The medical product according to claim 1, wherein vitamin A is present in the emulsion at a concentration of at least 20 IU vitamin A per gram of lipid (IU/gram).

9. The medical product according to claim 1, wherein the lipid emulsion further comprises vitamins selected from the group consisting of vitamins B2, B3, B5, B8, B9 and B12.

10. The medical product according to claim 1, wherein the medicinal product comprises a light-protective outer wrapping.

11. The medical product according to claim 1, wherein the flexible bag comprises an inner lining containing a polyolefin, wherein the inner lining is free of polyvinyl chloride (PVC), plasticizers, adhesives and latex.

12. The medical product according to claim 1, wherein the vitamin A is stable in the lipid emulsion for at least three months when stored at a temperature between 1 and 50° C.

13. The medical product according to claim 1, wherein the vitamin A is stable in the lipid emulsion for at least 6 months at a temperature of from 1° C. to 32° C.

14. The medical product according to claim 1, wherein the lipid emulsion is a sterilized lipid emulsion.

15. The medical product according to claim 1, wherein the lipid emulsion does not comprise macronutrients selected from the group consisting of carbohydrates and proteins.

16. The medical product according to claim 1, wherein the emulsion and medical product are configured for parenteral administration.

17. A medical product according to claim 1, wherein the lipid emulsion is contained in one chamber of a multi chamber container having at least two, at least three, at least four, at least five or at least six chambers.

18. The medical product according to claim 17, wherein the container comprises at least a first chamber containing a carbohydrate formulation, a second chamber containing an amino acid formulation, a third chamber containing a lipid formulation, and optionally comprises electrolytes and/or vitamins and/or trace elements in the first, second and/or third chamber.

19. The medical product according to claim 17, wherein the lipid emulsion is present in a fourth chamber.

20. The medical product according to claim 17, wherein the lipid emulsion is present in a chamber comprising a lipid formulation.

21. A method of preparing a medical product for preventing or correcting vitamin A deficiency in a patient according to any one of the preceding claims, wherein the lipid emulsion comprises a lipid phase and an aqueous phase and is prepared by the steps comprising: a. Separately heating up the lipid phase and the aqueous phase to a temperature of from 60° C. to 90° C. under agitation; b. Adding vitamin A, and optionally vitamin D, vitamin E and/or vitamin K to the lipid phase; c. Preparing the pre-emulsion by transferring the lipid phase to the aqueous phase under agitation; d. Homogenizing the pre-emulsion at a temperature of from 40° C. to 60° C. under pressure; e. Optionally adding water to adjust the required volume and concentrations; f. Adjusting the lipid emulsion to a concentration of dissolved oxygen (DO) of no more than 1.5 ppm and a pH value of 5-9, and g. Sterilizing the solution, preferably by terminal heat sterilization, more preferably by terminal heat sterilization with moist heat.

22. A method for preventing or correcting vitamin A deficiency in a subject, comprising administering a sterilized lipid emulsion according to claim 1 by parenteral administration to said subject.

23. The method according to claim 1, wherein the vitamin A is present in form of retinyl palmitate.

24. The method according to claim 3, wherein the low peroxide level oil is selected from the group consisting of soybean oil with low peroxides, olive oil, medium chain triglycerides, fish oil, fish oil extract, krill oil, algae oil, safflower oil, sunflower oil, corn oil, coconut oil, palm kernel oil, rapeseed oil, fungal oil and hydrogenated oils or mixtures thereof.

25. The method according to claim 6, wherein the antioxidant agent is selected from the group consisting of EDTA, tocopherol, ascorbyl palmitate and butylhydroxytoluol (BHT).

26. The method according to claim 8, wherein the vitamin A is present in the emulsion at a concentration of 20 to 80.000 IU/gram.

27. The method according to claim 9, wherein the lipid emulsion further comprises vitamins B2, B5 and B12.

28. The method according to claim 15, wherein the emulsion does not comprise any nutrients besides lipids and vitamins.

Description

DESCRIPTION OF THE FIGURES

[0223] FIG. 1: Examples of compounds comprised by the term vitamin A comprised by the present invention.

[0224] FIG. 2: The graph shows the domain of stability (white area) of vitamin A. Stability is defined as a recovery of from 80% to 120%. The hatched area shows where vitamin A is not stable any more in dependency on oxygen levels over time. Accordingly, at an oxygen level of about 0.300 ppm vitamin A after 6 months is no longer considered stable, i.e. recovery drops below 80%.

EXAMPLES

[0225] The invention is further described by the following examples. These are not intended to limit the scope of the invention but represent preferred embodiments and/or certain aspects of the invention provided for greater illustration of the invention described herein.

Example 1: Methods for Determining Vitamin A Concentration

[0226] Determination of fat-soluble vitamins can be accomplished by Ultra Performance Liquid Chromatography (UPLC), which separates components of a solution by partitioning of the analytes between a mobile liquid phase and a liquid stationary phase (reversed phase mode). The resulting difference in elution time allows to independently detect the different analytes. It is also possible to determine vitamin A by using HPLC with UV, fluorescence (FLD), electrochemical (ED), or evaporative light scattering (ELSD) detection methods. Generally, care should be taken to reduce exposure of the samples to light and use the respective light-protective equipment. For example, Vitamin A concentrations can be determined by high-performance liquid chromatography (HPLC) as described by Lee et al., Simultaneous Determination of Vitamin A and E in Infant Formula by HPLC with Photodiode Array Detection, Korean J Food Sci Ani Resour 31(2) 191-199. The standard method for the quantitative determination of vitamin a comprises saponification of the test material with aqueous ethanolic potassium hydroxide, and the liberation of vitamin A by extraction with n-hexane. After concentration of the extract, the residue is dissolved in methanol and the vitamin A content is determined after HPLC separation on a RP-C18 column by means of an UV or fluorescence detector.

Example 2: Methods for Determining the Concentration of Dissolved Oxygen (DO)

[0227] Various methods can be used to determine the DO content of a given solution. Generally, electrochemical or optical sensors are used for determining the DO concentration according to the invention. A preferred method comprises using a fiber-optic oxygen meter such as MICROX TX3, which is a single-channel, temperature-compensated oxygen meter with fiber-optic trace oxygen microsensors based on a glass fiber (e.g. 140 μm). The optical oxygen microsensors (also called optodes) do not consume oxygen, their signal does not depend of the flow rate of the sample, the diameter of the microsensor tip is e.g. <50 μm, they measure oxygen in both liquid and gas phase and they have an on-line temperature compensation of the oxygen content. For data visualization during measurements, the oxygen meter is connected to a LCD & Data-Logger Unit.

[0228] The oxygen measure and adjustment are based on an equilibrium between exposure to nitrogen and oxygen containing gases during the mixing and filling steps of the process. An acute and regular monitoring of the solution DO throughout these process steps allows to control the oxygen level within the final container. Besides, the headspace of the bag can be filled with a specific volume of nitrogen or oxygen to reach the final targeted level of DO.

Example 3: Recovery of Vitamin A from Mixed Micelle and Lipid Emulsion Formulation Under Different Conditions

[0229] Stability of vitamin A in terminally heat-sterilized compositions such as lipid emulsions and solutions comprising mixed micelles have been examined in laboratory experiments. Multiple studies have been performed, as summarized in Table 4.

TABLE-US-00004 TABLE 4 Summary of studies and experiments performed in order to optimize the composition of the lipid emulsion comprising vitamin A to be comprised in a medical product of the invention. Outcome, Formulation Pharmaceutical Formulation Recovery of study form comprising Container Process Vitamin A Study A Mixed micelles A/D3/E/K Non-PVC, Terminal heat 26.2-27.2% sorbitol non-oxygen sterilization recovery 6 barrier bags months at 25° C. Study A1 Mixed micelles A/D/E/K Non-PVC, Terminal heat 26.8-26.9% sorbitol citric acid non-oxygen sterilization recovery 6 barrier bags months at 25° C. Study A2 Mixed micelles A/D/E/K Non-PVC, Non 56.6-90.6% sorbitol non-oxygen sterilized recovery 6 barrier bags months at 25° C. Study A3 Mixed micelles A/D/E/K Non-PVC, Not 57.5-58.3% sorbitol/citric acid non-oxygen sterilized recovery 6 barrier bags months at 25° C. Study B1 Emulsion A/D/E/K Non-PVC oxygen Terminal heat 77.0-78.7% 20% lipid emulsion; barrier bags sterilization recovery 6 (80% olive oil, months at 40° C. 20% soybean oil) ascorbyl palmitate Study B2 Mixed micelles A/D/E/K Non-PVC oxygen Terminal heat 31.6-36.6% ascorbyl palmitate barrier bags sterilization recovery 1 month at 40° C. Study B3 Micellar A/D/E/K Non-PVC oxygen Terminal heat 30.2-33.8% solution Polysorbate 80 & 20 barrier bags sterilization recovery 1 PEG 400 month at 40° C. sorbitol Study C1 Lipid emulsion A/D/E/K Non-PVC oxygen Terminal heat 95% recovery 3 10% lipid emulsion; barrier bags + sterilization months at 40° C. soybean oil oxygen absorber ascorbyl palmitate Study C2 Lipid emulsion A/D/E/K Non-PVC, Terminal heat 90% recovery 3 20% lipid emulsion; non-oxygen sterilization months at 40° C. soybean oil barrier bags ascorbyl palmitate Study C3 Lipid emulsion A/D/E/K Non-PVC, non- Terminal heat 90% recovery 3 5% lipid emulsion; oxygen barrier sterilization month at 40° C. olive oil bags + oxygen ascorbyl palmitate absorber Study D1 Lipid emulsion A/D/E/K Non-PVC, non- Terminal heat 78.0-86.0% 10% lipid emulsion; oxygen barrier sterilization recovery 6 soybean oil bags + oxygen months at 40° C. absorber

[0230] The experiments were performed with vitamin formulations comprising combinations of vitamins A, D, E and K. The results indicated that recovery rates for vitamin A are favorable especially in lipid emulsions, such as, for example, a 10% lipid emulsion with soybean or olive oil or mixtures of these oils, see also Study C1. However, 5% emulsions (e.g. Study C3) as well as 20% emulsions (Study C2) also gave good results, especially considering that the formulations were stored in non-oxygen barrier bags on the latter cases. Therefore, lipid emulsions in the range of from 5% to 20% oil phase in a range of from 5% to 20% w/v of an oil are recommendable for formulations for stably accommodating vitamin A. In addition, using oxygen barrier bags and potentially also oxygen absorbers further improve the stability and thus recovery of vitamin A after storage (Study C1).

[0231] In contrast, mixed micelle formulations could not provide for a reasonable stability of vitamin A, even in the presence of oxygen barrier bags (Study B2, B3) and in the presence of various antioxidants, such as, for example, sorbitol, citric acid or ascorbyl palmitate, and where the mixed micelle formulation was not terminally heat-sterilized (Studies A2 and A3). Using oxygen-barrier bags increased the stability of vitamin A (Study B1) but could not bring it to levels obtained with lipid emulsions in oxygen-barrier bags.

[0232] Using oxygen barrier bags clearly further improved the stability of vitamin A. Accordingly, it could be confirmed that oxygen levels play an important role in the stability of vitamin A. This was further investigated in Example 4.

Example 4: Impact of Oxygen on the Stability of Vitamin A

[0233] The stability of vitamin A was tested in a 10% soybean lipid emulsion having a peroxide level of below 5 milliequivalents (mEq) O.sub.2/kg. The lipid emulsion contained vitamin A in a concentration of 1 dd/25 mL, as well as vitamin E in a concentration of 1 dd/25 mL and the pH was adjusted to 5.9 with HCl.

[0234] FIG. 2 depicts the dependency of vitamin A recovery on the presence of dissolved oxygen. Independently of the light exposure, it was found that vitamin A is not stable in the presence of oxygen of above 0.3 ppm for more than 6 months at 40° C. Specifically, it was found that for a recovery of at least 80% after 6 months at 40° C., as indicated in FIG. 2, DO level of less than about 0.3 ppm is required. In contrast, no such dependency could be found for vitamin E, which underlines the need to carefully adjust the conditions under which vitamin A is formulated into a parenteral nutrition formulation, specifically in a large volume container such as a multi-chamber container which should also be terminally heat-sterilized.

Example 5: Impact of Heat Exposure on the Stability of Vitamin A

[0235] A 10% lipid emulsion based on soybean oil containing vitamin A at a concentration of 1 dd/25 ml was provided in a flexible container having a volume of 25 mL at a native pH of about 7.5-8.0. The container consisted of a non-oxygen barrier material. The container was overpouched with a light protective material and an oxygen absorber was added, meaning that no residual oxygen remains in the formulation. The formulation was then submitted to different sterilization conditions. The recovery of vitamin A after sterilization and storage for 6 months at 40° C. was assessed. The results are summarized in Table 5. The C.sub.0 value is a measure of the total heat exposure of the API vitamin A. The results demonstrate that vitamin A is susceptible to the total heat exposure it is submitted to, which is a critical component for producing a product according to the invention, especially when the vitamin A formulation forms part of a multi-chamber container having a large volume, such as a 2-, 3-, four- or five-chamber container which, when terminally heat sterilized, requires a significantly higher heat exposure to arrive at a required F.sub.0 compared to, for example, a small container of less than, for example, 100 mL, such as a 25 mL or 50 mL container, where also light exposure and oxygen levels can be controlled much more easily.

TABLE-US-00005 TABLE 5 Effect of heat on the stability of vitamin A. The heat exposure of the compound is provided as C.sub.0 in minutes, which gives a measure for the total heat exposure to which vitamin A is subjected. T0 represents the recovery of vitamin A before sterilization. Recovery rates after storage for 6 months at 40° C. show that the impact of steam sterilization on the vitamin A stability is more pronounced over longer storage times. Obviously, a higher heat exposure during sterilization has a long-term negative effect on vitamin A stability. Sterilization Steam Water cascade Method sterilization sterilization C0 (min.) 77 49 37 T0 104% 96% 97% T6M40° C.  78% 82% 86%

Example 6: Impact of pH on the Stability of Vitamin A

[0236] Two batches of a vitamin A containing formulation as shown in Table 6 were tested regarding the impact of pH on the stability of vitamin A. Both batches were formulated as 5% lipid emulsions with olive oil and stored in an oxygen-barrier material flexible container (overpouched with light protective material and with oxygen absorber) having a volume of 25 mL.

TABLE-US-00006 TABLE 6 Effect of pH on vitamin A stability after sterilization and storage at 40° C. for 6 months. T0 refers to the recovery rate before sterilization. Batch 1 Batch 2 Emulsion type 5% emulsion 5% emulsion (olive oil) (olive oil) Vitamins concentration 1 dd/25 mL 1 dd/25 mL Bag material Oxygen-barrier Oxygen-barrier pH Native (7.5-8) Adjusted (5.9) T0 unsterilized 100% 100% T6M40° C. sterilized 73% 87.5%

[0237] Surprisingly, the recovery rate for vitamin A improves when adjusting the pH to a pH which is below the native one at about 7.5 to 8.0. Accordingly, the pH contributes together with other parameters to the stability of vitamin A in a product according to the invention, specifically also when the vitamin A formulation forms part of a terminally heat-sterilized multi-chamber container having a high volume.