Vitamin D3 and 7-dehydrocholesterol eutectic and preparation method and application thereof

Abstract

The invention relates to a vitamin D3 and 7-dehydrocholesterol eutectic as well as a preparation method and application thereof. The eutectic is prepared from the following raw materials: vitamin D3 and 7-dehydrocholesterol in a molar ratio of (1-1.2): (1-1.2). The yield of the obtained eutectic substance is high, the preparation method is easy to operate, high-toxicity raw materials and waste residues difficult to treat do not exist, and the vitamin D3 eutectic method is more environmentally friendly and high in eutectic efficiency.

Description

Technical Field

[0001] This invention belongs to the field of cocrystal technology, and relates to a vitamin D3 and 7-dehydrocholesterol cocrystal, its preparation method and application. Background Technology

[0002] Vitamin D3, also known as cholecalciferol, is an essential vitamin for promoting human health and the normal growth and reproduction of poultry. Vitamin D3 has physiological functions such as promoting intestinal calcium absorption, regulating calcium and phosphorus metabolism, inducing calcium and phosphorus deposition in bones, enhancing the human immune system, promoting bone growth, and preventing rickets.

[0003] Patent CN 108129371 A discloses that calcidiol and vitamin D3 crystals are added to acetonitrile at room temperature to form an unsaturated solution. After cooling to -20°C and standing for 24 hours, powder is precipitated. After centrifugation and filtration, a cocrystal of calcidiol and vitamin D3 is obtained with a cocrystal yield of 79.3%. Patent CN 104356038A discloses that vitamin D2 and vitamin D3 powders are added to solvents such as ethyl acetate, toluene, n-hexane, methanol, and ethanol to dissolve them. After the solvent evaporates, a cocrystal is obtained.

[0004] Currently, there are few reported methods for preparing vitamin D3 cocrystals to improve its stability. Due to the unstable nature of vitamin D3, there is an urgent need to provide a simple method to enhance its stability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a vitamin D3 and 7-dehydrocholesterol cocrystal, its preparation method, and its applications.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a vitamin D3 and 7-dehydrocholesterol cocrystal, wherein the raw materials for preparing the cocrystal include vitamin D3 and 7-dehydrocholesterol in a molar ratio of (1-1.2):(1-1.2).

[0008] The specific point values ​​in (1-1.2) can be selected from 1, 1.02, 1.04, 1.06, 1.08, 1.1, 1.12, 1.14, 1.16, 1.18, 1.2, etc. Other specific point values ​​within the above range can also be selected, which will not be elaborated here.

[0009] 7-Dehydrocholesterol (7-DHC) is a precursor for the synthesis of vitamin D3 (VD3). Due to their similar structures, the principle of "like dissolves like" is employed, using 7-dehydrocholesterol as a substrate to co-crystallize vitamin D3 from an organic solvent. The process is simple, produces no waste, and operates under mild conditions, resulting in a high yield of the co-crystallized product. The co-crystallized product significantly enhances the stability of vitamin D3.

[0010] Preferably, the eutectic has characteristic peaks at 2θ of 13.4°, 14.4°, 16.4°, 18.8°, and 21.6°.

[0011] In a second aspect, the present invention provides a method for preparing the vitamin D3 and 7-dehydrocholesterol cocrystal according to the first aspect, the preparation method comprising:

[0012] (1) Mix vitamin D3 with an organic solvent to obtain a vitamin D3 solution;

[0013] (2) Slowly add 7-dehydrocholesterol powder to vitamin D3 solution, stir to co-crystallize, filter, and the filter cake is the co-crystallized product.

[0014] Preferably, the mass ratio of vitamin D3 to organic solvent in step (1) is 1:(2-6), wherein the specific point values ​​in (2-6) can be selected from 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, 6, etc. Other specific point values ​​within the above range can be selected, and will not be described in detail here.

[0015] Preferably, the slow addition rate is 0.08-0.12 g / s, such as 0.08 g / s, 0.09 g / s, 0.1 g / s, 0.11 g / s, 0.12 g / s, etc. Other specific values ​​within the above range can be selected, and will not be elaborated here.

[0016] Preferably, the organic solvent in step (1) includes a polar solvent.

[0017] This invention has found that polar solvents are more effective than non-polar solvents.

[0018] Preferably, the polar solvent includes any one or a combination of at least two of methanol, ethanol, isopropanol or n-butanol.

[0019] Preferably, the temperature for stirring the eutectic is 10-20℃, such as 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, etc. Other specific values ​​within the above range can be selected, and will not be elaborated here.

[0020] Preferably, the stirring time for eutectic is 1-3 hours, such as 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, etc. Other specific values ​​within the above range can be selected, and will not be elaborated here.

[0021] Preferably, the stirring speed for eutectic is 300-400 rpm, such as 300 rpm, 310 rpm, 320 rpm, 330 rpm, 340 rpm, 350 rpm, 360 rpm, 370 rpm, 380 rpm, 390 rpm, 400 rpm, etc. Other specific values ​​within the above range can be selected, and will not be elaborated here.

[0022] Thirdly, the present invention provides the application of the vitamin D3 and 7-dehydrocholesterol cocrystal according to the first aspect in the long-term preservation of vitamin D3.

[0023] The cocrystal prepared in this application maintains a high vitamin D3 content within 50 days, and its stability is far greater than that of vitamin D3 monomer. Preparing the cocrystal from vitamin D3 and 7-dehydrocholesterol significantly improves the stability of vitamin D3. Furthermore, due to the significant difference in solubility between vitamin D3 and 7-dehydrocholesterol, this characteristic can be utilized for simple separation in subsequent applications, thus enhancing the stability of vitamin D3 without increasing the operational difficulty of its use.

[0024] Methods for separating vitamin D3 and 7-dehydrocholesterol from cocrystals include:

[0025] The eutectic was mixed with a mixed solvent of methanol and n-hexane, with a volume ratio of methanol to n-hexane of (2-8):1. The concentration of the eutectic in the mixed solvent was 2-8 wt%. The mixed solution was crystallized at -20 to 0°C, and the resulting crystal cake was pure 7-dehydrocholesterol. At this point, about 20% of 7-dehydrocholesterol remained in the solution. After concentration, it was crystallized again at -20 to 0°C. The content of 7-DHC to VD3 in the resulting crystal cake was close to 1:1. The above process was repeated on the resulting crystal cake until no more crystal cakes were produced. At this point, the content of VD3 in the crystallization solution was >99%. The crystallization solution was then crystallized at -4 to 8°C to obtain VD3 crystals.

[0026]

[0027] Using the method described in this application, the final yield of vitamin D3 is >96%.

[0028] 7-DHC does not involve yield and is always recycled in the form of eutectic. The portion of vitamin D3 not included in the vitamin D3 crystal yield exists in the crystallization liquid and eutectic liquid and can also be recycled and reused.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The process provided by this invention is simple to operate and produces no waste residue;

[0031] 2. The process does not require complex equipment and the process conditions are mild;

[0032] 3. The eutectic obtained in this application has a high yield. Attached Figure Description

[0033] Figure 1 The images show X-ray diffraction patterns of the eutectic obtained in Example 1, 7-dehydrocholesterol crystals, and vitamin D3 crystals. Detailed Implementation

[0034] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0035] Example 1

[0036] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal, the preparation method comprising:

[0037] (1) Add 10g of vitamin D3 to 40g of ethanol solvent and stir to dissolve;

[0038] (2) Slowly add 10g of 7-dehydrocholesterol powder to the above solution, stir at 15°C for 2 hours to form a eutectic, and filter to obtain a eutectic cake and a eutectic liquid.

[0039] The mass of the eutectic cake is 18.8g, and the mass of the solid in the eutectic liquid is 1.2g.

[0040] Example 2

[0041] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal, the preparation method comprising:

[0042] (1) Add 10g of vitamin D3 to 20g of isopropanol solvent and stir to dissolve;

[0043] (2) Slowly add 10g of 7-dehydrocholesterol powder to the above solution, stir at 15°C for 3 hours to form a eutectic, and filter to obtain a eutectic cake and a eutectic liquid.

[0044] The mass of the eutectic cake is 18.1g, and the mass of the solid in the eutectic liquid is 1.9g.

[0045] Example 3

[0046] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal, the preparation method comprising:

[0047] (1) Add 10g of vitamin D3 to 60g of n-butanol solvent and stir to dissolve;

[0048] (2) Slowly add 10g of 7-dehydrocholesterol powder to the above solution, stir at 20°C for 1 hour at a stirring speed of 350rpm, and filter to obtain eutectic cake and eutectic liquid.

[0049] The mass of the eutectic cake is 18.3g, and the mass of the solid in the eutectic liquid is 1.7g.

[0050] Example 4

[0051] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal, the preparation method comprising:

[0052] (1) Add 10g of vitamin D3 to 30g of methanol solvent and stir to dissolve;

[0053] (2) Slowly add 10g of 7-dehydrocholesterol powder to the above solution, stir at 10°C for 2 hours to form a eutectic, and filter to obtain a eutectic cake and a eutectic liquid.

[0054] The mass of the eutectic cake is 18.6g, and the mass of the solid in the eutectic liquid is 1.4g.

[0055] Example 5

[0056] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal, which differs from Example 1 only in that ethanol is replaced with n-hexane, while other operations remain unchanged.

[0057] The mass of the obtained eutectic cake was 15.1 g, and the mass of the solid in the eutectic liquid was 4.9 g.

[0058] Example 6

[0059] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal, which differs from Example 1 only in that ethanol is replaced with ethyl acetate, while other operations remain unchanged.

[0060] The mass of the obtained eutectic cake was 14.2 g, and the mass of the solid in the eutectic liquid was 5.8 g.

[0061] Example 7

[0062] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal. The only difference between this method and Example 1 is that step (2) is to "mix 10g of 7-dehydrocholesterol powder with the solution obtained in step (1), stir the cocrystal at 15°C for 2 hours at a stirring speed of 400 rpm, and filter to obtain a cocrystal cake and a cocrystal liquid".

[0063] The mass of the resulting eutectic cake was 15.6 g, and the mass of the eutectic solution was 4.4 g.

[0064] Example 8

[0065] This embodiment provides a method for preparing a vitamin D3 and 7-dehydrocholesterol cocrystal. The only difference between this method and Example 1 is that step (2) is: "10g of 7-dehydrocholesterol powder is added to 10g of ethanol and mixed evenly. The 7-dehydrocholesterol solution is slowly added dropwise to the solution obtained in step (1). The mixture is stirred at 15°C for 2 hours at a stirring speed of 400 rpm. The mixture is then filtered to obtain a cocrystal cake and a cocrystal liquid."

[0066] The mass of the resulting eutectic cake was 17.5g, and the mass of the eutectic solution was 2.5g.

[0067] Test Example 1

[0068] X-ray powder diffraction test

[0069] Test method: The eutectic cake obtained in Example 1 was dried and then thoroughly ground to ensure that the surface of the sample was a very flat plane before testing.

[0070] Scanning angle 5°-50°, angle increment 0.05, voltage 35KV, current 25mA.

[0071] The results are as follows Figure 1 As shown, the XRD spectra of the eutectic were compared with those of 7-DHC crystal and VD3 crystal. The eutectic showed characteristic peaks at 2θ of 13.4°, 14.4°, 16.4°, 18.8°, and 21.6°.

[0072] Test Example 2

[0073] Yield test

[0074]

[0075]

[0076] Table 1

[0077] Eutectic cake yield (%) Eutectic solution yield (%) Example 1 94 6 Example 2 90.5 9.5 Example 3 91.5 8.5 Example 4 93 7 Example 5 75.5 24.5 Example 6 71 29 Example 7 78 22 Example 8 87.5 12.5

[0078] As shown in Table 1, the yield of the eutectic cake obtained in this application is relatively high (greater than 90%), and changes in the mixing method of 7-dehydrocholesterol and vitamin D3 or the replacement of the polar solvent with a polar solvent will affect the yield of the eutectic cake.

[0079] Test Example 3

[0080] Stability test

[0081] Weigh 3g of vitamin D3 crystals and the eutectic cakes prepared in Examples 1-8 and place them in an oven at 40℃. Take samples daily and analyze the remaining amount of vitamin D3 by liquid chromatography.

[0082]

[0083] The results are shown in Table 2.

[0084] Table 2

[0085]

[0086] Test Example 4

[0087] Isolation of Vitamin D3 from Cocrystal

[0088] The eutectic cake prepared in Example 1 was dissolved in a mixed solvent of methanol and n-hexane at a volume ratio of 5:1, and the concentration of the eutectic in the mixed solvent was 5 wt%. Crystallization was carried out at -10°C, and the precipitate was 7-dehydrocholesterol. The remaining crystallization solution was concentrated and then crystallized again at -10°C. The ratio of 7-dehydrocholesterol to vitamin D3 in the resulting crystal cake was approximately 1:1. The above process was repeated with the resulting crystal cake until no more crystal cake was formed. The resulting crystallization solution was then crystallized at -4°C to obtain vitamin D3 crystals. Purity was analyzed by liquid chromatography, and the yield was calculated.

[0089]

[0090] The obtained vitamin D3 crystals had a purity of 99.7%, and the overall yield of vitamin D3 was 99.2%.

[0091] The applicant declares that this invention illustrates a vitamin D3 and 7-dehydrocholesterol cocrystal, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this invention.

[0092] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0093] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A vitamin D3 and 7-dehydrocholesterol cocrystal, characterized in that, The raw materials for preparing the eutectic include vitamin D3 and 7-dehydrocholesterol in a molar ratio of (1-1.2):(1-1.2).

2. The vitamin D3 and 7-dehydrocholesterol cocrystal according to claim 1, characterized in that, The eutectic has characteristic peaks at 2θ of 13.4°, 14.4°, 16.4°, 18.8°, and 21.6°.

3. A method for preparing the vitamin D3 and 7-dehydrocholesterol cocrystal according to claim 1 or 2, characterized in that, The preparation method includes: (1) Mix vitamin D3 with an organic solvent to obtain a vitamin D3 solution; (2) Slowly add 7-dehydrocholesterol powder to vitamin D3 solution, stir to co-crystallize, filter, and the filter cake is the co-crystallized product.

4. The preparation method according to claim 3, characterized in that, The mass ratio of vitamin D3 to organic solvent in step (1) is 1:(2-6); Preferably, the slow addition rate is 0.08-0.12 g / s.

5. The preparation method according to claim 3 or 4, characterized in that, The organic solvent in step (1) includes polar solvents.

6. The preparation method according to claim 5, characterized in that, The polar solvent includes any one or a combination of at least two of methanol, ethanol, isopropanol, or n-butanol.

7. The preparation method according to any one of claims 3-6, characterized in that, The temperature for stirring the eutectic is 10-20℃.

8. The preparation method according to any one of claims 3-7, characterized in that, The stirring time for eutectic is 1-3 hours.

9. The preparation method according to any one of claims 3-8, characterized in that, The stirring speed for the eutectic process is 300-400 rpm.

10. The application of the vitamin D3 and 7-dehydrocholesterol cocrystal according to claim 1 or 2 in the long-term preservation of vitamin D3.

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