Application of aloe polysaccharide in improving solubility and storage stability of poorly soluble substances

Abstract

The application discloses application of aloe polysaccharide in improving solubility and storage stability of difficultly soluble substances. The aloe polysaccharide can be used as a solubilizer of the difficultly soluble substances. The preparation method of the aloe polysaccharide comprises the following steps: removing both ends of fresh Aloe barbadensis leaves, and soaking in pure water for 1-2 days; removing the epidermis after water washing to obtain aloe gel to be ground; grinding the aloe gel to be ground to obtain an aloe polysaccharide solution; placing the aloe polysaccharide solution in a stirring tank, stirring under the condition of 4-15 DEG C and performing light treatment for at least 24 hours, and then collecting aloe polysaccharide pervaporation membranes on the liquid surface in a high-temperature film forming tank under the condition of 75-95 DEG C to obtain the aloe polysaccharide pervaporation membranes. In the application, the aloe polysaccharide pervaporation membranes can be used to improve the solubility and stability of difficultly soluble substances (such as fumaric acid) at normal temperature, and storage precipitation is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to a new application field of aloe polysaccharide, in particular to the application of aloe polysaccharide in improving the solubility and storage stability of poorly soluble substances. BACKGROUND

[0002] A solubilizer is a functional additive that can significantly improve the solubility of poorly soluble substances (such as lipid-soluble drugs and oil-soluble ingredients) in solvents (usually water). The types of solubilizers in the prior art include surfactants (which reduce interfacial tension and form micelles to encapsulate hydrophobic molecules), cyclodextrins (which form host-guest complexes by encapsulating hydrophobic cavities), and amphiphilic polymers (which combine with substances through hydrophobic blocks and maintain water solubility through hydrophilic blocks). However, there are significant problems in the application of existing solubilizers that need to be addressed: ① Ionic solubilizers damage cell membrane integrity, thereby having cytotoxicity; ② Some solubilizers (such as Cremophor) are prone to oxidative degradation, or the dissolved substances precipitate during storage at room temperature, resulting in instability; ③ The use of solubilizers requires heating or specific pH environments, leading to complex operations.

[0003] Therefore, the discovery and application of a solubilizer that is simple to operate and can improve the solubility and stability of poorly soluble substances at room temperature can effectively solve the above problems. SUMMARY

[0004] The present application proposes the application of aloe polysaccharide in improving the solubility and storage stability of poorly soluble substances. When used as a solubilizer, aloe polysaccharide solves the problems of poor stability, high biological safety, and complex operation of existing solubilizers.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] The preparation method of aloe polysaccharide in the present application refers to the method for promoting aloe polysaccharide to form a pervaporation membrane disclosed in patent CN118253272A, which includes the following steps:

[0007] The two ends of fresh Aloe vera leaves are removed and soaked in pure water for 1-2 days; after water washing, the epidermis is removed to obtain aloe gum to be ground; the aloe gum to be ground is ground to obtain an aloe polysaccharide solution. The present application uses a grinding method instead of a crushing method, which aims to stimulate the parenchyma cells of aloe to secrete more polysaccharides through friction, thereby accelerating the release of polysaccharides during the extraction process and improving the extraction efficiency. The present application also does not use a stirring method, mainly considering that the high-speed stirring process can cause the ultra-long molecular chains of polysaccharides to be sheared and broken, and the short chains can accelerate the hydrolysis of polysaccharides, resulting in a decrease in the molecular weight of polysaccharides.

[0008] In the present application, the aloe gel can be selected from manual grinding, wall breaking machine grinding (Philips wall breaking machine HR3868), shear tank grinding (Shangde machinery LV-631-50) or automatic grinding device, wherein the automatic grinding device is selected from the grinding device disclosed in the Chinese patent application with publication number CN115846015A, which comprises a support, a cylindrical tank body for containing aloe gel is installed on the support, and a grinder is arranged in the cylindrical tank body; the cylindrical tank body is open at the top for aloe gel feeding; a discharge port is arranged at the bottom side of the cylindrical tank body; the discharge port is connected with a quick-mount butterfly valve as a discharge valve; an axle hole is arranged at the center of the bottom of the cylindrical tank body; the output shaft of a shear motor is connected with a rotating shaft through the axle hole through a shaft coupling; the shear motor drives the grinder through the rotating shaft; and the bottom of the tank body of the grinding device is in a semicircular arc shape. When shearing, the running speed of the upper layer of aloe gel is greater than that of the lower layer of aloe gel, the aloe gel with a faster flow rate can drive the adjacent aloe gel with a slower flow rate, and the aloe gel with a slower flow rate can hinder the adjacent aloe gel with a faster flow rate, so that internal friction occurs between the aloe gels with different flow rates, the internal friction of the aloe gel is orderly and regular, and finally the viscosity of the upper layer of aloe gel is higher than that of the lower layer of aloe gel. Among the several grinding methods, the aloe polysaccharide solution obtained by manual grinding and automatic grinding device has the highest viscosity, and the efficiency of the automatic grinding device is the highest, so the automatic grinding device can be preferentially selected in terms of work efficiency.

[0009] The aloe polysaccharide solution is placed in a stirring tank, stirred and subjected to light treatment at 4-15 DEG C for at least 24 hours, and then the aloe polysaccharide pervaporation membrane on the liquid surface is collected in a high-temperature film forming tank at 75-95 DEG C.

[0010] In the present application, the light treatment is ordinary white light irradiation treatment, and the ordinary white light is defined as the full wavelength range of visible light, and further, can be understood as light with a wavelength of 390-780 nm.

[0011] In the present application, the aloe polysaccharide pervaporation membrane can be used to improve the solubility and stability of the poorly soluble substance (such as fumaric acid) at room temperature, avoid precipitation during storage, and simplify the solubilization process when the aloe polysaccharide is used as a solubilizer: without the addition of organic solvents or the participation of complex equipment. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The photos show the dissolution of fumaric acid in aloe polysaccharide solutions with different concentrations;

[0013] Figure 2 The photos show the dissolution of fumaric acid in water with different concentrations;

[0014] Figure 3 The graph shows the relationship between the content of fumaric acid and the solubility of fumaric acid in water and aloe polysaccharide solution.

[0015] Figure 4 The crystallization condition photos of the aloe polysaccharide solution and the dissolved fumaric acid in water after room temperature and light avoidance treatment for 7 days;

[0016] Figure 5 The result chart of the liquid chromatography detection of the aloe polysaccharide solution sample (10 mg / mL) dissolved fumaric acid diluted 400 times;

[0017] Figure 6 The dissolution condition photos of the dissolution of fumaric acid in the solutions of different concentrations of the commercially available aloe polysaccharide and the aloe polysaccharide solution. DETAILED DESCRIPTION

[0018] In order to make the skilled in the art more clearly and intuitively understand the present application, the present application will be further described below in combination with the drawings.

[0019] The present application is based on the extracted aloe polysaccharide, and the possibility of the aloe polysaccharide to improve the solubility of the poorly soluble substance in water is explored. The poorly soluble substance in the present application takes fumaric acid as an example. The fumaric acid is also known as trans-butenedioic acid, fumaric acid, and corydalis acid, and its chemical formula is C4H4O4. It is an unsaturated dicarboxylic acid derived from butene, and is a colorless and flammable crystal.

[0020] Example 1 Preparation of aloe polysaccharide

[0021] The preparation steps of the aloe polysaccharide include:

[0022] Both ends of fresh aloe vera leaves are removed and soaked in pure water for 1-2 days; after washing with water, the epidermis is removed to obtain aloe vera gel to be ground; the aloe vera gel to be ground is sheared in an automatic aloe vera grinding device to complete grinding, and aloe vera polysaccharide solution is obtained; the automatic aloe vera grinding device is a grinding device disclosed in a Chinese patent application with publication number CN115846015A, which includes a support, a cylindrical tank for holding aloe vera gel is installed on the support, and a grinder is arranged in the cylindrical tank; the cylindrical tank is open at the top for aloe vera gel feeding; a discharge port is arranged on the side of the bottom of the cylindrical tank; the discharge port is connected with a quick-assembly butterfly valve as a discharge valve; a shaft hole is arranged at the center of the bottom of the cylindrical tank; the output shaft of a shearing motor is connected with a rotating shaft through the shaft hole through a shaft coupling; the shearing motor drives the grinder through the rotating shaft; and the bottom of the tank of the grinding device is in a semicircular arc shape. When shearing, the running speed of the upper layer of aloe vera gel is greater than that of the lower layer of aloe vera gel, the aloe vera gel with a faster flow rate can drive the adjacent aloe vera gel with a slower flow rate, and the aloe vera gel with a slower flow rate can hinder the adjacent aloe vera gel with a faster flow rate, so that internal friction occurs between the aloe vera gels with different flow rates, the internal friction of the aloe vera gel is orderly and regular, and finally the viscosity of the upper layer of aloe vera gel is higher than that of the lower layer of aloe vera gel. The viscosity of the aloe vera polysaccharide solution obtained through the automatic aloe vera grinding device is comparable to that of the aloe vera polysaccharide solution obtained through manual grinding, and the efficiency is higher.

[0023] The aloe vera polysaccharide solution is placed in a stirring tank, stirred and subjected to ordinary white light illumination treatment at 4-15°C for at least 24 hours, and then the aloe vera polysaccharide pervaporation membrane on the surface of the liquid is collected in a high-temperature film-forming tank at 75-95°C (80°C is used in this embodiment).

[0024] The stirring tank adopts an ellipsoidal bottom, and the temperature control of the aloe vera polysaccharide solution in the stirring tank is realized by using a jacket circulation system. The jacket circulation system cools the stirring tank from the outside. The jacket is a closed space installed on the outside of the stirring tank, which forms a heat conduction channel with the wall of the stirring tank. By circulating cooling medium (such as alcohol and cooling water) in the channel, the aloe vera polysaccharide solution in the stirring tank can be cooled, and the temperature of the aloe vera polysaccharide solution is maintained in the range of 4-15°C. The stirring tank adopts an ellipsoidal bottom design, which is mainly to promote the circulation and mixing of the aloe vera polysaccharide solution. The ellipsoidal bottom design can reduce the dead angle, so that the aloe vera polysaccharide solution is more easily stirred uniformly by the stirrer, reduces the local flow rate difference in the mixing process, and improves the mixing efficiency. In addition, the ellipsoidal bottom can reflect light at multiple angles to the solution, improving the illumination efficiency.

[0025] The temperature of the aloe polysaccharide solution in the high-temperature film forming tank is controlled at 75-95°C. Similarly, the high-temperature film forming tank adopts a jacket circulating system to control the temperature of the aloe polysaccharide solution in the high-temperature film forming tank. The jacket circulating system heats the high-temperature film forming tank from the outside. The jacket is a closed space installed on the outside of the high-temperature film forming tank, which forms a heat conduction channel with the wall of the high-temperature film forming tank. By circulating the heating medium (such as heat-conducting oil and water) in the channel, the aloe polysaccharide solution in the high-temperature film forming tank can be heated, and the temperature of the aloe polysaccharide solution is maintained in the range of 75-95°C, so that the aloe polysaccharide pervaporation membrane can be continuously formed in the high-temperature film forming tank.

[0026] The light intensity at the center of the aloe polysaccharide solution in the stirring tank should not be less than 800 lumens. The intensity of the light intensity can be monitored by setting a light monitoring member. The light monitoring member can be a photodiode type illuminance sensor or a photosensitive resistance type illuminance sensor. The present application does not limit the light monitoring member, and the light monitoring member cannot be less than 800 lumens. It can ensure that the photochemical reaction of the aloe polysaccharide solution has enough energy input. The light treatment is ordinary white light irradiation treatment. The definition of ordinary white light is the full wavelength range of visible light. Further, it can be understood as light with a wavelength of 390-780 nm.

[0027] Low-temperature treatment helps to maintain the stability and activity of the aloe polysaccharide solution, reduces its degradation or denaturation, and slows down the degradation rate of the aloe polysaccharide solution. Stirring can ensure that the components in the aloe polysaccharide solution are uniformly distributed and form sufficient vortex to reduce local concentration differences. It can also make the aloe polysaccharide solution receive uniform light and air contact, avoiding local degradation of the aloe polysaccharide solution, and providing better conditions for the subsequent membrane pervaporation process.

[0028] Appropriate light helps to trigger or accelerate the photochemical reaction in the aloe polysaccharide solution. The aloe polysaccharide solution is reacted for at least 24 hours under low temperature, stirring and light. The degree of hydrolysis of the aloe polysaccharide solution is higher, and the viscosity is lower (in the viscosity detection of the aloe polysaccharide solution without light treatment and the aloe polysaccharide solution with light treatment under room temperature 20°C conditions, it is found that the viscosity of the aloe polysaccharide solution without light treatment is 280.25 mpa·s, and the viscosity of the aloe polysaccharide solution with light treatment is 135.00 mpa·s. Obviously, light can reduce the viscosity of the aloe polysaccharide solution).

[0029] Example 2 Fumaric acid solubilization experiment

[0030] First, the aloe polysaccharide prepared in Example 1 is used as a solubilizer to co-dissolve with fumaric acid. The solution is completely dissolved by ultrasonic treatment at 60°C for half an hour overnight. The obtained solution is stable and does not precipitate at room temperature (25°C) for a long time.

[0031] Detailed implementation steps

[0032] The aloe polysaccharide prepared in Example 1 was dissolved in water to obtain an aloe polysaccharide solution with a mass / volume concentration of 50 mg / mL (50 mg of aloe polysaccharide was added to 1 mL of water), and the prepared aloe polysaccharide solution was equally added to 6 centrifuge tubes. Then, fumaric acid was added to the aloe polysaccharide solution in the 6 centrifuge tubes, respectively, and the mass / volume ratio of fumaric acid to aloe polysaccharide solution in the 6 centrifuge tubes was 10 mg / mL to 80 mg / mL (i.e., the amount of fumaric acid added to the 6 centrifuge tubes was calculated according to the mass / volume ratio of fumaric acid to aloe polysaccharide solution of 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, 60 mg / mL, and 80 mg / mL). The 6 centrifuge tubes were subjected to ultrasonic treatment for half an hour and heating at 60°C overnight, and photographs were taken for recording. Figure 1

[0033] In addition, 5 centrifuge tubes were taken, and equal amounts of deionized water were added. Fumaric acid was added to the water in the 5 centrifuge tubes, respectively, and the mass / volume ratio of fumaric acid to water in the 5 centrifuge tubes was 10 mg / mL to 60 mg / mL (i.e., the amount of fumaric acid added to the 5 centrifuge tubes was calculated according to the mass / volume ratio of fumaric acid to water of 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, and 60 mg / mL). The 5 centrifuge tubes were subjected to ultrasonic treatment for half an hour and heating at 60°C overnight, and photographs were taken for recording. Figure 2

[0034] The solubility of fumaric acid in the aloe polysaccharide solution and water after the addition of fumaric acid to the centrifuge tubes and the ultrasonic treatment and heating at 60°C overnight was counted, and the results are shown in Table 1 and Figure 3

[0035] Table 1 Solubility of fumaric acid in water and aloe polysaccharide solution and 7-day room temperature storage stability

[0036]

[0037] As can be seen from Figures 1-3 , the solubility of fumaric acid in water is 10 mg / mL, and the solubility of fumaric acid in the aloe polysaccharide solution can reach more than 60 mg / mL.

[0038] Example 3 Solubility stability experiment of fumaric acid in aloe polysaccharide solution

[0039] The 6 centrifuge tubes containing the aloe polysaccharide solution and the added fumaric acid (the mass / volume ratio of fumaric acid to aloe polysaccharide solution was 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, and 60 mg / mL, respectively) were placed at room temperature in the dark for 7 days, and photographs were taken for recording.​​​​

[0040] In addition, considering that the solubility of fumaric acid in water is low, three centrifuge tubes containing water and fumaric acid (the mass / volume ratio of fumaric acid to water is 10 mg / mL, 20 mg / mL and 30 mg / mL, respectively) were placed in the dark at room temperature for 7 days, and photographs were taken for record.

[0041] The photographs of the aloe polysaccharide solution and water-soluble fumaric acid after being placed in the dark at room temperature for 7 days are shown in Figure 4 As shown in the photographs, the results show that after being stored at room temperature (25°C) for 7 days, the fumaric acid dissolved in the aloe polysaccharide solution is clear without fumaric acid crystals precipitating in the range of 10 mg / mL to 40 mg / mL, while the fumaric acid dissolved in water all precipitates fumaric acid crystals (a small amount of fumaric acid crystals precipitates at the bottom at 10 mg / mL, which is not obvious in the photograph). It can be known that the fumaric acid dissolved in the aloe polysaccharide solution of the present application not only can promote the dissolution of fumaric acid (the solubility reaches more than 60 mg / mL), but also can improve the storage stability at room temperature (stable without crystal precipitation in the range of 10 mg / mL to 40 mg / mL).

[0042] To ensure the structural stability of fumaric acid in the aloe polysaccharide solution after being stored at room temperature (25°C) for 7 days, the fumaric acid samples (10 mg / mL) dissolved in the aloe polysaccharide solution on the first day and after being stored at room temperature for 7 days were diluted 400 times and subjected to liquid chromatography detection. The detailed method for detecting the content of fumaric acid by HPLC is as follows:

[0043] 1. Chromatographic column: C18 column with octadecylsilane bonded silica gel as the filler;

[0044] 2. Mobile phase: 0.2% phosphoric acid solution-acetonitrile (90%:10%);

[0045] 3. Detection wavelength: 210 nm;

[0046] 4. Flow rate: 0.6 mL / min;

[0047] 5. Injection volume: 10 μL;

[0048] 6. Column temperature: 30°C.

[0049] The liquid chromatography detection results are shown in Figure 5 As can be seen from Figure 5 , the retention time, peak shape and concentration of the two samples of fumaric acid dissolved in the aloe polysaccharide solution on the first day and after being stored at room temperature for 7 days are consistent, indicating that the structure of fumaric acid is stable during storage.

[0050] Example 4

[0051] To verify the uniqueness of the aloe polysaccharide prepared in Example 1 as a stable solubilizer, commercially available aloe raw liquid-coarse polysaccharide (A) and aloe polysaccharide solution (B) obtained from aloe grinding paste in aloe polysaccharide preparation were prepared into a solution with a mass / volume ratio of 50 mg / mL, and the method in Example 2 was used to add fumaric acid to different centrifuge tubes containing A and B solutions respectively (the amount of fumaric acid added to 3 centrifuge tubes containing A solution was calculated according to the mass / volume ratio of fumaric acid to A solution of 10 mg / mL, 20 mg / mL and 30 mg / mL, and the amount of fumaric acid added to another 3 centrifuge tubes containing B solution was calculated according to the mass / volume ratio of fumaric acid to B solution of 10 mg / mL, 20 mg / mL and 30 mg / mL), 6 centrifuge tubes were treated by ultrasonic at 60°C for half an hour, overnight, photographed and recorded, and the results are shown in Figure 6 It can be seen from Figure 6 that the solubility of fumaric acid in the two solutions is 10 mg / mL, which is not different from that in water.

[0052] The aloe polysaccharide prepared in Example 1 of the present application has been subjected to light and film removal treatment, and a hydrophilic-hydrophobic polysaccharide is obtained. Through experiments, it is found that the solubilization effect of the aloe polysaccharide on poorly soluble substances is significant and can be stably and long-term stored at room temperature; the core principle of promoting the dissolution of poorly soluble substances may lie in its unique molecular self-assembly ability, which "disguises" hydrophobic molecules as water-soluble complexes to improve the solubility of poorly soluble substances and stably store them by reducing interfacial tension or forming stable micelles / inclusion compounds.

[0053] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and apply the present application. Those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the present application is not limited to the embodiments herein, and improvements and modifications of the present application made by those skilled in the art according to the disclosure of the present application should be within the scope of protection of the present application.

Claims

1. Use of aloe polysaccharide as a solubilizer for improving the solubility of a poorly soluble substance, wherein the poorly soluble substance is fumaric acid. The preparation method of the aloe polysaccharide comprises the following steps: The two ends of fresh Aloe vera leaves are removed, and the leaves are soaked in pure water for 1-2 days; after water washing, the epidermis is removed to obtain aloe gel to be ground; The aloe gel to be ground is ground to obtain an aloe polysaccharide solution; The aloe polysaccharide solution is placed in a stirring tank, stirred at 4-15°C, and subjected to light treatment for at least 24 hours, and then the aloe polysaccharide pervaporation membrane on the liquid surface is collected in a high-temperature film forming tank at 75-95°C to obtain the aloe polysaccharide.

2. Use according to claim 1, wherein The light treatment is ordinary white light irradiation treatment.

3. The use according to claim 1, wherein The aloe polysaccharide is prepared into a 50 mg / mL solution as a solubilizer.

4. A method of using a solubilizer characterized by, The method comprises the following steps: The aloe polysaccharide is dissolved in water to obtain a 50 mg / mL aloe polysaccharide solution as a solubilizer; The poorly soluble substance is added to the aloe polysaccharide solution, and ultrasonic treatment is performed at 60°C for half an hour to dissolve the poorly soluble substance overnight; the poorly soluble substance is fumaric acid. The preparation method of the aloe polysaccharide comprises the following steps: The two ends of fresh Aloe vera leaves are removed, and the leaves are soaked in pure water for 1-2 days; after water washing, the epidermis is removed to obtain aloe gel to be ground; the aloe gel to be ground is sheared in an automatic aloe gel grinding device to complete the grinding to obtain an aloe polysaccharide solution; The aloe polysaccharide solution is placed in a stirring tank, stirred at 4-15°C, and subjected to light treatment for at least 24 hours, and then the aloe polysaccharide pervaporation membrane on the liquid surface is collected in a high-temperature film forming tank at 75-95°C to obtain the aloe polysaccharide.

5. The method of use of claim 4, wherein, The light treatment is ordinary white light irradiation treatment.

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