CN117562869B - Magnesium hydroxide nanoparticles for treating joint pain, preparation method and application thereof - Google Patents

Abstract

The present invention belongs to the field of medicine, and specifically relates to a magnesium hydroxide nanoparticle for treating joint pain and a preparation method thereof. The preparation method is as follows: dissolving a soluble magnesium salt in purified water to obtain a magnesium salt solution; dissolving a soluble metal hydroxide in purified water to obtain a metal hydroxide solution; dissolving a phospholipid in an organic solvent to obtain a phospholipid solution; subjecting the phospholipid solution to rotary evaporation to remove organic reagents, adding a magnesium salt solution to hydration after a thin film is formed to obtain a hydration liquid; adding a metal hydroxide solution to the hydration liquid for nano-treatment, and the preparation method is simple and easy to control, and magnesium hydroxide nanoparticles can be prepared only by magnesium salt, hydroxide and phospholipid, and rat experiments have verified that after magnesium salt is prepared into nano-scale magnesium hydroxide by means of pharmaceutical preparation technology, it has the effect of joint analgesia, and the analgesic effect time is significantly prolonged, which will greatly reduce the frequency of administration, and thus reduce the pain of patients.

Description

Magnesium hydroxide nanoparticles for treating joint pain, preparation method and application thereof

Technical Field

The invention belongs to the field of medicine, and specifically relates to magnesium hydroxide nanoparticles for treating joint pain, a preparation method and application thereof.

Background technique

Osteoarthritis (OA) is a degenerative disease with joint pain as the main symptom caused by fibrosis, cracking, ulceration and loss of articular cartilage caused by multiple factors. It often affects the knee joint, hip joint, spine and hands. Its pathological characteristics are mainly degeneration and destruction of articular cartilage, subchondral bone sclerosis or cystic changes, bone hyperplasia at the joint edge and synovitis. OA seriously affects the joint function and quality of life of patients. Studies have found that OA, especially symptomatic knee OA, can significantly increase the all-cause mortality of patients. Unfortunately, there is currently no safe and effective treatment that can delay the progression of OA at home and abroad.

Joint pain is the most common clinical manifestation of OA, and analgesia is the main demand of OA patients when they seek medical treatment. As the disease progresses, OA patients often experience persistent pain. Therefore, achieving long-term and safe analgesia is of great significance to OA patients.

At present, the treatment methods for OA patients are mainly joint analgesia. Although there are many types, there are many problems. For example, acetaminophen has always been the first-line drug for the treatment of OA pain, but high-quality research evidence in recent years shows that it is not only ineffective in relieving OA pain compared with placebo, but also significantly increases the risk of gastrointestinal side effects; oral non-steroidal anti-inflammatory drugs have a clear effect on relieving OA pain, but the cardiovascular and gastrointestinal side effects caused by long-term use are worrying; oral tramadol is recommended as a "first-line drug" by the 2013 edition of the American Orthopaedic Association and the 2012 edition of the American College of Rheumatology OA Guidelines, but recent studies have found that oral tramadol can significantly increase all-cause mortality, myocardial infarction, and hip fracture incidence compared with non-steroidal anti-inflammatory drugs (it has been written into the 2019 edition of the American College of Rheumatology OA Guidelines and no longer recommends tramadol as a "first-line drug"); intra-articular injection of hormones is widely used and has a significant short-term analgesic effect, but intra-articular injection of hormones has important problems that need to be solved, such as a short-term analgesic effect, insufficient effect, and safety risks. Therefore, there is an urgent need to further explore therapeutic drugs with significant efficacy and high safety for long-term analgesia of OA.

Therefore, based on this, the technical solution of the present invention is proposed.

Summary of the invention

In order to solve the problems existing in the prior art, the present invention provides a magnesium hydroxide nanoparticle for treating joint pain and a preparation method thereof. The preparation method is simple and easy to control, and magnesium hydroxide nanoparticles can be prepared only by magnesium salt, hydroxide and phospholipid, and rat experiments have verified that after magnesium salt is prepared into nano-scale magnesium hydroxide by means of pharmaceutical preparation technology, it has the effect of joint analgesia, and the analgesic effect time is significantly prolonged, which will greatly reduce the frequency of administration, thereby reducing the pain of patients.

The present invention provides magnesium hydroxide nanoparticles for treating joint pain, wherein the magnesium hydroxide nanoparticles contain magnesium hydroxide and phospholipids.

Preferably, the magnesium hydroxide nanoparticles comprise a "core-shell" structure, wherein:

The core layer is magnesium hydroxide and the shell layer is phospholipid.

Preferably, the phospholipid is one of natural soybean phospholipid, natural egg yolk phospholipid or synthetic phospholipid (such as hydrogenated phospholipid).

Preferably, the phospholipid is one of phospholipids S45, S75, S100, SPC, E80, EPCS, EPG, SPC-3, PC98-T, PL-100M, HSPC, PGE, PGSH, DS-PL95E, DSPE, DPPA, DSPA or DMPC.

Preferably, the average particle size of the magnesium hydroxide nanoparticles is 50 to 550 nm.

Based on the same technical concept, the present invention further provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) dissolving a soluble magnesium salt in purified water to obtain a magnesium salt solution;

(2) dissolving a soluble metal hydroxide in purified water to obtain a metal hydroxide solution;

(3) dissolving the phospholipid in an organic solvent to obtain a phospholipid solution;

(4) performing rotary evaporation on the phospholipid solution to remove the organic reagent, and after a thin film is formed, adding the magnesium salt solution to hydrate the solution to obtain a hydrated solution;

(5) Adding the metal hydroxide solution to the hydration liquid for nano-processing, and obtaining the magnesium hydroxide nanoparticles for treating joint pain.

Preferably, in step (1), the soluble magnesium salt is a combination of one or more of anhydrous magnesium sulfate, magnesium sulfate monohydrate, magnesium sulfate heptahydrate, magnesium chloride, and magnesium chloride hexahydrate.

Preferably, in step (2), the metal hydroxide is sodium hydroxide or potassium hydroxide, or a combination of both.

Preferably, in step (3), the organic solvent is volatile and can dissolve phospholipids, and is a combination of one or more of ethanol, dichloromethane or acetone.

Preferably, in step (5), the nano-treatment is carried out by one of probe ultrasonic treatment, high-pressure homogenization treatment or ball mill treatment.

Based on the same technical concept, the present invention further provides an application of the magnesium hydroxide nanoparticles for treating joint pain, wherein the magnesium hydroxide nanoparticles are used to prepare a drug for treating joint pain caused by osteoarthritis.

The beneficial effects of the present invention are:

The preparation method of the present invention is simple and easy to control. Magnesium hydroxide nanoparticles can be prepared only by magnesium salt, hydroxide and phospholipids. It has been verified through rat experiments that after magnesium salt is prepared into nano-scale magnesium hydroxide by means of pharmaceutical preparation technology, it has the effect of joint analgesia, and the analgesic effect time is significantly prolonged, which will greatly reduce the frequency of drug administration and thus reduce the pain of patients.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG. 1 is a TEM image of magnesium hydroxide nanoparticles in Experimental Example 1.

FIG. 2 is a data diagram showing the mechanical withdrawal threshold results of rats in each group in Experimental Example 2.

FIG. 3 is a data diagram showing the difference in weight bearing between the two feet of rats in each group in Experimental Example 2.

Detailed ways

To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

Example 1

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 393.6 mg of magnesium sulfate heptahydrate in 4 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 8 mg of sodium hydroxide and 1 mL of purified water to obtain a sodium hydroxide solution;

(3) Dissolve 125 mg of egg yolk phospholipid E80 in 20 mL of dichloromethane to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration solution, and then ultrasonicated for 10 minutes with a 220 W power probe. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 338.5 nm as measured by a laser particle size analyzer.

Example 2

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 393.6 mg of magnesium sulfate heptahydrate in 4 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 12 mg of sodium hydroxide and 1 mL of purified water to obtain a sodium hydroxide solution;

(3) Dissolve 125 mg of egg yolk phospholipid E80 in 30 mL of dichloromethane to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated solution;

(5) The sodium hydroxide solution is quickly added to the hydration solution, and then ultrasonicated for 10 minutes with a 220 W power probe. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 445.0 nm as measured by a laser particle size analyzer.

Example 3

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 393.6 mg of magnesium sulfate heptahydrate in 4 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 16 mg of sodium hydroxide and 1 mL of purified water to obtain a sodium hydroxide solution;

(3) Dissolve 125 mg of egg yolk phospholipid E80 in 20 mL of dichloromethane to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration solution, and then ultrasonicated for 10 minutes with a 220 W power probe. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 539.5 nm as measured by a laser particle size analyzer.

Example 4

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 393.6 mg of magnesium sulfate heptahydrate in 4 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 32 mg of sodium hydroxide and 1 mL of purified water to obtain a sodium hydroxide solution;

(3) Dissolve 125 mg of egg yolk phospholipid E80 in 20 mL of dichloromethane to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration liquid, and then treated by a high-pressure homogenizer at 6000 psi for 5 minutes. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 398.5 nm as measured by a laser particle size analyzer.

Example 5

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 192 mg of anhydrous magnesium sulfate in 4 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 8 mg of sodium hydroxide and 1 mL of purified water to obtain a sodium hydroxide solution;

(3) Dissolve 125 mg of egg yolk phospholipid E80 in 20 mL of dichloromethane to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration solution, and then ultrasonicated for 10 minutes with a 220 W power probe. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 313.6 nm as measured by a laser particle size analyzer.

Example 6

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 1.2 g of magnesium sulfate heptahydrate in 12 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 48 mg of sodium hydroxide and 3 mL of purified water to obtain a sodium hydroxide solution;

(3) Dissolve 350 mg of soybean lecithin S100 in 60 mL of dichloromethane to obtain a lecithin solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration liquid, and then treated by a high-pressure homogenizer at 6000 psi for 5 minutes. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 363.9 nm as measured by a laser particle size analyzer.

Example 7

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 393.6 mg of magnesium sulfate heptahydrate in 4 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 8 mg of sodium hydroxide and 1 mL of purified water to obtain a sodium hydroxide solution;

(3) Dissolve 60 mg of egg yolk phospholipid E80 in 20 mL of dichloromethane to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated solution;

(5) The sodium hydroxide solution is quickly added to the hydration solution, and then ultrasonicated for 10 minutes with a 220 W power probe. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 411.7 nm as measured by a laser particle size analyzer.

Example 8

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 440 mg of magnesium sulfate monohydrate in 8 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 16 mg of sodium hydroxide and 2 mL of purified water to obtain a sodium hydroxide solution;

(3) dissolving 200 mg of egg yolk lecithin PC98-T in 50 mL of anhydrous ethanol to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration liquid, and then the hydration liquid is processed by a ball mill (Emax ball mill produced by Retsch, Germany) at 800 rpm for 2 h. After the process is completed, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 206.5 nm as measured by a laser particle size analyzer.

Example 9

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 200 mg of anhydrous magnesium chloride (Aladdin, purity 99%) with 8 mL of purified water to obtain a magnesium chloride solution;

(2) Mix and dissolve 16 mg of sodium hydroxide and 2 mL of purified water to obtain a sodium hydroxide solution;

(3) dissolving 200 mg of egg yolk lecithin PC98-T in 50 mL of anhydrous ethanol to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium chloride solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration liquid, and then the hydration liquid is processed by a ball mill (Emax ball mill produced by Retsch, Germany) at 800 rpm for 2 h. After the process is completed, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 228.1 nm as measured by a laser particle size analyzer.

Example 10

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 420 mg of magnesium chloride hexahydrate (Aladdin, purity 99%) in 8 mL of purified water to obtain a magnesium chloride solution;

(2) Mix and dissolve 16 mg of sodium hydroxide and 2 mL of purified water to obtain a sodium hydroxide solution;

(3) dissolving 200 mg of egg yolk lecithin PC98-T in 50 mL of anhydrous ethanol to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium chloride solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration liquid, and then the hydration liquid is processed by a ball mill (Emax ball mill of Retsch, Germany) at 800 rpm for 2 hours. After completion, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 235.0 nm as measured by a laser particle size analyzer.

Embodiment 11

This embodiment provides a method for preparing magnesium hydroxide nanoparticles for treating joint pain, the preparation method comprising the following steps:

(1) Mix and dissolve 440 mg of magnesium sulfate monohydrate in 8 mL of purified water to obtain a magnesium sulfate solution;

(2) Mix and dissolve 16 mg of sodium hydroxide and 2 mL of purified water to obtain a sodium hydroxide solution;

(3) dissolving 800 mg of egg yolk lecithin PC98-T in 50 mL of anhydrous ethanol to obtain a phospholipid solution;

(4) transferring the phospholipid solution to a round-bottom flask, removing the organic reagent by a rotary evaporator to form a thin film on the flask wall, and then hydrating the thin film with the magnesium sulfate solution to obtain a hydrated liquid;

(5) The sodium hydroxide solution is quickly added to the hydration liquid, and then the mixture is processed by a ball mill (Emax ball mill of Retsch, Germany) at 1000 rpm for 6 h. After the processing, the magnesium hydroxide nanoparticles for treating joint pain are obtained. The average particle size thereof is 65.3 nm as measured by a laser particle size analyzer.

Comparative Example 1

125 mg of egg yolk phospholipid E80 was dissolved in 20 mL of dichloromethane and transferred to a round-bottom flask. The organic reagent was removed by a rotary evaporator to form a thin film on the flask wall. 5 mL of purified water was used to hydrate the thin film to make it fall off to form a hydrated liquid, and then ultrasonicated with a power probe of 220 W for 10 minutes to obtain blank liposomes.

Comparative Example 2

(1) dissolving 393.6 mg of magnesium sulfate heptahydrate in 4 mL of purified water to obtain a magnesium sulfate solution;

(2) Dissolve 8 mg of sodium hydroxide in 1 mL of purified water to obtain a sodium hydroxide solution;

(3) The sodium hydroxide solution was quickly added to the magnesium sulfate solution, and then ultrasonicated for 10 minutes with a power probe of 220 W. The results showed that the system presented an obvious white precipitate, and the particle size was beyond the measurement range of the laser particle size analyzer.

Test Example 1

The internal structure of the magnesium hydroxide nanoparticles of the present invention was observed.

The structure of the magnesium hydroxide nanoparticles prepared in Example 1 was observed by transmission electron microscopy (TEM). The result is shown in FIG1 . The magnesium hydroxide nanoparticles prepared in the present invention are spherical in shape, and the magnesium hydroxide can be coated with phospholipids.

Test Example 2

The effect of the magnesium hydroxide nanoparticles of the present invention was tested.

1. OA rat model

Sodium iodoacetate was injected into the articular cavity of the knee joint of SD rats to construct an OA rat model. When the rat knee joint became swollen and the pain threshold was significantly reduced, the OA rat model was obtained.

(II) Pharmacodynamic studies

By intra-articular injection, OA model rats were treated with normal saline (referred to as normal saline group), blank liposomes prepared in Comparative Example 1 (referred to as blank liposome group), magnesium sulfate solution (magnesium sulfate heptahydrate was dissolved in normal saline, referred to as magnesium sulfate solution group), magnesium hydroxide nanoparticle liquid prepared in Example 1 (referred to as magnesium hydroxide nanoparticle group 1), magnesium hydroxide nanoparticle liquid prepared in Example 3 (referred to as magnesium hydroxide nanoparticle group 2), and magnesium hydroxide nanoparticle liquid prepared in Example 11 (referred to as magnesium hydroxide nanoparticle group 3).

In addition, an equal volume (100 μL) of normal saline was injected into the knee joint cavity of normal rats as a control (recorded as the normal group). The drug concentration for each group was 0.4 mmol/mL (calculated as magnesium), and the drug was administered on the 7th day after modeling, for a total of 1 dose. From the first day of administration, the mechanical withdrawal threshold and the difference in weight between the two feet of each group of rats were measured once a week. The results are shown in Figures 2 and 3, respectively.

As shown in Figures 2 and 3, the magnesium hydroxide nanoparticles prepared by the present invention can effectively and durably relieve the joint pain of OA rats. At the same time, these results fully illustrate that the magnesium hydroxide nanoparticles of the present invention can be used to prepare drugs for treating joint analgesia.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (9)

1. A magnesium hydroxide nanoparticle for treating joint pain, wherein the magnesium hydroxide nanoparticle comprises magnesium hydroxide and a phospholipid, the magnesium hydroxide nanoparticle comprising a "core-shell" structure, wherein:

the core layer is magnesium hydroxide, and the shell layer is phospholipid.

2. The magnesium hydroxide nanoparticle for treating joint pain according to claim 1, wherein the phospholipid is one or more of a natural soybean phospholipid, a natural egg yolk phospholipid, or a synthetic phospholipid.

3. The magnesium hydroxide nanoparticle according to claim 2, wherein the phospholipid is one or more of the group consisting of phospholipids S45, S75, S100, SPC, E80, EPCS, EPG, SPC-3, PC98-T, PL-100M, HSPC, PGE, PGSH, DS-PL95E, DSPE, DPPA, DSPA, and DMPC.

4. The magnesium hydroxide nanoparticle for treating joint pain according to claim 3, wherein the average particle size of the magnesium hydroxide nanoparticle is 50-550 nm.

5. The method for preparing the magnesium hydroxide nanoparticles for treating joint pain according to any one of claims 1 to 4, wherein the method comprises the following steps:

(1) Dissolving soluble magnesium salt in purified water to obtain magnesium salt solution;

(2) Dissolving soluble metal hydroxide in purified water to obtain a metal hydroxide solution;

(3) Dissolving phospholipid in an organic solvent to obtain a phospholipid solution;

(4) Performing rotary evaporation on the phospholipid solution to remove an organic reagent, and adding the magnesium salt solution for hydration after a film is formed to obtain hydration liquid;

(5) And adding the metal hydroxide solution into the hydration liquid for nanocrystallization treatment, and obtaining the magnesium hydroxide nanoparticles for treating joint pain after the nanocrystallization treatment is completed.

6. The method of preparing magnesium hydroxide nanoparticles for treating joint pain according to claim 5, wherein in step (1), the soluble magnesium salt is one or more of anhydrous magnesium sulfate, magnesium sulfate monohydrate, magnesium sulfate heptahydrate, anhydrous magnesium chloride, and magnesium chloride hexahydrate.

7. The method for preparing magnesium hydroxide nanoparticles for treating joint pain according to claim 5, wherein in step (2), said metal hydroxide is one or a combination of two of sodium hydroxide and potassium hydroxide.

8. The method for preparing magnesium hydroxide nanoparticles for treating joint pain according to claim 5, wherein in step (5), said nanocrystallization is performed by one of probe sonication, high-pressure homogenization, and ball mill treatment.

9. The use of the magnesium hydroxide nanoparticles for treating joint pain according to any one of claims 1 to 4, wherein the magnesium hydroxide nanoparticles are used for preparing a medicament for treating joint pain of osteoarthritis.