Nano-formulations for joint pain relief and their preparation methods and uses

Abstract

The present invention discloses a nano-preparation for joint pain relief, the nano-preparation comprises glucocorticoids and nano-carriers, the nano-carriers mainly comprise phospholipids and auxiliary agents, and the auxiliary agents comprise polyoxyethylene castor oil. The nano-preparation of the present invention can be used for joint pain relief, has a large drug loading capacity, can be maintained in the joint cavity for at least 4 weeks, and has a better analgesic effect on OA than commercially available GC injections, and can be maintained for at least 4 weeks. The present invention further discloses the preparation method and use of this nano-preparation, which has a simple process, a particle size smaller than 200 nm, can be terminally sterilized by methods such as probe ultrasonic, high pressure homogenization or microporous filter membrane sterilization, and has a relatively low preparation cost.

Description

[Technical field]

[0001] The present invention relates to the field of biomedicine, and in particular to a nano-formulation for joint pain relief and its preparation method and use. [Background technology]

[0002] Osteoarthritis (OA) is a multifactor-induced aging disease with joint pain as its main symptom, and the disability rate is high, placing a heavy burden on the nation and society. The main complaint of OA patients is pain relief. Glucocorticoids (GCs) are a type of steroid-based low-molecular-weight drug with diverse pharmacological effects. They can exert an analgesic effect by suppressing inflammatory responses, and are widely used for pain relief in OA. However, GCs are poorly soluble, have a short maintenance time for analgesic effects, are insufficient in efficacy, and have safety issues, which are important problems to be solved. The average retention period of tretinoin sustained-release suspension injections in the knee joints of patients with knee osteoarthritis is 3.8 days, and the frequency of joint cavity injections is high. Therefore, it is of great significance to improve the solubility of GCs, reduce the number of GC administrations, and sustain the analgesic effect in knee osteoarthritis.

[0003] The solubility of drugs is usually improved by encapsulating them in liposomes or nanocarriers made of polymeric materials, but liposomes have a low drug loading capacity for GCs and the drug is prone to precipitation in a short time. It is also possible to improve the solubility of GCs by encapsulating them in nanocarriers prepared from polymeric materials, but there are few polymeric materials available for injection into humans, and it is difficult to achieve long-term release of drugs after injection into the joint cavity. With the widespread application of biopolymer materials in the pharmaceutical field, polymer-based sustained-release microspheres have gradually become one of the research hotspots for new drug formulations. Currently, polymer sustained-release microspheres on the market are mainly polylactic acid-hydroxyacetic acid (PLGA) sustained-release microspheres. When GC (trimethoprim, dexamethasone, dexamethasone palmitate, etc.) is encapsulated in PLGA microspheres and injected into the joint cavity, the analgesic effect of GC on OA lasts for 4 to 12 weeks, and the drug residence time and analgesic time in the joint cavity correlate with the particle size of the microspheres. However, if the particle size of the microspheres is larger than 25 μm, there is a risk of promoting the occurrence of joint inflammation. In addition, the preparation process of PLGA sustained-release microspheres is complicated, terminal sterilization is difficult, and lactic acid and hydroxyacetic acid generated during decomposition may cause a decrease in the pH in the joint cavity and promote the occurrence of an inflammatory reaction. Summary of the Invention

[0004] The technical problem that the present invention aims to solve is to overcome the defects and drawbacks described in the background art and provide a nano-preparation for joint analgesia consisting of glucocorticoid, phospholipid and polyoxyethylene castor oil, which can achieve long-term sustained release of the drug (more than 4 weeks), has a simple preparation process that is easy to control and sterilize, and not only solves the problem of poor solubility of GC, but also the excipients used do not cause risks such as local pH reduction.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A nano-formulation for joint pain relief, the nano-formulation comprising a glucocorticoid and a nano-carrier, the nano-carrier mainly comprising a phospholipid and an auxiliary agent, the auxiliary agent comprising polyoxyethylene castor oil.

[0007] According to the research, the inventors found that the glucocorticoids could not be encapsulated in stable nanoparticles using only phospholipids or only polyoxyethylene castor oil. After glucocorticoids were loaded into nanoparticles made of phospholipids and polyoxyethylene castor oil, the ability to suppress the expression of inflammatory factors in macrophages was enhanced (see Figure 1, the degree of inflammation in the joint is closely correlated with joint pain), and the nanoformulations made of phospholipids and polyoxyethylene castor oil unexpectedly achieved a long-term sustained release effect in arthritic inflamed joints (see Figure 2), and furthermore, the nanoparticles loaded with these glucocorticoids achieved long-term pain relief (see Figure 3).

[0008] In the above nanoformulation, preferably, the glucocorticoid comprises one or more of clobetasol propionate, difluprednisol acetate, dexamethasone propionate, difluprednisolone, mometasone furoate, difluprednisolone valerate, betamethasone butyrate propionate, fluocortisol acetate, hydrocortisone butyrate, beclomethasone propionate, diproterenol propionate, betamethasone valerate, dexamethasone valerate, prednisolone valerate acetate, fluocinolone acetonide, hydrocortisone butyrate, clobetasone butyrate, aclometasone propionate, tretinoin, flumethasone neopentylate, prednisolone, hydrocortisone, dexamethasone, dexamethasone palmitate, triamcinolone palmitate. More preferably, it comprises one or more of dexamethasone, dexamethasone palmitate, tretinoin, prednisolone.

[0009] Preferably, the phospholipids comprise one or more of natural soybean phospholipids, natural lecithin, synthetic phospholipids, more preferably the phospholipids E80, S100, PC98-T, HSPC.

[0010] Preferably, the polyoxyethylene castor oil comprises one or more of polyoxyethylene 35 castor oil (EL-35), polyoxyethylene 40 castor oil (EL-40), polyoxyethylene 40 hydrogenated castor oil (HEL-40), polyoxyethylene 60 hydrogenated castor oil (HEL-60). More preferably, solid polyoxyethylene castor oil (at least one of HEL-40 and HEL-60) is used in combination with liquid polyoxyethylene castor oil (at least one of EL-35 and EL-40) to further improve drug loading capacity.

[0011] Preferably, the excipient further comprises 15-hydroxystearic acid polyethylene glycol ester (trade name Kolliphor HS15), the addition of 15-hydroxystearic acid polyethylene glycol ester provides a higher drug loading capacity.

[0012] Thus, according to a preferred embodiment, the auxiliary comprises polyoxyethylene 40 hydrogenated castor oil (HEL-40), polyoxyethylene 35 castor oil (EL-35) and 15-hydroxystearic acid polyethylene glycol ester. More preferably, the auxiliary consists of polyoxyethylene 40 hydrogenated castor oil (HEL-40), polyoxyethylene 35 castor oil (EL-35) and 15-hydroxystearic acid polyethylene glycol ester.

[0013] According to another preferred embodiment, the auxiliary comprises polyoxyethylene 60 hydrogenated castor oil (HEL-60), polyoxyethylene 35 castor oil (EL-35) and 15-hydroxystearic acid polyethylene glycol ester. More preferably, the auxiliary consists of polyoxyethylene 60 hydrogenated castor oil (HEL-60), polyoxyethylene 35 castor oil (EL-35) and 15-hydroxystearic acid polyethylene glycol ester.

[0014] According to another preferred embodiment, the auxiliary comprises polyoxyethylene 40 hydrogenated castor oil (HEL-40), polyoxyethylene 40 castor oil (EL-40) and 15-hydroxystearic acid polyethylene glycol ester. More preferably, the auxiliary consists of polyoxyethylene 40 hydrogenated castor oil (HEL-40), polyoxyethylene 40 castor oil (EL-40) and 15-hydroxystearic acid polyethylene glycol ester.

[0015] According to another preferred embodiment, the auxiliary comprises polyoxyethylene 60 hydrogenated castor oil (HEL-60), polyoxyethylene 40 castor oil (EL-40) and 15-hydroxystearic acid polyethylene glycol ester. More preferably, the auxiliary consists of polyoxyethylene 60 hydrogenated castor oil (HEL-60), polyoxyethylene 40 castor oil (EL-40) and 15-hydroxystearic acid polyethylene glycol ester.

[0016] When the coagent is a combination of the above three coagents, the three coagents may be present in any weight ratio.

[0017] Also, when polyoxyethylene 60 hydrogenated castor oil (HEL-60) and polyoxyethylene 35 castor oil (EL-35) are used in combination, or polyoxyethylene 60 hydrogenated castor oil (HEL-60) and 15-hydroxystearic acid polyethylene glycol ester are used in combination, nanoparticles with higher drug loading capacity can be prepared.

[0018] Thus, according to the most preferred embodiment, the auxiliary comprises polyoxyethylene 60 hydrogenated castor oil (HEL-60) and polyoxyethylene 35 castor oil (EL-35).More preferably, the auxiliary consists of polyoxyethylene 60 hydrogenated castor oil (HEL-60) and polyoxyethylene 35 castor oil (EL-35).

[0019] According to another most preferred embodiment, the auxiliary comprises polyoxyethylene 60 hydrogenated castor oil (HEL-60) and 15-hydroxystearic acid polyethylene glycol ester. More preferably, the auxiliary consists of polyoxyethylene 60 hydrogenated castor oil (HEL-60) and 15-hydroxystearic acid polyethylene glycol ester.

[0020] When the coagent is a combination of two coagents described above, the two coagents may be present in any weight ratio.

[0021] Preferably, the mass ratio of the phospholipid to the auxiliary is (1:20) to (20:1), preferably (1:10) to (10:1), more preferably (1:5) to (5:1), and even more preferably (1:2) to (2:1). Most preferably, the mass ratio of the phospholipid to the auxiliary is 3:5.

[0022] Preferably, the drug loading capacity of the glucocorticoid is 0.5-20%.

[0023] Preferably, the particle size of the nanoformulation is less than 200 nm.

[0024] Preferably, the formulation of the nano formulation is an injectable solution or a lyophilized powder for injection.

[0025] Based on the general inventive concept, the present invention also provides a method for preparing the nano-preparation for joint analgesia, which includes the steps of dissolving glucocorticoid, phospholipid and polyoxyethylene castor oil in an organic solvent, removing the organic reagent by vacuum evaporation, adding water to remove the film, and then obtaining the nano-preparation by probe ultrasonication, high pressure homogenization or pressing into a microporous membrane.

[0026] Based on the general inventive concept, the present invention also provides the use of said nanoformulation in the preparation of a medicament for joint analgesia in osteoarthritis. Effect of the Invention

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The nano-preparation of the present invention can be used for joint analgesia, has a large drug loading capacity, and can be maintained in the joint cavity for at least 4 weeks. It has a better analgesic effect on OA than commercially available GC injections, and can be maintained for at least 4 weeks.

[0029] 2. The preparation method of the present invention has a simple preparation process, the particle size is smaller than 200 nm, terminal sterilization can be achieved by methods such as probe ultrasonic, high-pressure homogenization or microporous filter membrane sterilization, and the preparation cost is relatively low. [Brief description of the drawings]

[0030] In order to more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the following briefly describes the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these accompanying drawings without creative labor. [Figure 1]1 shows the in vitro bioactivity study results of the nano-formulation prepared in Example 2 (after 24h of drug treatment), where a) the relative expression level of cell-encoded TNF-α gene mRNA, b) the relative expression level of cell-encoded IL-1β gene mRNA, c) the relative expression level of cell-encoded IL-6 gene mRNA, d) the relative expression level of cell-encoded IL-4 gene mRNA, e) the relative expression level of cell-encoded IL-10 gene mRNA, and f) the relative expression level of cell-encoded iNOS gene mRNA. *P<0.05, ***P<0.001, ****P<0.0001. [Diagram 2] 1 shows experimental results of biodistribution of the nanoformulations prepared in Examples 1 and 2, in which a) is a small animal in vivo fluorescence imaging image of the distribution of NPs (HEL-40) and NPs (HEL-60) in the body of an OA model rat, and b) is a semi-quantitative histogram (n=3) of the distribution of NPs (HEL-40) and NPs (HEL-60) in the inflamed joints of an OA model rat. [Diagram 3] Pharmacodynamic experimental results of the nanoformulation prepared in Example 2, where a) the change in threshold of mechanical paw contraction of the right hind paw of OA model rats (n=7), ****P<0.0001, compared with commercially available injection solution (TA IR); b) the change in difference in weight bearing of both paws of OA model rats (n=7), **P<0.01, compared with commercially available injection solution (TA IR). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] In order to facilitate understanding of the present invention, the present invention will be described more comprehensively and in detail below in conjunction with the accompanying drawings and preferred embodiments of the specification, but the scope of protection of the present invention is not limited to the following specific examples.

[0032] Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used in this specification are only used for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention.

[0033] Unless otherwise specified, various raw materials, reagents, instruments and devices used in the present invention can all be purchased from the market or prepared by existing methods.

[0034] Equipment and reagents used in the present invention: RV10 rotary evaporator (IKA Group, Germany), JY92-II ultrasonic cell disrupter (Ningbo Xinzhi Scientific Instrument Research Institute), EmulsiFlex-C5 high pressure emulsion homogenizer (AVESTIN, Canada), MS105DU electronic balance (METTLER TOLEDO, USA), Zetasizer Nano zsu3100 laser particle size analyzer (Malvern, UK), ModulyoD freeze dryer (Thermo, USA), Lumina 3 small animal live imager (Perkin Elmer, USA).

[0035] Tretinoin (Aladdin Reagents (Shanghai) Co., Ltd.), Dexamethasone (Aladdin Reagents (Shanghai) Co., Ltd.), Dexamethasone Palmitate (Aladdin Reagents (Shanghai) Co., Ltd.), Prednisolone (Aladdin Reagents (Shanghai) Co., Ltd.), Egg Yolk Lecithin E80 (Lipoid, Germany), Soy Lecithin S100 (Lipoid, Germany), Polyoxyethylene 35 Castor Oil (EL-35) (BASF, Germany), Polyoxyethylene 40 Castor Oil (EL-40) (BASF, Germany), Polyoxyethylene 40 Hydrogenated Castor Oil (HEL-40) (BASF, Germany), Polyoxyethylene 60 Hydrogenated Castor Oil (HEL-60) (BASF, Germany), 15-Hydroxystearic Acid Polyethylene Glycol Ester (HS15) (BASF, Germany), DiD (Biotium, USA), Tretinoin Injection (Kunming Zhida Pharmaceutical Co., Ltd.).

[0036] <Example 1> The tretinoin (TA)-loaded nanoparticles for joint pain relief are prepared by the following method: 4mg tretinoin, 125mg phospholipid E80, 70mg HEL-40 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and sonicated with an ice-water bath probe. The particle size is 133nm.

[0037] <Example 2> The tretinoin (TA)-loaded nanoparticles for joint pain relief are prepared by the following method: 4mg tretinoin, 100mg phospholipid E80, 100mg HEL-60 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and sonicated with an ice-water bath probe. The particle size is 120nm.

[0038] <Example 3> Dexamethasone palmitate-loaded nanoparticles for joint pain relief, the recipe of which includes dexamethasone palmitate, phospholipid S100, HEL-40, and the dosage form is injection. The preparation method is as follows: 4 mg dexamethasone palmitate, 125 mg phospholipid S100, and 70 mg HEL-40 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and sonicated with an ice-water bath probe. The particle size is 144 nm.

[0039] <Example 4> Dexamethasone palmitate-loaded nanoparticles for joint pain relief, the recipe of which includes dexamethasone palmitate, phospholipid S100, HEL-60, and the dosage form is injection. The preparation method is as follows: 4 mg dexamethasone palmitate, 100 mg phospholipid S100, and 100 mg HEL-60 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and sonicated with an ice-water bath probe. The particle size is 128 nm.

[0040] <Example 5> Dexamethasone-loaded nanoparticles for joint pain relief, the recipe of which includes dexamethasone, phospholipid S100, HEL-60, and the dosage form is injection. The preparation method is as follows: 2mg dexamethasone, 50mg phospholipid S100, and 10mg HEL-60 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated with saline and homogenized under high pressure. The particle size is 118nm.

[0041] <Example 6> The prednisolone-loaded nanoparticles for joint pain relief, the recipe of which includes prednisolone, phospholipid PC98-T, HEL-60, and the dosage form is an injection solution. The preparation method is as follows: 1mg prednisolone, 40mg phospholipid PC98-T, and 4mg HEL-60 are dissolved in a mixture of chloroform and ethanol, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and homogenized under high pressure. The particle size is 129nm.

[0042] <Example 7> Dexamethasone-loaded nanoparticles for joint pain relief, the recipe of which includes dexamethasone, phospholipid HSPC, HEL-60, and the dosage form is injection. The preparation method is as follows: 4mg dexamethasone, 30mg phospholipid HSPC, and 150mg HEL-60 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated with saline and homogenized under high pressure. The particle size is 105nm.

[0043] <Example 8> Dexamethasone palmitate-loaded nanoparticles for joint pain relief, the recipe of which includes dexamethasone palmitate, phospholipid E80, HEL-60, and the dosage form is injection. The preparation method is as follows: 2mg dexamethasone palmitate, 15mg phospholipid E80, and 150mg HEL-60 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated with saline and homogenized under high pressure. The particle size is 92nm.

[0044] <Example 9> The tretinoin (TA)-loaded nanoparticles for joint pain relief are prepared by the following method: 20mg tretinoin, 100mg phospholipid E80, 40mg HS15, and 60mg HEL-60 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and homogenized under high pressure. The particle size is 124nm.

[0045] <Example 10> Dexamethasone-loaded nanoparticles for joint pain relief, the recipe of which includes dexamethasone, phospholipid E80, HS15, EL-35, and the dosage form is injection. The preparation method is as follows: 20mg dexamethasone, 100mg phospholipid E80, 40mg HS15, and 60mg EL-35 were dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated with saline and homogenized under high pressure. The particle size was 118nm.

[0046] <Example 11> A tretinoin (TA)-loaded nanoparticle for joint pain relief, the recipe of which includes tretinoin (TA), phospholipid E80, EL-35, and HEL-40, and the dosage form is an injection solution. The preparation method is as follows: 20mg tretinoin, 100mg phospholipid E80, 50mg EL35, and 50mg HEL-40 are dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and homogenized under high pressure. The particle size is 136nm.

[0047] <Example 12> Dexamethasone-loaded nanoparticles for joint pain relief, the recipe of which includes dexamethasone, phospholipid E80, EL-35, HEL-60, and the dosage form is injection. The preparation method is as follows: 20mg dexamethasone, 100mg phospholipid E80, 50mg EL-35, and 50mg HEL-60 were dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated with saline and homogenized under high pressure. The particle size was 132nm.

[0048] <Example 13> The tretinoin (TA)-loaded nanoparticles for joint pain relief, the recipe of which includes tretinoin (TA), phospholipid E80, and HEL-40, and the dosage form is freeze-dried powder for injection. The preparation method is as follows: 4 mg tretinoin, 125 mg phospholipid E80, and 70 mg HEL-40 were dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, hydrated by adding pure water, sonicated with an ice-water bath probe, and then added with 10% mannitol by mass and volume, and lyophilized.

[0049] <Example 14> Dexamethasone nanoparticles for joint pain relief, its recipe includes dexamethasone, phospholipid E80, HEL-60, and its dosage form is freeze-dried powder for injection. Its preparation method is as follows: 4 mg of dexamethasone, 100 mg of phospholipid E80, and 100 mg of HEL-60 were dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, hydrated by adding pure water, sonicated with an ice-water bath probe, and then added with 10% by weight of mannitol and lyophilized.

[0050] <Comparative Example 1> The tretinoin (TA)-loaded nanoparticles for joint pain relief are prepared by the following method: Dissolve 4 mg tretinoin, 125 mg phospholipid E80, and 4 mg HEL-40 in chloroform, concentrate under reduced pressure to remove organic reagents, then add saline to hydrate and sonicate with an ice-water bath probe. The solution becomes opaque and accompanied by a precipitate.

[0051] <Comparative Example 2> The tretinoin (TA)-loaded nanoparticles for joint pain relief are prepared by the following method: 4mg tretinoin, 4mg phospholipid E80, and 125mg HEL-40 were dissolved in chloroform, concentrated under reduced pressure to remove organic reagents, then hydrated by adding saline and sonicated with an ice-water bath probe. The particle size was 203nm and precipitated within 30min.

[0052] To further demonstrate the effectiveness of the nanoformulations of the present invention, the following experiment was performed. 1) Effect of compositional components on drug loading capacity of nanoformulations In the present invention, glucocorticoid-loaded nanoparticles were prepared using phospholipids or polyoxyethylene castor oil alone by the same nanoparticle preparation method (thin film hydration method) as in the examples, and at the same time, the ratio of phospholipids to polyoxyethylene castor oil was fixed to investigate the effects of different polyoxyethylene castor oil composition components and the presence or absence of HS15 on the properties of glucocorticoid-loaded nanoparticles prepared from nanoparticles. As shown in Table 1, tretinoin-loaded nanoparticles prepared using phospholipids E80 or HEL-60 alone were very unstable or could not encapsulate the drug well, so that it was necessary to use a combination of phospholipids E80 and HEL-60 at a certain ratio to prepare nanoparticles that meet the requirements of the inventors. In addition, when HEL-60 and EL-35 or HEL-60 and HS15 are used in combination, nanoparticles with higher drug loading capacity can be prepared. Table 1: Effect of different compositional components on the properties of glucocorticoid nanoparticles prepared from nanoparticles JPEG2025506762000002.jpg56170

[0053] 2) Examination of in vitro biological activity Mouse-derived macrophages RAW264.7 were inoculated into 12-well cell culture plates, allowed to adhere to the walls, and stimulated with LPS for 24 h. The medium was replaced with drug-containing medium, and then TA solution (referred to as TA IR) and TA-loaded NPs (TA concentration 4 μg / mL, drug-free medium treatment was used as the control, and TA-loaded NPs were prepared according to Example 2 and referred to as TA-NPs) were incubated for 24 h. The concentrations of IL-1β, TNF-α, IL-6, IL-10, IL-4, and iNOS were measured using real-time fluorescent quantitative PCR. The LPS-treated cells and the LPS-treated but not TA-treated cells were referred to as the "control" and "LPS" groups, respectively. As can be seen from Figure 1, compared with other treatment methods, TA-NPs treatment significantly reduced the expression of inflammatory factor genes in macrophages.

[0054] 3) OA rat model Sodium iodoacetate was injected into the articular cavity of the knee joint of SD rats, and an OA rat model was established when the knee joint of the rat became swollen and the pain threshold was significantly decreased.

[0055] 4) Biodistribution experiment Glucocorticoids were replaced with the fluorescent marker DiD, and nanoformulations were prepared according to Example 1 and Example 2, denoted as NPs(HEL-40) and NPs(HEL-60), respectively. DiD solution (denoted as DiD), NPs(HEL-40) and NPs(HEL-60) were injected into the knee joint cavity of OA rats, respectively, and the fluorescence intensity in the inflamed joints of the rats was examined by a small animal live imager on days 0, 1, 2, 3, 7, 14, 21 and 28, respectively.

[0056] As can be seen in Figure 2, compared with DiD, NPs (HEL-60) and NPs (HEL-40) were maintained in the joint cavity of OA model rats for at least 28 days. These results suggest that NPs have good sustained release properties in the inflamed joint cavity.

[0057] 5) Pharmacodynamic research OA model rats were treated by injection with saline (referred to as saline), commercially available tretinoin injection (referred to as TA IR), TA-loaded NPs (referred to as TA-NPs) prepared in Example 2, and drug-free NPs (referred to as vehicle) prepared in Example 2, respectively, by joint cavity injection, and an equal volume of saline was injected into the knee joint cavity of normal rats as a control (referred to as control). TA was administered once in total at a dose of 60 μg per knee joint on the 7th day after modeling. From the first day of administration, the mechanical paw withdrawal threshold and the difference in weight bearing between both paws were measured once a week for each group. On the 35th day, the behavioral test of the rats was performed.

[0058] As can be seen from Figure 3, NPs treatment can effectively alleviate joint inflammation in OA rats compared with other methods. These results fully demonstrate that arthritis synovial bicellular targeted drug delivery is effective in OA treatment. In other words, the nanoformulation prepared in this invention has good prospects for the preparation of osteoarthritis joint pain relief drugs.

Claims

1. A nano-formulation for joint pain relief, comprising a glucocorticoid and a nano-carrier, the nano-carrier mainly comprising a phospholipid and an auxiliary agent, and the auxiliary agent comprising polyoxyethylene castor oil.

2. 2. The nanoformulation of claim 1, wherein the glucocorticoid comprises one or more of clobetasol propionate, difluprednisol acetate, dexamethasone propionate, difluprednisolone, mometasone furoate, difluprednisolone valerate, betamethasone butyrate propionate, fluocortisol acetate, hydrocortisone butyrate, beclomethasone propionate, diproterenol propionate, betamethasone valerate, dexamethasone valerate, prednisolone valerate acetate, fluocinolone acetonide, hydrocortisone butyrate, clobetasone butyrate, aclometasone propionate, tretinoin, flumethasone neopentylate, prednisolone, hydrocortisone, dexamethasone, dexamethasone palmitate, triamcinolone palmitate.

3. 2. The nanoformulation of claim 1, wherein the phospholipid comprises one or more of natural soybean phospholipids, natural lecithin, and synthetic phospholipids.

4. 2. The nanoformulation of claim 1, wherein the polyoxyethylene castor oil comprises one or more of polyoxyethylene 35 castor oil, polyoxyethylene 40 castor oil, polyoxyethylene 40 hydrogenated castor oil, polyoxyethylene 60 hydrogenated castor oil.

5. The nanoformulation of claim 1, characterized in that the auxiliary agent further comprises 15-hydroxystearic acid polyethylene glycol ester.

6. The nanoformulation of claim 1, characterized in that the auxiliary agents include polyoxyethylene 60 hydrogenated castor oil (HEL-60), polyoxyethylene 35 castor oil (EL-35) and 15-hydroxystearic acid polyethylene glycol ester.

7. The nanoformulation of claim 1, characterized in that the auxiliary agents include polyoxyethylene 60 hydrogenated castor oil (HEL-60) and polyoxyethylene 35 castor oil (EL-35).

8. The nanoformulation of claim 1, characterized in that the auxiliary agents include polyoxyethylene 60 hydrogenated castor oil (HEL-60) and 15-hydroxystearic acid polyethylene glycol ester.

9. The nanoformulation according to claim 1, characterized in that the mass ratio of the phospholipid to the auxiliary is (1:20) to (20:1).

10. The nano-preparation according to claim 9, characterized in that the mass ratio of the phospholipid to the auxiliary is (1:10) to (10:1).

11. The nanoformulation according to any one of claims 1 to 10, characterized in that the drug loading capacity of the glucocorticoid is 0.5-20%, the particle size of the nanoformulation is smaller than 200 nm, and the dosage form of the nanoformulation is an injection solution or a lyophilized powder for injection.

12. A method for preparing the nano-preparation for joint analgesia according to any one of claims 1 to 11, comprising the steps of dissolving a glucocorticoid, a phospholipid and polyoxyethylene castor oil in an organic solvent, removing the organic reagent by evaporation under reduced pressure, adding water to remove the film, and then obtaining the nano-preparation by probe ultrasonication, high pressure homogenization or pressing into a microporous membrane.

13. Use of the nanoformulation according to any one of claims 1 to 11 or prepared by the preparation method according to claim 12 in the preparation of a medicament for joint analgesia in osteoarthritis.

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