Application of LXH-2103 in preparation of medicine for treating pain and medicine dependence and medicine composition of LXH-2103

Abstract

The invention belongs to the technical field of medicine, and particularly relates to application of LXH-2103 in preparation of medicine for treating pain and medicine dependence and a medicine composition of the LXH-2103. According to the application of the LXH-2103 disclosed by the invention in pain, the pain is acute incision pain, osteoarthritis pain, sciatica and cancer pain. The intravenous injection dosage of the medicine in an acute incision pain model animal is 7.5-20 mg / kg, and the oral administration dosage of the medicine in gavage is 20 mg / kg. The injection dosage of the medicine for treating osteoarthritis pain and sciatica is 2.5-7.5 mg / kg, and the oral administration dosage of the medicine for gavage is 20 mg / kg. The injection dosage of the medicine for cancer pain is 3-12 mg / kg, and the oral administration dosage of the medicine for gavage is 30 mg / kg. According to the establishment of the LXH-2103 in the pain model and the application of the LXH-2103 in the pain, a plurality of pain animal models are established, and the application of the LXH-2103 in the pain treatment is evaluated.

Description

Technical Field

[0001] This invention belongs to the technical field of pharmaceuticals, specifically relating to the application of LXH-2103 in the preparation of drugs for treating pain and drug dependence, and pharmaceutical compositions thereof. Background Technology

[0002] Tramadol, a centrally acting analgesic with both μ-opioid receptor agonism and serotonin / norepinephrine (5-HT / NE) reuptake inhibition mechanisms, is widely used for moderate to severe pain management due to its lower respiratory depression and addiction risk compared to traditional opioids. However, its analgesic efficacy exhibits significant individual variability: approximately 20%–30% of patients experience treatment failure due to insufficient production of the active metabolite nortramadol caused by CYP2D6 gene polymorphisms (such as a weak metabolic phenotype). This metabolic dependence severely limits the clinical applicability of tramadol, especially in individuals with weak CYP2D6 metabolism (such as certain Asian and African populations).

[0003] Nortetramadol hydrochloride (LXH-2103), as the main active metabolite of tramadol, theoretically avoids efficacy fluctuations caused by gene polymorphisms because it acts directly on μ-opioid receptors and does not require CYP2D6 metabolic activation. Studies have confirmed that nortetramadol retains the safety advantages of tramadol, namely low respiratory depression and low addictiveness, while also exhibiting more stable pharmacokinetic characteristics. Nevertheless, its clinical translation still faces the following key bottlenecks: Current research on nortramadol focuses on oral formulations, with no intravenous formulations yet available for clinical use, resulting in a lack of reliable dosing regimens for acute and severe pain. Furthermore, existing data do not systematically evaluate its differentiated efficacy against different pain subtypes, making it difficult to guide precise analgesia.

[0004] Previous studies have focused only on the μ-opioid receptor affinity of nortramadol, and have not yet elucidated its interaction with δ / κ-opioid receptors, orphan receptors (such as NOP receptors) or other pain regulation pathways (such as the cannabinoid system and NMDA receptors). Furthermore, there is a lack of quantitative analysis on its contribution to the inhibition of 5-HT / NE reuptake, which limits a comprehensive understanding of its multi-target synergistic mechanism.

[0005] US Patent Application No. 201916362139A discloses a method for treating pain, comprising administering an oral analgesic formulation containing nortramadol to human subjects suffering from moderate to severe pain, severe enough to require opioid analgesia and for whom alternative treatment is inadequate. Paragraphs 0164-0167 disclose nortramadol for injection, for use in experiments following intravenous injection, evaluating only the effect of the compound in cold pain (pain caused by cold). Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for establishing pain models with LXH-2103 and the application of LXH-2103 in pain, thereby constructing a variety of pain models.

[0007] The present invention relates to the application of LXH-2103 in the preparation of drugs for treating pain and drug dependence, wherein the pain is acute incision pain, osteoarthritis pain, cancer pain, or sciatica. Single or multiple administrations are permitted.

[0008] The drug is administered at an injection dose of 7.5-20 mg / kg for acute incisional pain, or at an oral dose of 20 mg / kg.

[0009] The drug is administered at an injection dose of 2.5-7.5 mg / kg or an oral dose of 10-30 mg / kg for osteoarthritis pain.

[0010] The drug is administered at an injection dose of 3-12 mg / kg for cancer pain, or at an oral dose of 30 mg / kg.

[0011] The drug is administered at an injection dose of 2.5-7.5 mg / kg for sciatica, or orally at 20 mg / kg, in a single or multiple doses.

[0012] Osteoarthritis pain is joint damage-related pain induced by sodium iodoacetate.

[0013] The pharmaceutical composition for treating acute incisional pain prepared from LXH-2103 includes LXH-2103 or a pharmaceutically acceptable salt thereof, and is available in injection or oral dosage forms.

[0014] The pharmaceutical composition for treating osteoarthritis pain prepared from LXH-2103 includes LXH-2103 or a pharmaceutically acceptable salt thereof, and is available in injection or oral dosage form.

[0015] The pharmaceutical composition for treating cancer pain prepared from LXH-2103 includes LXH-2103 or a pharmaceutically acceptable salt thereof, and is available in injection or oral dosage form.

[0016] The pharmaceutical composition for treating sciatica prepared from LXH-2103 includes LXH-2103 or a pharmaceutically acceptable salt thereof, and is available in injection or oral dosage form.

[0017] The oral dosage forms mentioned above are preferably tablets, dispersible tablets, or capsules.

[0018] The osteoarthritis pain described is joint injury-related pain induced by intra-articular injection of sodium iodoacetate (MIA).

[0019] The sciatica (neuropathic pain) mentioned above refers to pain associated with chronic constriction injury of the sciatic nerve (CCI).

[0020] LXH-2103 (nortramadol hydrochloride) showed analgesic effects comparable to tramadol hydrochloride at low doses (2.5 mg / kg), and significantly better analgesic effects than tramadol hydrochloride at medium to high doses (5-10 mg / kg).

[0021] LXH-2103 has a rapid onset of analgesia (0.25 hours) and a long duration of analgesia (up to 6 hours).

[0022] The composition provided by this invention has high safety, and no obvious adverse reactions were observed during the experiment.

[0023] This invention demonstrates through non-clinical animal experiments that LXH-2103 exhibits significantly superior therapeutic efficacy compared to the parent compound in the following pain models: In a rat model of incisional pain (simulating acute postoperative pain): intravenous injection of 7.5 mg / kg and 20 mg / kg of LXH-2103 significantly increased paw withdrawal pressure in rats at 2 and 4 hours post-administration, respectively (P≤0.01). Oral administration of 20 mg / kg of LXH-2103 significantly improved hyperalgesia within 0.25–8 hours post-administration (P≤0.05 or P≤0.01). Pharmacokinetic studies showed that the AUC of LXH-2103 after intravenous injection increased with increasing dose.

[0024] In a mouse model of osteoarthritis pain (MIA-induced): intravenous injection of 2.5 mg / kg and 7.5 mg / kg of LXH-2103 dose-dependently increased paw constriction pressure (p<0.01), with effects lasting up to 1 hour and 2 hours post-administration, respectively. Oral administration of 20 mg / kg of LXH-2103 significantly improved hyperalgesia within 0.5–2 hours (p<0.05).

[0025] Cancer pain model (breast cancer bone metastasis pain model): Intravenous injection of LXH-2103 at doses of 3 mg / kg, 6 mg / kg, and 12 mg / kg increased paw withdrawal pressure (pain threshold) in mice in a dose-dependent manner, with the effect lasting up to 8 hours after administration (P<0.05 or P<0.01). Oral administration of 30 mg / kg of LXH-2103 significantly improved hyperalgesia 2-4 hours after administration (P<0.01).

[0026] In a sciatic nerve ligation model (neuropathic pain), intravenous injection of 2.5 mg / kg and 7.5 mg / kg of LXH-2103 solution dose-dependently increased the claw retraction pressure in CCI model rats (p<0.05), with an analgesic effect lasting 4-6 hours. Oral administration of 20 mg / kg of LXH-2103 significantly improved hyperalgesia (p<0.05).

[0027] This invention, through in vitro experiments, revealed that compound LXH-2103 exhibits significant agonistic activity against μ-type opioid receptors (MOR) (agonistic rate 81.57%), while simultaneously demonstrating significant inhibitory activity against the nicotinic acetylcholine receptor α7 subtype (nAChRα7 / RIC3) (inhibition rate 97.61%). Based on this, this invention proposes a novel use for compound LXH-2103 in the preparation of drugs for treating pain and / or drug dependence.

[0028] This invention further investigated a rat model of incisional pain, finding that LXH-2103 exhibited significant analgesic effects within a dose range of 2.5-10 mg / kg. Its analgesic effect was observed within 0.25 hours, peaked at 0.5 hours, and lasted for up to 6 hours. Compared to tramadol hydrochloride, LXH-2103 demonstrated superior analgesic efficacy at the same dose, with significantly prolonged analgesic duration in the high-dose group (10 mg / kg) and the medium-dose group (5 mg / kg).

[0029] Compared with the prior art, the beneficial effects of the present invention are: (1) The active compound LXH-2103 (nortramadol hydrochloride) of the present invention does not need to be activated by CYP2D6 metabolism and can directly exert analgesic effect, which solves the problem of low efficacy of tramadol in 20%-30% of weak metabolizers due to gene polymorphism, and is applicable to a wider range of people.

[0030] (2) The present invention is the first to demonstrate that intravenous injection of LXH-2103 is significantly superior to tramadol in various pain models (incision pain, osteoarthritis pain, cancer pain, sciatica).

[0031] (3) This invention is the first to discover that LXH-2103 has the dual effects of μ opioid receptor agonism (81.57%) and nAChRα7 inhibition (97.61%). While synergistically relieving pain, it may reduce the risk of drug dependence through non-opioid pathways, breaking through the limitation of existing research that only focuses on μ receptors. Attached Figure Description

[0032] Figure 1 This is a graph showing the change in claw retraction pressure before and after animal modeling in Example 1. Figure 2 This is a graph showing the changes in paw retraction pressure values ​​in animals before and after drug administration in Example 1. Figure 3 This is a graph showing the change in claw retraction pressure before and after animal modeling in Example 2; Figure 4 This is a graph showing the changes in paw retraction pressure values ​​in animals before and after drug administration in Example 2; Figure 5 This is a graph showing the change in claw retraction pressure before and after animal modeling in Example 3. Figure 6 This is a graph showing the changes in paw retraction pressure before and after drug administration in animals in Example 3; Figure 7 This is a graph showing the change in claw retraction pressure before and after animal modeling in Example 4; Figure 8 This is a graph showing the changes in paw retraction pressure before and after drug administration in animals in Example 4. Figure 9 This is a radar chart showing the receptor-ligand binding assay results for Example 5. Figure 10 The graph shows the effect of test substance administration on the pain threshold of rat plantar incisions in Example 6. Figure 11 The graph shows the effect of administration of the test substance in Example 6 on the pain threshold of the rat foot incision at different time points. Detailed Implementation

[0033] The present invention will be further described below with reference to specific embodiments.

[0034] Example 1 Acute incision pain: 1. Sample information and preparation method 1.1 Test sample 1: LXH-2103 solution; Route of administration: Intravenous injection.

[0035] Dosage: 7.5 mg / kg, 20 mg / kg.

[0036] Preparation method: Dilute LXH-2103 solution (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2303002) with sterile water for injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22070102) in proportion to prepare solutions of 0.75mg / mL and 20mg / mL.

[0037] 1.2 Test sample 2: LXH-2103 Administration route: oral or gavage.

[0038] Dosage: 20 mg / kg (2 test samples).

[0039] Preparation method: Dissolve and dilute LXH-2103 (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2207301) with sterile water for injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22070102) to prepare a 2mg / mL solution.

[0040] 2. Animal model: Sprague-Dawley rat (SD rat) incision pain model Animal selection: SD rats that passed the health examination, whose left hind paw pain threshold was measured by the Von Frey method and whose claw retraction pressure was >18.0g.

[0041] Model establishment: Eligible SD rats were anesthetized with isoflurane. After disinfecting the left hind paw with povidone-iodine solution, a 1cm longitudinal incision was made starting 0.5cm from the proximal end of the foot and extending towards the toes, penetrating the skin, fascia, and muscles of the foot, keeping the origin, insertion, and attachment points of the muscles intact. Hemostasis was achieved by applying pressure to the incision, thus establishing the incision pain model.

[0042] 3. Animal grouping Six animals were randomly selected as the normal control group based on their body weight, and the remaining animals were used to establish the model. On the day of model establishment, the pain value of the left hind foot was measured using the Von Frey method. Twenty-four animals (based on animal body weight) with a pain value reduction of ≥30% were selected and randomly divided into four groups: model control group, low-dose group of test product 1 (2.5 mg / kg), high-dose group of test product 1 (7.5 mg / kg), and group of test product 2 (20 mg / kg), with six animals in each group.

[0043] 4. Dosage frequency and method The normal control group received no medication, the model control group received sterile water for injection, test sample 1 group received different doses of test sample 1, and test sample 2 group received test sample 2. The model control group and test sample 1 group were administered intravenously, while test sample 2 group was administered by gavage. All groups received a single dose.

[0044] 5. Testing indicators: 5.1 Von Frey Test: Place the animal in the test container to allow it to acclimatize to the test environment. After the animal settles down, measure the claw retraction pressure of its left hind paw (if the animal still does not exhibit claw retraction when the pressure reaches its maximum value of 50g, manually stop the test to avoid tissue damage; record the claw retraction pressure value as 50g). When the animal exhibits rapid claw retraction or paw licking behavior, manually record the claw retraction pressure value displayed on the instrument interface. (If the measurement process is stopped due to spontaneous animal activity, it needs to be repeated. If unsure, multiple measurements can be taken and the average value calculated to ensure that the animal's claw retraction is caused by mechanical stimulation).

[0045] Testing instrument: Dynamic plantar tactile sensor (Model: 37550; Manufacturer: Ugo Basile).

[0046] 5.2PK parameters: Blood collection points: Before and after administration of intravenous injection in animals, 2 min, 10 min, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h and 24 h; before and after administration of oral gavage in animals, 10 min, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 10 h and 24 h.

[0047] Blood collection method: Before blood collection, place centrifuge tubes containing EDTA-K2 in a refrigerator at 5°C or in an icebox filled with crushed ice; collect approximately 0.25 mL of blood from the jugular vein and add it to the centrifuge tube, manually inverting it at least 5 times, and store and transport it in an icebox filled with crushed ice; centrifuge within 2 hours after blood collection at 2000g for 10 minutes at 5°C, and then transfer to a storage temperature below -60°C. The Watson LIMS 7.5 system was used for sample management.

[0048] 6. Application Effects: 6.1 Von Frey Test The claw retraction pressure values ​​before and after animal modeling are shown in the figure. Figure 1 The claw retraction pressure value after animal modeling was significantly lower than that before modeling (10.62±3.71g vs 27.16±3.10g, P≤0.01), indicating that the incision pain model of SD rats was successfully established. The claw retraction pressure values ​​of animals before and after drug administration are shown in the figure. Figure 2 The results showed: The constriction pressure values ​​at 0.25h, 0.5h, 1h and 2h after intravenous injection of 7.5mg / kg were 45.13±10.6g, 44.94±7.69g, 43.57±7.16g and 22.42±6.11g, respectively, which were significantly higher than those of the model control group at the same time point (P≤0.01).

[0049] The retraction pressure values ​​of the 20 mg / kg intravenous injection group at 0.25 h, 0.5 h, 1 h, 2 h, 4 h, 6 h, and 8 h were all higher than those of the model control group. Specifically, the retraction pressure values ​​at 0.25 h, 0.5 h, 1 h, 2 h, and 4 h were 48.86±2.09 g, 47.26±4.28 g, 46.08±5.62 g, 44.46±6.91 g, and 20.37±7.78 g, respectively, all of which were significantly higher than those of the model control group at the same time point (P≤0.01 or P≤0.05).

[0050] The retraction pressure values ​​of the group that received oral gavage of 20 mg / kg were higher than those of the model control group at 0.25 h, 0.5 h, 1 h, 2 h, 4 h, 6 h, and 8 h after administration. Among them, the retraction pressure values ​​at 0.25 h, 0.5 h, 1 h, 4 h, 6 h, and 8 h were significantly higher than those of the model control group at the same time point (P≤0.01 or P≤0.05).

[0051] A single intravenous injection of 7.5 mg / kg and 20 mg / kg of LXH-2103 increased the claw retraction pressure in SD rats with incisional pain in a dose-dependent manner, with the effects lasting up to 2 h and 4 h after administration, respectively. A single oral gavage administration of 20 mg / kg of LXH-2103 improved hyperalgesia in animals 0.25 h after administration, with the effects lasting up to 8 h.

[0052] 6.2PK parameters Following intravenous administration of LXH-2103, the exposure of LXH-2103 in SD rats increased with increasing dose. After a single oral gavage administration of LXH-2103 at a dose of 20 mg / kg to SD rats, the absolute bioavailability (F%, expressed as AUC) of LXH-2103 in the animals, relative to intravenous administration (20 mg / kg), was significantly higher. last The percentage (calculated) is 10.87%.

[0053] Table 1. Main kinetic parameters in rats of each group after a single intravenous injection.

[0054] Table 2. Main kinetic parameters in rats after a single oral gavage administration.

[0055] in conclusion Following intravenous administration of test sample 1 at doses of 7.5 and 20 mg / kg, the exposure (AUC) of LXH-2103 in SD rats was determined. last The value increases with increasing dosage, and the increase is greater than the increase in dosage.

[0056] Following a single oral gavage administration of test sample 20 mg / kg to SD rats, the absolute bioavailability (F%, expressed as AUC) of LXH-2103 in the animals relative to intravenous administration (20 mg / kg) was as follows: last The percentage (calculated) is 10.87%.

[0057] Example 2 Osteoarthritis pain 1. Sample information and preparation method 1.1 Test sample 1: LXH-2103 solution; Route of administration: Intravenous injection.

[0058] Dosage: 2.5 mg / kg, 7.5 mg / kg.

[0059] Preparation method: Dilute LXH-2103 solution (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2303002) with sterile water for injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K23012907) in a certain proportion to prepare solutions of 0.25 mg / mL (low-dose group of test sample 1) and 0.75 mg / mL (high-dose group of test sample 1).

[0060] 1.2 Test sample 2: LXH-2103 Administration route: oral or gavage.

[0061] Dosage: 20 mg / kg (2 test samples).

[0062] Preparation method: Dissolve and dilute LXH-2103 (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2207301) with sterile water for injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K23012907) to prepare a 2mg / mL solution.

[0063] 1.3 Modeling agent: Sodium iodoacetate (MIA) solution Preparation method: Accurately weigh an appropriate amount of sodium iodoacetate powder (manufacturer: Sigma Aldrich, batch number SLCK0391), add an appropriate amount of 0.9% sodium chloride injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22090305), vortex to mix, and prepare a sodium iodoacetate solution with a final concentration of 40 mg / mL.

[0064] 2. Animal model: Sprague-Dawley rat (SD rat) osteoarthritis model Animal selection: SD rats that passed the health examination, whose left hind paw pain threshold was measured by the Von Frey method and whose claw retraction pressure was >18.0g.

[0065] Model establishment: Eligible SD rats were anesthetized with isoflurane, and the skin of the left knee joint of the animals was prepared. The animals in the model group were injected with 50 μL of sodium iodoacetate solution (40 mg / mL) into the joint cavity, while the animals in the sham operation group were given 50 μL of 0.9% sodium chloride injection.

[0066] 3. Animal grouping Six animals were randomly selected as the normal control group based on their body weight, and the remaining animals were used to establish the model. Seven days after the model was established, the left hind paw retraction pressure was measured using the Von Frey method. Twenty-four animals (based on animal body weight) with significantly reduced paw retraction pressure were selected and randomly divided into four groups: the model control group, the low-dose group of test product 1 (2.5 mg / kg), the high-dose group of test product 1 (7.5 mg / kg), and the group of test product 2 (20 mg / kg), with six animals in each group.

[0067] 4. Dosage frequency and method The normal control group received no medication, the model control group received 0.9% sodium chloride injection, the test sample group 1 received different doses of test sample 1, and the test sample group 2 received test sample 2. The model group and the test sample group 1 were administered intravenously, while the test sample group 2 was administered by gavage. All groups were administered a single dose.

[0068] 5. Detection indicator: Von Frey test Place the animal in the test container to acclimatize it to the test environment. Once the animal is calm, measure the claw retraction pressure in its left hind paw. (If the animal does not retract its paw when the pressure reaches its maximum value of 50g, manually stop the measurement to avoid tissue damage; record the claw retraction pressure value as 50g.) When the animal exhibits rapid claw retraction or paw licking behavior, manually record the claw retraction pressure value displayed on the instrument interface. (If the measurement process is stopped due to spontaneous animal activity, it needs to be repeated. If unsure, multiple measurements can be taken and the average value calculated to ensure that the animal's claw retraction is caused by mechanical stimulation.)

[0069] Testing instrument: Dynamic plantar tactile sensor (Model: 37550; Manufacturer: Ugo Basile).

[0070] 6. Application Effects: The claw retraction pressure values ​​before and after animal modeling are shown in the figure. Figure 3 The results showed that the claw retraction pressure value after animal modeling was significantly lower than that before modeling (13.62±4.42 g vs 27.53±4.62 g P≤0.01), indicating that the SD rat bone and joint model was successfully established.

[0071] The claw retraction pressure values ​​of animals before and after drug administration are shown in the figure. Figure 4 The results showed: The claw retraction pressure values ​​at 0.25h, 0.5h and 1h after intravenous injection of 2.5mg / kg were 40.58±10.21g, 37.97±7.85g and 24.53±5.85g, respectively, which were significantly higher than those of the model control group at the same time point (P≤0.01).

[0072] The claw retraction pressure values ​​at 0.25h, 0.5h, 1h and 2h after intravenous injection of 7.5mg / kg were 48.56±3.54g, 46.91±6.77g, 50.00±0.00g and 33.05±11.70g, respectively, all of which were significantly higher than those of the model control group at the same time point (P≤0.01).

[0073] The constriction pressure values ​​in all groups increased in a dose-dependent manner after intravenous injection.

[0074] The constriction pressure values ​​at 0.5h, 1h and 2h after oral gavage of 20mg / kg were 23.69±14.25g, 25.33±13.28g and 25.76±7.50g, respectively, which were significantly higher than those of the model control group at the same time point (P≤0.01 or P≤0.05).

[0075] Conclusion: Under the conditions of this experiment, a single intravenous administration of test product 1 at 2.5 mg / kg and 7.5 mg / kg could increase the claw retraction pressure value of SD rats with osteoarthritis in a dose-dependent manner, with the effect lasting until 1 h and 2 h after administration, respectively; a single oral administration of test product 2 at 20 mg / kg could improve the animals' hyperalgesia in 0.5 h, lasting until 2 h.

[0076] Example 3 Cancer pain 1. Sample information and preparation method 1.1 Test sample 1: LXH-2103 solution; Route of administration: Intravenous injection.

[0077] Dosage: 3 mg / kg, 6 mg / kg, 12 mg / kg Preparation method: Dissolve and dilute LXH-2103 solution (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2303002) with 0.9% sodium chloride injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22061001) to prepare solutions of 1.2mg / mL, 0.6mg / mL and 0.3mg / mL.

[0078] 1.2 Test sample 2: LXH-2103 Administration route: oral or gavage.

[0079] Dosage: 30 mg / kg (2 test samples).

[0080] Preparation method: Dissolve and dilute LXH-2103 (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2207301) with 0.9% sodium chloride injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22061001) to prepare a 3mg / mL solution.

[0081] 1.3 Positive control drug: Tramadol hydrochloride injection Route of administration: Intravenous injection.

[0082] Dosage: 6 mg / kg Preparation method: Dissolve and dilute tramadol hydrochloride injection (manufacturer: Grunethal GmbH, batch number 01394T) with 0.9% sodium chloride injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22061001) to prepare a solution of 0.6 mg / mL.

[0083] 2. Animal Model: Balb / c nude mouse bone cancer pain model induced by human breast cancer cells MDA-MB-231. Cell line information: Human breast cancer cell line MDA-MB-231 (Source: Cell Bank of the Chinese Academy of Sciences, China Center for Type Culture Collection) Model establishment: After isoflurane induction anesthesia in the model animals, anesthesia was maintained with isoflurane using a respiratory anesthesia machine. Once the mice were fully anesthetized, they were placed in a supine position with the knee joint bent. A 1 mL sterile insulin syringe needle was inserted into the left tibia from the upper end, drilling along the long axis of the tibia to reach the medullary cavity. 5 μL of MDA-MB-231 cell suspension was then injected into the tibial medullary cavity. After injection, the needle was held for approximately 1 minute and then slowly withdrawn. In the sham-operated group, 5 μL of serum-free culture medium was administered into the medullary cavity, and the remaining procedures were the same.

[0084] 3. Animal grouping Animals that passed the health check underwent the Von Frey test. Based on the claw retraction pressure value and animal weight, 6 animals were randomly selected as the sham surgery group, and the remaining animals were used for modeling. Three weeks after modeling, the Von Frey test was performed again. 36 animals with a significant decrease in claw retraction pressure value were selected and randomly divided into 6 groups based on animal weight: model control group, positive control group, low-dose group of test product 1 (3 mg / kg), medium-dose group of test product 1 (6 mg / kg), high-dose group of test product 1 (12 mg / kg), and group of test product 2 (30 mg / kg), with 6 animals in each group.

[0085] 4. Dosage frequency and method The sham surgery group received no medication, the model control group received 0.9% sodium chloride injection, the positive control group received tramadol hydrochloride injection, the test sample 1 group received different doses of test sample 1 solution, and the test sample 2 group received test sample 2. The positive control model control group and the test sample 1 group were administered intravenously, while the test sample 2 group was administered by gavage. Administered once daily for a total of 7 times.

[0086] 5. Detection indicator: Von Frey test Place the animal in the test container to acclimatize it to the test environment. Once the animal is calm, measure the claw retraction pressure in its left hind paw. (If the animal does not retract its paw when the pressure reaches its maximum value of 15g, manually stop the measurement to avoid tissue damage; record the claw retraction pressure value as 15g.) Manually record the claw retraction pressure value displayed on the instrument interface when the animal exhibits rapid claw retraction or paw licking behavior. (If the measurement process is stopped due to spontaneous animal activity, it needs to be repeated. If unsure, multiple measurements can be taken and the average value calculated to ensure that the animal's claw retraction is caused by mechanical stimulation.)

[0087] Testing instrument: Dynamic plantar tactile sensor (Model: 37450 / 37550; Manufacturer: Ugo Basile).

[0088] 6. Application Effects: The claw retraction pressure values ​​before and after animal modeling are shown in the figure. Figure 5 After modeling, the average claw retraction pressure value of the model group animals was significantly reduced, indicating that the administration of MDA-MB-231 breast cancer cells into the tibial medullary cavity can induce a decrease in the pain threshold of Balb / c nude mice, i.e., hyperalgesia.

[0089] Changes in paw retraction pressure before and after drug administration in animals are shown in the figure. Figure 6 The results showed that intravenous administration of 6 mg / kg of the positive control tramadol hydrochloride injection, either once or for 7 consecutive days, significantly increased the paw retraction pressure of BALB / cnude mice inoculated with MDA-MB-231 breast cancer cells in the tibia; intravenous administration of 3 mg / kg, 6 mg / kg, and 12 mg / kg of the test product 1 LXH-2103 solution, either once or for 7 consecutive days, improved hyperalgesia in BALB / cnude mice in a dose-dependent manner; and intragastric administration of 30 mg / kg of the test product 2 LXH-2103, either once or for 7 consecutive days, significantly improved hyperalgesia in BALB / cnude mice.

[0090] Example 4 Sciatica 1. Sample information and preparation method 1.1 Test sample 1: LXH-2103 solution; Route of administration: Intravenous injection.

[0091] Dosage: 7.5 mg / kg, 20 mg / kg.

[0092] Preparation method: Dilute LXH-2103 drug solution (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2303002) with 0.9% sodium chloride injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22090305) in a certain proportion to prepare solutions of 0.25 mg / mL (low-dose group of test sample 1) and 0.75 mg / mL (high-dose group of test sample 1).

[0093] 1.2 Test sample 2: LXH-2103 Administration route: oral or gavage.

[0094] Dosage: 20 mg / kg (2 test samples).

[0095] Preparation method: Dissolve and dilute LXH-2103 (manufacturer: Shandong Xinhua Pharmaceutical Co., Ltd., batch number 2207301) with 0.9% sodium chloride injection (manufacturer: Hunan Kelun Pharmaceutical Co., Ltd., batch number K22090305) to prepare a 2mg / mL solution.

[0096] 2. Animal model: Chronic sciatic nerve compression injury (CCI) model in SD rats Animal selection: SD rats that passed the health examination, whose left hind paw pain threshold was measured by the Von Frey method and whose claw retraction pressure was >18.0g.

[0097] Model establishment: After anesthetizing the animal with isoflurane, the skin of the left hind limb was prepared, and the skin of the leg was obliquely incised to expose the sciatic nerve by separating the muscle gaps. Four small knots were gently tied along the main trunk of the sciatic nerve using 4-0 non-absorbable surgical sutures (silk sutures), with each knot spaced approximately 1 mm apart. The pressure applied was such that the animal's toes twitched slightly when the first knot was tied. After the surgery, the skin was sutured and disinfected with iodine.

[0098] 3. Animal grouping Based on the claw retraction pressure value and animal weight, 6 animals were randomly selected as the sham-operated group, and the remaining animals were used for modeling. On day 11 of modeling, the sham-operated group and the model animals underwent the Von Frey test again. 24 animals with a significant decrease in claw retraction pressure value were selected from the model animals and randomly divided into 4 groups based on animal weight: model control group, low-dose test product 1 group (2.5 mg / kg), high-dose test product 1 group (7.5 mg / kg), and test product 2 group (20 mg / kg), with 6 animals in each group.

[0099] 4. Dosage frequency and method The sham surgery group received no medication, the model control group received 0.9% sodium chloride injection, the test sample 1 group received different doses of test sample 1, and the test sample 2 group received test sample 2. The model control group and the test sample 1 group were administered intravenously, while the test sample 2 group was administered by gavage. All groups received a single dose.

[0100] 5. Detection indicator: Von Frey test Place the animal in the test container to acclimatize it to the test environment. Once the animal is calm, measure the claw retraction pressure in its left hind paw. (If the animal does not retract its paw when the pressure reaches its maximum value of 50g, manually stop the measurement to avoid tissue damage; record the claw retraction pressure value as 50g.) When the animal exhibits rapid claw retraction or paw licking behavior, manually record the claw retraction pressure value displayed on the instrument interface. (If the measurement process is stopped due to spontaneous animal activity, it needs to be repeated. If unsure, multiple measurements can be taken and the average value calculated to ensure that the animal's claw retraction is caused by mechanical stimulation.)

[0101] Testing instrument: Dynamic plantar tactile sensor (Model: 37550; Manufacturer: UgoBasile).

[0102] 6. Application Effects: See the claw retraction pressure values ​​before and after animal modeling. Figure 7 The average claw retraction pressure value of the model animals decreased significantly after modeling compared to before modeling. This indicates that sciatic nerve injury in SD rats leads to a decrease in the pain threshold, i.e., hyperalgesia.

[0103] Changes in paw retraction pressure before and after drug administration in animals are shown in the figure. Figure 8 The results showed that a single intravenous administration of 2.5 mg / kg and 7.5 mg / kg of test product 1 LXH-2103 solution could increase the claw retraction pressure value caused by chronic compression injury of the sciatic nerve in SD rats in a dose-dependent manner, and a single oral gavage administration of 20 mg / kg of test product 2 LXH-2103 could significantly improve the animals' pain hypersensitivity.

[0104] Example 5 Receptor-ligand binding assay 1. Sample Information 1.1 Test substance: LXH-2103 reference standard, manufactured by Shandong Xinhua Pharmaceutical Co., Ltd., batch number: Y2408001.

[0105] 1.2 Solvent: Dimethyl sulfoxide (DMSO), Brand: Sigma, Batch No.: BCCG0991.

[0106] 2. Preparation method The LXH-2103 reference standard was dissolved and diluted with different volumes of DMSO in proportion to prepare a stock solution of 15 mmol / L.

[0107] 3. Model: In vitro model of 70 test targets.

[0108] 4. Test content and detection methods: 4.1 GPCR target: Gp-coupled receptor activity assays (FLIPR method, IP-One method) Gs-coupled receptor activity assay (HTRF method) Gi-coupled receptor activity assay (HTRF method) 4.2 Ion Channel Targets: Manual patch-clamp detection (whole-cell recording method) High-throughput fluorescence imaging detection (FLIPR method) 4.3 Enzyme-related targets: Determination of COX1 and COX2 enzyme inhibitory activities Determination of PDE3A and PDE4D2 enzyme inhibitory activities Determination of LCK enzyme inhibitory activity Assay for AchE enzyme inhibitory activity Determination of MAO A enzyme inhibitory activity 4.4 Detection of nuclear receptor targets (reporter gene assay) 4.5 Detection of transporter target (fluorescence method) 5. Application Results: The radar chart of the receptor-ligand binding assay results is shown below. Figure 9 The results showed that the test substance LXH-2103 reference standard, at 15 μmol / L, had an agonistic effect on the MOR target (81.57%) and an inhibitory effect on the nAChRα7 / RIC3 target (97.61%). It had no significant agonistic or inhibitory effect on the remaining 68 targets, with agonistic or inhibitory rates all less than 50%. This indicates that LXH-2103 reference standard has significant analgesic and dependence potential and may reduce the risk of drug dependence by modulating the cholinergic system.

[0109] Example 6 Acute incision pain 2 1. Drug Information 1.1 Test substance: LXH-2103 injection, manufactured by Shandong Xinhua Pharmaceutical Co., Ltd., batch number: 2411211.

[0110] 1.2 Positive drug: Tramadol Hydrochloride Injection, manufactured by Shandong Xinhua Pharmaceutical Co., Ltd., batch number: 02528V.

[0111] 1.3 Other reagents: physiological saline, manufactured by Zhejiang Tianrui Pharmaceutical Co., Ltd., batch number: 124030801.

[0112] 2. Preparation method: 2.1 Tramadol Hydrochloride Injection: Dilute Tramadol Hydrochloride Injection with physiological saline to prepare a solution with a concentration of 1 mg / mL.

[0113] 2.2 LXH-2103: Dilute LXH-2103 injection with physiological saline to prepare solutions with concentrations of 1 mg / mL, 0.5 mg / mL, and 0.25 mg / mL.

[0114] 3. Animal model: SD rat foot incision pain model.

[0115] Model establishment: The rats were anesthetized with isoflurane. After disinfecting the skin of their right hind paw with povidone-iodine, a 1cm incision was made from 0.5cm from the heel toward the toes. The plantar muscles were separated and the muscle fibers were longitudinally separated down to the fascia layer. The muscle integrity was maintained. After applying pressure to stop bleeding, the skin was sutured and the wound was disinfected.

[0116] 4. Animal grouping: Before modeling, the Von Frey (Up-Down method) was used to test the baseline plantar pain threshold of all rats. Ten rats were randomly selected as the blank control group, and the remaining animals were used for modeling. On the second day after modeling, the plantar pain threshold of the affected side of the rats was measured as their pain threshold after modeling. Based on the pain threshold after modeling, the rats were evenly divided into 5 groups: the model group, the tramadol group, and the LXH-2103 treatment group (10 mg / kg, 5 mg / kg, and 2.5 mg / kg), with 10 rats in each group.

[0117] 5. Dosage frequency and method: The blank control group (Control) and model group (Model) were given 10 mL of normal saline, the tramadol group was given 10 mg / kg of tramadol hydrochloride injection, and the LXH-2103 administration group was given different doses of LXH-2103 injection. All groups were administered intravenously as a single dose.

[0118] 6. Detection indicator: VonFrey test The up-down method was used for measurement: Rats were placed in a test container, and after the animals acclimatized, the hind paw retraction pressure of each rat was vertically stimulated with a Von Frey probe. (A positive reaction was indicated by immediate rapid retraction, leg lifting, or paw licking after stimulation, or immediate retraction after probe removal. Measurements were taken approximately 10 seconds apart; no reaction after probe stimulation was considered a negative reaction.) A series of probes (0.4, 0.6, 1, 1.4, 2, 4, 6, 8, 10, 15 g) were used to stimulate the rats. Starting with a 2 g probe, if a retraction reaction occurred, it was recorded as X, and a weaker probe (1.4 g) was used; if no retraction reaction occurred, it was recorded as 0, and a stronger probe (4 g) was used.

[0119] For rats using a 15g probe, the 50% withdrawal threshold is recorded as 15g; if a 0.4g probe is used, the 50% withdrawal threshold is recorded as 0.4g. If neither 15g nor 0.4g probes are used, the threshold is calculated using the following formula: 50%MWT(g)=(10[Xf+kδ]) / 10000 50%MWT means that at this stimulus intensity, rats have approximately a 50% chance of foot withdrawal. Xf = the value of the last Von Frey probe used (in log).

[0120] K value: can be obtained from a table based on the measured sequence. δ is the average difference between the series of stimuli (in logarithmic units, 0.224 here).

[0121] 7. Application Effects: Analgesia results as Figure 10 , Figure 11 As shown in the figure. After surgical modeling, the mechanical pain threshold of rats in each group decreased to 3.11±0.65g. After drug treatment, the pain threshold of rats in the model group remained relatively stable, showing a statistically significant difference compared with the blank control group (p<0.01 vs. Control). The pain threshold of rats in the other drug treatment groups increased to varying degrees.

[0122] At 0.25h, 0.5h, 1h, 2h and 4h after administration: the mechanical pain threshold of the rat foot in each administration group was significantly increased, and the difference was statistically significant compared with the model group (p<0.01 vs. Model). Six hours after administration: The pain threshold of rats in the model group was 3.11±0.65g, the pain threshold of rats in the positive control group (tramadol hydrochloride injection 10mg / kg) was 3.88±0.74g, and the pain thresholds of rats in the test substance LXH-2103 injection groups (10mg / kg, 5mg / kg, and 2.5mg / kg) were 7.78±1.76g, 6.53±1.82g, and 5.06±1.16g, respectively. Compared with the model group, the pain thresholds were significantly increased, and all showed statistically significant differences (p<0.05, p<0.01 vs. Model).

[0123] in conclusion: In this experiment on the local analgesic effect of the test substances on surgical incision pain in rat paws: all test substances showed effective local analgesia 0.25 h after administration, reaching peak analgesia at 0.5 h, and gradually weakening after 1 h, with a significant decrease in analgesia effect by 6 h after administration. The 2.5 mg / kg, 5 mg / kg, and 10 mg / kg doses of the test substance LXH-2103 injection showed a good dose-response relationship. The analgesic efficacy and duration of action of the 5 mg / kg and 10 mg / kg doses of LXH-2103 were superior to those of the 10 mg / kg positive control drug tramadol hydrochloride; the analgesic effect of the 2.5 mg / kg dose of LXH-2103 was comparable to that of tramadol hydrochloride. The effective analgesic duration of both tramadol hydrochloride and the test substance LXH-2103 lasted for more than 4 h after administration, and their analgesic effect gradually disappeared after 6 h.

Claims

1. Use of LXH-2103 in the manufacture of a medicament for the treatment of pain and drug dependency, characterized in that: The pain is acute incision pain, osteoarthritis pain, cancer pain or sciatica.

2. Use of LXH-2103 according to claim 1 for the preparation of a medicament for the treatment of pain and drug dependency, characterized in that: The injection dose of the drug for acute incision pain is 7.5-20 mg / kg, or the oral dose is 20 mg / kg.

3. Use of LXH-2103 according to claim 1 for the preparation of a medicament for the treatment of pain and drug dependency, characterized in that: The injection dose of the drug for osteoarthritis pain is 2.5-7.5 mg / kg, or the oral dose is 10-30 mg / kg.

4. Use of LXH-2103 according to claim 1 for the preparation of a medicament for the treatment of pain and drug dependency, characterized in that: The injection dose of the drug for cancer pain is 3-12 mg / kg, or the oral dose is 30 mg / kg.

5. Use of LXH-2103 according to claim 1 for the preparation of a medicament for the treatment of pain and drug dependency, characterized in that: The injection dose of the drug for sciatica is 2.5-7.5 mg / kg, or oral 20 mg / kg, single or multiple administration.

6. Use of LXH-2103 according to claim 1 or 3 for the preparation of a medicament for the treatment of pain and drug dependency, characterized in that: The osteoarthritis pain is sodium iodoacetate-induced joint injury-related pain.

7. A pharmaceutical composition for the treatment of acute incisional pain prepared from LXH-2103 according to claim 1 or 2, characterized by: It comprises LXH-2103 or a pharmaceutically acceptable salt thereof, and the dosage form is injection or oral dosage form.

8. A pharmaceutical composition for the treatment of osteoarthritic pain prepared from the LXH-2103 of claim 1 or 3. It comprises LXH-2103 or a pharmaceutically acceptable salt thereof, and the dosage form is injection or oral dosage form.

9. A pharmaceutical composition for the treatment of cancer pain prepared from LXH-2103 as claimed in claim 1 or 4. It comprises LXH-2103 or a pharmaceutically acceptable salt thereof, and the dosage form is injection or oral dosage form.

10. A pharmaceutical composition for the treatment of sciatica prepared from LXH-2103 as claimed in claim 1 or 5. It comprises LXH-2103 or a pharmaceutically acceptable salt thereof, and the dosage form is injection or oral dosage form.

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