High concentration injection solutions comprising dihydrocannabidiol di(hetero)arylate derivatives, methods of making and uses thereof

Abstract

The application belongs to the technical field of biological medicine, and particularly relates to a high-concentration injection of di(hetero)aromatic formate derivative containing dihydrocannabidiol and a preparation method and application thereof. The di(hetero)aromatic formate derivative containing dihydrocannabidiol as an active ingredient, or a pharmaceutically acceptable salt thereof, a solubilizing agent, an osmotic pressure regulator, a pH regulator, a buffer, and a solvent; the application breaks through the water-solubility limitation of PSF1-5 through a specific solubilizing prescription, and successfully prepares a high-concentration clear injection. When subcutaneously administered, only a small volume is needed to reach an effective dose, and swelling pain and irritation of local tissues are significantly reduced. Meanwhile, the application of the high-concentration injection in preparing a medicine for treating acute pain is provided.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to a high-concentration injection solution containing dihydrocannabidiol di(hetero)carbamate derivatives, its preparation method, and its application. Background Technology

[0002] Pain management has always been a major challenge in clinical medicine. Traditional short-acting analgesics require frequent administration, which not only increases patient suffering and the workload of medical staff, but also easily leads to drastic fluctuations in blood drug concentration and adverse reactions. Conventional low-concentration formulations have problems such as large administration volume, significant subcutaneous irritation, rapid elimination from the body, short duration of action, and poor long-term patient compliance, making it difficult to meet the clinical need for long-acting analgesia. High-concentration, small-volume subcutaneous injection formulations are an important direction for the development of analgesic drug formulations. They can significantly reduce the administration volume while ensuring the dosage, reduce local tissue irritation, improve drug absorption and residence time in the body, and improve therapeutic efficacy and ease of use.

[0003] However, the development of high-concentration injections faces a core pharmaceutical challenge: how to dissolve a sufficient amount of poorly soluble active ingredients within a limited volume and maintain the physicochemical stability of the formulation during storage and use.

[0004] The applicant's previously developed PSF1-5 series compounds possess analgesic activity, but they are yellow oily substances that are extremely poorly soluble in water. Conventional solubilization methods are insufficient to prepare them into high-concentration, clear, and stable injectable solutions. This solubility bottleneck directly results in the following: if conventional low-concentration formulations are administered, the required injection volume is too large, which subcutaneous tissues cannot tolerate; if attempts are made to increase the concentration, process problems such as drug precipitation, formulation turbidity, and inability to filter for sterilization arise. Therefore, developing a formulation technology that can overcome the solubility limitations of PSF1-5 and achieve high-concentration, clear injectable solutions is a prerequisite for their application in clinical analgesia.

[0005] The applicant has previously developed a series of dihydrocannabidiol di(hetero)carbamate derivatives, namely PSF1-5, see patents CN116983265A (PSF2), CN116983266A (PSF4), CN116983267A (PSF3), CN116983263A (PSF1), and CN116983264A (PSF5). These patents confirm that PSF1-5, as a dihydrocannabidiol di(hetero)carbamate derivative, has a protective effect against oxidative damage to nerve cells and can alleviate insulin resistance. However, the aforementioned prior art does not disclose the application of PSF1-5 in the treatment of pain.

[0006] PSF1-5 is a yellow, oily substance that is extremely poorly soluble in water. In conventional dosage form development, its extremely low water solubility leads to low formulation concentrations. For subcutaneous injection, this often requires a large volume of solution, which can cause severe local irritation and swelling, as well as affect drug absorption and patient compliance. High-concentration, small-volume subcutaneous injection formulations are currently an important development direction for improving patient experience and achieving long-acting administration. However, for poorly soluble drugs, how to prepare high-concentration, stable, isotonic, and low-irritation clear injection solutions without using large amounts of toxic organic solvents remains a significant technical challenge in pharmaceutical formulation.

[0007] Therefore, the present invention aims to develop a safe and stable high-concentration PSF1-5 injection formulation and process, and to evaluate its analgesic effect and time-effect characteristics in an acute pain model. Summary of the Invention

[0008] This invention aims to address the problem of low formulation concentration and large injection volume caused by the extremely poor water solubility of PSF1-5, and provides a high-concentration, isotonic, and low-irritation subcutaneous injection solution of PSF1-5 and its preparation method. This invention also aims to confirm the long-lasting analgesic effect of this injection solution in the treatment of acute pain.

[0009] In a first aspect, the present invention provides a high-concentration injection containing a dihydrocannabidiol di(hetero)carbamate derivative, comprising a dihydrocannabidiol di(hetero)carbamate derivative or a pharmaceutically acceptable salt thereof as an active ingredient, a solubilizer, an osmotic pressure regulator, a pH regulator, a buffer, and a solvent; wherein the concentration of the dihydrocannabidiol di(hetero)carbamate derivative or a pharmaceutically acceptable salt thereof in the injection is 2%-8%; The general structural formula of the di(hetero)arylformate derivative of dihydrocannabidiol is shown in Formula I below:

[0010] Formula I; Where R can be any of the following structures: (1); (2); (3); (4);

[0015] (5).

[0016] Specifically, the di(hetero)carbamate derivatives of dihydrocannabidiol are any one of the following compounds:

[0017] PSF1: Dihydrocannabidiimidazol carbamate;

[0018] PSF2: Dihydrocannabidiol-2,6-dioxapiperazine carboxylate;

[0019] PSF3: dihydrocannabidioxanone dinicotinate;

[0020] PSF4: dihydrocannabidiol difuranose ester;

[0021] PSF5: Dihydrocannabidiol dibenzoate; all subsequent uses are abbreviated by number.

[0022] The osmotic pressure regulator is mannitol and / or sodium chloride; the buffer is histidine; the pH regulator is hydrochloric acid and / or sodium hydroxide, and the pH is adjusted to 5.5-6.5 using hydrochloric acid and / or sodium hydroxide; the solubilizer is polysorbate 80.

[0023] The pH of the injection solution is 5.5-6.5, and the osmotic pressure is 290-310 mOsmol / kg.

[0024] The injection solution is a clear liquid and contains no foreign matter visible to the naked eye.

[0025] The injection solution described in this invention is a clear liquid. This clear state is achieved by solubilizing PSF1-5 with polysorbate 80—polysorbate 80 forms nanomicelles (particle size 10-100 nm) in aqueous solution, encapsulating the oily PSF1-5 within the micelles, forming a thermodynamically stable true solution or micelle solution, rather than a macroscopic oil-water two-phase emulsion. Because the micelle size is much smaller than the wavelength of visible light, the solution appears clear, meeting the clarity requirements for injection solutions in the Chinese Pharmacopoeia.

[0026] Preferably, the dihydrocannabidiol di(hetero)carbamate derivative is dihydrocannabidiol diimidazocarbamate.

[0027] A second aspect of the present invention provides a method for preparing a high-concentration injection of a di(hetero)arylformate derivative containing dihydrocannabidiol, comprising the following steps: (1) Dissolve the osmotic pressure regulator and buffer in part of the solvent, then add the solubilizer and stir until the system is clear and transparent. Add the pH regulator to adjust the pH to 5.5-6.5 to obtain the solubilizing buffer base solution; (2) Dispersion and dissolution of active ingredients: Dihydrocannabidiol di(hetero)carbamate derivatives or pharmaceutically acceptable salts thereof are slowly added to the solubilizing buffer base solution and stirred at low speed at 50-100 rpm until completely dissolved; (3) Add solvent to make up the volume, and let stand to remove bubbles; (4) Sterilization filtration and aseptic packaging.

[0028] In step (4), a 0.22 μm microporous membrane is used for terminal sterilization filtration.

[0029] A third aspect of the present invention provides the use of a high-concentration injection of a di(hetero)arylformate derivative containing dihydrocannabidiol in the preparation of a medicament for treating acute pain.

[0030] The drug is administered via subcutaneous injection.

[0031] The drug has a long-lasting analgesic effect, with analgesia lasting from 1 to 7 days or more.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) This invention overcomes the water solubility limitations of PSF1-5 through a specific solubilizing formulation, successfully preparing a high-concentration, clear injection solution. When administered subcutaneously, only a very small volume is needed to achieve an effective dose, significantly reducing local swelling, pain, and irritation.

[0033] 2) This invention achieves long-lasting analgesia and exhibits a unique biphasic drug release characteristic. The injection solution of this invention displays a unique biphasic drug release characteristic after subcutaneous administration: the first analgesic peak is rapidly reached 0.25 h after administration, with a pain threshold increase rate of 128%, indicating that the free drug released in the solubilizer is rapidly absorbed into the bloodstream, achieving rapid onset of action; a second potent analgesic peak appears 6 h after administration, with a pain threshold increase rate of 118%. This is presumably due to the change in the local physiological environment (pH, temperature, ionic strength changes) after subcutaneous injection of the high-concentration formulation, leading to the disintegration of the solubilizer system. PSF1-5 undergoes in-situ microprecipitation to form a drug reservoir, and subsequently, the drug in the reservoir slowly redissolves and is continuously absorbed into the bloodstream, thus achieving long-lasting analgesia for up to 7 days. This biphasic drug release characteristic achieves an organic combination of rapid onset of action and long-lasting maintenance.

[0034] 3) The present invention has stable physicochemical properties, high safety, and the formulation isotonic and pH is suitable. It has passed sterility and endotoxin tests and has good prospects for industrial production and clinical application. Attached Figure Description

[0035] Figure 1 A graph showing the pain threshold improvement rate of PSF1 at various time points; Figure 2 A graph showing the pain threshold improvement rate at each time point for the five components PSF1, PSF2, PSF3, PSF4, and PSF5; Figure 3 This is a graph showing the results of the L6 cell stimulation assay. Detailed Implementation

[0036] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0037] The processes, conditions, reagents, and experimental methods used in implementing this invention, except as specifically mentioned below, are all common knowledge and general knowledge in the field, and this invention does not have any particular limitations. Experimental methods in the embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer.

[0038] Unless otherwise stated, all technical terms and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. However, in the event of any conflict, the specification containing the definitions shall prevail.

[0039] Experimental materials: PSF1-5 is a yellow oily substance with a purity of ≥98%. It is free of pyrogens and impurities, exhibits good batch stability, and meets the quality standards for pharmaceutical raw materials.

[0040] The preparation method of PSF1-5 is described in the following patent examples: PSF1: CN116983263A, PSF2: CN116983265A, PSF3: CN116983267A, PSF4: CN116983266A, PSF5: CN116983264A, The reference drug was ibuprofen, and the excipients included sodium chloride, histidine, polysorbate 80, and water for injection, all of which were injection grade. The experimental animals were SPF-grade male ICR mice, 6-8 weeks old, weighing 18-22 g, provided by the Experimental Animal Center, animal license number: SCXK (Zhejiang) 2023-0004. They were housed in a barrier environment at a temperature of (23±2)℃ and a relative humidity of 50%-60%, with 12 h / 12 ​​h light-dark alternation, and free access to food and water. After one week of acclimatization, they were used for experiments.

[0041] The main experimental instruments include an ultra-clean workbench, a precision pH meter, an osmotic pressure meter, a 0.22 μm hydrophilic PES sterilization filter, and an intelligent hot plate analgesia detector. All instruments are calibrated before the experiment to ensure that the experimental data are accurate and reliable.

[0042] Example The method for preparing the high-concentration injection containing dihydrocannabidiol di(hetero)carbamate derivatives: The prescription (taking the preparation of 100 mL of injection solution as an example) is shown in Table 1 below: Table 1 Prescription Table

[0043] Preparation of high-concentration PSF1 injection: Taking the preparation of 100 mL injection as an example, the prescription composition is: PSF1 3.75 g, polysorbate 80 10.0 g, mannitol 5.0 g, sodium chloride 0.6 g, histidine 0.2 g, and water for injection added to 100 mL.

[0044] (1) Preparation of the solubilizing buffer system: Weigh 5.0 g of mannitol, 0.6 g of sodium chloride, and 0.2 g of histidine, add 60 mL of water for injection (4℃), and stir until completely dissolved. Add 10.0 g of polysorbate 80, and continue stirring until the system is clear and transparent. Adjust the pH to 6.0±0.2 (5.5-6.5) with 1M hydrochloric acid or 1M sodium hydroxide to obtain the solubilizing buffer base solution.

[0045] (2) Dispersion and dissolution of active ingredients: Adjust the stirring speed to 75 rpm (50-100 rpm), slowly add 13.75 g of PSF, and continue stirring for 30-60 min until completely dissolved.

[0046] (3) Degassing: Add water for injection to 100 mL, and let stand at 4℃ in the dark for 15-20 min to degas.

[0047] (4) Sterile filtration and dispensing: The solution is filtered sequentially through 0.45 μm and 0.22 μm microporous membranes and aseptically dispensed into 1 mL pre-filled syringes to obtain PSF1 high concentration injection solution.

[0048] High-concentration injections of PSF2, PSF3, PSF4, and PSF5 are prepared using the same formulation and process as described above, except that PSF1 is replaced with the corresponding compound.

[0049] The solubilizing effect of polysorbate 80 ensures that PSF1-5 dissolves completely, forming a homogeneous and stable solution. 1. Formulation quality evaluation In accordance with the relevant quality standards for injectable preparations in the Pharmacopoeia of the People's Republic of China (2025 Edition), a systematic quality evaluation was conducted on the prepared PSF1-5 high-concentration subcutaneous injection solution. The main test indicators included the appearance of the preparation, solution pH value, osmotic pressure, content of active ingredients, sterility, bacterial endotoxins, and visible foreign matter. The quality of the preparation was strictly controlled to ensure that all indicators met the pharmaceutical standards for subcutaneous injections and met the requirements for subsequent animal experiments and subsequent formulation development.

[0050] 2. Evaluation of analgesic activity (mouse hot plate test) The in vivo analgesic activity of the formulation was evaluated using the hot plate test in mice. ICR mice were first acclimatized, and their baseline pain thresholds were measured. Mice with significant individual differences were excluded, and the mice were then randomly assigned to groups. The experiment consisted of a dose screening group and a component control group. The dose screening group had five PSF1 concentration gradients: 15 mg / kg, 37.5 mg / kg, 75 mg / kg, 150 mg / kg, and 300 mg / kg. Simultaneously, a 37.5 mg / kg ibuprofen positive control, a CBD control, and a saline negative control were established. The component control group had a fixed optimal dose of 37.5 mg / kg and included PSF1, PSF2, PSF3, PSF4, and PSF5 experimental groups, with corresponding ibuprofen and saline control groups. The CBD reference standard was prepared using the same solvent system as the PSF group. To ensure solvent consistency, the same dosage volume was administered subcutaneously. The pain threshold of mice was measured at 0.25 h, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, and 7 d after administration. The percentage increase in pain threshold in each group was calculated to evaluate the analgesic effect, onset rate, and duration of action of the drugs in different groups.

[0051] 3. Results 3.1 Results of formulation quality testing This study successfully prepared high-concentration subcutaneous injection solutions of PSF1-5. The resulting preparations were all colorless and clear liquids, free from turbidity, precipitation, flocculent matter, and visible foreign matter. The pH of the solution was stable at 5.8–6.2, the osmotic pressure was 290–310 mOsmol / kg, and the content of active ingredients was 95.0%–105.0% of the labeled amount. The results of sterility and bacterial endotoxin tests met the pharmaceutical standards of the Pharmacopoeia of the People's Republic of China. The preparations were of stable quality and had good safety, fully meeting the requirements for subcutaneous injection and animal efficacy experiments.

[0052] 3.2 Screening results of analgesic effects of different doses of PSF1 Different dosages of PSF1 formulations showed significant differences in analgesic effects, as shown in the data on pain threshold elevation at various time points. Figure 1As shown in the figure. Based on the analysis of analgesic intensity and duration at various time points, the 37.5 mg / kg dose group of PSF1 showed rapid onset of action, the best peak analgesic effect, and strong long-term stability, which was significantly better than the other dose groups, the ibuprofen control group, and the saline group. Therefore, 37.5 mg / kg was determined to be the optimal experimental dose for the PSF1-5 series components.

[0053] 3.3 Comparison of analgesic effects of different components of PSF1-5 At a fixed optimal dosage of 37.5 mg / kg, the analgesic activities of five components (PSF1, PSF2, PSF3, PSF4, and PSF5) were compared and evaluated. The pain threshold elevation rate data at each time point are as follows: Figure 2 As shown in the figure. Overall results indicate that all five PSF components exhibit rapid onset of action, strong peak effect, and long-lasting analgesia. The overall analgesic activity trend is PSF1 > PSF5 > PSF4 > PSF2 > PSF3 > CBD. All PSF components showed rapid onset of action within 0.25 h after administration, with a pain threshold increase rate of 108%–128%, significantly higher than the 26% in the ibuprofen control group and 2% in the CBD group. Peak analgesia was reached at 6 h, with a pain threshold increase rate of 98%–118%, while the ibuprofen group showed no analgesic effect (pain threshold increase rate of -4%) and the CBD group showed -3%. The analgesic effect remained stable for 7 days, with significantly better analgesic effects at each time point than the positive and negative controls. The saline group showed no significant analgesic effect throughout the treatment, further confirming the superior long-lasting analgesic advantage of the PSF1-5 formulations.

[0054] This invention presents a high-concentration, small-volume subcutaneous injection formulation and process that effectively solves the technical problems of low concentration, large administration volume, easy aggregation of active ingredients, and poor storage stability of PSF1-5 in conventional formulations. The nitrogen protection, low-temperature and light-protected storage environment, and slow-speed fractional dissolution strategy employed in the preparation process minimize oxidative degradation and shear denaturation of the PSF active ingredients. The two-stage gradient sterilization filtration process ensures the clarity of the formulation solution while strictly meeting the sterility requirements of the injection. The process is simple to operate, with controllable parameters, and possesses good potential for industrial production. This formulation uses injection-grade sodium chloride, histidine, and polysorbate 80 as excipients, and the system pH and osmotic pressure are optimized (pH 5.5~6.5, measured 6.0±0.2). Subcutaneous injection irritation test showed that no obvious edema, congestion and inflammatory cell infiltration were observed at the injection site of the preparation of the present invention. The local irritation score was 0-1 (0 for no irritation and 1 for mild irritation), which was significantly lower than that of the saline control group (0-1). This confirms that the preparation has good subcutaneous tissue compatibility and low irritation, which can effectively reduce local tissue reaction after subcutaneous administration and improve medication safety and patient compliance.

[0055] Pharmacodynamic experiments have fully demonstrated that the high-concentration subcutaneous injection of PSF1-5 possesses comprehensive advantages such as rapid onset of action, high-intensity analgesia, and ultra-long duration of action. Compared with traditional short-acting ibuprofen analgesics, a single dose can achieve long-term analgesia for more than 7 days, significantly reducing the frequency of clinical administration and avoiding the adverse reactions and cumbersome procedures associated with frequent medication. It is highly suitable for long-term pain management scenarios such as postoperative pain, chronic persistent pain, and cancer pain. Furthermore, all five PSF components exhibited stable analgesic activity, with PSF1 showing the best analgesic effect, providing sufficient experimental evidence for subsequent screening of optimal monomers and development of novel long-acting analgesic formulations. Compared with existing conventional analgesics, the PSF1-5 subcutaneous injection developed in this invention has significant innovative advantages in terms of administration method, long-term effect, safety, and practicality, providing a reliable technical path for the formulation transformation and clinical application of PSF-like active ingredients.

[0056] This invention successfully established a stable, controllable, and industrially scalable preparation process for high-concentration PSF1-5 subcutaneous injection. The optimized formulation is reasonable, and the process is mature. The prepared injection solution meets the standards for pharmaceutical subcutaneous injections in terms of properties, pH value, and osmotic pressure. Mouse hot plate pharmacodynamic experiments confirmed that 37.5 mg / kg is the optimal dosage for the PSF series components. At this dosage, all five active monomers of PSF1-5 exhibit excellent efficacy with rapid onset, strong analgesia, and a duration of action exceeding 7 days, significantly outperforming the traditional analgesic ibuprofen. The high-concentration PSF1-5 subcutaneous injection prepared in this study combines the advantages of high concentration, small volume, low irritation, high stability, and long-lasting analgesia, effectively compensating for the shortcomings of traditional short-acting analgesics. It has broad clinical application prospects and can provide important experimental support and technical reference for the research and industrialization of novel long-acting analgesics.

[0057] L6 cell stimulation assay protocol and data (PSF1-5) I. Experimental Methods 1. Cell Culture Rat L6 skeletal muscle myoblasts were cultured in DMEM medium containing 10% fetal bovine serum at 37 ℃ and 5% CO2. After cell confluence, the medium was replaced with DMEM medium containing 2% horse serum to induce differentiation of L6 myoblasts into multinucleated myotube cells (approximately 5-7 days) for later use.

[0058] 2. Preparation of the test substance PSF1-5 high-concentration injection group: each compound injection solution is prepared according to the patented formula (active ingredient 3.75%, polysorbate 80 10.0%, mannitol 5.0%, sodium chloride 0.6%, histidine 0.2%). Blank excipient group: excipient solution without PSF active ingredient (polysorbate 80 10.0%, mannitol 5.0%, sodium chloride 0.6%, histidine 0.2%). Positive control group: Mitoxantrone was used as a positive control; Negative control group: physiological saline.

[0059] Each group was diluted to the experimental concentration with cell culture medium, and the pH was adjusted to 5.5-6.5.

[0060] 3. Cell treatment Differentiated and mature L6 myotube cells were co-incubated with the test substance at 37 °C for 1 hour. After incubation, the test substance was carefully removed, the cells were washed twice with PBS, and detection solution containing Calcein-AM fluorescent dye was added. The cells were then incubated at 37 °C in the dark for 30 minutes.

[0061] 4. Fluorescence detection The fluorescence intensity was detected using a fluorescence microplate reader (excitation wavelength 485 nm, emission wavelength 535 nm). The fluorescence intensity of the negative control group (saline group) was normalized to 100%, and the relative fluorescence intensity (i.e., cell viability) of each group was calculated to reflect cell membrane integrity and cell activity.

[0062] 5. Statistical Analysis All experiments were repeated three times, with three replicates per group. Data are expressed as mean ± standard deviation, and one-way ANOVA was used for comparisons between groups.

[0063] 6. Experimental Results The results of the L6 cell stimulation test are as follows: Figure 3 As shown in the results of the L6 cell stimulation assay, the relative fluorescence intensities of the high-concentration PSF1-5 injection groups were 87.2%, 92.5%, 83.9%, 89.6%, and 91.3%, respectively, while that of the blank excipient group was 94.8%. There were no significant differences between the PSF groups, the blank excipient group, and the negative control group (physiological saline, 100.0%). The relative fluorescence intensity of the positive control group (mitoxantrone) was 35.1%, significantly lower than that of the negative control group and other groups (p<0.01). These results indicate that the high-concentration PSF1-5 injection prepared in this invention has no significant cytotoxicity to L6 myotube cells, and the blank excipient system also does not cause cell damage. Subcutaneous injection shows good safety, and the irritation is independent of the potency of the active ingredient.

[0064] Experimental Example: Evaluation of the non-addictive properties of the active ingredient PSF1-5 in this invention To evaluate the drug addiction of the active ingredient PSF1-5 of the present invention, the present invention carried out a conditioned place preference (CPP) experiment to evaluate its psychological dependence, and evaluated its physical dependence after withdrawal through open field test (OFT) and elevated plus maze test (EPM).

[0065] 1. Experimental Materials and Methods 1.1 Experimental Animals SPF-grade male Kunming mice, aged 6-8 weeks, weighing 25-30 g, were purchased from Speyford (Beijing) Biotechnology Co., Ltd. [Production License No.: SCXK (Jing) 2024-0001]. The animals were housed in an SPF-grade animal room at a temperature of 22-25°C, with 12 h light / 12 h dark alternation, and free access to food and water. All animal experiments were conducted in accordance with the relevant regulations of the Laboratory Animal Ethics Committee.

[0066] 1.2 Drugs and Reagents Each component of PSF1-5 (purity ≥98%, provided by the Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences); morphine hydrochloride injection (commercially available specification, positive control drug); normal saline; DMSO (dimethyl sulfoxide, pharmaceutical grade); 75% alcohol.

[0067] Before administration, each component of PSF1, PSF2, PSF3, PSF4 and PSF5 was respectively dissolved in DMSO to prepare stock solutions, which were diluted to the required concentration with normal saline respectively before use (final concentration of DMSO ≤5%), and each component was administered by intraperitoneal injection respectively.

[0068] 1.3 Main Instruments Conditioned place preference box, open field test box, elevated plus maze and VisuTrack animal behavioral video analysis software (Shanghai XinRuan Information Technology Co., Ltd.).

[0069] 1.4 Experimental Grouping and Administration Regimen Mice were randomly divided into the following groups, with 10 mice in each group: First batch: blank control group (normal saline), solvent control group (5% DMSO), positive control group (morphine 3 mg / kg), PSF1 group (10 mg / kg), PSF5 group (10 mg / kg).

[0070] Second batch: blank control group (normal saline), solvent control group (5% DMSO), positive control group (morphine 3 mg / kg), PSF2 group (20 mg / kg), PSF3 group (20 mg / kg), PSF4 group (20 mg / kg).

[0071] All administrations were performed by intraperitoneal injection.

[0072] 2. Experimental Procedure 2.1 Conditional Place Preference (CPP) Experiment The experiment consisted of three phases: pre-test (3 days), training (12 days, drug-environment pairing), and post-test (1 day). The changes in the time mice spent in the drug-accompanied box before and after training (CPP score) were compared among the groups.

[0073] The training phase lasted for 12 days (days 1 to 12). A partition was inserted, and training was alternated between medication-accompanied and non-medication-accompanied boxes, 6 times each. On medication-accompanied box training days (days 1, 3, 5, 7, 9, and 11): Mice in each drug-treated group were intraperitoneally injected with the corresponding drug 30 minutes before training (PSF1-5 groups and the solvent control group were injected with the corresponding drug or 5% DMSO saline solution; the positive control group was injected with morphine; and the blank control group was injected with saline solution). After 30 minutes, the mice were placed in the medication-accompanied box and left for 35 minutes before being removed. On non-medication-accompanied box training days (days 2, 4, 6, 8, 10, and 12): Mice in all groups were not given any medication and were directly placed in the non-medication-accompanied box, left for 35 minutes, and then removed.

[0074] 2.2 Withdrawal Behavioral Experiments On days 7 and 8 after CPP training, the open field test (OFT) and elevated cross maze test (EPM) were conducted to evaluate voluntary activities and anxiety-like behaviors after drug withdrawal.

[0075] OFT metrics: total distance traveled, number of times entering the central zone, time spent in the central zone, average speed, and number of supporting stands.

[0076] EPM metrics: number of times the arm is opened and the dwell time in the arm.

[0077] 2.3 Statistical Analysis Experimental data are expressed as mean ± standard deviation (Mean ± SD). One-way ANOVA was used for comparisons among multiple groups; LSD method was used for pairwise comparisons when variances were homogeneous, and Dunnett's T3 method was used when variances were unequal. Paired t-tests were used to compare pre-test and post-test CPP scores. A p-value < 0.05 was considered statistically significant. GraphPad Prism 9.0 was used as the statistical software.

[0078] 3. Experimental Results 3.1 Results of the CPP experiment (evaluation of psychological dependence) The results are shown in Table 2. The positive control group (morphine) mice showed a significantly higher post-test CPP score than the pre-test (P<0.001), indicating a clear conditional position preference. However, the post-test CPP scores of all PSF1-5 groups showed no significant difference compared to the pre-test (P>0.05), and were comparable to the blank control group and the solvent control group. These results indicate that none of the components of PSF1-5 induces psychological dependence.

[0079] Table 2: Comparison of CPP scores before and after the test in each group of mice (s, Mean±SD, n=10)

[0080] 3.2 Results of the withdrawal behavior experiment (evaluation of physical dependence) Open field test (OFT) results (Table 3): The total range of motion and central area activity of mice in the morphine withdrawal group were significantly reduced, while the number of times they supported themselves on their feet was significantly increased (P<0.05), exhibiting typical anxiety-like behavior. There were no significant differences in any behavioral indicators of mice in the PSF1-5 groups compared with the blank control group (P>0.05).

[0081] Table 3: Comparison of Open Field Test (OFT) Results among Different Groups of Mice (Mean±SD, n=10)

[0082] The results of the elevated cross maze (EPM) test (Table 4) showed that the morphine withdrawal group had significantly less time spent in the open arm and fewer entries than the blank control group (P<0.05). There were no significant differences between the PSF1-5 groups and the blank control group (P>0.05).

[0083] Table 4: Comparison of Elevated Cross Maze (EPM) results among different groups of mice (Mean±SD, n=10)

[0084] In summary, the active ingredients PSF1-5 involved in this invention do not induce psychological dependence in the conditional position preference test, do not cause anxiety-like behavior after withdrawal, and do not induce physical dependence. These results strongly demonstrate that the PSF1-5 series of compounds do not have addictive potential and possess the good safety profile required for use as a chronic pain treatment drug.

Claims

1. A high-concentration injection containing a di(hetero)aryl carbamate derivative of dihydrocannabidiol, characterized in that, The solution contains a di(hetero)carbamate derivative of dihydrocannabidiol or a pharmaceutically acceptable salt thereof as the active ingredient, a solubilizer, an osmotic pressure regulator, a pH regulator, a buffer, and a solvent; the concentration of the di(hetero)carbamate derivative of dihydrocannabidiol or a pharmaceutically acceptable salt thereof in the injection solution is 2%-8%; The general structural formula of the di(hetero)arylformate derivative of dihydrocannabidiol is shown in Formula I below: Formula I; Where R can be any of the following structures: （1）； （2）； （3）； （4）； （5）。 2. The high-concentration injection solution containing dihydrocannabidiol di(hetero)carbamate derivatives according to claim 1, characterized in that, The osmotic pressure regulator is mannitol and / or sodium chloride; the buffer is histidine; and the solubilizer is polysorbate 80.

3. The high-concentration injection solution containing a di(hetero)arylformate derivative of dihydrocannabidiol according to claim 1, characterized in that, The pH value of the injection solution is 5.5-6.5, and the osmotic pressure is 290-310 mOsmol / kg.

4. The high-concentration injection solution containing dihydrocannabidiol di(hetero)carbamate derivatives according to claim 1, characterized in that, The injection solution is a clear liquid and contains no foreign matter visible to the naked eye.

5. The high-concentration injection solution containing dihydrocannabidiol di(hetero)carbamate derivatives according to claim 1, characterized in that, The dihydrocannabidiol di(hetero)carbamate derivative is dihydrocannabidiol diimidazocarbamate.

6. A method for preparing a high-concentration injection of a di(hetero)arylformate derivative containing dihydrocannabidiol as described in any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Preparation of solubilizing buffer system: Dissolve the osmotic pressure regulator and buffer in part of the solvent, then add the solubilizer, stir until the system is clear and transparent, add pH regulator to adjust the pH, and obtain solubilizing buffer base solution; (2) Dispersion and dissolution of active ingredients: Add the di(hetero)aryl ester derivative of dihydrocannabidiol or its pharmaceutically acceptable salt to the solubilizing buffer base solution and stir until completely dissolved; (3) Add solvent to make up the volume, and let stand to remove bubbles; (4) Sterilization filtration and aseptic packaging.

7. The method for preparing a high-concentration injection of a di(hetero)arylformate derivative containing dihydrocannabidiol according to claim 6, characterized in that, In step (4), a 0.22 μm microporous membrane is used for terminal sterilization filtration.

8. The use of a high-concentration injection of a di(hetero)arylformate derivative comprising dihydrocannabidiol as described in any one of claims 1 to 5 in the preparation of a medicament for treating acute pain.

9. The application according to claim 8, characterized in that, The drug is administered via subcutaneous injection.

10. The application according to claim 8, characterized in that, The drug has a long-lasting analgesic effect, with analgesia lasting from 1 to 7 days or more.

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