Use of di(hetero)arylate derivatives of dihydrocannabidiol in combination with local anesthetics for the preparation of medicaments with analgesic or local anesthetic action and pharmaceutical compositions thereof

Abstract

The application belongs to the technical field of biological medicine, and particularly relates to application of a di(hetero)aromatic carboxylic acid ester derivative of dihydrocannabidiol combined with a local anesthetic in preparation of a medicine with analgesic or local anesthetic effect and a medicine composition thereof. The di(hetero)aromatic carboxylic acid ester derivative of dihydrocannabidiol comprises the derivative or a pharmaceutically acceptable salt thereof; and the combination of one or more local anesthetics; and is prepared into a long-acting sustained-release preparation, such as a sustained-release injection, an in-situ gel, an injectable suspension, a freeze-dried powder injection or a matrix sustained-release tablet. The composition can significantly prolong the time of local anesthetic or analgesic effect, reduce the toxicity of the local anesthetic, and achieve separation of sensory nerve and motor nerve block, and the PSF1 composition is the best. The application provides a new local anesthetic medicine solution with long-acting, high selectivity and low toxicity for clinical use, and can be widely applied to postoperative analgesia, local anesthesia and chronic pain treatment.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to the application of dihydrocannabidiol di(hetero)carbamate derivatives in combination with local anesthetics in the preparation of drugs with analgesic or local anesthetic effects, and the pharmaceutical composition thereof. Background Technology

[0002] Local anesthetics play an irreplaceable role in clinical surgical anesthesia, postoperative pain control, interventional analgesia, and chronic pain management. Commonly used amide-type local anesthetics, such as bupivacaine hydrochloride, ropivacaine, and lidocaine, can rapidly block sensory nerve conduction, achieving comprehensive local anesthesia and analgesia. However, traditional formulations are eliminated from the body quickly, and the duration of action after a single dose is limited, requiring repeated administration or continuous infusion, increasing the complexity of clinical procedures and patient discomfort. Furthermore, rapid absorption of local anesthetics into the bloodstream can easily cause central nervous system and cardiovascular toxicity, manifesting as dizziness, convulsions, arrhythmias, and even cardiac arrest, limiting their safe clinical use. In addition, conventional local anesthetics often block sensory nerves along with varying degrees of motor nerve block, affecting early postoperative mobilization and functional recovery, reducing anesthetic comfort and clinical benefits.

[0003] 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.

[0004] PSF1-5 series compounds possess excellent biocompatibility, in vivo degradability, structural modifiability, and drug loading capacity. These characteristics make them promising candidates as functional carrier materials or active auxiliary ingredients, enabling controlled drug release through various mechanisms, reducing burst release effects, prolonging duration of action, and minimizing systemic exposure and toxic side effects.

[0005] However, there is currently no research on the systematic combination of PSF1-5 with commonly used local anesthetics in clinical practice to develop a combined drug composition that can simultaneously achieve long-acting analgesia, reduce toxicity, and separate sensory and motor nerve blockade.

[0006] Therefore, developing a novel combination drug composition that combines PSF1-5 with local anesthetics, and achieving its long-lasting effect, high selectivity, and low toxicity through innovative formulation technology, is of great theoretical and practical significance for improving the clinical efficacy and safety of local anesthesia and analgesia. Summary of the Invention

[0007] This invention aims to solve the problems of short duration of action, high toxicity, and easy induction of motor nerve block in existing local anesthetics, and provides an application of dihydrocannabidiol di(hetero)carbamate derivatives in combination with local anesthetics in the preparation of drugs with analgesic or local anesthetic effects.

[0008] The present invention also provides pharmaceutical compositions thereof, said compositions being long-acting sustained-release formulations.

[0009] The application of dihydrocannabidiol di(hetero)carbamate derivatives in combination with local anesthetics in the preparation of drugs with analgesic or local anesthetic effects, as described in this invention, includes dihydrocannabidiol di(hetero)carbamate derivatives or pharmaceutically acceptable salts thereof; and the combined use of one or more local anesthetics; 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: Dihydrocannabidiol diimidazocarbamate;

[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 local anesthetics include bupivacaine hydrochloride or its pharmaceutical salt, ropivacaine or its pharmaceutical salt, procaine or its pharmaceutical salt, chloroprocaine or its pharmaceutical salt, bupivacaine or its pharmaceutical salt, lidocaine or its pharmaceutical salt, articaine or its pharmaceutical salt, and tetracaine or its pharmaceutical salt.

[0023] The drug has the effect of prolonging the duration of local anesthesia or analgesia.

[0024] The drug also has the effect of reducing the toxicity of local anesthetics and / or achieving the separation of sensory and motor nerve blockade.

[0025] The dosage forms used in combination include one of the following: sustained-release injection, in situ gel, injectable suspension, lyophilized powder for injection, and matrix sustained-release tablet.

[0026] The pharmaceutical composition for the combined use of dihydrocannabidiol di(hetero)carbamate derivatives and local anesthetics according to the present invention includes dihydrocannabidiol di(hetero)carbamate derivatives or pharmaceutically acceptable salts thereof; and one or more local anesthetics; The dihydrocannabidiol di(hetero)carbamate derivative is any one of PSF1-5.

[0027] The local anesthetics include bupivacaine hydrochloride or its pharmaceutical salt, ropivacaine or its pharmaceutical salt, procaine or its pharmaceutical salt, chloroprocaine or its pharmaceutical salt, bupivacaine or its pharmaceutical salt, lidocaine or its pharmaceutical salt, articaine or its pharmaceutical salt, and tetracaine or its pharmaceutical salt.

[0028] The weight ratio of the dihydrocannabidiol di(hetero)carbamate derivative or its pharmaceutically acceptable salt to the local anesthetic is from 1:1 to 10:1.

[0029] Preferably, the weight ratio of the dihydrocannabidiol di(hetero)carbamate derivative or its pharmaceutically acceptable salt to the local anesthetic is 4:1 to 10:1.

[0030] The dosage forms used in combination include one of the following: sustained-release injection, in situ gel, injectable suspension, lyophilized powder for injection, and matrix sustained-release tablet.

[0031] The combined pharmaceutical composition further includes pharmaceutically acceptable excipients, including one or more of the following: carrier, diluent, excipient, filler, binder, wetting agent, disintegrant, emulsifier, solubilizer, osmotic pressure regulator, surfactant, coating material, colorant, pH adjuster, antioxidant, antibacterial agent, or buffer.

[0032] Combinations can include, for example, combinations of diluents and solubilizers, pH adjusters and antioxidants, antibacterial agents and buffers, etc. Any other combination can be chosen, which will not be elaborated here.

[0033] The present invention also provides a method for preparing the above-described combination pharmaceutical composition. This method involves mixing PSF1-5 compounds with a local anesthetic and one or more pharmaceutically acceptable excipients, and then preparing a long-acting sustained-release formulation using emulsification-solvent evaporation, in-situ gel solidification, solid dispersion, freeze-drying, or tableting processes.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The compositions of the present invention, particularly the combination of PSF1 and bupivacaine, can significantly prolong the duration of local analgesia to more than 12 hours, while pure bupivacaine only lasts for a few hours. This greatly reduces the frequency of administration, improves patient compliance, and reduces medical costs.

[0035] (2) The composition of the present invention significantly improves the acute toxicity index LD by reducing the release rate and systemic absorption of local anesthetics. 50 This reduces local muscle stimulation scores, decreases the risk of systemic toxicity such as central seizures, and improves blood compatibility (reduced hemolysis rate). This makes the therapeutic window of the local anesthetic wider and its use safer.

[0036] (3) Surprisingly, the combination of PSF1-5 and local anesthetics in this invention provides effective sensory blockade while having almost no impact on motor nerve function, and the motor blockade score remains at a normal level. This solves a major clinical pain point of traditional local anesthetics and has important value for early postoperative mobilization and functional rehabilitation.

[0037] (4) The present invention has successfully developed a variety of dosage forms, including sustained-release injections, in-situ gels, injectable suspensions, lyophilized powder injections and matrix sustained-release tablets, covering the mainstream clinical administration routes and providing flexible and diverse options for long-acting local anesthesia and analgesia in different scenarios.

[0038] (5) PSF1-5, as a carrier or active auxiliary ingredient, can not only regulate the release of local anesthetics, but more importantly, its combination with local anesthetics produces a comprehensive synergistic effect that goes beyond simple superposition, and has a significant improvement in efficacy, safety and selective inhibition. Brief Description of the Drawings

[0039] Figure 1 Equal radiation diagrams of PSF1 - PSF5 combined with bupivacaine hydrochloride respectively; Figure 2 Equal radiation diagram of CBD combined with bupivacaine hydrochloride. Detailed Embodiments

[0040] To further elaborate on the technical means and effects adopted by the present invention, the following further illustrates the technical solution of the present invention in combination with the preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0041] During the process of implementing the present invention, conditions, reagents, experimental methods, etc., except for the specifically mentioned content below, are all common knowledge and well-known common sense in the art, and the present invention has no particularly restricted content. For the experimental methods without specific conditions noted in each embodiment, they are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0042] Unless otherwise stated, the meanings of all professional terms and scientific terms used in this specification are the same as those generally understood by those skilled in the technical field to which the present invention belongs. However, in case of conflict, this specification including the definitions shall prevail.

[0043] Experimental Animals: Healthy SPF - grade SD rats with a body weight of 180 - 220 g were selected, provided by the Experimental Animal Center, and the animal license number was: SCXK[Zhe]2023 - 0004. Feeding environment: temperature (23 ± 2)°C, relative humidity 50% - 60%, 12 h / 12 h light - dark cycle, free access to food and water. After 3 days of adaptive feeding, the experiment was carried out.

[0044] Drugs and Reagents: PSF1 - 5 (self - made in the laboratory, purity ≥ 98%, property: yellow oily substance, specification: 10 g / bottle); bupivacaine hydrochloride, ropivacaine, lidocaine; dichloromethane, absolute ethanol, hydroxypropyl methylcellulose, glyceryl trilaurate, cholesterol, mannitol, trehalose, microcrystalline cellulose, lactose, magnesium stearate, etc. were all of analytical purity; phosphate - buffered saline (PBS, pH 7.4) was self - made in the laboratory; the experimental water was injection water.

[0045] The preparation method of the PSF1 - 5 oily substances refers to the embodiments of the following patents: PSF1: CN116983263A, PSF2: CN116983265A, PSF3: CN116983267A, PSF4: CN116983266A, PSF5: CN116983264A.

[0046] Experimental instruments: High-speed shear emulsifier (FLUKO); rotary evaporator (EYELA); constant temperature water bath (Jinghong); vacuum freeze dryer (Christ); single-punch tablet press (Shanghai Tianju); high performance liquid chromatograph (Agilent 1260); intelligent hot plate apparatus (Chengdu Taimeng); electronic balance (Mettler PL2002); membrane filtration device (0.22 μm, Millipore).

[0047] Example 1 Preparation of PSF-bupivacaine sustained-release injection: Accurately weigh 100 mg each of yellow oily PSF1, PSF2, PSF3, PSF4, and PSF5, and add 5 mL of a mixed organic solvent prepared by mixing dichloromethane and anhydrous ethanol at a volume ratio of 7:3. Stir magnetically at room temperature for 30 min until the water-insoluble PSF oil completely dissolves, yielding a lipid-soluble organic oil phase. Separately weigh 15 mg of bupivacaine hydrochloride and add 1 mL of sterile water for injection. Stir at room temperature until completely dissolved, yielding a water-soluble aqueous phase. Add the bupivacaine aqueous solution dropwise to the PSF organic oil phase at a low speed, and emulsify at 10,000 rpm for 5 min to form a homogeneous and stable O / W emulsion. The water-insoluble PSF is dispersed into nano-droplets. Completely remove the organic solvent by rotary evaporation under reduced pressure at 40°C to obtain PSF. Bupivacaine complex sustained-release nanocolloid concentrate (average particle size 120~180 nm, PDI < 0.25). Add sterile pH 7.4 PBS buffer to a final volume of 5 mL, filter through a 0.22 μm aqueous sterile filter membrane for sterilization, and obtain PSF-bupivacaine sustained-release injection (nanocolloid emulsion type). Store in the dark and refrigerated for later use.

[0048] Examples 2-5 are other dosage forms that can be implemented according to the present invention. Although the pharmacodynamic evaluation of the present invention uniformly uses sustained-release injections, the technical solutions of the present invention can also be prepared into other dosage forms to meet different clinical needs.

[0049] Examples 2-5 Preparation of PSF5-ropivacaine sustained-release gel: Accurately weigh 80 mg of yellow, oily, water-insoluble PSF5 and 20 mg of hydroxypropyl methylcellulose. First, add 1 mL of anhydrous ethanol and stir magnetically until the PSF oil is completely dissolved. Then, slowly add 4 mL of sterile water for injection and continue dispersing. Add 12 mg of ropivacaine hydrochloride and stir at room temperature for 20 min until dissolved. Stir at low speed in a 40 ℃ water bath for 30 min to allow the excipients to fully swell and mix. Cool to room temperature, degas under vacuum for 15 min, and remove impurities through a 0.45 μm filter membrane (because the oil droplet size is less than 450 nm, it can pass through the filter membrane completely without clogging) to obtain PSF5. Ropivacaine in situ sustained-release gel rapidly forms a semi-solid gel under the action of interstitial fluid after local injection, achieving long-lasting sustained release.

[0050] Example 3 Preparation of PSF2-lidocaine sustained-release suspension: Weigh 90 mg of PSF2 and dissolve it in 4 mL of dichloromethane. Stir for 15 min until completely dissolved. Add 10 mg of lidocaine, 5 mg of trilaurate, and 2 mg of cholesterol and stir until well mixed. Remove all dichloromethane by vacuum distillation at 40 °C to obtain PSF2. Lidocaine oily solid dispersion; add 30 mg of sterile mannitol and 4 mL of sterile PBS buffer (pH 7.4) to the oily dispersion, and vortex at high speed for 3 min to disperse thoroughly. After sterilization with a 0.22 μm filter membrane, add PBS to 5 mL to obtain a sustained-release suspension (150~220 nm, PDI < 0.28).

[0051] PSF3 Preparation of lidocaine sustained-release suspension and PSF4 The preparation of lidocaine sustained-release suspension is the same as described above for PSF2. Preparation process of lidocaine sustained-release suspension.

[0052] Example 4 Preparation of PSF1-Bupivacaine sustained-release lyophilized powder for injection PSF1 was prepared according to the method in Example 1. Bupivacaine complex colloid; add mannitol 20 mg / mL and trehalose 10 mg / mL as lyophilization protectant, stir thoroughly and mix well; dispense into vials. Pre-freeze at 40℃ for 4 hours, then transfer to a vacuum freeze dryer and vacuum dry for 24 hours; stopper and cap to obtain a slow-release lyophilized powder for injection. Add water for injection and shake to reconstitute before use.

[0053] Example 5 PSF1-5 Preparation of local anesthetic matrix sustained-release tablets: 1. Preparation of PSF1-5 embedding system: Preparation of sodium alginate aqueous phase: Accurately weigh 2.00 g of pharmaceutical grade sodium alginate powder, sprinkle it into 90 mL of deionized water in small amounts several times to prevent clumping, stir magnetically at 300 rpm for 2 h at room temperature until no gel clumps are formed, seal and place in a 4 ℃ environment for low-temperature hydration for 12~16 h overnight, take it out the next day, warm it to room temperature for 30 min, add deionized water to make up to 100 mL, prepare a 2% (w / v) sodium alginate aqueous solution, and use 0.5 M HCl solution to accurately adjust the pH to 4.0±0.05 for later use; Preparation of the drug-loaded organic phase: Separately, 90 mL of anhydrous ethanol and 10 mL of deionized water were mixed to obtain a 90% (v / v) ethanol aqueous solution. 2.00 g of pharmaceutical-grade zein was accurately weighed and added in batches. The mixture was magnetically stirred at 400 rpm at room temperature for 2 h until the protein was completely swollen and dissolved, forming a 2% (w / v) homogeneous and transparent zein organic solution. 2.67 g of PSF1-5 with a purity ≥98% was accurately weighed and added to the above protein ethanol solution. After sealing in the dark, the mixture was continuously magnetically stirred at 400 rpm at room temperature for 1 h until no free oil droplets were visible to the naked eye and the system was a uniform pale yellow dispersion. The pH of the drug-loaded organic phase was adjusted to 4.0±0.05 using 0.5 M HCl solution. Take 100 mL of the drug-loaded organic phase. Measure 300 mL of a 2% sodium alginate aqueous solution (adjusted to pH 4.0) at a 1:3 organic phase to aqueous phase volume ratio and place it in a beaker. Under high-speed shear dispersion conditions of 10,000 rpm, rapidly add the drug-loaded organic phase to the aqueous phase in a thin stream (total addition time controlled within 1-2 min). The system immediately forms a milky white suspension of nascent composite particles. After all the organic phase has been added, reduce the stirring speed to 800-1000 rpm and continue stirring at room temperature for 10-15 min to allow sufficient electrostatic complexation between zein and sodium alginate. Then, transfer the entire suspension to a rotary evaporator flask, setting the water bath temperature to 45 ℃ and the vacuum degree to -0.06 to -0.08. Ethanol was removed by rotary distillation under reduced pressure at MPa. During operation, the vacuum should be slowly increased from low vacuum to prevent protein foaming and boiling. Distillation continued until no liquid was distilled from the condenser and the material had no irritating ethanol odor. After the alcohol removal was completed, the milky white granular suspension was collected. Trehalose, accounting for 5% of the total solids, was added as a freeze-drying protectant and stirred to dissolve and disperse evenly. The mixture was then dispensed into freeze-drying trays for freeze-drying (pre-freezing temperature ≤ -40 ℃, sublimation drying stage controlled below -20 ℃, and desorption drying stage gradually heated to room temperature). Finally, PSF1-5 zein-sodium alginate composite granule dry powder (embedding system) was obtained. The measured drug loading of pure PSF active ingredient in the powder was 38.2%. It was sealed and stored in a dry place away from light.

[0054] 2. Preparation of PSF1 / PSF5-Bupivacaine matrix sustained-release tablets: Take 50 mg of PSF1 or PSF5 fine powder (powder D50 = 80~120 μm, D90 ≤ 200 μm, original PSF dispersed droplet size 120~180 nm, PDI < 0.25; 50 mg in the formula is the equivalent dose of pure PSF active ingredient after conversion, composite particle feed amount = 50 ÷ 38.2% ≈ 130.9 mg, total mass of composite particles = target pure PSF mass ÷ drug loading), 5 mg of bupivacaine hydrochloride, add 20 mg of microcrystalline cellulose, 15 mg of lactose, and 10 mg of hydroxypropyl methylcellulose, and mix evenly; prepare a soft mass with an appropriate amount of 70% ethanol, granulate through a 20-mesh sieve; dry with hot air, granulate, add 1 mg of magnesium stearate and mix evenly; compress into tablets using a single-punch tablet press to prepare PSF1-5 respectively. Local anesthetic matrix sustained-release tablets can be used orally or implanted locally to achieve long-lasting analgesia.

[0055] [Active Pharmaceutical Ingredient Forms, Dosage Conversion, and Quality Control Standards] 1. PSF1-5 are two forms of pharmaceutical raw materials. (1) Lipid-soluble pure active monomer: yellow oily substance with a purity of ≥98%, which can be directly used in injectable sustained-release preparations (sustained-release injections, in-situ gels, injectable suspensions, lyophilized powder injections). The weighing mass is the same as the mass of the pure active substance and no conversion is required. (2) Proteoglycan-encapsulated solid particles: Zeolite-sodium alginate lyophilized powder, only for oral / implantable matrix sustained-release tablets. The measured drug loading of PSF pure active ingredient in the powder is 38.2%. The equivalent dose of pure active ingredient needs to be calculated based on the drug loading.

[0056] 2. Standardized Dosage Conversion Formula Equivalent pure PSF active ingredient mass = encapsulated powder sample mass × measured drug loading percentage (quality control acceptable range 36.0%~40.0%) All weight ratios, in vitro and in vivo efficacy dosages, and toxicity evaluation dosages of the compositions in this invention are calculated based on equivalent pure PSF active monomers.

[0057] 3. Quality control parameters for the complete encapsulation and freeze-drying process Pre-freezing: -40 ℃, 6 h; Sublimation drying: 10 Pa, -20 ℃, 24 h; Desorption drying: 10 Pa, 25 ℃, 12 h; The finished product has a moisture content of ≤3.0%, residual ethanol solvent of ≤5000 ppm, an encapsulation rate of ≥85%, and a drug loading of 36.0%~40.0% (actual drug loading of 38.2%).

[0058] 3. Particle size quality standards 1) Pure PSF emulsified nanocolloids (for injection): average particle size 120~180 nm, PDI < 0.25; 2) Encapsulated lyophilized powder (for tableting): D50 = 80~120 μm, D90 ≤ 200 μm; 3) Oily solid dispersions (for suspensions): D50 = 50~100 μm.

[0059] Experimental methods 1. In vitro drug release experiment The PSFs prepared in Example 1 were examined using dynamic dialysis. In vitro release behavior of bupivacaine sustained-release injection. Using pH 7.4 PBS as the release medium, at a temperature of (37±0.5)℃ and a rotation speed of 50 r / min, each group of formulations with an equivalent dose of bupivacaine was accurately weighed / measured and placed in a dialysis bag, clamped at both ends, and immersed in the release medium. Samples of 5 mL were taken at 0.5, 1, 2, 4, 8, 12, 24, 48, and 72 h, and fresh medium of the same temperature was added simultaneously. The concentration of free bupivacaine in the samples was determined by HPLC, and the cumulative release rate was calculated. For each group, n=3, and the results are expressed as x±s.

[0060] 2. Evaluation of analgesic effect (hot plate test in rats) SPF-grade SD rats were randomly divided into 6 groups, with 6 rats in each group.

[0061] PSF1 group: administered the PSF1-bupivacaine sustained-release injection prepared in Example 1.

[0062] PSF2 group: administered PSF2-bupivacaine sustained-release injection prepared by the method in Example 1.

[0063] PSF3 group: administered PSF3-bupivacaine sustained-release injection prepared by the method in Example 1.

[0064] PSF4 group: administered PSF4-bupivacaine sustained-release injection prepared by the method in Example 1.

[0065] PSF5 group: administered PSF5-bupivacaine sustained-release injection prepared by the method of Example 1.

[0066] Bupivacaine control group: administered commercially available pure bupivacaine injection.

[0067] CBD served as the positive control group: CBD-bupivacaine sustained-release injection was prepared using the same emulsification process as in Example 1.

[0068] The dosage for all groups was 8 mg / kg of bupivacaine, administered via perisciatic nerve injection.

[0069] The pain threshold of rats was measured using a smart hot plate apparatus. The baseline pain threshold before drug administration and the changes in pain threshold at 0.5, 1, 2, 3, 4, 6, 8, and 12 hours after drug administration were recorded, and the analgesic rate was calculated.

[0070] Analgesia rate / % = (Pain threshold after drug administration) (Base pain threshold) / (Base pain threshold) × 100%.

[0071] 3. Evaluation of motor nerve blockade During the evaluation of analgesic effect, the hind limb motor function of rats was observed, referring to the classic motor blockade scoring criteria: 1 point = normal motor function; 2 points = mild motor impairment; 3 points = significant motor impairment; 4 points = complete blockade. The motor blockade scores of rats in each group were recorded at different time points, with n=6 in each group. The results are expressed as x±s.

[0072] 4. Safety Evaluation Acute toxicity: The LD50 of mice in each group was determined using the Bliss method. 50 Observe the animals' behavior, poisoning symptoms and mortality after administration, and calculate the median lethal dose.

[0073] Local muscle stimulation: The drug was injected into the quadriceps femoris muscle of rats. After 24 hours, the rats were sacrificed and their tissues were collected for histological observation and scoring. 0 points were no stimulation and 3 points were severe stimulation.

[0074] Systemic toxicity: Observe the animals' mental state, reflexes, convulsions, respiration, heart rhythm and other indicators after administration, and record abnormal reactions.

[0075] Hemolysis test: The hemolysis of red blood cells was observed using an in vitro test tube method, the hemolysis rate was calculated, and blood compatibility was evaluated.

[0076] 5. Radiation Analysis Experiment 5.1 Experimental Materials and Methods 5.1.1 Laboratory Animals SPF-grade SD rats, weighing 180–220 g, were selected. The housing environment and operating procedures were consistent with those described in the previous analgesia and safety evaluation experiments. Before the experiment, a hot plate test was used to screen rats for a baseline pain threshold of 10–30 s. Rats exhibiting pain escape responses such as licking their hind paws or lifting their paws within 30 s were selected. Individuals with a pain threshold below 10 s or above 30 s were excluded.

[0077] 5.1.2 Test Drugs and Formulations The test substances in the single-drug group were: PSF1, PSF2, PSF3, PSF4, PSF5 (yellow oily substance, purity ≥98%), bupivacaine hydrochloride, and CBD. Combination formulations: PSF1-5 combined with bupivacaine hydrochloride sustained-release injection and CBD-bupivacaine hydrochloride sustained-release injection, respectively; the preparation process, active component mass ratio, and solvent system of all combination formulations are completely consistent with the sustained-release injection of Example 1 of this invention, and the mass ratio of PSF / CBD to bupivacaine hydrochloride is 6.7:1. Blank solvent: sterile pH 7.4 phosphate buffer (PBS). All single-drug and combination components were prepared using this solvent to form a series of gradient concentration working solutions.

[0078] 5.1.3 Detection Model and Calculation Standards Using a rat hot plate analgesia model, analgesic intensity was quantified as the percentage of maximum probable analgesic effect (% MPE). A 50% MPE was set as the median effective dose (ED). The ED of each test substance administered alone and in combination was calculated using the Bliss probability unit method. 50 .

[0079] The Chou-Talalay joint index method is used to calculate the combined interaction index CI. The calculation formula is as follows: CI = D A / ED 50(A) + D B / ED 50(B) In the formula: D A、 D B The actual dosage of PSF (or CBD) and bupivacaine hydrochloride when the combined system achieves a 50% MPE effect; ED 50(A)、 ED 50(B) The half-maximal effective dose when the corresponding substance is administered alone.

[0080] Interaction determination criteria: CI < 0.9: The two drugs have a significant synergistic effect. 0.9≤CI≤1.1: The combined use of the two drugs only results in a simple additive effect; CI>1.1: The two drugs have an antagonistic effect when used in combination, and the analgesic effect is reduced after combination compared with that of the single drug.

[0081] All experimental data were analyzed using SPSS 26.0 statistical software. Quantitative data were expressed as mean ± standard deviation (x̄ ± s). One-way ANOVA was used for overall comparisons among multiple groups, and LSD-t tests were used for pairwise comparisons between groups. Repeated measures data (dynamic indicators at different time points) were analyzed using repeated measures ANOVA. Drug interactions were analyzed using the Chou-Talalay combination index method, with the median effective dose (ED) calculated as [value missing]. 50 LD50 50 The probability was calculated using the Bliss unit method. A p-value < 0.05 was considered statistically significant, and a p-value < 0.01 was considered highly statistically significant.

[0082] Experimental results 1. Results of in vitro drug release experiments The PSF-bupivacaine compositions exhibited varying degrees of sustained-release characteristics under pH 7.4 PBS and 37 ℃ conditions, as shown in Table 1. The PSF1 group showed the most stable release curve with no significant burst release; the release rate was 12.5±0.8% at 0.5 h, 82.3±3.0% at 24 h, and a cumulative release of 90.2±2.1% at 72 h. The PSF5 group had a slightly faster release rate than PSF1, with a cumulative release of 82.5±1.8% at 72 h. The PSF2, PSF3, and PSF4 groups showed relatively rapid initial release, with 17.8%-19.2% at 0.5 h and 57.9%-59.2% at 4 h, followed by a gradual plateau in later stages, with a release of 75.8%-77.1% at 72 h. Overall, the results indicate that PSF1 and PSF5 possess superior long-acting sustained-release regulation capabilities, enabling stable and continuous drug release.

[0083] Table 1. Cumulative in vitro release rate of PSF1-5 (%, x±s)

[0084] 2. Analgesic effect evaluation results The hot plate test in rats showed that PSF The bupivacaine combination showed rapid onset of action, significantly better analgesic effect than the control group, and a significantly prolonged duration of action (see Table 2). At 0.5 h post-administration, the analgesic rate in all groups exceeded 92.5%, comparable to the 94.2±2.7% in the bupivacaine control group, indicating that the combination formulation did not affect the onset speed of the local anesthetic. Over time, the analgesic rate in the control group decreased rapidly, reaching only 0.5±0.1% at 12 h. The analgesic attenuation trend in the CBD-positive control group was similar to that of PSF2-4, with an analgesic rate of 2.4±0.3% at 12 h. The analgesic effect in all four groups was relatively short-lived, with an analgesic rate of only 2.1%-2.5% at 12 hours. In the PSF5 group, the analgesic rate decreased to 10.2±1.2% at 12 hours. The PSF1 group had the longest duration of analgesia, maintaining an analgesic effect of 35.6±2.5% at 12 hours, significantly higher than the other groups. A cross-sectional comparison showed that PSF1 had the best long-acting analgesic effect, followed by PSF5, while PSF2, PSF3, and PSF4 were roughly equivalent to CBD in analgesia.

[0085] Table 2. Analgesia rate of PSF1-5 (%, x±s)

[0086] 3. Results of motor nerve blockade The motor blockade scores are shown in Table 3. In all PSF1-5 groups and the CBD-positive control group, the motor blockade scores at 0.5, 1, 2, 4, and 8 hours were approximately 1.0 ± 0.0, indicating normal motor function without significant blockade. In the bupivacaine control group, the scores at 0.5 hours and 1 hour were 1.8 ± 0.2 and 2.0 ± 0.2, respectively, showing significant motor nerve blockade, which gradually recovered after 4 hours. These results confirm that the PSF carrier and CBD can achieve separation of sensory and motor blockade, preserving effective analgesia without affecting motor function.

[0087] Table 3. Mean scores of motor blockade (x±s)

[0088] 4. Safety evaluation results The core safety indicators are shown in Table 4. Acute toxicity: LD50 in PSF1 group 50 The highest (128.6 mg / kg) was observed in the PSF5 group, followed by the PSF2 group (105.2 mg / kg). The four groups had a LD50 of 85.8–87.2 mg / kg, while the CBD-positive control group had an LD50 of 85.8–87.2 mg / kg. 50 The concentration was 86.8 mg / kg, similar to PSF2-4, and significantly higher than the bupivacaine control group (78.5 mg / kg). Local muscle irritation: The PSF group scores ranged from 0.2±0.1 to 0.5±0.2, while the control group scored 1.2±0.3, indicating significantly lower local irritation in the PSF group. Systemic toxicity: Animals in the PSF group showed no abnormalities in mental state, activity, or reflexes, and no convulsions occurred; the control group experienced mild convulsions and other toxic reactions. Hemolysis rate: The hemolysis rate in the PSF group ranged from 1.2±0.3% to 2.2±0.5%, significantly lower than the control group's 3.5±0.6%, indicating good blood compatibility.

[0089] Table 4 Safety Evaluation Results

[0090] 5. Results of Isoradiometric Analysis Experiment This experiment used 50% MPE as the analgesic effect endpoint and employed the Bliss method to determine the median effective dose (ED) of each individual drug and the combined formulation. 50 Substitute the values ​​into the Chou-Talalay formula to calculate the interaction index (CI) for each combination, and draw an isoradiogram to visually demonstrate the combined effect.

[0091] The efficacy results of monotherapy showed that each PSF derivative had analgesic activity, and the analgesic activity was ranked as follows: PSF1 > PSF5 > PSF2 ≈ PSF3 ≈ PSF4 ≈ CBD; bupivacaine hydrochloride had the best analgesic activity when administered alone.

[0092] After PSF1~PSF5 and CBD were combined with bupivacaine hydrochloride in the fixed ratios of Example 1, the CI values ​​and interaction types of each combined system are as follows: PSF1 + bupivacaine hydrochloride: CI=0.62, indicating significant synergistic effect; PSF2 + bupivacaine hydrochloride: CI=0.84, indicating synergistic effect; PSF3 + bupivacaine hydrochloride: CI=0.85, indicating synergistic effect; PSF4 + bupivacaine hydrochloride: CI=0.83, indicating synergistic effect; PSF5 + bupivacaine hydrochloride: CI=0.75, indicating synergistic effect; CBD + bupivacaine hydrochloride: CI=0.98, which is considered a simple additive effect.

[0093] Figure 1 Radiometric plots of PSF1~PSF5 in combination with bupivacaine hydrochloride: the horizontal axis represents the dose of bupivacaine hydrochloride (mg / kg), and the vertical axis represents the dose of PSF (mg / kg); the colored dashed lines in the figure represent single-drug ED. 50 The theoretical pharmacodynamic additive curves were plotted, with different colored shapes representing the measured effect points of each combination. All measured data points corresponding to PSF1~PSF5 fell within the inner region of their respective theoretical additive curves, close to the origin, directly confirming that the combination of PSF derivatives and bupivacaine hydrochloride has a synergistic analgesic effect at the pharmacological level. This gain is different from the formulation that simply prolongs the analgesic duration by relying solely on physical sustained release. Figure 2 The figure shows the radiometric curves of CBD and bupivacaine hydrochloride in combination. As can be seen from the figure, the measured points of CBD and bupivacaine hydrochloride in combination are consistent with the theoretical summation curves. There is only a simple superposition of drug effects, and no additional synergistic gain.

[0094] This study successfully constructed various sustained-release formulations of PSF1-5 combined with commonly used local anesthetics, including injections, in-situ gels, suspensions, lyophilized powders for injection, and matrix sustained-release tablets, covering mainstream clinical drug delivery routes and providing flexible options for long-acting local anesthesia and analgesia in different scenarios. Experimental results systematically demonstrated the feasibility and advantages of PSF1-5 as a delivery carrier for local anesthetics from four dimensions: in vitro drug release, in vivo efficacy, blocking selectivity, and safety.

[0095] In vitro release results showed that different PSF materials had varying abilities to regulate drug release. PSF1 and PSF5 had more stable structures, forming denser colloidal or gel matrices, which effectively slowed down drug diffusion and dissolution rates, resulting in smoother release curves without significant burst release, thus reducing in vivo toxicity risks and prolonging the duration of action. PSF2 4. With stronger hydrophilicity or a looser structural framework, the drug release is faster in the early stages, making it more suitable for short- to medium-term analgesia. The in vitro release behavior of the CBD control formulation is largely consistent with that of PSF2-4, but its long-acting sustained-release capacity is weaker than that of PSF1 and PSF5. This suggests that flexible control from rapid onset to ultra-long duration of action can be achieved through PSF structure screening and formulation optimization.

[0096] In vivo analgesia studies showed that the PSF1-5 combination did not affect the onset rate of local anesthetics, achieving a high level of analgesia within 0.5 hours, meeting the clinical need for rapid anesthesia. CBD preparations also had a rapid onset, but the rate of attenuation of long-acting analgesia was similar to that of PSF2-4, with a significantly lower analgesic effect at 12 hours compared to PSF1. Compared to pure local anesthetics, the PSF group, especially the PSF1 group, showed a significantly prolonged analgesic duration, retaining effective analgesia for 12 hours, reducing the frequency of administration, improving patient compliance, and lowering medical costs. The mechanism lies in the PSF carrier forming a drug reservoir locally, achieving sustained drug release through a synergistic effect of diffusion and dissolution, maintaining an effective local drug concentration, and avoiding rapid metabolic clearance.

[0097] Motor nerve block is a key indicator affecting the clinical applicability of local anesthetics. In this study, none of the PSF compositions induced significant motor block, while the bupivacaine control group showed significant motor inhibition. This suggests that the PSF1-5 carrier can preferentially act on sensory nerve-related tissues or reduce drug exposure to motor nerves, achieving highly selective sensory block. This is beneficial for early postoperative ambulation and functional recovery, and has important clinical value in orthopedic, obstetric and gynecological, and outpatient surgery settings.

[0098] Safety evaluation results further support the clinical translational potential of the PSF composition. PSF1-5 material exhibits good biocompatibility, is degradable and has no cumulative toxicity, and significantly improves drug release rate and systemic absorption by reducing drug release rate and overall absorption. 50, reduce local irritation, reduce the risk of central convulsions and improve blood compatibility. All safety indicators of CBD are close to those of PSF2-4, and the safety window is significantly lower than that of PSF1 and PSF5. Compared with pure local anesthetics, the PSF composition improves the efficacy while increasing the safety window and reducing the risk of poisoning, making it more suitable for high-dose or long-term analgesic applications.

[0099] Using PSF1-5 as a carrier, sustained-release injections, in-situ gels, suspensions, lyophilized powder injections and matrix sustained-release tablets compatible with bupivacaine, ropivacaine and lidocaine can be successfully prepared. The preparation process is stable and feasible, suitable for large-scale preparation. PSF The local anesthetic composition has a rapid onset and a stable drug release, and can significantly prolong the local analgesia time, among which PSF1 The bupivacaine preparation has the best long-term efficacy, and still has a clear analgesic effect at 12 h. The analgesic duration of the CBD sustained-release preparation is only comparable to that of PSF2-4, and the long-term delivery performance is inferior to that of PSF1 and PSF5. The PSF composition can achieve sensory [[ID=⑧]] Motor block separation, without affecting motor function while producing effective analgesia, significantly improving the anesthetic selectivity and clinical comfort. The PSF composition has lower acute toxicity, less local irritation, no obvious systemic toxicity and good blood compatibility, and its safety is significantly better than that of pure local anesthetics. As a class of safe and efficient local anesthetic sustained-release carriers, PSF1-5 has important research value and broad clinical transformation prospects in the fields of postoperative analgesia, local anesthesia, chronic pain treatment, etc.

[0100] Experimental example: Non-addictive evaluation of the active ingredients PSF1-5 of the present invention To evaluate the drug addiction of the active ingredients PSF1-5 of the present invention, the present invention conducted a conditioned place preference (CPP) experiment to evaluate its psychological dependence, and evaluated its physical dependence after withdrawal through an open field test (OFT) and an elevated plus maze test (EPM).

[0101] 1. Experimental materials and methods 1.1 Experimental animals SPF-grade male Kunming mice, 6-8 weeks old, weighing 25-30 g, were purchased from Beijing Spey Foster Biotechnology Co., Ltd. [Production license number: SCXK (Beijing) 2024-0001]. The animals were housed in an SPF-grade animal room at a temperature of 22-25 °C, with a 12 h light / 12 h dark cycle, and free access to food and water. All animal experiments followed the relevant regulations of the Experimental Animal Ethics Committee.

[0102] [[ID=②4]]1.2 Drugs and reagents PSF1-5 components (purity ≥98%, provided by the Institute of Agricultural Product Processing, Chinese Academy of Agricultural Sciences); morphine hydrochloride injection (commercially available specification, positive control); physiological saline; DMSO (dimethyl sulfoxide, pharmaceutical grade); 75% alcohol.

[0103] Before administration, each of the PSF1, PSF2, PSF3, PSF4 and PSF5 components was dissolved in DMSO to prepare a stock solution. Before use, each solution was diluted with physiological saline to the required concentration (final DMSO concentration ≤ 5%) and administered via intraperitoneal injection.

[0104] 1.3 Main Instruments Conditional location preference box, open field test box, elevated cross maze and VisuTrack animal behavior video analysis software (Shanghai Xinruan Information Technology Co., Ltd.).

[0105] 1.4 Experimental grouping and dosing regimen Mice were randomly divided into the following groups, with 10 mice in each group: First batch: blank control group (physiological saline), solvent control group (5% DMSO), positive control group (morphine 3mg / kg), PSF1 group (10mg / kg), PSF5 group (10mg / kg).

[0106] The second batch consisted of: blank control group (physiological saline), solvent control group (5% DMSO), positive control group (morphine 3 mg / kg), PSF2 group (20 mg / kg), PSF3 group (20 mg / kg), and PSF4 group (20 mg / kg).

[0107] All medications were administered via intraperitoneal injection.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] EPM metrics: number of times the arm is opened and the dwell time in the arm.

[0113] 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.

[0114] 3. Experimental Results 3.1 Results of the CPP experiment (evaluation of psychological dependence) The results are shown in Table 5. 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), 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.

[0115] Table 5: Comparison of CPP scores before and after the test in each group of mice (s, Mean±SD, n=10)

[0116] 3.2 Results of the withdrawal behavior experiment (evaluation of physical dependence) Open field test (OFT) results (Table 6): 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).

[0117] Table 6: Comparison of Open Field Test (OFT) Results among Different Groups of Mice (Mean±SD, n=10)

[0118] The results of the elevated cross maze (EPM) test (Table 7) 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).

[0119] Table 7: Comparison of Elevated Cross Maze (EPM) results among different groups of mice (Mean±SD, n=10)

[0120] 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. The use of a dihydrocannabidiol di(hetero)carbamate derivative in combination with a local anesthetic in the preparation of a medicament having analgesic or local anesthetic effects, including a dihydrocannabidiol di(hetero)carbamate derivative or a pharmaceutically acceptable salt thereof; and the combined use of one or more local anesthetics; 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 application according to claim 1, characterized in that, The local anesthetics include bupivacaine hydrochloride or its pharmaceutical salt, ropivacaine or its pharmaceutical salt, procaine or its pharmaceutical salt, chloroprocaine or its pharmaceutical salt, bupivacaine or its pharmaceutical salt, lidocaine or its pharmaceutical salt, articaine or its pharmaceutical salt, and tetracaine or its pharmaceutical salt.

3. The application according to claim 2, characterized in that, The drug has the effect of prolonging the duration of local anesthesia or analgesia.

4. The application according to claim 3, characterized in that, The drug also has the effect of reducing the toxicity of local anesthetics and / or achieving the separation of sensory and motor nerve blockade.

5. The application according to claim 1, characterized in that, The dosage forms used in combination include one of the following: sustained-release injection, in situ gel, injectable suspension, lyophilized powder for injection, and matrix sustained-release tablet.

6. A pharmaceutical composition for use in combination with a dihydrocannabidiol di(hetero)carbamate derivative and a local anesthetic, characterized in that, Including dihydrocannabidiol di(hetero)carbamate derivatives or pharmaceutically acceptable salts thereof; and one or more local anesthetics; 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）。 7. The pharmaceutical composition for use in combination with a local anesthetic and a dihydrocannabidiol di(hetero)carbamate derivative according to claim 6, characterized in that, The local anesthetics include bupivacaine hydrochloride or its pharmaceutical salt, ropivacaine or its pharmaceutical salt, procaine or its pharmaceutical salt, chloroprocaine or its pharmaceutical salt, bupivacaine or its pharmaceutical salt, lidocaine or its pharmaceutical salt, articaine or its pharmaceutical salt, and tetracaine or its pharmaceutical salt.

8. The pharmaceutical composition for use in combination with a local anesthetic and a dihydrocannabidiol di(hetero)carbamate derivative according to claim 6, characterized in that, The weight ratio of the dihydrocannabidiol di(hetero)carbamate derivative or its pharmaceutically acceptable salt to the local anesthetic is from 1:1 to 10:

1.

9. The pharmaceutical composition for use in combination with a local anesthetic and a dihydrocannabidiol di(hetero)carbamate derivative according to claim 6, characterized in that, The dosage forms used in combination include one of the following: sustained-release injection, in situ gel, injectable suspension, lyophilized powder for injection, and matrix sustained-release tablet.

10. The pharmaceutical composition for use in combination with a local anesthetic and a dihydrocannabidiol di(hetero)carbamate derivative according to claim 6, characterized in that, The combined pharmaceutical composition also includes pharmaceutically acceptable excipients.

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