A compound phospholipid gel sustained-release preparation for postoperative analgesia

Abstract

The present application provides a kind of compound phospholipid gel sustained-release preparation and its preparation method.The preparation mainly contains local anesthetics, non-steroidal anti-inflammatory drugs, phospholipids and water for injection.The preparation can be injected around the surgical incision or directly instilled or coated on the surgical incision site to achieve long-acting analgesic purpose, for postoperative analgesia.

Description

TECHNICAL FIELD

[0001] The application relates to a high-stability compound phospholipid gel sustained-release preparation for postoperative analgesia which can be widely applied to industrial production and a preparation method and application thereof, and belongs to the technical field of medicines. BACKGROUND

[0002] Postoperative pain is generally caused by inflammation or pain behavior caused by nerve damage due to tissue damage during surgery. Postoperative pain often causes patients to have various emotional abnormalities, such as depression, anxiety, restlessness, sleep abnormalities, etc., and severe cases can cause disorders of gastrointestinal function, cardiopulmonary function, coagulation function and endocrine metabolism function. If not properly managed, postoperative pain can lead to impaired physical function and quality of life, increased morbidity, prolonged recovery time, increased risk of complications, in addition to increased hospitalization time, readmission rate and outpatient time, all of which lead to higher healthcare costs. Although with the progress of modern medicine, the research on the physiology and psychology of postoperative pain has made great progress, and the management of postoperative pain has also made great achievements in the past, but how to better control postoperative pain and reduce side effects and complications is still a great challenge.

[0003] Opioid drugs have long played an important role in postoperative pain management, although they have good analgesic effects, but at the same time are accompanied by very obvious side effects, including respiratory depression, cognitive impairment, nausea and vomiting, itching, urinary retention, constipation and other side effects, in addition to causing abuse and addiction risks. Therefore, the role of opioid analgesics in enhanced recovery surgery (ERAS) and multi-modal analgesia (MMA) has gradually developed into an auxiliary drug, and people have regained interest in non-opioid drug substitutes that can well control postoperative pain, including local anesthetics, non-steroidal anti-inflammatory drugs (NSAIDs), alpha-2 adrenergic receptor agonists, magnesium ions, ketamine, etc.

[0004] Local anesthetics are a class of drugs that can reversibly block the generation and conduction of sensory nerve impulses at the drug administration site, and are an important substitute for opioid analgesics. However, the commonly used local anesthetics in clinical practice all have the characteristics of short-acting and cannot achieve long-term analgesia. Among them, levobupivacaine hydrochloride as a long-acting local anesthetic, the analgesic time can only be maintained for about 6 hours. As relatively small molecules, local anesthetics can easily pass through the blood vessel wall and be removed from the injection site. This rapid redistribution from the administration site limits the duration of effective analgesia and the usefulness of this method for pain control. An effective method is to develop a delivery system that can allow local anesthetics to be released for a long time.

[0005] Non-steroidal anti-inflammatory drugs produce analgesic effects by interacting with cyclooxygenase enzymes in various tissues. Non-steroidal anti-inflammatory drugs (NSAIDs) have been well recognized for their analgesic effects on both acute and chronic pain, but are often accompanied by adverse effects secondary to systemic distribution, including upper gastrointestinal bleeding and renal side effects. One way to overcome these therapeutic limitations is to maximize drug levels at the site of action and minimize systemic exposure by directly administering the drug to the site of tissue injury. There are studies that have shown that by placing a non-steroidal anti-inflammatory drug ketoprofen gel directly on the surgical wound, there is better analgesic effect compared to oral administration (R.A. Dionne, D. Haynes, J.S. Brahim, J.S. Rowan, P.H. Guivarc'h, Analgesic effect of sustained-release flurbiprofen administered at the site of tissue injury in the oral surgery model, J Clin Pharmacol 44(12) (2004) 1418-24), but non-steroidal anti-inflammatory drugs have a "ceiling effect", that is, after a certain dose, the therapeutic effect does not increase but the side effects increase, and the use of multiple non-steroidal anti-inflammatory drugs can lead to the superposition of adverse reactions, so non-steroidal anti-inflammatory drugs can be used for postoperative analgesia but can only be used as an auxiliary analgesic and cannot completely replace the role of opioid drugs.

[0006] Sustained release delivery system refers to a drug delivery system in which the drug is slowly released from the preparation in the body at a non-constant rate, thereby prolonging the effect of the drug. Currently marketed long-acting sustained release preparations of bupivacaine include bupivacaine liposomes Exparel prepared by DepoFoam multi-capsule liposome technology, bupivacaine hydrochloride sponge implant Xaracoll prepared by technology, etc. The above sustained release preparations all have complex and cumbersome production processes, the overall production line needs to be customized and scaled up, and the enterprise has high requirements, and the materials are all synthetic polymer materials or organic solvents are used.

[0007] Patent CN 108379269 B discloses a sustained release preparation that can be used for postoperative analgesia, which contains phospholipids, glycerides, poloxamer, ethanol and three different local anesthetics. The invention can be directly injected into the pain site and can slowly release the drug in situ to achieve the purpose of long-acting analgesia. However, the invention contains ethanol, which is irritating to the skin and tissues at the wound site and may have certain side effects. In addition, although the invention uses a combination of three drugs, they are all local anesthetics and cannot enhance the analgesic effect.

[0008] In summary, it is necessary to provide a new preparation with high efficiency, low toxicity, good drug stability, low production cost, simple preparation method, suitable for large-scale industrial production and clinical use, which can make non-opioid analgesics have long-acting sustained-release and good analgesic effect, thereby reducing the need of patients for opioid analgesics and overcoming the side effects caused by the use of opioid analgesics. SUMMARY

[0009] One of the purposes of the present application is to overcome the defects of the prior art and provide a safe and effective analgesic preparation with long-acting sustained-release effect for postoperative analgesia for clinical use.

[0010] Local anesthetics and non-steroidal anti-inflammatory drugs are two types of drugs with different properties and mechanisms of action. Clinical studies have shown that the postoperative analgesic effect of bupivacaine / meloxicam PR preparation is significantly better than that of the two drugs alone (see "Current Status of Clinical Application Research of Meloxicam", Li Xinyu, Chinese Journal of Clinical Pharmacology and Therapeutics, Vol. 28, No. 02, 2023). However, local anesthetics are usually very easy to pass through the blood vessel wall and remove from the injection site, and they have the characteristic of short half-life; and compared with local anesthetics, the injection solution of non-steroidal anti-inflammatory drugs generally has a longer half-life in the body. The significant difference in metabolic behavior of the two drugs makes the synergistic effect of the combination of the two drugs not fully realized.

[0011] The present application creatively provides a phospholipid gel sustained-release preparation, which, on the one hand, simultaneously encapsulates local anesthetics and non-steroidal anti-inflammatory drugs in the preparation, so that the two drugs are slowly released at the same site at the same time, playing a synergistic analgesic effect, and the analgesic time can last up to 120 hours. The analgesic effect of the preparation encapsulating both local anesthetics and non-steroidal anti-inflammatory drugs after being instilled or coated on the postoperative incision site is significantly better than that of the preparation encapsulating only one of the two drugs. On the other hand, it successfully overcomes the above-mentioned defects existing in the application process of the two drugs, and can obtain the technical effect of fully utilizing the two drugs. The above-mentioned preparation can make the pharmacokinetic curves of the two drugs consistent and approximately synchronous within 120 hours after administration.

[0012] One of the purposes of the present application is to provide a phospholipid gel long-acting sustained-release preparation which can be injected or instilled or coated on the administration site, thereby releasing in situ to play a long-acting analgesic effect.

[0013] It is also found in the study that the viscosity of the preparation increases with the increase of the content of phospholipids, thereby prolonging the sustained-release time of the drug. However, a semi-solid dispersion system with too high viscosity is not suitable for use as an injection preparation. If the semi-solid preparation is covered on the surgical incision wound site by using instillation or coating method before postoperative suturing, the problem of injection difficulty caused by too high viscosity of the dispersion system can be avoided. Therefore, preferably, the administration method of the preparation is instillation or coating on the surgical incision wound site.

[0014] One of the objectives of the present application is to provide a compound phospholipid gel sustained-release preparation, which comprises a combination of a local anesthetic, a non-steroidal anti-inflammatory drug, a phospholipid, and an injection water or salt solution.

[0015] It is also found in the research that, compared with other phospholipid gel dispersion systems, the gel sustained-release preparation provided by the present application does not need to use any organic solvent to help dissolve, and is more gentle and friendly to the postoperative fragile and sensitive incision environment, and will not cause irritation to the tissues and skin at the surgical incision.

[0016] It is also found in the research that the use ratio and drug concentration of the local anesthetic and the non-steroidal anti-inflammatory drug do not affect the sustained-release curve of the drug in the body, so the gel sustained-release preparation can be used in combination with different drugs or different proportions of drugs according to different clinical use purposes.

[0017] Further, the gel sustained-release preparation can be added with other pharmaceutically acceptable adjuvants.

[0018] Further, the gel sustained-release preparation comprises 0.25-40 parts of a local anesthetic, 0.0015-20 parts of a non-steroidal anti-inflammatory drug, 20-70 parts of a phospholipid, and 30-80 parts of an injection water or salt solution by weight.

[0019] Further, the gel sustained-release preparation preferably comprises 0.5-20 parts of a local anesthetic, 0.0015-10 parts of a non-steroidal anti-inflammatory drug, 25-65 parts of a phospholipid, and 35-75 parts of an injection water or salt solution by weight.

[0020] Further, the local anesthetic is selected from one or more of lidocaine, tetracaine, procaine, bupivacaine, levobupivacaine, ropivacaine, or a pharmaceutically acceptable salt of the above-mentioned drugs, and is preferably one or more of bupivacaine, levobupivacaine, ropivacaine, or a pharmaceutically acceptable salt of the above-mentioned drugs.

[0021] Further, the weight percentage of the local anesthetic ranges from 0.25% to 40%, and preferably ranges from 1% to 15%.

[0022] Further, the non-steroidal anti-inflammatory drug is selected from acetylsalicylic acid, sodium salicylate, salsalate, benorylate, diflunisal, acetaminophen, phenacetin, ibuprofen, flurbiprofen, ketoprofen, naproxen, indoprofen, fenoprofen, pirprofen, suprofen, butibufen, oxaprozin, tiaprofenic acid, ketorolac, indomethacin, benzydamine, acemetacin, sulindac, zidometacin, tolmetin sodium, diclofenac sodium, etodolac, nabumetone, fenbufen, meloxicam, piroxicam, sudoxicam, isoxicam, tenoxicam, phenylbutazone, oxyphenbutazone, sulfinpyrazone, γ-ketoprofen, flufenamic acid, mefenamic acid, clonixin, celecoxib, rofecoxib, etoricoxib, nimesulide, etc., preferably one or more of meloxicam, piroxicam, sudoxicam, isoxicam, tenoxicam. Preferably, one or more of meloxicam, piroxicam, sudoxicam, isoxicam, tenoxicam, more preferably meloxicam.

[0023] Further, the weight percentage of the non-steroidal anti-inflammatory drug ranges from 0.0015% to 20%, preferably from 0.0015% to 10%, more preferably from 0.01 to 4.5%.

[0024] Further, the weight ratio of the local anesthetic and the non-steroidal anti-inflammatory drug is 1:0.01-60, preferably 1:0.025-1.0, more preferably 1:0.03-0.3.

[0025] Further, the phospholipid includes but is not limited to a combination of one or more of natural phospholipid, semi-synthetic phospholipid, synthetic phospholipid; wherein the natural lecithin includes but is not limited to egg yolk lecithin, soybean phospholipid, etc.; semi-synthetic phospholipid includes but is not limited to hydrogenated soybean phospholipid; synthetic phospholipid includes but is not limited to a combination of one or more of dipalmitoyl phosphatidyl ethanolamine, dipalmitoyl phosphatidyl choline, distearoyl phosphatidyl choline, dimyristoyl phosphatidyl choline, oleoyl phosphatidyl ethanolamine, dipalmitoyl phosphatidyl glycerol, dipalmitoyl phosphatidic acid, etc., preferably the phospholipid is preferably egg yolk lecithin and soybean phospholipid, and the weight percentage of the phospholipid is preferably 20%-70%, more preferably 25%-65%. Further, the other pharmaceutically acceptable excipients include cholesterol, and the weight percentage of the cholesterol is 0%-40%, preferably 4%-30%.

[0026] One of the purposes of the present application is to provide a preparation method of a compound phospholipid gel sustained-release preparation for postoperative analgesia, which is characterized by comprising the following steps:

[0027] (1) dissolving or suspending the drug in or in an appropriate amount of water for injection or salt solution to form a drug solution or drug suspension;

[0028] (2) adding phospholipid to the drug solution or drug suspension;

[0029] (4) stirring for an appropriate time until the preparation is a uniform, milky white cream. Preferably, the stirring is performed under aseptic conditions at room temperature, and the stirring time is 0.5-4h, preferably 1.5-2h.

[0030] The salt solution in step (1) is selected from one or more of normal saline, phosphate buffer, and carbonate buffer.

[0031] One of the purposes of the present application is to provide a use of a phospholipid gel long-acting sustained-release preparation for in-situ sustained release, which can be injected around a surgical incision or directly applied to the surgical incision site to achieve long-acting analgesic purposes for postoperative analgesia.

[0032] Advantages of the present application

[0033] (1) simple preparation method, easier for large-scale production;

[0034] (2) the carrier material is safe, non-toxic, biocompatible, biodegradable, and relatively safer;

[0035] (3) simple prescription composition, no organic solvents, non-toxic and non-irritating;

[0036] (4) can simultaneously encapsulate hydrophilic drugs and lipophilic drugs;

[0037] (5) the drug concentration and the ratio of combined drugs do not affect the in-vivo release curve of the drugs, and can be more widely used for various different drugs or different ratio combinations;

[0038] (6) the formulation of the present application makes the pharmacokinetic curves of two drugs with large differences in release curves consistent in the body, which is beneficial for the synergistic effect of the two drugs;

[0039] (7) both hydrophilic drugs and lipophilic drugs have a relatively stable release rate in the preparation, and there is no obvious burst release, which greatly enhances the safety of the drugs and reduces the possible toxicity of the drugs, especially the toxicity caused by the burst release of local anesthetics;

[0040] (8) the analgesic effect of the combination of the two drugs is obviously stronger than the use of one of the drugs alone, and the combination of the two drugs has a significant synergistic effect in this system. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 : In-vivo sustained release curves of two drugs in a compound phospholipid gel.

[0042] Figure 2 : In-vivo sustained release curves of two drugs in phospholipid gels with different prescription compositions.

[0043] Figure 3 : In-vivo sustained release curves of two drugs in compound phospholipid gels with different drug ratios.

[0044] Figure 4 In vivo release profile of bupivacaine in compound phospholipid gel with different concentrations of bupivacaine.

[0045] Figure 5 In vivo release profile of compound phospholipid gel and commercially available bupivacaine multivesicular liposomes.

[0046] Figure 6 Pharmacodynamic profile (PWT) of compound phospholipid gel (bupivacaine) and normal saline.

[0047] Figure 7 Pharmacodynamic profile (PWT) of phospholipid gels with different formulations.

[0048] Figure 8 Pharmacodynamic profile (PWT) of compound phospholipid gel and commercially available bupivacaine multivesicular liposomes.

[0049] Figure 9 Pharmacodynamic profile (PWT) of compound phospholipid gel and single-drug phospholipid gel.

[0050] Figure 10 Pharmacodynamic profile (PWT) of compound phospholipid gel (ropivacaine) and normal saline. DETAILED DESCRIPTION

[0051] The following examples are further illustrations of the application but are not intended to limit the scope of the application. The application is further described in detail in the following reference examples, but those skilled in the art will appreciate that the application is not limited to these examples and the preparation methods used. Moreover, those skilled in the art can make equivalent substitutions, combinations, modifications or modifications to the application according to the description of the application, but these will be included in the scope of the application.

[0052] Example 1

[0053] Take bupivacaine hydrochloride 350 mg, meloxicam 10.5 mg, add 3325 mg of water for injection, ultrasonic water bath until bupivacaine hydrochloride is completely dissolved, shake to disperse meloxicam; take egg yolk lecithin E80 3325 mg into the water phase, magnetic stirring for 1.5-2 h, until the preparation is a uniform milky white cream semi-solid, which is a compound phospholipid gel sustained-release preparation.

[0054] Example 2

[0055] Take bupivacaine hydrochloride 300 mg, meloxicam 9 mg, add 5335 mg of water for injection, water bath ultrasonic 5 min, bupivacaine hydrochloride is fully dissolved, shake to make meloxicam fully dispersed; take egg yolk lecithin E804 365 mg into the water phase, magnetic stirring 4 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained-release preparation.

[0056] Example 3

[0057] Take egg yolk lecithin E80 6.6 g, cholesterol 3.3 g, add appropriate amount of anhydrous ethanol, heat to dissolve to yellow clear solution, rotary evaporation to completely evaporate ethanol, take the yellowish residue for use.

[0058] Take bupivacaine hydrochloride 300 mg, meloxicam 9 mg, add 4850 mg of water for injection, water bath ultrasonic 5 min, bupivacaine hydrochloride is fully dissolved, shake to make meloxicam fully dispersed; take the above 4.85 g of yellowish solid into the water phase, magnetic stirring 1.5-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained-release preparation.

[0059] Example 4

[0060] Take bupivacaine hydrochloride 300 mg, meloxicam 27 mg, add 5200 mg of water for injection, water bath ultrasonic 5 min, bupivacaine hydrochloride is fully dissolved, shake to make meloxicam fully dispersed; take egg yolk lecithin E804 500 mg into the water phase, magnetic stirring 1.5-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained-release preparation.

[0061] Example 5

[0062] Take bupivacaine hydrochloride 300 mg, meloxicam 90 mg, add 5100 mg of water for injection, water bath ultrasonic 5 min, bupivacaine hydrochloride is fully dissolved, shake to make meloxicam fully dispersed; take egg yolk lecithin E804 500 mg into the water phase, magnetic stirring 1.5-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained-release preparation.

[0063] Example 6

[0064] Take bupivacaine hydrochloride 270 mg, meloxicam 8.1 mg, add 1650 mg of water for injection, water bath heating to bupivacaine hydrochloride completely dissolved, shake to make meloxicam fully dispersed; take egg yolk lecithin E80 1350 mg into the water phase, magnetic stirring 1.5-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained-release preparation.

[0065] Example 7

[0066] Take bupivacaine hydrochloride 360 mg, meloxicam 11 mg, add water for injection 1820 mg, water bath heating ultrasonic to bupivacaine hydrochloride completely dissolved, shaking to make meloxicam fully dispersed; take egg yolk lecithin E80 1820 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0067] Example 8

[0068] Take levobupivacaine hydrochloride 270 mg, meloxicam 8.1 mg, add water for injection 1500 mg, water bath ultrasonic 5 min, make levobupivacaine hydrochloride fully dissolved, shaking to make meloxicam fully dispersed; take egg yolk lecithin E80 1500 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0069] Example 9

[0070] Take ropivacaine hydrochloride 200 mg, meloxicam 4.5 mg, add water for injection 2400 mg, water bath ultrasonic 5 min, make ropivacaine hydrochloride fully dissolved, shaking to make meloxicam fully dispersed; take egg yolk lecithin E80 2400 mg into the water phase, mechanical stirring 1.5 h-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel preparation.

[0071] Example 10

[0072] Take ropivacaine hydrochloride 80 mg, flurbiprofen 48 mg, add water for injection 2130 mg, water bath ultrasonic 5 min, make ropivacaine hydrochloride fully dissolved, shaking to make flurbiprofen fully dispersed; take soybean phospholipid S100 1742 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0073] Example 11

[0074] Take bupivacaine 120 mg, flurbiprofen 36 mg, add water for injection 2114 mg, water bath ultrasonic 5 min, make bupivacaine and flurbiprofen fully dispersed; take soybean phospholipid S100 1730 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel preparation.

[0075] Example 12

[0076] Take tetracaine hydrochloride 200 mg, flurbiprofen 120 mg, add water for injection 2024 mg, water bath ultrasonic 5 min, tetracaine hydrochloride is fully dissolved, shake flurbiprofen fully dispersed; Take hydrogenated soybean phospholipid 1656 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation of uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0077] Example 13

[0078] Take tetracaine hydrochloride 200 mg, flurbiprofen 120 mg, add water for injection 2024 mg, water bath ultrasonic 5 min, tetracaine hydrochloride is fully dissolved, shake flurbiprofen fully dispersed; Take hydrogenated soybean phospholipid 1656 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation of uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0079] Example 14

[0080] Take tetracaine hydrochloride 200 mg, flurbiprofen 120 mg, add water for injection 2024 mg, water bath ultrasonic 5 min, tetracaine hydrochloride is fully dissolved, shake flurbiprofen fully dispersed; Take hydrogenated soybean phospholipid 1656 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation of uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0081] Example 15

[0082] Take tetracaine hydrochloride 200 mg, flurbiprofen 120 mg, add water for injection 2024 mg, water bath ultrasonic 5 min, tetracaine hydrochloride is fully dissolved, shake flurbiprofen fully dispersed; Take hydrogenated soybean phospholipid 1656 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation of uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0083] Example 16

[0084] Take tetracaine hydrochloride 200 mg, flurbiprofen 120 mg, add water for injection 2024 mg, water bath ultrasonic 5 min, tetracaine hydrochloride is fully dissolved, shake flurbiprofen fully dispersed; Take hydrogenated soybean phospholipid 1656 mg into the water phase, magnetic stirring 1.5 h-2 h, until the preparation of uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0085] Example 17

[0086] Take bupivacaine hydrochloride 2000 mg, meloxicam 100 mg, add water for injection 3325 mg, water bath ultrasonic bupivacaine hydrochloride and meloxicam dispersed; Take soybean phospholipid S100 2500 mg into the water phase, magnetic stirring 1.5h-2h, until the preparation is uniform cream white semi-solid, namely compound phospholipid gel sustained release preparation.

[0087] Effect experiment

[0088] Experiment 1 The sustained release effect of two drugs in the compound phospholipid gel in vivo

[0089] The preparation obtained by the method described in Example 1 was compared with the compound injection group in the in vivo pharmacokinetic experiment, wherein the compound injection group was prepared according to the concentration in Table 1 with water for injection as the solvent.

[0090] The specific method is:

[0091] 1.1 In vivo animal experiment

[0092] Take 10 healthy male SD rats and randomly divide them into 2 groups (n=5): compound preparation group and compound injection group. Each group is given at the same time, and the EP tube is moistened with heparin sodium at the preset time points of 0.5h, 1h, 2h, 4h, 8h, 12h, 24h, 36h, 48h, 60, 72h, 84h, 96h, 120h, 144h, 168h. The blood is taken from the orbital venous plexus, and the obtained blood is immediately centrifuged at 6000 rpm and 4°C for 5 min to obtain 100 μL of upper plasma, which is stored at -40°C.

[0093] Table 1:

[0094] Formulation group Injection solution group Bupivacaine concentration (w / v) 5％ 0.75％ Meloxicam concentration (w / v) 0.15％ 0.0225％ Bupivacaine administration dose 13 mg 13 mg Meloxicam administration dose 0.39 mg 0.39 mg

[0095] 1.2 Plasma treatment method

[0096] Add 5 times the volume of protein precipitant (methanol: acetonitrile = 1:5, v / v) to 100 μL of plasma sample, vortex for 5 min, centrifuge at 10000 rpm for 10 min, and filter the supernatant with a 0.22 μm organic filter membrane.

[0097] 1.3 Preparation of standard curve

[0098] 1.3.1 Preparation of bupivacaine standard curve

[0099] Take 20 mg of bupivacaine reference substance, accurately weighed, and 4.0 ml of methanol to make a 5.0 mg / ml solution. Take 1.0 ml of the 5.0 mg / ml bupivacaine solution and dilute it to 1.0 mg / ml with methanol as the bupivacaine stock solution. Dilute the stock solution with methanol to obtain bupivacaine solutions with concentrations of 10 ng / ml, 20 ng / ml, 50 ng / ml, 100 ng / ml, 200 ng / ml, 500 ng / ml, 1000 ng / ml, 2000 ng / ml, 5000 ng / ml, and 10000 ng / ml as the reference solution.

[0100] Take 100 μL of blank plasma and add 10.0 μL of the reference solution to make the plasma sample with bupivacaine concentrations of 1 ng / ml, 2 ng / ml, 5 ng / ml, 10 ng / ml, 20 ng / ml, 50 ng / ml, 100 ng / ml, 200 ng / ml, 500 ng / ml, 1000 ng / ml, and 2000 ng / ml, respectively. Add five times the volume of protein deposition agent (methanol: acetonitrile = 1:5, v / v) and mix well by vortexing for 5 min. Centrifuge at 10000 rpm for 10 min. Filter the supernatant with a 0.22 μm organic filter membrane and inject the sample. Perform linear regression with the plasma concentration as the horizontal coordinate and the peak area as the vertical coordinate to obtain the standard curve equation: y = 32.608x + 2383.4, R = 0.9995, with a linear range of 2 ng / ml-1000 ng / ml. 2

[0101] 1.3.2 Preparation of meloxicam standard curve

[0102] Take 20 mg of meloxicam reference substance, accurately weighed, and 4.0 ml of solvent (40% methanol, 23 mM sodium hydroxide) to make a 5.0 mg / ml solution. Sonicate for five minutes to ensure complete dissolution of the meloxicam. Take 1.0 ml of the 5.0 mg / ml meloxicam solution and dilute it to 1.0 mg / ml with the above-mentioned methanol solution as the meloxicam stock solution. Dilute the stock solution with methanol to obtain meloxicam solutions with concentrations of 20 ng / ml, 50 ng / ml, 100 ng / ml, 200 ng / ml, 500 ng / ml, 1000 ng / ml, 2000 ng / ml, 5000 ng / ml, 10000 ng / ml, 20000 ng / ml, 50000 ng / ml, and 100000 ng / ml as the reference solution.

[0103] ​Take 100 μL of blank plasma, add 10.0 μL of each control solution, so that the concentration of meloxicam in the plasma sample is 2 ng / ml, 5 ng / ml, 10 ng / ml, 20 ng / ml, 50 ng / ml, 100 ng / ml, 200 ng / ml, 500 ng / ml, 1000 ng / ml, 2000 ng / ml, 5000 ng / ml, 10000 ng / ml, add five times the volume of protein precipitant (methanol: acetonitrile = 1:5, v / v), vortex for 5 min, centrifuge at 10000 rpm for 10 min, filter the supernatant with a 0.22 μm organic filter membrane, and inject. Take the plasma concentration to be tested as the abscissa and the peak area as the ordinate to perform linear regression to obtain the calibration curve equation: y = 15.234x + 202.21, R2= 0.9997, the linear range is 2 ng / ml-10000 ng / ml.

[0104] Results:

[0105] Bupivacaine: The determination results are shown in Figure 1 A, Figure 1 B, bupivacaine in the compound injection can only be detected in the blood for 24 h, while the sustained release time of bupivacaine in the compound phospholipid gel can reach more than 120 h, and the comparison solution group has a significantly superior sustained release effect.

[0106] Meloxicam: The determination results are shown in Figure 1 C, meloxicam in the compound injection can maintain a relatively low blood drug concentration for 120 h, the sustained release time of meloxicam in the compound phospholipid gel can reach 144 h, and reaches a concentration peak at 24 h-36 h, and the overall blood drug concentration is much higher than that of the injection.

[0107] Effect of change of prescription composition on in vivo sustained release curve of two drugs in phospholipid gel

[0108] The preparations obtained by the methods described in Example 2 and Example 3 were subjected to in vivo pharmacokinetic experiments at the same dose.

[0109] Specific method:

[0110] Take 10 healthy male SD rats and randomly divide them into 2 groups (n = 5): prescription 1 group and prescription 2 group. Each group is administered at the same time, and the blood is taken from the pre-set time points 0.5 h, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 36 h, 48 h, 60 h, 72 h, 84 h, 96 h, 120 h, 144 h, 168 h by using heparin sodium moistened EP tubes to puncture the orbital plexus, and the obtained blood is immediately centrifuged at 6000 rpm and 4°C for 5 min to obtain 100 μL of upper plasma. Store in a refrigerator at -40°C for standby.

[0111] Table 2:

[0112] First group Second group Bupivacaine concentration (w / v) 3％ 3％ Meloxicam concentration (w / v) 0.09％ 0.09％ [E80: H20 (w / w)] 45 / 55 / (E80 + CHOL):H20 (w / w) / 50 / 50

[0113] The method for detecting the drug concentration in plasma is the same as that described in Experimental Example 1.

[0114] Results:

[0115] Bupivacaine: the determination results are as follows: Figure 2 A, after changing the prescription composition, the sustained release time of bupivacaine does not change significantly, but the plasma concentration before 24h is slightly different, and the plasma concentration of the prescription with added cholesterol is lower in the early stage, and the safety is better.

[0116] Meloxicam: the determination results are as follows: Figure 2 B, after changing the prescription composition, the release curve of the prescription with added cholesterol is slightly better than that of the prescription with only added egg yolk lecithin.

[0117] Experimental Example 3: Effect of the ratio of two drugs in the compound phospholipid gel on the in vivo sustained release curve

[0118] The preparations obtained by the methods described in Experimental Example 2, Experimental Example 4 and Experimental Example 5 were subjected to in vivo pharmacokinetic experiments at the same dose.

[0119] Specific method:

[0120] Fifteen healthy male SD rats were randomly divided into three groups (n=5): Experimental Group 1, Experimental Group 2 and Experimental Group 3. Each group was administered at the same time, and the blood was taken from the orbital plexus at the preset time points of 0.5h, 1h, 2h, 4h, 8h, 12h, 24h, 36h, 48h, 60h, 72h, 84h, 96h, 120h, 144h and 168h using an EP tube lubricated with heparin sodium. The obtained blood was immediately centrifuged at 6000rpm and 4°C for 5min to obtain 100μL of upper plasma. The plasma was stored at -40°C for standby.

[0121] First group Second group Third group Melox:Bup (w / w) 0.03 0.09 0.3

[0122] The method for detecting the drug concentration in plasma is the same as that described in Experimental Example 1.

[0123] Results:

[0124] Bupivacaine: the determination results are as follows: Figure 3 A, the ratio of meloxicam and bupivacaine in the experiment was 0.03, 0.09 and 0.3 respectively, and the comparative experiment showed that the sustained release curve of bupivacaine did not change when the ratio of the two drugs changed.

[0125] Meloxicam: the determination results are as follows: Figure 3 B, the sustained release curve of meloxicam in the preparation with different ratios did not change.

[0126] In summary, the ratio of the two drugs does not affect the release profile of the drug in vivo.

[0127] Experiment 4 Effect of the concentration of bupivacaine in the compound phospholipid gel on its in vivo release profile

[0128] The formulations obtained by the methods described in Example 2 and Example 6 were compared in an in vivo pharmacokinetic experiment at the same dose; the formulations obtained by the methods described in Example 1 and Example 7 were compared in an in vivo pharmacokinetic experiment at the same dose.

[0129] Specific method:

[0130] Twenty healthy male SD rats were randomly divided into four groups (n=5): each group was administered at the same time, and blood was taken from the orbital venous plexus at the predetermined time points of 0.5h, 1h, 2h, 4h, 8h, 12h, 24h, 36h, 48h, 60, 72h, 84h, 96h, 120h, 144h, 168h using an EP tube moistened with heparin sodium, and the obtained blood was immediately centrifuged at 6000 rpm at 4°C for 5 min to obtain 100 μL of upper plasma. The obtained blood was stored at -40°C for standby.

[0131] First group Second group Third group Fourth group Bupivacaine concentration (w / v) 3％ 8.3％ 5％ 9％ Meloxicam concentration (w / v) 0.09％ 0.25％ 0.15％ 0.27％ [E80: H20 (w / w)] 45 / 55 45 / 55 50 / 50 50 / 50

[0132] The method for detecting the concentration of the drug in the plasma is the same as the specific method described in Experimental Example 1.

[0133] Results:

[0134] Bupivacaine: The determination results are as follows: Figure 4 A, 4B; when other factors in the prescription (formulation prescription composition, phospholipid concentration, ratio of the two drugs) are unchanged, the change in the concentration of bupivacaine in the formulation does not affect its in vivo release profile.

[0135] Experiment 5 In vivo release profile of the compound phospholipid gel and commercially available bupivacaine polycystic liposomes

[0136] The formulation obtained by the method described in Example 1 was compared with commercially available bupivacaine polycystic liposome suspension in an in vivo pharmacokinetic experiment at the same dose.

[0137] Specific method:

[0138] Take 10 healthy male SD rats, randomly divided into 2 groups (n=5): experimental group 1, experimental group 2. Each group at the same time, with heparin sodium EP tube in pre-set time point 0.5h, 1h, 2h, 4h, 8h, 12h, 24h, 36h, 48h, 60, 72h, 84h, 96h, 120h, 144h, 168h timing to choose the orbital plexus blood, the blood obtained immediately at 6000rmp, 4℃ centrifugal 5min to obtain 100μL upper plasma. Cold storage at -40℃.

[0139] First group Second group Bupivacaine concentration (w / v) 5％ 1.33％ Meloxicam concentration (w / v) 0.15％ / [E80: H20 (w / w)] 50 / 50 / Bupivacaine administration dose 13 mg 13 mg Meloxicam administration dose 0.39 mg /

[0140] The method for detecting the concentration of drugs in plasma is the same as that described in Experimental Example 1.

[0141] Results:

[0142] Bupivacaine: the determination results are as follows Figure 5 A, 5B. Compared with the commercially available bupivacaine polycystic liposomes, the compound phospholipid gel has better late sustained release effect, lower blood drug concentration at the initial stage of administration, and better safety of the preparation.

[0143] Experimental 6 Compound phospholipid gel pharmacodynamic experiment

[0144] The preparation obtained by the method described in Example 1 was compared with an equal amount of normal saline in a pharmacodynamic comparison experiment.

[0145] Specific method:

[0146] 6.1 Modeling method:

[0147] 250-300g male SD rats, intraperitoneal injection of tribromoethanol anesthesia, sterile alcohol or iodophor wipe the right foot of the rat to disinfect; at the edge of the heel 0.5cm, use 11 surgical blade to make 1cm longitudinal incision on the skin and subfascial, gently separate the flexor digitorum brevis muscle from the surrounding tissue with blunt forceps, and gently lift the flexor digitorum brevis muscle from the heel to the toe with blunt forceps, then make a 1cm longitudinal incision on it; suture the wound.

[0148] 6.2 Administration method:

[0149] Due to the high viscosity of the preparation, a 21-gauge injection needle was selected to directly administer the preparation to the wound, and then sutured.

[0150] Formulation group Saline group Bupivacaine concentration (w / v) 5％ / Meloxicam concentration (w / v) 0.15％ / Bupivacaine administration dose 5.4 mg / Meloxicam administration dose 0.16 mg /

[0151] 6.3 Mechanical withdrawal threshold (PWT) test method

[0152] The rats need to adapt to the new environment for 3-5 days, and the baseline value is measured when they are fully adapted. If the baseline value is stable for three consecutive days, the experiment begins.

[0153] Test: The rats were placed in a transparent cage with a metal mesh floor at the bottom, and there was enough space to touch the rat's foot. The rats were placed in the transparent cage 30 min before the test, and the test began when the rats were calm and no longer randomly walking and lifting their feet. During the evaluation, the electronic pain tester probe was used to stimulate the rat's foot vertically with continuous force, and the rat's foot had a withdrawal reaction within 5 s, which was recorded as a positive reaction. The pain domain value was recorded, and each rat was evaluated three times with a 1 min interval, and the average value was taken. The last average value was recorded as the rat's mechanical withdrawal threshold (PWT). After surgery, the method was used continuously for 6-7 days.

[0154] Results: As shown in Table 1, the group administered with the compound phospholipid gel at the surgical incision site had a significant difference compared with the control group administered with only physiological saline. Figure 6

[0155] Experiment 7 Efficacy of phospholipid gels with different formulations

[0156] The formulations obtained by the methods described in Examples 2 and 3 were compared with physiological saline in the same dose for efficacy comparison experiments.

[0157]

[0158]

[0159] Specific method: The specific method described in Experiment 6

[0160] Results: As shown in Table 1, the group administered with the compound phospholipid gel at the surgical incision site had a significant difference compared with the control group administered with only physiological saline. Figure 7

[0161] Experiment 8 Efficacy comparison of compound phospholipid gel and commercially available bupivacaine multivesicular liposomes

[0162] The formulation obtained by the method described in Example 1 was compared with commercially available bupivacaine multivesicular liposomes in the same dose for efficacy comparison experiments.

[0163] Formulation group Liposome group Saline group Bupivacaine concentration (w / v) 5％ 1.33％ / Meloxicam concentration (w / v) 0.15％ / / Bupivacaine administration dose 6 mg 6 mg / Meloxicam administration dose 0.18 mg / /

[0164] Specific method: The specific method described in Experiment 6 Figure 8 Results: As shown in Table 1, the group administered with the compound phospholipid gel at the surgical incision site had a significant difference compared with the control group administered with only physiological saline.

[0165] ​​Experiment 9: Comparison of the efficacy of compound phospholipid gel and single-drug phospholipid gel

[0166] The efficacy of the compound phospholipid gel preparation obtained by the method described in Example 1 was compared with that of a phospholipid gel containing only bupivacaine or meloxicam at the same dosage.

[0167]

[0168]

[0169] Specific method: Same as the specific method described in Experiment 6.

[0170] Result: As Figure 9 As shown, the group receiving the compound phospholipid gel at the surgical incision site showed a significant difference compared to the control group receiving normal saline in the first five days post-surgery; the group receiving the phospholipid gel containing only bupivacaine or only meloxicam showed a significant difference compared to the control group receiving normal saline in the first two days post-surgery; the group receiving the phospholipid gel containing only bupivacaine or only meloxicam showed a significant difference compared to the compound phospholipid gel group in the first five days post-surgery, and the postoperative analgesic effect of the compound phospholipid gel was significantly better than that of the single medication.

[0171] Experiment 10: Pharmacodynamic Testing of Compound Phospholipid Gel (Ropivacaine)

[0172] The preparation obtained by the method described in Example 9 was compared with an equal amount of physiological saline in a pharmacological efficacy experiment.

[0173] Formulation group Saline group Ropivacaine concentration (w / v) 4％ / Meloxicam concentration (w / v) 0.09％ / Ropivacaine administration dose 7.2 mg / Meloxicam administration dose 0.18 mg 0.18ml

[0174] Specific method: Same as the specific method described in Experiment 6.

[0175] like Figure 10 As shown, the group that received compound phospholipid gel at the surgical incision site showed a significant difference compared to the control group that received only saline solution five days post-surgery.

[0176] In summary, the compound phospholipid gel sustained-release formulation for postoperative analgesia prepared by this invention not only requires less excipients and has a very simple preparation process, but also exhibits good drug stability and good excipient biocompatibility. Furthermore, the formulation prepared by this invention can significantly prolong the analgesic effect of postoperative pain and enhance the analgesic intensity of using a single analgesic. In addition, the sustained-release formulation prepared by this invention greatly increases medication safety. Therefore, the formulation prepared by this invention is expected to be used in large-scale industrial production for clinical use.

Claims

1. A complex phospholipid gel sustained-release preparation for in situ sustained release, characterized by, The preparation comprises 0.5-20 parts by weight of a local anesthetic, 0.0015-10 parts by weight of a non-steroidal anti-inflammatory drug, 25-65 parts by weight of a phospholipid, and 35-75 parts by weight of water for injection or a salt solution; the local anesthetic is selected from one or more of lidocaine, tetracaine, procaine, bupivacaine, levobupivacaine, ropivacaine, or a pharmaceutically acceptable salt thereof, and the non-steroidal anti-inflammatory drug is selected from one or more of meloxicam, piroxicam, sudoxicam, isoxicam, and tenoxicam.

2. The in situ sustained release phospholipid gel sustained release formulation according to claim 1, wherein, The local anesthetic is present in a weight percentage of 0.25%-40%, and the non-steroidal anti-inflammatory drug is present in a weight percentage of 0.0015%-20%.

3. The in situ sustained release phospholipid gel sustained release formulation according to claim 1, wherein, The local anesthetic is selected from levobupivacaine hydrochloride or ropivacaine, and is present in a weight percentage of 1%-15%, and the non-steroidal anti-inflammatory drug is meloxicam, and is present in a weight percentage of 0.0015%-10%.

4. The in situ sustained release phospholipid gel sustained release formulation according to claim 1, wherein, The non-steroidal anti-inflammatory drug is present in a weight percentage of 0.01%-4.5%.

5. The in situ sustained release phospholipid gel sustained release formulation according to claim 1, wherein, The phospholipid is selected from one or both of egg yolk lecithin and soybean lecithin.

6. The in situ sustained release phospholipid gel sustained release formulation according to claim 1, wherein, The phospholipid is egg yolk lecithin or soybean lecithin, and is present in a weight percentage of 20%-70%.

7. The in situ sustained release phospholipid gel sustained release formulation according to claim 1, wherein, The phospholipid is present in a weight percentage of 25%-65%.

8. The in situ sustained release phospholipid gel sustained release formulation according to any one of claims 1 to 7, wherein, The weight ratio of the local anesthetic to the non-steroidal anti-inflammatory drug is 1:0.025-1.

0.

9. The in situ sustained release phospholipid gel sustained release formulation according to any one of claims 1 to 7, wherein, The weight ratio of the local anesthetic to the non-steroidal anti-inflammatory drug is 1:0.03-0.

3.

10. The in situ sustained release phospholipid gel sustained release formulation according to any one of claims 1 to 7, wherein, The preparation does not contain an organic solvent.

11. The in situ sustained release phospholipid gel sustained release formulation according to any one of claims 1 to 7, wherein, The preparation further comprises cholesterol, which is present in a weight percentage of 4%-40%.

12. A process for the preparation of a sustained release formulation of a complex phospholipid gel for sustained release in situ as claimed in any of claims 1 to 10, wherein, The preparation comprises the following steps: (1) dissolving or suspending the drug in an appropriate amount of water for injection or a salt solution to form a drug solution or a drug suspension; (2) adding the phospholipid to the drug solution or the drug suspension; (3) stirring until the preparation is a uniform milky white cream; In step (1), the salt solution is selected from one or more of normal saline, a phosphate buffer, and a carbonate buffer.

13. The process for the preparation of the in situ sustained release complex phospholipid gel sustained release formulation as claimed in claim 12, wherein, In step (3), the stirring is performed under sterile conditions at room temperature, and the stirring time is 0.5-4 hours.

14. The process for the preparation of the in situ sustained release complex phospholipid gel sustained release formulation as claimed in claim 13, wherein, The stirring time is 1.5-2 hours.

15. Use of the in-situ sustained-release compound phospholipid gel sustained-release preparation of any one of claims 1-11 in the preparation of a medicament for postoperative analgesia.

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