Funnel chest correction metal plate with analgesic drug coating and preparation method of funnel chest correction metal plate

Abstract

The invention discloses a funnel chest correction metal plate with an analgesic drug coating and a preparation method of the funnel chest correction metal plate. The funnel chest correction metal plate comprises a funnel chest correction metal plate body and the drug coating, and the drug coating comprises a biodegradable drug carrier and a drug with an analgesic effect; after the funnel chest correction metal plate is implanted into a target position, the medicine in the medicine coating is continuously released for 7-14 days. The medicine and the degradable medicine carrier are prepared on the funnel chest correction metal plate body by utilizing a film technology to form the medicine carrier, so that after the funnel chest correction metal plate body is implanted into a human body, the medicine coating is directly brought into the human body and directly acts on a pain part, and the medicine is continuously released at the pain part for 7-14 days.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pectus carinatum correction, and particularly relates to a pectus carinatum correction metal plate with an analgesic drug coating and a preparation method thereof. BACKGROUND

[0002] The postoperative pain of pectus carinatum Nuss surgery is severe and long-lasting, mainly due to the lifting force of the steel plate on the ribs and the traction of the muscle tissue. At present, postoperative analgesia mainly depends on intravenous patient-controlled analgesia pump, epidural block or oral opioids, which have problems such as systemic side effects (such as nausea, vomiting, respiratory depression), complex operation or imperfect analgesia. Bupivacaine is a long-acting amide local anesthetic, but its conventional preparation only lasts for 4-12 hours, which cannot cover the most critical acute pain period (usually 3-7 days) after surgery.

[0003] Therefore, an ideal solution is urgently needed at present, that is, local administration, which can directly act on the pain site with high concentration of drugs, and minimize systemic exposure. SUMMARY

[0004] In view of this, the present application provides a pectus carinatum correction metal plate with an analgesic drug coating and a preparation method thereof. The drug and the degradable drug carrier are prepared on the pectus carinatum correction metal plate body by film technology to form a drug carrier, so that after the pectus carinatum correction metal plate body is implanted into the human body, the drug coating is directly brought into the body and directly acts on the pain site. The drug is continuously released at the pain site for 7-14 days.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows: The present application provides a pectus carinatum correction metal plate with an analgesic drug coating, which comprises a pectus carinatum correction metal plate body and a drug coating, wherein the drug coating comprises a biodegradable drug carrier and a drug with analgesic effect. After the pectus carinatum correction metal plate is implanted into the target position, the drug in the drug coating is continuously released for 7-14 days.

[0006] In a preferred embodiment, the drug carrier is polylactic acid-glycolic acid copolymer, and the molecular weight of the polylactic acid-glycolic acid copolymer is 10,000-50,000 Da. The molar ratio of lactic acid (LA) to glycolic acid (GA) in the polylactic acid-glycolic acid copolymer is 50:50 or 65:35.

[0007] In a preferred embodiment, the drug is bupivacaine base and / or bupivacaine hydrochloride.

[0008] In a preferred embodiment, the mass ratio of the drug to the drug carrier is 10-30%.

[0009] In a preferred embodiment, the funnel chest correction metal plate body is a medical-grade stainless steel plate and a titanium alloy plate.

[0010] The second aspect of the present application provides a method for preparing a funnel chest correction metal plate with an analgesic drug coating, comprising the following steps: S1: pretreatment: pretreating the funnel chest correction metal plate body; S2: drug coating material preparation: S3: using a coating process to prepare the drug coating material on the pretreated funnel chest correction metal plate body to obtain a drug coating with a predetermined thickness.

[0011] In a preferred embodiment, the pretreatment specifically includes: S101 neutral or alkaline degreasing: using a neutral or alkaline cleaning agent solution to ultrasonically clean at 60-70°C for 15 minutes to remove grease and contaminants; S102: acid etching activation: for titanium alloy, a mixed solution containing hydrofluoric acid and nitric acid is used for 30-60 seconds etching, followed by pure water rinsing; for stainless steel, aqua regia or sulfuric acid-hydrochloric acid mixed solution can be used for 30-60 seconds etching, followed by pure water rinsing; S103: plasma treatment: placing the cleaned funnel chest correction metal plate body into a plasma cleaning machine, and introducing argon or oxygen at a power of 100-500W for 5-10 minutes.

[0012] In a preferred embodiment, the step S2 specifically includes: mixing the drug carrier with the drug, or preparing a drug carrier-drug solution: dissolving the drug carrier in an organic solvent to form a polymer solution; dissolving the drug in an organic solvent to form a drug solution; slowly adding the drug solution to the polymer solution and stirring for 2-4h.

[0013] In a preferred embodiment, the organic solvent is any one or a mixture of several of dichloromethane, ethyl acetate, acetone, and N,N-dimethylformamide.

[0014] In a preferred embodiment, the step S3 uses an ultrasonic spraying process or an electrophoretic deposition process to prepare the drug coating material on the pretreated funnel chest correction metal plate body; After spraying or electrophoretic deposition is completed, drying, curing the drug coating, and sterilization are performed.

[0015] The present application has the following advantages and positive effects compared with the prior art due to the use of the above technical solutions: The present application releases the analgesic drug directly and continuously to the surgical wound area by setting the drug coating on the funnel chest correction metal plate body and using the biodegradable drug carrier. This local administration method maintains a high concentration of the drug at the pain target point, while the drug concentration in the systemic blood circulation is extremely low, thereby maximizing the avoidance of the side effects of systemic use and systemic use of analgesic drugs, and significantly improving the postoperative comfort and safety of the patient. The drug in the drug coating of the present application can be released for 7-14 days, which can complete the acute phase covering the most severe pain after Nuss surgery, provide seamless and stable analgesic guarantee for the patient, avoid the “explosive pain” caused by the fluctuation of the concentration of analgesic drugs, and solve the problem of “incomplete analgesia”.

[0016] The present application sets the drug coating on the funnel chest correction metal plate body. Once the metal plate body is implanted after the operation, the drug can take effect without relying on complex external equipment (such as an analgesic pump) or repeated intervention operations (such as epidural catheter maintenance). This greatly simplifies the analgesic management process of clinical medical care, reduces the investment of related manpower and material resources, and also reduces the potential risks such as infection caused by complex operation. DETAILED DESCRIPTION

[0017] The present application sets the drug coating on the funnel chest correction metal plate body. Once the metal plate body is implanted after the operation, the drug can take effect without relying on complex external equipment (such as an analgesic pump) or repeated intervention operations (such as epidural catheter maintenance). This greatly simplifies the analgesic management process of clinical medical care, reduces the investment of related manpower and material resources, and also reduces the potential risks such as infection caused by complex operation.

[0018] The present application sets the drug coating on the funnel chest correction metal plate body. Once the metal plate body is implanted after the operation, the drug can take effect without relying on complex external equipment (such as an analgesic pump) or repeated intervention operations (such as epidural catheter maintenance). This greatly simplifies the analgesic management process of clinical medical care, reduces the investment of related manpower and material resources, and also reduces the potential risks such as infection caused by complex operation.

[0019] The present application sets the drug coating on the funnel chest correction metal plate body. Once the metal plate body is implanted after the operation, the drug can take effect without relying on complex external equipment (such as an analgesic pump) or repeated intervention operations (such as epidural catheter maintenance). This greatly simplifies the analgesic management process of clinical medical care, reduces the investment of related manpower and material resources, and also reduces the potential risks such as infection caused by complex operation. The drug in the drug coating of the present application can be released for 7-14 days, which can complete the acute phase covering the most severe pain after Nuss surgery, provide seamless and stable analgesic guarantee for the patient, avoid the “explosive pain” caused by the fluctuation of the concentration of analgesic drugs, and solve the problem of “incomplete analgesia”.

[0020] This embodiment utilizes a drug-coated metal plate for pectus excavatum correction. Once implanted, the plate delivers analgesics directly to the painful area. This localized delivery method maintains a high drug concentration at the pain target while minimizing systemic bloodstream drug concentrations. This significantly improves postoperative comfort, safety, and recovery speed, eliminating the need for complex external devices (such as analgesia pumps) or repeated interventional procedures (such as epidural catheter maintenance). This greatly simplifies clinical analgesia management, reduces manpower and resource investment, and lowers the risk of infection associated with complex procedures.

[0021] Once the drug coating is applied, it can be continuously released at the painful site for 7-14 days, effectively covering the most intense acute phase of pain after Nuss surgery, significantly reducing postoperative pain, providing patients with seamless and stable analgesia, avoiding "burst pain" caused by fluctuations in analgesic drug concentration, and solving the problem of "incomplete analgesia".

[0022] In this embodiment, a biodegradable polymer, polylactic acid-glycolic acid copolymer (PLGA), is selected as the drug carrier. The degradation rate is precisely controlled by adjusting its molecular weight and the molar ratio of lactic acid (LA):glycolic acid (GA), thereby achieving continuous drug release from days to months. By combining PLGA with analgesic drugs and applying it to the surface of a metal plate using precision coating technology, a long-term local drug "warehouse" can be established at the implantation site, providing continuous, stable, and safe postoperative analgesia.

[0023] Precise control of the PLGA molecular weight, LA:GA molar ratio, and drug loading in the drug coating is necessary to achieve a stable and constant drug release over 7-14 days, avoiding burst release. Preferably, the molecular weight of the polylactic-co-glycolic acid copolymer is 10,000-50,000 Da; the higher the molecular weight, the slower the PLGA degradation and the longer the drug release period. The LA:GA molar ratio in the polylactic-co-glycolic acid copolymer is 50:50 or 65:35. A 50:50 LA:GA molar ratio results in faster PLGA degradation, suitable for a release period of 1-2 weeks; a 65:35 LA:GA molar ratio results in slightly slower PLGA degradation, suitable for a release period of 2-4 weeks.

[0024] In a preferred embodiment, the drug is bupivacaine base and / or bupivacaine hydrochloride. Bupivacaine is a long-acting amide local anesthetic. The base form of bupivacaine is more hydrophobic, has better compatibility with PLGA, and releases more slowly. The bupivacaine hydrochloride has better water solubility and may release slightly faster initially. It can be selected or mixed according to the desired release profile.

[0025] More preferably, the mass ratio of the drug to the drug carrier is 10-30%.

[0026] Preferably, the metal plate for correcting pectus excavatum is made of medical-grade stainless steel or titanium alloy, and more preferably medical-grade Ti-6Al-4V ELI titanium alloy or 316LVM stainless steel, which have excellent biocompatibility, mechanical strength and corrosion resistance.

[0027] Applying drug-coated metal plates to long-term implanted pectus excavatum faces significant technical challenges. The metal plate will be subjected to bending deformation and friction with the ribs during implantation, so the coating must have extremely strong adhesion to prevent peeling off during intraoperative procedures and in vivo service; bupivacaine is sensitive to heat and ultraviolet light, so the preparation process must be mild to maintain the chemical stability and biological activity of the drug; the coating product must be able to withstand terminal sterilization processes (such as ethylene oxide and radiation) without affecting its performance.

[0028] To address the aforementioned challenges, a second aspect of this embodiment provides a method for preparing a pectus excavatum corrective metal plate with an analgesic drug coating, comprising the following steps: S1: Pretreatment: Pretreatment of the metal plate body for pectus excavatum correction can enhance the adhesion of the drug coating to the base metal plate. S2: Preparation of drug coating materials: S3: The drug coating material is prepared on the pretreated funnel chest correction metal plate body using a coating process to obtain a drug coating of a preset thickness.

[0029] In a preferred embodiment, the preprocessing specifically includes: S101 Neutral or Alkaline Degreasing: Use a neutral or alkaline cleaning solution (such as 5% v / v Contrad 70®) to ultrasonically clean for 15 minutes at 60-70°C to remove grease and contaminants; S102: Acid etching activation: For titanium alloys, use a mixed solution containing hydrofluoric acid and nitric acid (e.g., 2% HF + 10% HNO3 by mass) for 30-60 seconds of etching, followed by a thorough rinse with pure water; for stainless steel, use aqua regia or a sulfuric acid-hydrochloric acid mixture for 30-60 seconds of etching, followed by a thorough rinse with pure water. S103: Plasma treatment: Place the cleaned funnel chest correction metal plate into a plasma cleaner, introduce argon or oxygen, and treat it for 5-10 minutes at a power of 100-500W. Plasma treatment can greatly increase the surface energy, introduce polar functional groups, and make the surface reach a "superhydrophilic" state, which greatly improves the wettability and adhesion of the subsequent coating solution.

[0030] In a preferred embodiment, step S2 specifically includes: The drug carrier is dissolved in an organic solvent to form a polymer solution; The drug is dissolved in an organic solvent to form a drug solution; Slowly add the drug solution to the polymer solution and stir for 2-4 hours.

[0031] The organic solvent needs to be able to dissolve both PLGA and bupivacaine well. Suitable solvents include any one or a mixture of several of dichloromethane, ethyl acetate, acetone, and N,N-dimethylformamide. Dichloromethane (DCM) is the best solvent for dissolving PLGA, but its high volatility requires precise process control. Ethyl acetate (EA) or acetone are alternatives with lower toxicity. A mixture of DCM and DMF (N,N-dimethylformamide) (e.g., 8:2 v / v) is often used. DMF, acting as a "non-solvent," can induce phase separation, helping to form a porous structure and regulating the release rate.

[0032] Accurately weigh PLGA powder and dissolve it in an organic solvent. Stir magnetically (>6 hours) or shake overnight until completely dissolved to form a polymer solution (e.g., 3-5% w / v). In another container, dissolve bupivacaine in an organic solvent. Under vigorous stirring, slowly add the drug solution to the polymer solution and continue stirring for 2-4 hours to form a homogeneous and clear PLGA / bupivacaine solution, with the drug mass relative to PLGA mass being 10%-30%.

[0033] Furthermore, the PLGA / bupivacaine solution needs to be filtered to remove any undissolved particles, such as 0.45 μm PTFE filter membranes, to prevent clogging of instruments in subsequent membrane processes.

[0034] In a preferred embodiment, step S3 uses ultrasonic spraying or electrophoretic deposition to prepare the drug coating material on the pretreated funnel chest correction metal plate body. Ultrasonic spraying is an ideal technology for achieving ultra-thin, uniform, and controllable coatings, and is particularly suitable for instruments with complex shapes.

[0035] Equipment: Ultrasonic spraying system (such as Sono-Tek, Misonix), including ultrasonic nozzles, XYZ three-axis motion platform, solution delivery pump, heated substrate stage, and fume hood. Process parameter optimization: Ultrasonic frequency: typically 20-120 kHz; higher frequencies produce finer atomized droplets (up to 10-20 μm), forming a smoother, denser film; Liquid flow rate: precision injection pump control, range 0.1-1.0 mL / min; low flow rate combined with multiple sprays allows for better thickness control. Atomizing gas: typically nitrogen (N2) or compressed air, pressure 0.1-0.5 psi, mainly used to deliver atomized droplets; excessive pressure can interfere with deposition. Nozzle-to-substrate distance: 2-5 cm; Substrate temperature: 40-60°C. Gentle heating accelerates solvent evaporation, prevents excessive droplet flow or coalesce, thus forming a uniform film and reducing the "coffee ring" effect. Scanning speed and number of passes: The nozzle moves relative to the metal plate at a speed of 100-500 mm / s, and the total coating thickness is controlled by this speed. Each pass adds only submicron thickness, and the target thickness (e.g., 5-20 μm) can be precisely achieved by increasing the number of passes. Process: The pretreated metal plate is fixed on a heated platform. The system runs automatically according to a preset program, with the nozzle performing a raster scan on the metal plate surface to deposit an extremely thin coating. The solvent evaporates instantly upon impact with the hot surface, and PLGA and bupivacaine cure into a film. This process is repeated until the target thickness is achieved. Advantages: Excellent coating uniformity, precise thickness control (CV <5%), high material utilization (>90%), suitable for complex geometries.

[0036] Electrophoretic deposition (EPD) uses an electric field to deposit charged colloidal particles onto a conductive substrate, and is also well-suited for obtaining uniform coatings on complex-shaped surfaces. Equipment: DC power supply, two electrodes (a metal plate as the working electrode and a platinum or stainless steel plate as the counter electrode), and an electrophoresis tank.

[0037] Process parameter optimization: Solution system: To charge PLGA / bupivacaine particles, a small amount of choline derivative (such as eugenolcholine) can be added as an inducing charge generator, or an ethanol-water mixed solvent (such as 4:1) can be used to induce charge generation.

[0038] Voltage: DC voltage, typically 10-100V.

[0039] Deposition time: 30s-10min. The longer the time, the thicker the coating.

[0040] Electrode spacing: 1-2cm.

[0041] Process: A pretreated metal plate is placed parallel to the counter electrode in an electrolytic cell containing a coating dispersion, serving as the working electrode (cathode or anode, depending on the particle charge). After the DC power is switched on, the charged PLGA / bupivacaine particles move directionally under the influence of the electric field and deposit on the surface of the metal plate, forming a dense coating. After removal, the plate is air-dried to allow the coating to cure.

[0042] Electrophoretic deposition provides excellent coverage for complex shapes, and the equipment is simple with a fast deposition rate.

[0043] After spraying or electrophoretic deposition, residual solvents may remain in the coating, requiring curing, such as vacuum drying: the coated metal plate is placed in a vacuum drying oven and dried for 24-48 hours at 25-30°C and -0.1 MPa. These mild conditions thoroughly remove residual solvents, preventing the formation of bubbles or cracks, while maximizing the protection of drug activity.

[0044] To further improve the crystallinity and stability of the coating, annealing can be performed below the glass transition temperature (Tg). For example, PLGA has a Tg of approximately 45°C and can be annealed at 40°C for 2 hours.

[0045] After curing and drying, sterilization and packaging are carried out: ethylene oxide (EtO) is chosen for sterilization. EtO is a low-temperature sterilization method (usually 30-60°C), which is very friendly to heat-sensitive drugs (bupivacaine melting point is about 107°C) and polymers (PLGA Tg ~45°C), maximizing the preservation of their chemical stability and release performance. Gamma irradiation will accelerate PLGA degradation and drug decomposition, while autoclaving is completely impractical.

[0046] Specific sterilization process: 1. Place the coated metal plate into a sterilization bag, then place it in the sterilization chamber and pre-treat it for a period of time under specific temperature and humidity conditions to bring the product to a suitable sterilization level.

[0047] 2. Introduce EtO gas (concentration usually 400-800 mg / L) and maintain exposure at 40-55°C for 1-4 hours; 3. The EtO gas adsorbed in the porous structure of PLGA must be completely removed. This requires a strict and continuously ventilated desorption chamber at 50-60°C for at least 48-72 hours until the EtO residue is below the specified limit (as required by ISO 10993-7).

[0048] Validation: Sterilization validation must be performed, including validation of sterilization effectiveness, detection of EtO residue (gas chromatography), and comparison of coating performance before and after sterilization (such as SEM observation of morphology, HPLC detection of drug content and purity, and in vitro release test).

[0049] The pectus excavatum correction metal plate with an analgesic drug coating provided in this embodiment has the following significant advantages: Long-lasting and stable analgesic effect: Through the controllable degradation of PLGA, bupivacaine is continuously released for 7-14 days, perfectly covering the acute pain period after surgery. Local action, systemic safety: It greatly reduces the dosage and side effects of systemic analgesics, and improves patient safety and comfort; Excellent coating performance: Ultrasonic spraying / electrophoretic deposition technology combined with rigorous surface pretreatment ensures high coating uniformity, high adhesion and good mechanical stability; The process is controllable and scalable: all process parameters (concentration, flow rate, speed, voltage, time) can be quantified and controlled, making it easy to scale up from the laboratory to industrial production; Excellent sterilization compatibility: The validated EtO sterilization process ensures product sterility without affecting core functions; Personalized customization potential: By adjusting parameters such as PLGA model, drug loading, and coating thickness, release curves can be customized for patients with different pain sensitivities.

[0050] The concept of this embodiment is further illustrated below with specific examples: Ultrasonic spraying method Substrate: Ti-6Al-4V ELI steel plate, subjected to alkaline washing, acid etching (2% HF + 10% HNO3, 45s), and plasma treatment (O2, 300W, 5min).

[0051] Drug coating solution: PLGA (50:50, molecular weight 30,000 Da), PLGA solution concentration 4% (w / v); bupivacaine base, drug loading 20% ​​(w / w, relative to PLGA); solvent is DCM / DMF (8:2 v / v).

[0052] Spraying parameters: frequency 48 kHz, liquid flow rate 0.3 mL / min, atomizing gas pressure 0.2 psi, distance 3 cm, substrate temperature 50°C, scanning speed 200 mm / s, 50 sprays.

[0053] Post-treatment: Place the coated metal plate in a vacuum drying oven and dry it for 24 hours at 30°C and -0.1MPa.

[0054] Sterilization: 1. Place the coated metal plate into a sterilization bag, then place it in the sterilization chamber and pre-treat it at 55°C and 60% humidity for a period of time to bring the product to the appropriate sterilization conditions.

[0055] 2. Introduce EtO gas at a concentration of 600 mg / L and maintain the exposure time at 40-55°C for 2 hours; 3. The EtO gas adsorbed in the porous structure of PLGA must be completely removed. This requires a strict and continuously ventilated desorption chamber at 50-60°C for at least 60 hours until the EtO residue is below the specified limit (as required by ISO 10993-7).

[0056] Results: A uniform coating of approximately 12 μm thickness was obtained, with an adhesion grade of 5B, and in vitro release lasted for 10 days without burst release.

[0057] The embodiments of the present invention have been described in detail above with reference to specific examples, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A pectus carinatum correction metal plate having an analgesic drug coating, characterized in that, A funnel chest correction metal plate body and a drug coating, the drug coating comprising a biodegradable drug carrier and a drug having analgesic effect; After the funnel chest correction metal plate is implanted into a target position, the drug in the drug coating is continuously released for 7-14 days.

2. The pectus carinatum correction metal sheet having an analgesic drug coating according to claim 1, characterized in that, The drug carrier is polylactic acid-glycolic acid copolymer, and the molecular weight of the polylactic acid-glycolic acid copolymer is 10,000-50,000 Da, and the molar ratio of lactic acid to glycolic acid in the polylactic acid-glycolic acid copolymer is 50:50 or 65:

35.

3. The pectus carinatum correction metal sheet having an analgesic drug coating according to claim 1, characterized in that, The drug is bupivacaine base and / or bupivacaine hydrochloride.

4. The pectus carinatum correction metal sheet having an analgesic drug coating according to claim 1, characterized in that, The mass ratio of the drug to the drug carrier is 10-30%.

5. The pectus carinatum correction metal sheet having an analgesic drug coating according to claim 1, characterized in that, The funnel chest correction metal plate body is a medical-grade stainless steel plate and a titanium alloy plate.

6. A method of manufacturing a pectus carinatum correction metal plate having an analgesic drug coating according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: S1： Pre-treatment: pre-treating the funnel chest correction metal plate body; S2: preparing a drug coating material; S3: preparing the drug coating material on the pre-treated funnel chest correction metal plate body by using a coating process to obtain a drug coating with a preset thickness.

7. The method for preparing the funnel chest corrective metal plate with an analgesic drug coating according to claim 6, characterized in that, The pre-treatment specifically comprises: S101 neutral or alkaline degreasing: ultrasonic cleaning at 60-70°C for 15 minutes using a neutral or alkaline cleaning agent solution to remove grease and contaminants; S102: acid etching activation: for titanium alloy, a mixed solution containing hydrofluoric acid and nitric acid is used for etching for 30-60 seconds, and then pure water is used for rinsing; for stainless steel, aqua regia or a mixed solution of sulfuric acid and hydrochloric acid can be used for etching for 30-60 seconds, and then pure water is used for rinsing; S103: plasma treatment: placing the cleaned funnel chest correction metal plate body into a plasma cleaning machine, and introducing argon or oxygen, and treating at a power of 100-500 W for 5-10 minutes.

8. The method for preparing the funnel chest corrective metal plate with an analgesic drug coating according to claim 6, characterized in that, The step S2 specifically comprises: mixing the drug carrier with the drug, or preparing a drug carrier-drug solution: dissolving the drug carrier in an organic solvent to form a polymer solution; dissolving the drug in an organic solvent to form a drug solution; slowly adding the drug solution to the polymer solution and stirring for 2-4 hours.

9. The method for preparing the funnel chest corrective metal plate with an analgesic drug coating according to claim 8, characterized in that, The organic solvent is any one or a mixture of several of dichloromethane, ethyl acetate, acetone, and N,N-dimethylformamide.

10. The method for preparing the funnel chest corrective metal plate with an analgesic drug coating according to claim 6, characterized in that, The step S3 uses an ultrasonic spraying process or an electrophoretic deposition process to prepare the drug coating material on the pre-treated funnel chest correction metal plate body; After spraying or electrophoretic deposition is completed, drying, curing the drug coating, and sterilization are further performed.