A propranolol hydrochloride drop, a preparation method and application thereof

Abstract

The application relates to the technical field of chemical medicine preparation, and particularly discloses a propranolol hydrochloride drop, a preparation method and application thereof, and the propranolol hydrochloride drop is characterized in that, based on 10ml, the following components are included: an active component carrier 500-520mg, a suspending agent 30-40mg, a sweetening agent 20-25mg, a pH regulator 0.06-0.10mg, essence 3-6mg, and water to 10ml. The propranolol hydrochloride drop provided by the application is accurate in dose, suitable in taste, good in stability and high in safety.

Description

Technical Field

[0001] This application relates to the field of chemical pharmaceutical formulation technology, and more specifically, it relates to a propranolol hydrochloride drop solution, its preparation method, and its application. Background Technology

[0002] Propranolol hydrochloride, chemically named 1-isopropylamino-3-(1-naphthoxy)-2-propanol hydrochloride, is a white or off-white crystalline powder with the molecular formula C2. 16 H 21 NO2·HCl, with a molecular weight of 295.81, is soluble in water or ethanol and slightly soluble in chloroform. Propranolol hydrochloride is commonly used to prevent and treat various diseases such as arrhythmia, angina pectoris, hypertension, myocardial infarction, coronary heart disease, and hyperthyroidism. With increased clinical application, it has been further discovered that it can also be used to treat sinus tachycardia during anesthesia, migraines, and to prevent esophageal variceal rupture, making its clinical applications extremely wide-ranging.

[0003] Currently, existing formulations of propranolol hydrochloride mainly include tablets and ordinary oral solutions, but they have significant drawbacks when used for infant treatment: the dosage for infants needs to be precisely controlled, while tablets need to be ground before use, which can easily cause dosage errors, and ordinary oral solutions lack targeted dosage gradient design, making it difficult to adapt to the medication needs of infants of different weights; therefore, there is an urgent need to develop an infant-specific formulation that is accurate in dosage, has a suitable taste, good stability, and high safety. Summary of the Invention

[0004] To address the problem of difficult dosage control in existing propranolol hydrochloride preparations, this application provides a propranolol hydrochloride drop solution, its preparation method, and its application.

[0005] Firstly, this application provides a propranolol hydrochloride drop solution, which adopts the following technical solution: A propranolol hydrochloride drop solution, based on 10 mL, comprises the following components: The active ingredient carrier is 500-520 mg, the suspending agent is 30-40 mg, the sweetener is 20-25 mg, the pH adjuster is 0.06-0.10 mg, the flavoring is 3-6 mg, and the water is added to 10 mL.

[0006] By adopting the above technical solution, the active ingredient carrier is compounded with suspending agent, sweetener, pH adjuster, and flavoring in proportion and then diluted with water to 10 mL, achieving synergistic optimization of multiple technical effects. The active ingredient carrier is prepared by loading propranolol hydrochloride onto a carrier, thus exerting the drug's efficacy and providing a sustained-release effect. The weak gel network formed by the suspending agent works synergistically with the active ingredient carrier, allowing the drops to maintain a uniform suspension state without stratification or precipitation over a long period of time. At the same time, the pH adjuster precisely controls the pH of the system to 5.0-7.0, which not only meets the stability requirements of propranolol hydrochloride but also matches the physiological environment of the infant's gastrointestinal tract, eliminating the risk of gastrointestinal irritation. The sweetener and natural flavoring work together to mask the taste, significantly improving long-term medication adherence. The drops are measured in drops, allowing for flexible adjustment of the dosage according to the infant's weight, thereby solving the problem of difficult dosage control in infants.

[0007] Optionally, the method for preparing the active component carrier includes the following steps: (1) Disperse the carrier material in water, heat it to 65-75℃, stir it at a constant temperature, and obtain a carrier material dispersion; (2) Dissolve povidone in water, add propranolol hydrochloride, stir to form a povidone-drug solution, add the carrier material dispersion obtained in step (1) to the povidone-drug solution, stir at constant temperature and spray dry to obtain the active component carrier. The mass ratio of the carrier material, povidone and propranolol hydrochloride is 10-20:4-6:2-4.

[0008] By adopting the above technical solution, povidone is non-irritating, has excellent biocompatibility, and is metabolically unburdensome. The amide bonds and methylene groups on the povidone molecular chain can form a hydrogen-bonded hydrophobic synergistic complex with propranolol hydrochloride, which can significantly improve the solubility of propranolol hydrochloride and solve the problem of poor water solubility and easy precipitation of lipid-soluble drugs. The carrier material is a carrier with excellent biodegradability and inclusiveness, and has the advantages of low price, non-toxicity, and strong adsorption. The carrier material has abundant pores from the surface to the particle center, giving it high pore volume and specific surface area, thus possessing the advantage of high loading capacity. First, povidone forms hydrogen bonds with propranolol hydrochloride, anchoring the drug molecules to the povidone molecular chain. Then, the carrier material dispersion is added dropwise. The core is to use the porous structure of the carrier material to achieve physical adsorption, increase the loading capacity, and thus achieve the slow release of propranolol hydrochloride, improving drug utilization.

[0009] Optionally, the carrier material is one or more of dextrin, polyvinyl alcohol, potato starch, and wheat starch.

[0010] Optionally, the method for preparing the suspending agent includes the following steps: Hydroxyethyl cellulose was dissolved in an aqueous ethanol solution, the pH of the system was adjusted to between 8 and 10, acetic anhydride was added dropwise, and after the reaction was complete, the mixture was washed, dried, and pulverized to obtain a suspending agent. The mass ratio of acetic anhydride to hydroxyethyl cellulose was 0.1-0.2:1.

[0011] By adopting the above technical solution, hydroxyethyl cellulose (HEC) is a white or pale yellow, odorless, and non-toxic nonionic cellulose ether prepared by reacting alkali cellulose and ethylene oxide. It possesses certain thickening, adhesive, emulsifying, and film-forming properties. However, HEC has a high molecular weight and lacks hydrophobic groups that match the hydrophilic groups in its macromolecular chain, resulting in strong swelling in aqueous solutions and very low solubility in water, making it difficult to improve some of its properties. Therefore, HEC is modified using the preparation method of octenyl succinate starch ester, undergoing an esterification reaction. During the reaction, the acid anhydride ring... The ester bond is opened at one end, and combines with the hydroxyl group on the hydroxyethyl cellulose molecule at the other end, while a carboxylic acid is produced. No toxic solvents are added during the entire modification process, achieving green modification and enabling the finished product to be used in the pharmaceutical field. After esterification with acetic anhydride, the emulsification stability and thickening properties of hydroxyethyl cellulose are significantly improved, thereby avoiding the aggregation and clumping of the active ingredients in propranolol hydrochloride drops, ensuring that the drops maintain a uniform suspension state during storage and transportation, maintaining the stability of particle size, avoiding accelerated sedimentation caused by increased particle size, and ensuring the consistency of the physical state of the formulation from production to the end of use.

[0012] Optionally, the sweetener is one or more of sucrose, fructose, simple syrup, sucralose, mannitol, and sodium saccharin; the flavoring is one or more of strawberry flavoring, orange flavoring, lemon flavoring, apple flavoring, and grape flavoring.

[0013] By adopting the above technical solution and adding sweeteners to the drops, the core is to solve the technical pain points of poor user compliance and experience caused by the bitterness, spiciness and odor of the active ingredients, improve the smoothness of the taste and reduce irritation; the fragrance can accurately mask unpleasant odors, reduce resistance, improve the comfort of the smell, avoid odor residue, and significantly improve the olfactory comfort of the product.

[0014] Optionally, the pH adjuster is one or more of citric acid, malic acid, and tartaric acid.

[0015] By adopting the above technical solutions, the pH value of the system can be precisely controlled to ensure that the active ingredients always maintain their functional conformation, avoid the failure of activity caused by conformational changes, and ensure the consistency of the product's activity from production to the end of use.

[0016] Secondly, this application provides a method for preparing propranolol hydrochloride drops, which adopts the following technical solution: A method for preparing propranolol hydrochloride drops includes the following steps: Add the suspending agent to the water while stirring. After dissolving, add the sweetener, flavoring, and active ingredient carrier, stir to dissolve, adjust the pH to between 3.0 and 3.5 with a pH adjuster, add water to 10 mL, filter, and fill.

[0017] By adopting the above technical solution, using conventional processes such as stirring and dissolving, step-by-step feeding, pH calibration and volume adjustment, no new special production equipment is required. The suspending agent, sweetener, flavoring and pH adjuster are all commonly used excipients in the pharmaceutical field. There are no compatibility issues between them and propranolol hydrochloride and other excipients. They can be directly integrated into existing pharmaceutical drop production lines. The production process is highly stable and suitable for large-scale mass production.

[0018] Optionally, the filter membrane material is one or more of polypropylene, polyethersulfone, and polytetrafluoroethylene, and the pore size of the filter membrane is 0.22-40 μm.

[0019] By adopting the above technical solution, the filter membrane is made of one or more of the following materials: polypropylene, polyethersulfone, and polytetrafluoroethylene. With a pore size design of 0.22-40μm, it can achieve multi-dimensional and precise removal of impurities and the influence of microorganisms, avoiding the irritation or compatibility problems that may be caused by adding preservatives.

[0020] Thirdly, this application provides the use of the propranolol hydrochloride drops described in the first aspect or the propranolol hydrochloride drops prepared by the preparation method described in the second aspect in the preparation of a medicament for treating proliferative infantile hemangiomas.

[0021] Optionally, the drops are equipped with an oral applicator with a precision of 0.1 ml and a single drop content of 0.56 mg / drop.

[0022] By adopting the above technical solutions, the dosage of each administration can be precisely controlled, achieving precise, convenient, and safe administration of drops.

[0023] In summary, this application has the following beneficial effects: 1. In this application, a drop for the treatment of proliferative infantile hemangiomas is prepared using the active ingredient propranolol hydrochloride and excipients such as suspending agents, sweeteners, pH adjusters, and flavorings. This dosage form uses drops as the basic unit of measurement, and micro-dosage and stepwise administration can be achieved by adjusting the number of drops. This solves the problems of tablets being unable to be split for dosage or oral liquids having large dosage errors when poured, thus improving the convenience of use.

[0024] 2. In this application, the dual synergistic effect of pore adsorption of the carrier material and hydrogen bonding-hydrophobic encapsulation of povidone is utilized to significantly enhance the solubility and high loading rate of propranolol hydrochloride, realize the slow release of propranolol hydrochloride, and thus improve the utilization rate of propranolol hydrochloride.

[0025] 3. In this application, acetic anhydride is used to modify hydroxyethyl cellulose. The grafted acetic anhydride contains hydrophobic and hydrophilic groups. After modification, the emulsifying properties and apparent viscosity of hydroxyethyl cellulose are significantly improved, thereby improving the stability of propranolol hydrochloride drops. Detailed Implementation

[0026] The following embodiments provide a further detailed description of this application. Preparation example of active component carrier

[0027] Source of raw materials: Povidone is selected from BASF (China) Co., Ltd., model K30.

[0028] Preparation Example 1-1: (1) 20g of carrier material was dispersed in 100g of purified water, stirred at 500rpm for 40min, heated to 75℃, and stirred for 30min to obtain a carrier material dispersion. The carrier material was selected from Shandong Jiake Biotechnology Co., Ltd., with a specification of 99%. (2) Add 6g of povidone to 50g of purified water, stir and dissolve at 50℃ for 30min, add 4g of propranolol hydrochloride, continue stirring for 60min to form a povidone-drug solution, drop the carrier material dispersion obtained in step (1) into the povidone-drug solution, stir at 50℃ for 90min, pass through a 120-mesh sieve, and spray dry to obtain the active component carrier; wherein the spray drying process parameters are: inlet air temperature: 135℃, outlet air temperature: 65℃, feed rate: 8mL / min, atomization pressure: 0.25MPa, fan speed: 40000rpm.

[0029] Preparation Example 1-2: (1) 15g of carrier material was dispersed in 100g of purified water, stirred at 400rpm for 30min, heated to 70℃, and stirred for 25min to obtain a carrier material dispersion. The carrier material was polyvinyl alcohol selected from Merck Chemical Technology (Shanghai) Co., Ltd., with a content of 99%. (2) Add 5g of povidone to 50g of purified water, stir and dissolve at 45℃ for 30min, add 3g of propranolol hydrochloride, continue stirring for 50min to form a povidone-drug solution, drop the carrier material dispersion obtained in step (1) into the povidone-drug solution, stir at 45℃ for 70min, pass through a 120-mesh sieve, and spray dry to obtain the active component carrier; wherein the spray drying process parameters are: inlet air temperature: 135℃, outlet air temperature: 65℃, feed rate: 8mL / min, atomization pressure: 0.25MPa, fan speed: 40000rpm.

[0030] Preparation Examples 1-3: (1) 10g of carrier material was dispersed in 100g of purified water, stirred at 300rpm for 20min, heated to 65℃, and stirred for 20min to obtain a carrier material dispersion. The carrier material was wheat starch, selected from Anhui Shanhe Pharmaceutical Excipients Co., Ltd., with product number 01. (2) Add 4g of povidone to 50g of purified water, stir and dissolve at 40℃ for 30min, add 2g of propranolol hydrochloride, continue stirring for 30min to form a povidone-drug solution, drop the carrier material dispersion obtained in step (1) into the povidone-drug solution, stir at 40℃ for 60min, pass through a 120-mesh sieve, and spray dry to obtain the active component carrier; wherein the spray drying process parameters are: inlet air temperature: 135℃, outlet air temperature: 65℃, feed rate: 8mL / min, atomization pressure: 0.25MPa, fan speed: 40000rpm.

[0031] Preparation Example 1-4: The difference from Preparation Example 1-1 is that povidone was not added. 20g of carrier material and 4g of propranolol hydrochloride were dispersed in 100g of purified water, stirred at 500rpm for 40min, heated to 75℃, and stirred for 30min to obtain a carrier material dispersion. The dispersion was passed through a 120-mesh sieve and spray-dried to obtain the active component carrier. The spray drying process parameters were: inlet air temperature: 135℃, outlet air temperature: 65℃, feed rate: 8mL / min, atomization pressure: 0.25MPa, and fan speed: 40000rpm.

[0032] Preparation Example 1-5: The difference from Preparation Example 1-1 is that no carrier material was added. 6g of povidone was added to 50g of purified water and stirred at 50℃ for 30min. 4g of propranolol hydrochloride was added and stirred for another 60min to form a povidone-drug solution. The solution was passed through a 120-mesh sieve and spray-dried to obtain the active component carrier. The spray drying process parameters were: inlet air temperature: 135℃, outlet air temperature: 65℃, feed rate: 8mL / min, atomization pressure: 0.25MPa, and fan speed: 40000rpm. Preparation example of suspending agent

[0033] Source of raw materials: Hydroxyethyl cellulose, type 250HHX PH.

[0034] Preparation Example 2-1: Dilute 0.2g of acetic anhydride 10 times with anhydrous ethanol for later use. Weigh 1g of hydroxyethyl cellulose and dissolve it in 10g of 90% ethanol aqueous solution. Adjust the pH of the system to 10 with 5% sodium hydroxide solution. Slowly add the diluted acetic anhydride. Maintain the pH of the system at 10 with 3.0% sodium hydroxide solution. After the reaction is complete, add hydrochloric acid to terminate the reaction. Wash three times with anhydrous ethanol, dry at 60℃ for 8h, and pulverize to obtain the suspending agent.

[0035] Preparation Example 2-2: 0.15g of acetic anhydride was diluted 10 times with anhydrous ethanol for later use. 1g of hydroxyethyl cellulose was weighed and dissolved in 10g of 90% ethanol aqueous solution. The pH of the system was adjusted to 9 with 5% sodium hydroxide solution. The diluted acetic anhydride was slowly added dropwise. The pH of the system was maintained at 9 with 3.0% sodium hydroxide solution. After the reaction was completed, hydrochloric acid was added to terminate the reaction. The mixture was washed three times with anhydrous ethanol, dried at 60℃ for 8 hours, and pulverized to obtain the suspending agent.

[0036] Preparation Example 2-3: 0.1g of acetic anhydride was diluted 10 times with anhydrous ethanol for later use. 1g of hydroxyethyl cellulose was weighed and dissolved in 10g of 90% ethanol aqueous solution. The pH of the system was adjusted to 8 with 5% sodium hydroxide solution. The diluted acetic anhydride was slowly added dropwise. The pH of the system was maintained at 8 with 3.0% sodium hydroxide solution. After the reaction was completed, hydrochloric acid was added to terminate the reaction. The mixture was washed three times with anhydrous ethanol, dried at 60℃ for 8 hours, and pulverized to obtain the suspending agent. Example

[0037] Example 1: A propranolol hydrochloride drop, based on 10 mL, with the raw material composition shown in Table 1. The active component carrier in Table 1 was prepared by Preparation Example 1-1; the suspending agent was prepared by Preparation Example 2-1; the sweetener was sodium saccharin, selected from Hunan Huana Pharmaceutical Chiral Pharmaceutical Co., Ltd.; the pH adjuster was citric acid, selected from Hunan Ercon Pharmaceutical Co., Ltd.; and the water was purified water.

[0038] The preparation method of this propranolol hydrochloride drops includes the following steps: Add purified water to a 10mL beaker, keeping the water temperature below 40℃. Add 40mg of suspending agent while stirring, and stir to dissolve for 45min. Then add 25mg of sweetener, 6mg of flavoring, and 520mg of active ingredient carrier in sequence, and stir to dissolve for 20min. Take a sample to test the pH, and use a pH adjuster to control the pH of the system to 3.3. Add purified water to 10mL, filter through a 40μm polypropylene filter membrane, and fill into an oral liquid pharmaceutical polyester bottle. Seal the bottle with an oral liquid pharmaceutical polyester cap. It is equipped with a 1ml oral administration device with an accuracy of 0.1ml and a single drop content of 0.56mg / drop.

[0039] Table 1. Raw material ratios of propranolol hydrochloride drops in Examples 1-4 Raw materials (mg) Example 1 Example 2 Example 3 Example 4 Active component carrier 520 510 505 500 Suspending agent 40 35 32 30 sweeteners 25 23 22 20 pH adjuster 0.1 0.08 0.07 0.06 essence 6 5 4 3 water Add to 10mL Add to 10mL Add to 10mL Add to 10mL Example 2: A propranolol hydrochloride drop, which differs from Example 1 in that the active component carrier is prepared by Preparation Example 1-2, the suspending agent is prepared by Preparation Example 2-2, and the raw material amounts are shown in Table 1.

[0040] Example 3: A propranolol hydrochloride drop, which differs from Example 1 in that the active component carrier is prepared by Preparation Examples 1-3, the suspending agent is prepared by Preparation Examples 2-3, and the raw material amounts are shown in Table 1.

[0041] Example 4: A propranolol hydrochloride drops, which differs from Example 1 in the amount of raw materials used, as shown in Table 1.

[0042] Example 5: A propranolol hydrochloride drop, which differs from Example 1 in that the active ingredient carrier is prepared from Preparation Examples 1-4.

[0043] Example 6: A propranolol hydrochloride drop, which differs from Example 1 in that the active ingredient carrier is prepared from Preparation Examples 1-5.

[0044] Example 7: A propranolol hydrochloride drop, which differs from Example 1 in that the suspending agent is hydroxyethyl cellulose, which has not been modified with acetic anhydride. Comparative Example

[0045] Comparative Example 1: A propranolol hydrochloride drop, which differs from Example 1 in that the active ingredient is not loaded with a carrier.

[0046] Comparative Example 2: A propranolol hydrochloride drop solution, which differs from Example 1 in that no suspending agent is added. Performance testing

[0047] Propranolol hydrochloride drops were prepared according to the methods in the examples and comparative examples, and their performance was tested according to the following methods. The test data are recorded in Tables 2, 3, and 4.

[0048] Referring to the "Guiding Principles for Stability Testing of Raw Materials and Preparations" in the 2020 edition of the Chinese Pharmacopoeia, the propranolol hydrochloride drops prepared in the examples and preparation examples were placed under high temperature (40℃) and light (4500±500lx) for 30 days. The stability was investigated using pH value, density, sedimentation volume ratio, viscosity, and content as indicators, as shown in Tables 2, 3, and 4.

[0049] Table 2. Stability test data of propranolol hydrochloride drops prepared in the examples and comparative examples at 0 days. detection indicators pH value Density (g / mL) Settlement volume ratio Viscosity (S62, 30 rpm) cP Content (mg / mL) Example 1 3.43 1.007 1.00 490 20.0 Example 2 3.42 1.009 1.00 488 20.2 Example 3 3.36 1.007 1.00 475 20.1 Example 4 3.33 1.006 1.00 477 20.3 Example 5 3.53 1.008 0.98 493 20.5 Example 6 3.51 1.005 0.97 482 19.2 Example 7 3.56 1.006 0.90 433 19.7 Comparative Example 1 3.48 1.004 0.96 440 19.3 Comparative Example 2 3.42 1.003 0.88 403 19.6 Table 3. Stability test data of propranolol hydrochloride drops prepared in the examples and comparative examples at 40°C for 30 days. detection indicators pH value Density (g / mL) Settlement volume ratio Viscosity (S62, 30 rpm) cP Content (mg / mL) Example 1 3.42 1.007 1.00 486 20.4 Example 2 3.47 1.008 1.00 486 20.3 Example 3 3.35 1.006 1.00 476 20.4 Example 4 3.32 1.005 1.00 475 20.1 Example 5 3.52 1.008 0.98 495 20.3 Example 6 3.53 1.005 0.96 483 19.3 Example 7 3.55 1.006 0.91 430 19.6 Comparative Example 1 3.45 1.004 0.96 444 19.5 Comparative Example 2 3.44 1.003 0.87 410 19.2 Table 4. Stability test data of propranolol hydrochloride drops prepared in the examples and comparative examples after 30 days of light exposure. detection indicators pH value Density (g / mL) Settlement volume ratio Viscosity (S62, 30 rpm) cP Content (mg / mL) Example 1 3.45 1.008 1.00 492 20.2 Example 2 3.44 1.006 1.00 483 20.4 Example 3 3.38 1.005 1.00 478 20.5 Example 4 3.38 1.007 1.00 474 20.3 Example 5 3.57 1.008 0.97 497 20.2 Example 6 3.55 1.005 0.96 485 19.4 Example 7 3.58 1.006 0.92 425 19.4 Comparative Example 1 3.43 1.004 0.95 442 19.3 Comparative Example 2 3.47 1.003 0.86 412 19.0 As can be seen from Examples 1-4 and Tables 2, 3, and 4, the propranolol hydrochloride drops prepared in this application have excellent stability.

[0050] Combining Examples 1 and 7, and referring to Tables 2, 3, and 4, it can be seen that compared to Example 1, the sedimentation volume ratio and viscosity of the propranolol hydrochloride drops prepared in Example 7 are lower. This indicates that by modifying hydroxyethyl cellulose with acetic anhydride and carrying out an esterification reaction, the thickening properties and apparent viscosity of hydroxyethyl cellulose are significantly improved after modification, thereby improving the stability of the propranolol hydrochloride drops.

[0051] Combining Example 1 and Comparative Example 2, and referring to Tables 2, 3, and 4, it can be seen that compared to Example 1, the sedimentation volume ratio and viscosity of the propranolol hydrochloride drops prepared in Comparative Example 2 are lower. This indicates that the addition of a suspending agent can prevent the aggregation and clumping of the active ingredients in the propranolol hydrochloride drops, ensure that the drops maintain a uniform suspension state during storage and transportation, maintain the stability of particle size, avoid accelerated sedimentation caused by increased particle size, and ensure the consistency of the physical state of the formulation from production to the end of use.

[0052] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A propranolol hydrochloride drop solution, characterized in that, Based on 10 mL, the following components are included: The active ingredient carrier is 500-520 mg, the suspending agent is 30-40 mg, the sweetener is 20-25 mg, the pH adjuster is 0.06-0.10 mg, the flavoring is 3-6 mg, and the water is added to 10 mL.

2. The propranolol hydrochloride drops according to claim 1, characterized in that, The method for preparing the active component carrier includes the following steps: (1) Disperse the carrier material in water, heat it to 65-75℃, stir it at a constant temperature, and obtain a carrier material dispersion; (2) Dissolve povidone in water, add propranolol hydrochloride, stir to form a povidone-drug solution, add the carrier material dispersion obtained in step (1) to the povidone-drug solution, stir at constant temperature and spray dry to obtain the active component carrier. The mass ratio of the carrier material, povidone and propranolol hydrochloride is 10-20:4-6:2-4.

3. The propranolol hydrochloride drops according to claim 2, characterized in that, The carrier material is one or more of dextrin, polyvinyl alcohol, potato starch, and wheat starch.

4. The propranolol hydrochloride drops according to claim 1, characterized in that, The method for preparing the suspending agent includes the following steps: Hydroxyethyl cellulose was dissolved in an aqueous ethanol solution, the pH of the system was adjusted to between 8 and 10, acetic anhydride was added dropwise, and after the reaction was complete, the mixture was washed, dried, and pulverized to obtain a suspending agent. The mass ratio of acetic anhydride to hydroxyethyl cellulose was 0.1-0.2:

1.

5. The propranolol hydrochloride drops according to claim 1, characterized in that, The sweetener is one or more of sucrose, fructose, simple syrup, sucralose, mannitol, and sodium saccharin; the flavoring is one or more of strawberry flavoring, orange flavoring, lemon flavoring, apple flavoring, and grape flavoring.

6. The propranolol hydrochloride drops according to claim 1, characterized in that, The pH adjuster is one or more of citric acid, lactic acid, malic acid, and tartaric acid.

7. A method for preparing propranolol hydrochloride drops according to any one of claims 1-6, characterized in that, Includes the following steps: Add the suspending agent to the water while stirring. After dissolving, add the sweetener, flavoring, and active ingredient carrier, stir to dissolve, adjust the pH to between 3.0 and 3.5 with a pH adjuster, add water to 10 mL, filter, and fill.

8. The method for preparing propranolol hydrochloride drops according to claim 7, characterized in that, The filter membrane is made of one or more of polypropylene, polyethersulfone, and polytetrafluoroethylene, and the pore size of the filter membrane is 0.22-40 μm.

9. The application of the propranolol hydrochloride drops according to any one of claims 1-8, characterized in that, Application in the preparation of drugs for the treatment of proliferative infantile hemangiomas.

10. The application of propranolol hydrochloride drops according to claim 9, characterized in that, The drops are equipped with an oral applicator with a precision of 0.1 ml and a single drop content of 0.56 mg / drop.