Medical freeze-drying dressing containing high-concentration L-lactic acid and capable of being rapidly dissolved

Abstract

The invention provides a medical freeze-dried dressing which comprises the following components in parts by weight: 10-60 parts of L-lactic acid, 20-50 parts of a freeze-drying protective agent, 2-15 parts of sodium hyaluronate, 2-10 parts of an osmotic pressure regulator and 800-3000 parts of a biological polysaccharide flushing glue solution. The dressing is prepared by a specific component combination and a freeze-drying process, has the characteristics of high-concentration L-lactic acid and quick dissolution, can be used for wound nursing in the medical field, and can optimize the dissolving property and stability of the dressing by adjusting the proportion of each component and freeze-drying parameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological medicine, in particular to a medical lyophilized dressing containing high-concentration L-lactic acid and capable of rapid dissolution. BACKGROUND

[0002] Existing medical lyophilized dressings usually use various moisturizers, colloids or synthetic materials as main components to provide wound protection and promote healing. However, these dressings often face the problem of slow dissolution speed or insufficient stability when containing high concentrations of active ingredients. Currently, there is no combination of L-lactic acid, sodium hyaluronate and biological polysaccharide rinse gel as the main component in the market. This combination may have potential in improving the biocompatibility and dissolution efficiency of the dressing, but requires precise proportioning and process control to achieve. SUMMARY

[0003] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the abstract and title of the specification to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0004] In view of the problems in the prior art, the present application is proposed.

[0005] Therefore, the purpose of the present application is to overcome the shortcomings of the prior art and provide a medical lyophilized dressing containing high-concentration L-lactic acid and capable of rapid dissolution.

[0006] The present application aims to provide a medical lyophilized dressing containing high-concentration L-lactic acid and capable of rapid dissolution. By selecting specific raw material combinations and proportions, the dressing can improve the acid-base balance of the wound environment, promote tissue repair, and maintain good physical form.

[0007] The dressing includes L-lactic acid, lyophilization protectant, sodium hyaluronate, osmotic pressure regulator and biological polysaccharide rinse gel in parts by weight. Specifically, L-lactic acid 10-60 parts, lyophilization protectant 20-50 parts, sodium hyaluronate 2-15 parts, osmotic pressure regulator 2-10 parts, biological polysaccharide rinse gel 800-3000 parts.

[0008] Further optimization, L-lactic acid can be 15-50 parts by weight, sodium hyaluronate 4-10 parts, biological polysaccharide rinse gel 1200-2500 parts, lyophilization protectant 25-45 parts, osmotic pressure regulator 3-7 parts.

[0009] The freeze-drying protective agent can be mannitol, and the osmotic pressure regulator can be sodium chloride. The synergistic effect of these components helps to maintain the structural integrity of the dressing during the freeze-drying process and the uniformity of the solution after dissolution.

[0010] The preparation method of the dressing comprises mixing and dissolving each raw material and then performing freeze-drying treatment. The freeze-drying process involves pre-freezing, primary drying and secondary drying stages, and the specific parameters can be adjusted as needed to ensure that the pore structure of the dressing is conducive to rapid rehydration.

[0011] Advantages of the present application:

[0012] The dressing of the present application can maintain a high concentration of L-lactic acid while achieving a faster dissolution time, thereby facilitating clinical application. In addition, the combination helps to improve the moisturizing property and biocompatibility of the dressing, making it suitable for most non-chronic wounds. DETAILED DESCRIPTION

[0013] To make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the embodiments of the present application.

[0014] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other manners different from those described herein, and those skilled in the art can make similar extensions without departing from the scope of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0015] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor does it mean an embodiment that is separate or selectively excluded from other embodiments.

[0016] The raw materials used in the present application are all commercially available products, and the specific sources are shown in Table 1.

[0017] Table 1

[0018] Name Manufacturer Biological polysaccharide rinse solution Guizhou Jinjiu Biotechnology Co., Ltd. L-lactic acid Wuhan Kangqiong Biomedical Technology Co., Ltd. Sodium hyaluronate Boleme Life Science and Technology Co., Ltd.

[0019] Example 1

[0020] The present embodiment provides a medical freeze-dried dressing containing high-concentration L-lactic acid and capable of rapid dissolution.

[0021] Specifically, 42 parts of L-lactic acid, 4.6 parts of sodium hyaluronate, 32 parts of mannitol, 3.8 parts of sodium chloride and 1200 parts of biological polysaccharide rinse gel are taken, stirred until completely dissolved, and a uniform solution is formed. Then, the solution is divided into a mold and subjected to freeze-drying treatment.

[0022] The freeze-drying process includes: a pre-freezing stage at -40°C for 4 hours; a primary drying stage where the temperature is raised from -40°C to -10°C under a vacuum of 0.1 mbar for 8 hours; and a secondary drying stage where the temperature is raised from -10°C to 25°C under a vacuum of 0.05 mbar for 6 hours. The freeze-dried product is a sponge-like dressing.

[0023] To evaluate the performance of the dressing, a dissolution test was conducted: 0.5 g of the dressing was placed in 10 mL of 1.5% sodium citrate solution at room temperature, and the dissolution time was recorded. Simultaneously, the pH and osmotic pressure of the dissolved solution were measured. For stability testing, after storage at 25°C and 60% relative humidity for 6 months, the percentage change in dissolution time was remeasured.

[0024] Further analysis showed that the dressing at this ratio maintained a porous structure in the presence of high concentrations of L-lactic acid, which facilitated rapid water penetration and thus shortened the dissolution time.

[0025] Compared to formulations with low concentrations of L-lactic acid, this embodiment demonstrates a better ability to maintain an acidic environment, which helps control bacteria during the wound healing process.

[0026] This formulation uses mannitol as a freeze-drying protectant to ensure uniform crystal formation during the freeze-drying process and prevent collapse. The addition of sodium chloride adjusts the osmotic pressure, making the dissolved solution closer to physiological conditions and reducing potential irritation.

[0027] The content of the biopolysaccharide rinsing solution provides a sufficient gelling matrix, enabling the dressing to form a stable colloid after rehydration, effectively improving the dressing's extensibility and facilitating wound coverage. The moisturizing effect of sodium hyaluronate synergistically complements the acidification of L-lactic acid, optimizing overall biocompatibility.

[0028] Example 2

[0029] This embodiment provides a medical freeze-dried dressing containing a high concentration of L-lactic acid and capable of rapid dissolution.

[0030] Take 19 parts of L-lactic acid, 8 parts of sodium hyaluronate, 32 parts of mannitol, 3.8 parts of sodium chloride, and 1600 parts of biological polysaccharide rinsing solution, stir to dissolve, dispense into portions, and freeze dry.

[0031] The freeze-drying parameters are the same as in Example 1: the pre-freezing stage is maintained at -40°C for 4 hours; the first drying stage is maintained at -10°C with a vacuum of 0.1 mbar for 8 hours; the second drying stage is maintained at 25°C with a vacuum of 0.05 mbar for 6 hours.

[0032] Dissolution tests, pH values, osmotic pressure and stability assessments were performed, following the same methods as in Example 1.

[0033] In this embodiment, increasing the content of the biopolysaccharide rinsing adhesive improved the viscosity of the dressing, thus enhancing its adhesion to the wound surface.

[0034] Meanwhile, compared with Example 1, this formulation forms a more uniform gel solution after dissolution, which is beneficial for the uniform distribution of active ingredients.

[0035] Reducing the L-lactic acid content slightly weakens the acidity, but the moisturizing effect is maintained by increasing the proportion of sodium hyaluronate. The fixed amounts of mannitol and sodium chloride ensure consistent freeze-drying protection and osmotic pressure regulation.

[0036] In practice, this adjustment can be optimized based on wound type; for example, higher biopolysaccharide content is prioritized to enhance gelation in post-laser / photon surgery wounds. This process avoids complex equipment, requiring only a standard stirrer and freeze dryer, and meets the requirements for industrial production.

[0037] Comparative Example 1

[0038] Take 11 parts of L-lactic acid, and the remaining components and amounts are the same as in Example 1, namely 4.6 parts of sodium hyaluronate, 32 parts of mannitol, 3.8 parts of sodium chloride, and 1200 parts of biopolysaccharide rinsing solution, and mix and dissolve them. The freeze-drying parameters are the same as in Example 1, and the same performance evaluation is performed.

[0039] Analysis showed that low L-lactic acid content resulted in insufficient acidity, leading to a higher pH after dissolution, which may affect the acidification effect on the wound and also resulted in poor stability.

[0040] The porosity of this formulation decreases after freeze-drying, resulting in slower water permeation. Compared to the previous example, the lack of a high concentration of L-lactic acid provides a synergistic effect, leading to a decline in overall performance.

[0041] Comparative Example 2

[0042] Take 57 portions of L-lactic acid, and the rest are the same as in Example 1. The freeze-drying parameters are the same as in Example 1, and the same evaluation is performed.

[0043] High levels of L-lactic acid increase the brittleness of the dressing, making it prone to structural disintegration after freeze-drying, resulting in uneven dissolution. Low pH values ​​may cause irritation, and stability tests show significant changes.

[0044] Comparative Example 3

[0045] Take 3.4 parts of sodium hyaluronate, and the rest are the same as in Example 1. The freeze-drying parameters are the same as in Example 1, and the results are evaluated.

[0046] Low sodium hyaluronate content leads to reduced moisturizing properties, making the dressing prone to absorbing moisture after drying, affecting storage, prolonging dissolution time, and reducing overall biocompatibility.

[0047] Comparative Example 4

[0048] Take 11.2 parts of sodium hyaluronate, and the rest are the same as in Example 1. The freeze-drying parameters are the same as in Example 1, and the results are evaluated.

[0049] High sodium hyaluronate content results in excessively high solution viscosity, which clogs pores after freeze-drying, slowing dissolution. This reduces stability and makes the solution prone to clumping.

[0050] Comparative Example 5

[0051] Take 800 portions of the biopolysaccharide rinsing solution, and follow the same procedure as in Example 1. The freeze-drying parameters are the same as in Example 1, and the results are evaluated.

[0052] Low levels of bioactive polysaccharides result in a thin adhesive solution and unstable dressing form. After dissolution, it exhibits poor uniformity, reduced spreadability, and uneven coverage.

[0053] Comparative Example 6

[0054] Take 2800 portions of the biopolysaccharide rinsing solution, and follow the same procedure as in Example 1. The freeze-drying parameters are the same as in Example 1, and the results are evaluated.

[0055] High levels of bioactive polysaccharides make the mixture too dense, resulting in uneven coverage, easy clumping, low freeze-drying efficiency, and prolonged dissolution time. Stability tests show significant changes.

[0056] Comparative Example 7

[0057] Sodium hyaluronate was replaced with 4.6 parts of carbomer, and the rest remained the same as in Example 1. The freeze-drying parameters were the same as in Example 1, and the results were evaluated.

[0058] After replacement, the dressing exhibited poor expansion, increased stickiness, incomplete dissolution, and clumping. Its moisturizing effect was also inferior to sodium hyaluronate.

[0059] Comparative Example 8

[0060] The biopolysaccharide rinsing solution was replaced with 1200 parts of a 5% trehalose solution, and the rest remained the same as in Example 1. The freeze-drying parameters were the same as in Example 1, and the results were evaluated.

[0061] Replacement results in a thinner dressing texture, reduced adhesion, and unstable solution after dissolution. The gelling effect is lost, making the dressing brittle.

[0062] Comparative Example 9

[0063] L-lactic acid was replaced with 42 parts chitosan, and the rest remained the same as in Example 1. The freeze-drying parameters were the same as in Example 1, and the results were evaluated.

[0064] After replacement, the acidity disappeared, the dressing's function changed, and it was no longer suitable for its original purpose. The dissolution time was significantly prolonged, and the pH value increased.

[0065] Comparative Example 10

[0066] The freeze-drying parameters were modified as follows: pre-freezing at -30°C for 3 hours; first drying at -30°C to 0°C, 0.2 mbar for 6 hours; second drying at 0°C to 40°C, 0.1 mbar for 5 hours. The rest were the same as in Example 1, and the results were evaluated.

[0067] Parameter adjustments resulted in incomplete freeze-drying, high residual moisture content, and slow dissolution. It also exhibited poor stability and was prone to hygroscopicity.

[0068] Comparative Example 11

[0069] Freeze-drying parameters: Pre-freeze -50°C for 6 hours; First drying -50°C to -20°C, 0.05 mbar for 12 hours; Second drying -20°C to 20°C, 0.02 mbar for 8 hours. The rest are the same as in Example 1. Evaluation was then conducted.

[0070] Excessive freeze-drying time results in a denser structure, affecting the dissolution rate. It also leads to high energy consumption, which is detrimental to production.

[0071] Comparative Example 12

[0072] Add 1200 parts of purified water, without adding the biopolysaccharide rinsing solution, otherwise follow the same procedure as in Example 1. The freeze-drying parameters are the same as in Example 1, and the results are evaluated.

[0073] The absence of this ingredient results in dressings lacking gelling properties, insufficient viscosity, poor extensibility, uneven dissolution, and unstable form.

[0074] Comparative Example 13

[0075] It does not contain sodium hyaluronate, and is otherwise the same as in Example 1. The freeze-drying parameters are the same as in Example 1, and the results are evaluated.

[0076] The lack of moisturizers makes dressings dry and brittle, prolongs dissolution time, weakens moisturizing properties, and reduces biocompatibility.

[0077] Comparative Example 14

[0078] It does not contain L-lactic acid, but is otherwise the same as in Example 1. The freeze-drying parameters are the same as in Example 1, and the results are evaluated.

[0079] Lacking core components, it loses its acidity and has incomplete function. It has poor solubility and weak stability.

[0080] Table 2

[0081] Group Dissolution time (s) pH value Osmotic pressure (mOsm / L) 6-month stability change (%) Example 1 45 4.2 290 <10 Example 2 50 4.8 282 <15 Comparative Example 1 65 5.4 305 20 Comparative Example 2 70 3.5 318 25 Comparative Example 3 60 4.3 295 20 Comparative Example 4 75 4.4 310 25 Comparative Example 5 62 4.2 305 18 Comparative Example 6 80 4.6 300 22 Comparative Example 7 85 4.5 290 30 Comparative Example 8 78 4.3 295 28 Comparative Example 9 90 8.5 225 35 Comparative Example 10 68 4.6 292 20 Comparative Example 11 72 4.4 298 25 Comparative Example 12 82 4.2 275 32 Comparative Example 13 76 4.3 296 27 Comparative Example 14 88 7.8 230 30

[0082] As shown in Table 2, through the comparison of the above examples and comparative examples, it can be seen that when the proportions of each component are within the specified range and appropriate freeze-drying parameters are used, the dressing has a shorter dissolution time and better stability.

[0083] This indicates that synergistic effects between components are key; for example, L-lactic acid provides an acidic environment, sodium hyaluronate enhances moisturizing, biopolysaccharides rinse the gel and improve gelation, while freeze-drying protectants and osmotic pressure regulators maintain structural and osmotic pressure balance.

[0084] In practical applications, these formulations can be tailored to specific wound needs to optimize performance. All testing methods are standard in the field; for example, dissolution tests are simulated using a shaker, pH and osmotic pressure are determined using electrodes and freezing point methods, and stability is assessed under controlled conditions to evaluate the rate of change.

[0085] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A medical lyophilized dressing containing a high concentration of L-lactic acid and capable of rapid dissolution, characterized in that: The medical freeze-dried dressing, by weight, comprises 10-60 parts of L-lactic acid, 20-50 parts of freeze-drying protectant, 2-15 parts of sodium hyaluronate, 2-10 parts of osmotic pressure regulator, and 800-3000 parts of biological polysaccharide rinsing solution.

2. The medical freeze-dried dressing as described in claim 1, characterized in that: The weight of L-lactic acid is 15 to 50 parts.

3. The medical freeze-dried dressing as described in claim 1, characterized in that: The sodium hyaluronate is present in parts by weight of 4 to 10.

4. The medical freeze-dried dressing as described in claim 1, characterized in that: The weight of the biopolysaccharide rinsing solution is 1200-2500 parts.

5. The medical freeze-dried dressing as described in claim 1, characterized in that: The freeze-drying protectant is 25 to 45 parts by weight.

6. The medical freeze-dried dressing as described in claim 1, characterized in that: The osmotic pressure regulator is 3 to 7 parts by weight.

7. The medical freeze-dried dressing as described in claim 1, characterized in that: The freeze-drying protectant is mannitol.

8. The medical freeze-dried dressing as described in claim 1, characterized in that: The osmotic pressure regulator is sodium chloride.

9. The method for preparing the medical freeze-dried dressing as described in claim 1, characterized in that: This includes mixing and dissolving the raw materials, followed by freeze-drying. The freeze-drying process includes pre-freezing, primary drying, and secondary drying stages.

10. The medical freeze-dried dressing as described in claim 9, characterized in that: The pre-freezing temperature is -40 to -50℃, and the time is 4 to 6 hours; the first drying is carried out by raising the temperature from the pre-freezing temperature to -10 to -20℃, with a vacuum degree of 0.05 to 0.1 mbar, for 8 to 12 hours; the second drying is carried out by raising the temperature to 20 to 30℃, with a vacuum degree of 0.02 to 0.05 mbar, for 6 to 8 hours.