An artificial tear and a method for characterizing protein removal from contact lens care solutions

Abstract

This application relates to an artificial tear solution and a method for characterizing the protein removal effect of contact lens solution. The artificial tear solution comprises the following components: PBS buffer, lysozyme, sodium hyaluronate, and sodium formate. This invention effectively prevents protein denaturation and improves the stability of the artificial tear solution by adding sodium formate to a conventional artificial tear solution. The addition of sodium hyaluronate makes the protein more difficult to wash off, thereby effectively improving the adhesion of proteins to RGP lenses. Furthermore, the drying process further fixes the protein, thus enabling a more accurate characterization of the protein removal effect of the contact lens solution.

Description

Technical Field

[0001] This application relates to the fields of medical devices and testing and analysis, specifically to an artificial tear solution and a method for characterizing the protein removal effect of contact lens care solution. Background Technology

[0002] Cell shedding from the ocular epidermis and protein deposition on contact lenses are considered major causes of reduced oxygen permeability of corneal contact lenses and ocular complications. Currently, the main approach to addressing this issue is to clean and care for corneal contact lenses using contact lens solutions. To evaluate the protein removal effectiveness of contact lens solutions, a corresponding protein content detection method is needed. The mainstream method for detecting the protein removal effect of contact lens solutions on corneal contact lenses involves preparing a protein solution (i.e., artificial tears, whose main components are PBS buffer and lysozyme) using PBS solution. The lens is then immersed in the protein solution for a period of time, and the difference in protein content before and after immersion is used to quantify the amount of protein adsorbed by the lens. The immersed corneal contact lens is then cleaned to remove the protein, and the ratio of the amount of protein eluted by the solution to the amount adsorbed by the lens is taken as the protein removal rate. However, this method suffers from difficulties in protein adsorption on the lens, weak protein adsorption, and unstable denaturation of the protein solution during adsorption. This results in low specificity of the detection method, leading to unstable, reproducible, and highly subjective results, making it difficult to accurately characterize the protein removal effect of contact lens solutions.

[0003] Based on this, the technical solution proposed in this application is intended to solve the above problems. Summary of the Invention

[0004] Protein deposits on contact lenses primarily originate from tears, which are mostly water, along with some proteins, lipids, carbohydrates, and inorganic salts. The main proteins are lysozyme, albumin, and immunoglobulins, with lysozyme being the most abundant. Existing technologies generally use lysozyme as the representative in the formulation of artificial tears. Conventional artificial tears (mainly composed of PBS buffer and lysozyme) are often difficult to deposit and adsorb on corneal contact lenses, especially rigid corneal contact lenses made of fluorosilicone materials. Furthermore, they exhibit weak adsorption and the protein solution is prone to denaturation during the adsorption process. Typically, contact lenses soaked in conventional artificial tears can have some protein removed with saline solution alone. This interferes with the verification of the actual protein removal effect of contact lens solutions. To address these shortcomings, the purpose of this invention is to provide an improved artificial tear that can effectively increase the amount of protein adsorbed on corneal contact lenses and prevent protein solution deterioration during the adsorption process. Furthermore, based on this improved artificial tear, a method for characterizing the protein removal effect of contact lens solutions is provided.

[0005] To address the aforementioned technical problems, this application provides the following technical solution.

[0006] In a first aspect, this application provides an artificial tear fluid comprising the following components: PBS buffer, lysozyme, sodium hyaluronate, and sodium formate.

[0007] Preferably, the concentration of sodium hyaluronate in the artificial tears is 0.1–1.0 mg / ml, and the concentration of sodium formate is greater than 0.5 mg / ml.

[0008] More preferably, the concentration of sodium hyaluronate in the artificial tears is 0.15–1.0 mg / ml, and the concentration of sodium formate is 0.5–1.0 mg / ml.

[0009] Preferably, the artificial tears also contain glucose at a concentration of 0.7–5.0 mg / ml.

[0010] More preferably, the artificial tears also contain glucose at a concentration of 1.0 to 1.5 mg / ml.

[0011] Preferably, the concentration of lysozyme in the artificial tears is 2.0–2.5 mg / ml.

[0012] Preferably, the PBS buffer includes NaCl, Na2HPO4·12H2O, and NaH2PO4·2H2O.

[0013] Preferably, in the artificial tears, the concentration of NaCl is 6.0–10.0 mg / ml, the concentration of Na2HPO4·12H2O is 4.0–7.0 mg / ml, and the concentration of NaH2PO4·2H2O is 0.4–0.7 mg / ml.

[0014] Secondly, the present invention provides the use of the aforementioned artificial tears in the preparation of a test reagent for characterizing the protein removal effect of contact lens care solution.

[0015] Thirdly, the present invention provides a method for characterizing the protein removal effect of contact lens care solution, comprising the following steps:

[0016] S1. After drying the prepared artificial tears at 30-120℃ for a certain period of time, add purified water to reconstitute the solution to obtain the dried and reconstituted solution, and then test the total protein content.

[0017] S2. Place the RGP lens in the prepared artificial tears and dry it at 30-120℃ for a certain period of time to obtain a lens with adsorbed protein.

[0018] S3. After removing the lens with adsorbed protein, the remaining artificial tears are reconstituted in purified water and the amount of residual protein is then tested.

[0019] S4. Place the lens with adsorbed protein taken out in step S3 into the contact lens care solution or physiological saline to be characterized. After treatment, detect the protein content in the contact lens care solution and physiological saline to be characterized. Then calculate the protein removal rate of the contact lens care solution and physiological saline to be characterized and compare the removal effect.

[0020] The protein content of the solution obtained in each step was determined by HPLC.

[0021] Preferably, when using HPLC detection, the chromatographic conditions include: a mobile phase of a mixture of TFA and acetonitrile; and a flow rate of 0.5–2.0 ml / min.

[0022] Preferably, the protein clearance rate of the contact lens care solution to be characterized is calculated using the following formula:

[0023] P1 = C3 / (C - C1) * 100%

[0024] The formula for calculating the protein clearance rate of the physiological saline is as follows:

[0025] P2 = C4 / (C-C1) * 100%

[0026] Wherein, P1 is the protein clearance rate of the contact lens care solution or saline to be characterized, P2 is the protein clearance rate of saline, C is the total protein content of artificial tears, C1 is the residual protein content, C3 is the protein content in the contact lens care solution to be characterized, and C4 is the protein content in saline.

[0027] Preferably, the chromatographic conditions used for the HPLC detection further include:

[0028] The column temperature is 25–35℃;

[0029] The running time is 15 minutes;

[0030] The injection volume is 5–20 μL;

[0031] The detector is an ultraviolet detector.

[0032] Compared with the prior art, the positive effects of this invention are as follows:

[0033] 1) This invention provides an improved artificial tear solution. By adding a specific amount of sodium formate to the conventional artificial tear solution, the stability of the artificial tear solution can be effectively prevented from deteriorating. By adding a specific amount of sodium hyaluronate, which has a high viscosity, the protein is more difficult to wash off, thereby effectively improving the adhesion of protein to RGP lenses and avoiding errors caused by protein falling off the lens due to poor adhesion. Therefore, it can more accurately characterize the protein removal effect of the contact lens solution.

[0034] 2) Based on the improved artificial tears, this invention further provides a method for characterizing the protein removal effect of hydrogen peroxide contact lens cleaning solution. In the process, the protein is further fixed on the lens by drying at 30-120°C, and the protein content in each analyte is detected by HPLC, thereby improving the accuracy of detecting the protein removal effect. Attached Figure Description

[0035] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0036] Figure 1 The high-performance liquid chromatograms of the blank solution and the control solution are shown according to the method of Example 1; where 1 is the chromatogram of the control solution and 2 is the chromatogram of the blank solution.

[0037] Figure 2 The figure shows the high performance liquid chromatogram of formulation 1 determined according to the method of Example 2; the solid triangles indicate the characteristic peaks of the freshly prepared test solution, and the hollow triangles indicate the characteristic peaks of the test solution after drying at 37°C and then reconstituted. Detailed Implementation

[0038] Unless otherwise stated, implied from the context, or as is customary in the art, all parts and percentages in this application are based on weight. Where applicable, any patent, patent application, or disclosure relating to this application is incorporated herein by reference in its entirety, and its equivalent patent families are also incorporated herein by reference. If the definitions of specific terms disclosed in the prior art are inconsistent with any definitions provided in this application, the definitions provided in this application shall prevail.

[0039] The numerical ranges in this application are approximate values ​​and therefore may include values ​​outside the range unless otherwise stated. A numerical range includes all values ​​from the lower limit to the upper limit, increasing by one unit, provided there is an interval of at least two units between any lower and any higher value. For example, if a component, physical, or other property (such as molecular weight, melt index, etc.) is described as 100 to 1000, this means that all individual values, such as 100, 101, 102, etc., are explicitly listed, as well as all subranges, such as 100 to 166, 155 to 170, 198 to 200, etc. For ranges containing values ​​less than 1 or fractions greater than 1 (e.g., 1.1, 1.5, etc.), one unit is appropriately considered as 0.0001, 0.001, 0.01, or 0.1. For ranges containing single digits less than 10 (e.g., 1 to 5), one unit is generally considered as 0.1. These are merely specific examples of what is intended to be expressed, and all possible combinations of values ​​between the listed minimum and maximum values ​​are considered to be clearly stated in this application. It should also be noted that the terms "first," "second," etc., used herein are not intended to specify a particular order, but are merely used to distinguish substances with different structures.

[0040] When referring to chemical compounds, unless explicitly stated otherwise, the singular includes all isomers and vice versa (e.g., "hexane" includes all isomers of hexane, individually or collectively). Additionally, unless explicitly stated otherwise, nouns described with "an," "a," or "the" also include their plural forms.

[0041] The terms “comprising,” “including,” “having,” and their derivatives do not exclude the presence of any other components, steps, or processes, regardless of whether such other components, steps, or processes are disclosed in this application. To eliminate any doubt, unless expressly stated otherwise, all compositions using the terms “comprising,” “including,” or “having” in this application may contain any additional additives, excipients, or compounds. Conversely, except for those necessary for operational performance, the term “substantially constitutes…” excludes any other components, steps, or processes described below with respect to that term. The term “consisting of…” does not include any components, steps, or processes not specifically described or listed. Unless expressly stated otherwise, the term “or” refers to the individual members listed or any combination thereof.

[0042] The following examples provide an artificial tear solution comprising the following components: PBS buffer, lysozyme, sodium hyaluronate, and sodium formate.

[0043] In one specific embodiment, glucose is also included.

[0044] In one specific embodiment, the artificial tears specifically include the following components at the following concentrations: glucose 0.7–5.0 mg / ml, sodium hyaluronate 0.1–1.0 mg / ml, sodium formate greater than 0.5 mg / ml, lysozyme 2.0–2.5 mg / ml, NaCl 6.0–10.0 mg / ml, Na₂HPO₄·12H₂O 4.0–7.0 mg / ml, and NaH₂PO₄·2H₂O 0.4–0.7 mg / ml. In this invention, the concentration ranges of the lysozyme and PBS buffer used are not limited to the aforementioned ranges; their concentrations can be those commonly used in artificial tears.

[0045] In one specific embodiment, the concentration of glucose can be 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 mg / ml or a range or subrange between any two of these values. As a further preferred range, the concentration of glucose is 1.0 to 1.5 mg / ml.

[0046] In one specific embodiment, the concentration of sodium hyaluronate can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 mg / ml, or a range or subrange between any two of these values. As a further preferred range, the concentration of sodium hyaluronate is 0.15–1.0 mg / ml.

[0047] In one specific embodiment, the concentration of sodium formate can be 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 mg / ml or any two of these values, or a sub-range thereof. As a further preferred range, the concentration of sodium formate is 0.5–1.0 mg / ml.

[0048] In one specific embodiment, the concentration of lysozyme can be 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 mg / ml or any two of these values ​​or a subrange thereof.

[0049] In one specific embodiment, the concentration of NaCl can be 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 mg / ml or any range or subrange between any two of these values.

[0050] In one specific embodiment, the concentration of Na2HPO4·12H2O can be 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0 mg / ml or any range or subrange between any two of these values.

[0051] In one specific embodiment, the concentration of NaH2PO4·2H2O can be 0.4, 0.5, 0.6, 0.7 mg / ml or any range or subrange between any two of these values.

[0052] The following embodiments also provide a method for characterizing the protein removal effect of contact lens care solution, including the following steps:

[0053] S1. Dry the prepared artificial tears at 30-120℃ for a certain time (the time is not particularly limited, and the solution should be completely dried). Then, add purified water to reconstitute the solution to obtain the dried and reconstituted solution. HPLC is used to detect the total protein content.

[0054] S2. Place the RGP lens in the prepared artificial tears and dry it at 30-120°C for a certain period of time (the time is not particularly limited, and the solution should be completely dried) to obtain the lens with adsorbed protein.

[0055] S3. After removing the lens with adsorbed protein, the remaining artificial tears were reconstituted in purified water and the residual protein was detected by HPLC.

[0056] S4. Place the lens with adsorbed protein taken out in step S3 into the contact lens care solution or physiological saline to be characterized. After treatment, detect the protein content in the contact lens care solution and physiological saline to be characterized. Then calculate the protein removal rate of the contact lens care solution and physiological saline to be characterized and compare the removal effect.

[0057] The formula for calculating the protein clearance rate of the contact lens care solution used for characterization is as follows:

[0058] P1 = C3 / (C - C1) * 100%

[0059] The formula for calculating the protein clearance rate of the physiological saline is as follows:

[0060] P2 = C4 / (C-C1) * 100%

[0061] Wherein, P1 is the protein clearance rate of the contact lens care solution or saline to be characterized, P2 is the protein clearance rate of saline, C is the total protein content of artificial tears, C1 is the residual protein content, C3 is the protein content in the contact lens care solution to be characterized, and C4 is the protein content in saline.

[0062] In one specific embodiment, in steps S1 and S2, the drying temperature can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, or any two of these values ​​or a sub-range thereof. More preferably, it is 35-38°C, and most preferably, it is 37°C.

[0063] In one specific embodiment, the drying step at 30–120°C specifically involves air drying in a forced-air drying oven at 30–120°C. The air drying time is not specifically limited, but is based on the time required for the solution to completely dry.

[0064] In one specific embodiment, the liquid chromatograph used may be an Agilent 1260 HPLC system or other equivalent HPLC system.

[0065] In one specific embodiment, the chromatographic column used is a TSKgel G3000SW. XL 7.8*300mm5μm.

[0066] In one specific embodiment, the mobile phase used is a mixed mobile phase of TFA and acetonitrile, wherein the volume ratio of TFA to acetonitrile is 75:25 to 65:35 (v / v). For example, the volume ratio can be 75:25, 70:30, 65:35, or any range or subrange between any two of these values.

[0067] In one specific embodiment, the mass percentage of TFA in the mixed mobile phase is not particularly limited, as it will not significantly affect the experiment; its presence is sufficient for use in this invention. For example, the mass percentage of TFA used may be 0.1%.

[0068] In one specific embodiment, other chromatographic conditions are as follows: the mobile phase flow rate is 0.5–2 mL / min, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 mL / min, or any two values ​​therein or a sub-range thereof. The column temperature is 25–35 °C, for example, 25 °C, 30 °C, 35 °C, or any two values ​​therein or a sub-range thereof. The chromatograph run time is 15 min. The injection volume of the sample is 5–20 μl. Detection is performed using an ultraviolet detector at a wavelength of 204 nm.

[0069] Example

[0070] The technical solution of this application will be clearly and completely described below with reference to the embodiments of this application. Unless otherwise specified, the reagents and raw materials used can be purchased commercially. Experimental methods in the following embodiments that do not specify specific conditions are performed according to conventional methods and conditions, or according to the product instructions.

[0071] Example 1

[0072] This embodiment investigated the protein stability of different artificial tear formulations. The composition and concentration of each artificial tear formulation are shown in Table 1.

[0073] Prepare artificial tear formulations 1-6 according to the components and concentrations in Table 1. Accurately weigh 2 ml of each prepared artificial tear and transfer it to a 10 ml volumetric flask. Dilute to the mark with purified water and shake well before testing (this is a freshly prepared test solution).

[0074] Take another empty RGP lens cup, precisely add 2 ml of freshly prepared artificial tears, and air dry in a forced-air drying oven at 37°C for 24 hours. Reconstitute the artificial tears in the empty cup with an appropriate amount of purified water, and transfer the entire reconstituted solution to a 10 ml volumetric flask. Rinse the empty cup three times with purified water, and transfer the rinsing solution to the 10 ml volumetric flask as well. Finally, dilute to the mark with purified water, shake well, and prepare for testing (this is the dried and reconstituted solution to be tested).

[0075] Purified water was used as a blank solution, and 2.2 mg / ml lysozyme solution (prepared from standard samples) was used as a control solution.

[0076] The protein content of the aforementioned test solution, blank solution, and control solution was determined by HPLC under the following conditions:

[0077] 1) Detection instrument: Agilent 1260 HPLC system

[0078] 2) Chromatographic conditions:

[0079] Mobile phase: 0.1% TFA:acetonitrile = 70:30 (v / v)

[0080] Flow rate: 1.0 ml / min

[0081] Injection volume: 10 μl

[0082] Column temperature: 30℃

[0083] Wavelength: 204nm

[0084] Running time: 15min

[0085] The high-performance liquid chromatogram results of the blank solution and the control solution are as follows: Figure 1 As shown, by Figure 1It is evident that HPLC detection does not interfere with specificity.

[0086] The peak areas of proteins in the freshly prepared test solutions and the reconstituted test solutions after drying at 37℃ are compared in Table 2. The high-performance liquid chromatography (HPLC) results for the freshly prepared test solution and the reconstituted test solution after drying at 37℃ for Formula 1 are shown in Table 2. Figure 2 As shown.

[0087] Table 1. Composition of Artificial Tears in Formulas 1-5

[0088] Ingredients (mg / ml) Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 NaCl 8.3 8.3 8.3 8.3 8.3 8.3 <![CDATA[Na2HPO4·12H2O]]> 5.993 5.993 5.993 5.993 5.993 5.993 <![CDATA[NaH2PO4·2H2O]]> 0.528 0.528 0.528 0.528 0.528 0.528 Lysozyme 2.2 2.2 2.2 2.2 2.2 2.2 glucose 1.0 / 1.0 1.0 1.0 1.0 Sodium hyaluronate 0.15 / 0.15 0.15 0.15 0.15 Sodium formate 1.0 / / 0.1 0.5 / Sodium citrate / / / / / 0.5

[0089] Table 2 Comparison of Peak Area

[0090]

[0091]

[0092] As shown in Table 2 above, the peak area of ​​the conventional artificial tears in Formula 2, after being dried at 37°C and reconstituted, was significantly smaller than that of the freshly prepared formula. This indicates that protein degradation occurs during the drying process at 37°C, resulting in a significant decrease in protein content and poor stability after reconstitution. In contrast, Formula 3, which adds glucose and sodium hyaluronate to the conventional artificial tears formula, also showed a significantly smaller peak area after reconstitution at 37°C compared to the freshly prepared formula. This suggests that adding glucose and sodium hyaluronate does not improve protein stability and may even exacerbate it. Formulas 4-6 are based on Formula 3, with the addition of sodium formate or sodium citrate, followed by drying at 37°C, reconstitution, and peak area measurement. The results show that: Formula 4 has a significantly higher peak area after reconstitution at 37°C compared to Formula 3, but its peak area is still significantly smaller than the freshly prepared formula; Formula 5 further increases the peak area after reconstitution at 37°C compared to Formula 4, and is very close to the freshly prepared peak area, indicating that Formula 5 can significantly improve protein stability; Formula 6 does not increase the peak area after reconstitution at 37°C compared to Formula 3, indicating that adding sodium citrate to Formula 6 does not improve protein stability. Furthermore, the results for Formula 1 show that the peak area immediately after preparation is very close to that after reconstitution at 37°C. Figure 2 This indicates that its protein solution is also very stable.

[0093] The results above show that formulas 1 and 5, which contain sodium formate at a concentration of not less than 0.5 mg / ml, can effectively prevent protein deterioration, thereby improving the stability of the protein solution and ensuring that the protein content in the artificial tears after drying at 37°C and then reconstituted is basically consistent with that in the freshly prepared artificial tears.

[0094] Example 2

[0095] This embodiment investigated the protein adsorption and removal effects of different artificial tear formulations. The composition and concentration of each artificial tear formulation are shown in Table 3 below.

[0096] Table 3. Composition of Artificial Tears in Formulas 1-2 and 7-10

[0097]

[0098]

[0099] The effects of various artificial tear formulations on protein adsorption and removal on corneal contact lenses were tested. The specific steps are as follows:

[0100] 1. Determination of total protein content in artificial tears

[0101] Take an empty RGP lens cup, precisely add 2 ml of artificial tears, and air dry in a forced-air drying oven at 37°C for 24 hours. Reconstitute the artificial tears in the empty cup with an appropriate amount of purified water, and transfer the entire reconstituted solution to a 10 ml volumetric flask. Rinse the empty cup three times with purified water, transferring the rinsing solution to the 10 ml volumetric flask as well. Finally, dilute to the mark with purified water, shake well, and prepare for testing. The protein content in this solution is taken as the total protein content (C).

[0102] 2. Protein adsorption

[0103] Six unworn RGP lenses were placed in six different RGP lens cups, each with its concave side facing up. 2 ml of artificial tears was precisely added to each cup. The cups were then air-dried at 37°C for 24 hours to obtain protein-adsorbed lenses. The protein-adsorbed lenses were removed and placed in six different platinum neutralization cups. The remaining artificial tears in the RGP lens cups were reconstituted with an appropriate amount of purified water. The reconstituted solution was transferred to a 10 ml volumetric flask. The empty flask was rinsed three times with purified water, and the rinse solution was transferred to the 10 ml volumetric flask as well. Finally, the solution was diluted to the mark with purified water and shaken well before analysis. The protein content in this solution was recorded as the residual protein amount, C1.

[0104] The amount of protein adsorbed by the lens, C2, is equal to the difference between the total content of the protein solution, C, and the residual amount of adsorbed protein, C1, i.e., C2 = C - C1.

[0105] 3. Protein clearance

[0106] Lenses with adsorbed protein were placed in six different platinum neutralization cups. Three of these cups were precisely filled with 10 ml of the same hydrogen peroxide solution, while the other three were precisely filled with 10 ml of physiological saline. Neutralization time was 6 hours. After protein removal, the protein content in the hydrogen peroxide solution was C3, and the protein content in the physiological saline solution was C4.

[0107] The protein content of each test solution was detected using the same high-performance chromatography conditions as in Example 1.

[0108] 4. Calculation formula

[0109] The protein clearance rate of hydrogen peroxide solution, P1 = C3 / (C-C1)*100%

[0110] Protein clearance rate of physiological saline P2 = C4 / (C-C1)*100%

[0111] 5. Judgment Criteria

[0112] When the protein removal effect (P1) of hydrogen peroxide solution is greater than that of physiological saline (P2), it indicates that the solution has a protein removal effect; otherwise, it does not. Furthermore, the larger the difference between P1 and P2, the better the protein removal effect of the solution.

[0113] The protein adsorption and removal effects of each formulation of artificial tears are shown in Table 4.

[0114] Table 4 Comparison of protein adsorption and removal effects of different formulations

[0115]

[0116]

[0117] As can be seen from the results in Table 4 above, Formula 2 is a conventional artificial tear formula. The amount of protein adsorbed and removed by its hydrogen peroxide solution and physiological saline is similar, so the protein removal rate is also similar. This is because the protein solution of Formula 2 is not firmly adsorbed on the lens and is easily detached during the test, so it cannot accurately characterize the protein removal effect of the hydrogen peroxide solution.

[0118] In Formulas 1, 7, and 10, the amount of protein adsorbed by hydrogen peroxide solution and saline is similar, but the amount of protein removed by hydrogen peroxide solution is significantly greater than that removed by saline. Therefore, the protein removal rate obtained using hydrogen peroxide solution is significantly higher than that using saline, with greater distinguishability. This is mainly because Formulas 1, 7, and 10 contain a certain amount of glucose and sodium hyaluronate. Glucose has viscosity during protein adsorption, which can firmly adhere more adsorbed protein to the lens; while sodium hyaluronate has high viscosity, making it more difficult to wash off the protein. Both can effectively improve the adhesion of protein to RGP lenses, thereby avoiding errors caused by protein falling off the lens due to weak adhesion. Therefore, it can more accurately characterize the protein removal effect of the solution.

[0119] Since sodium hyaluronate was not added in Formula 8, the amount of protein adsorbed and removed by hydrogen peroxide solution and saline solution were similar, and the resulting protein removal rates were also similar. Therefore, it was still impossible to accurately characterize the protein removal effect of hydrogen peroxide solution.

[0120] Although the amount of protein removed by the hydrogen peroxide solution in Formula 9 is significantly greater than that removed by the saline solution, and can be used to characterize the protein removal effect of the solution, the absence of glucose prevents the protein adsorbed on the lens from adhering firmly to the lens. This causes some of the adsorbed protein to detach during lens treatment, resulting in a significantly lower amount of protein removed compared to Formula 1.

[0121] Comparative Example 1

[0122] This comparative example used conventional artificial tears (Formula 2 in Tables 1 and 3) as the test solution, and the protein adsorption and removal effects of RGP lenses were detected by UV-Vis spectrophotometry. The specific steps are as follows:

[0123] Unworn RGP lenses were placed in an RGP lens cup, and 2 ml of artificial tears were precisely added to the cup. The lenses were then soaked at 37°C for 65 hours. After soaking, the lenses were cleaned to remove protein, and the ratio of the amount of protein removed by the cleaning solution to the amount of protein adsorbed on the lens was used as the protein removal rate. The results are shown in Table 5. Show.

[0124] Table 5 shows the detection results using a UV-Vis spectrophotometer.

[0125]

[0126] As can be seen from the results in Table 5 above, the residual protein concentration after adsorption is higher than the total protein concentration, indicating that the protein in the artificial tear has deteriorated (underwent a hyperchromic reaction) during the adsorption process, and the protein in the artificial tear is unstable.

[0127] Comparative Example 2

[0128] This comparative example used conventional artificial tears (Formula 2 in Tables 1 and 2) as the test solution, and employed a UV-Vis spectrophotometer to detect the protein adsorption and removal effects of RGP lenses. The only difference from Comparative Example 1 was that in this comparative example, each solution was soaked at 37°C for only 24 hours.

[0129] The results are shown in Table 6 (protein concentration: 2.2 mg / ml, absorbance: 1.196, relative response factor: 1.84).

[0130] Table 6. Test results of contact lenses without air drying.

[0131]

[0132] As shown in Table 6 above, the protein removal rate of hydrogen peroxide contact lens solution is higher than 100%, indicating that the amount of protein removed by the solution is greater than the amount of protein adsorbed by the lens, a conclusion that contradicts common sense. This is because the ultraviolet detection method lacks specificity; furthermore, proteins in conventional artificial tears undergo degradation (hyperchromic reaction) during the soaking and adsorption process, and this hyperchromic reaction intensifies with increasing protein adsorption time, leading to an increase in the absorbance value of the remaining protein solution after adsorption, thus making it impossible to obtain accurate protein removal results.

[0133] Comparative Example 3

[0134] This comparative example uses the artificial tears from Formula 1 in Example 2 as the test solution, and high-performance liquid chromatography (HPLC) is used to detect the protein adsorption and removal effects of RGP lenses (HPLC detection conditions are the same as in Example 1). The only difference from the method in Example 2 is that in this comparative example, the solutions are not dried in a forced-air drying oven at 37°C, but are simply soaked at 37°C for 24 hours.

[0135] The results are shown in Table 7. Without the air-drying process, the amount of adsorbed protein is extremely small, while the amount of eluted protein is 0, resulting in no elution effect.

[0136] Table 7. HPLC detection results without air drying.

[0137]

[0138] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. A method for characterizing the protein removal effect of contact lens care solution, characterized in that, Includes the following steps: S1. After drying the prepared artificial tears at 30-120℃, add purified water to reconstitute the solution to obtain the dried and reconstituted solution, and then test the total protein content. S2. Place the RGP lens in artificial tears and dry it at 30-120°C to obtain a lens with adsorbed protein. S3. Remove the lens with the adsorbed protein, and reconstitute the remaining artificial tears with purified water before testing for residual protein. S4. Place the lens with adsorbed protein taken out in step S3 into the contact lens care solution and physiological saline, respectively. After treatment, detect the protein content in the contact lens care solution and physiological saline, then calculate the protein removal rate of the contact lens care solution and physiological saline, and compare the removal effect. The artificial tears comprise the following components: PBS buffer, lysozyme, sodium hyaluronate, sodium formate, and glucose; the concentration of sodium hyaluronate is 0.1–1.0 mg / ml; the concentration of sodium formate is 0.5–1.0 mg / ml; and the concentration of glucose is 1.0–1.5 mg / ml. The protein content of the solution obtained in each step was determined by HPLC. The chromatographic conditions used for HPLC detection included: a mobile phase of TFA and acetonitrile; and a flow rate of 0.5–2.0 ml / min.

2. The method for characterizing the protein removal effect of contact lens care solution according to claim 1, characterized in that, The formula for calculating the protein clearance rate of the contact lens care solution to be characterized is as follows: P1=C3 / (C-C1) 100% The formula for calculating the protein clearance rate of the physiological saline is as follows: P2=C4 / (C-C1) 100% Wherein, P1 is the protein clearance rate of the contact lens care solution to be characterized, P2 is the protein clearance rate of physiological saline, C is the total protein content of artificial tears, C1 is the residual protein content, C3 is the protein content in the contact lens care solution to be characterized, and C4 is the protein content in physiological saline.

3. The method for characterizing the protein removal effect of contact lens care solution according to claim 1, characterized in that, The concentration of sodium hyaluronate in the artificial tears is 0.15–1.0 mg / ml.

4. The method for characterizing the protein removal effect of contact lens care solution according to claim 1, characterized in that, The concentration of lysozyme in the artificial tears is 2.0–2.5 mg / ml; The PBS buffer solution includes NaCl, Na2HPO4·12H2O, and NaH2PO4·2H2O; The artificial tears contain NaCl at a concentration of 6.0–10.0 mg / ml, Na2HPO4·12H2O at a concentration of 4.0–7.0 mg / ml, and NaH2PO4·2H2O at a concentration of 0.4–0.7 mg / ml.

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