Eye drop composition containing baicalin as well as preparation method and application of eye drop composition

Abstract

The invention relates to the field of medicines, and particularly discloses an eye drop composition containing baicalin as well as a preparation method and application of the eye drop composition. Wherein the eye drop composition is prepared from the following raw materials: baicalin, sodium hyaluronate, an antioxidant, a buffering agent, an osmotic pressure regulator, a pH regulator and a solvent, and the weight volume ratio of the baicalin is 0.5-1.0%; the weight volume ratio of the sodium hyaluronate is 0.05 to 0.2 percent; the weight volume ratio of the antioxidant is 0-0.08%; the pH (Potential of Hydrogen) value of the eye drop composition is 4.5 to 7.0. The eye drop composition disclosed by the invention has relatively good stability, is not easy to degrade baicalin, and can be applied to preparation of medicines for preventing and treating early stage of cataract morbidity.

Description

Technical Field

[0001] The present application relates to the field of medicine, and more specifically, to an eye drop composition containing baicalin, and a preparation method and application thereof. Background Art

[0002] Cataract is caused by the denaturation of lens protein, which leads to lens opacity. Its main symptom is visual impairment. With the extension of the world's average life expectancy, the number of cataract patients is increasing. At present, the treatment of cataract is still surgical treatment. To smoothly implement cataract surgery and effectively promote the recovery of physiological visual function, it is necessary to continuously improve the surgical incision, capsulorhexis shape, operation efficiency, artificial lens design, etc., in the hope of restoring the patient's eye physiological function. After all, surgical treatment has risks and economic pressures. Looking forward to the future, the treatment of cataracts should focus on prevention. For example, the regeneration of the lens, the study of the lens' own antioxidant system, and drug prevention all require further research.

[0003] Scutellaria baicalensis Georgi is derived from the dried root of Scutellaria baicalensis, a plant of the Labiatae family. Baicalin is a flavonoid compound extracted and separated from the root of Scutellaria baicalensis. It has antibacterial, diuretic, anti-inflammatory, anti-allergic, ultraviolet absorption, oxygen free radical scavenging and spasmolytic effects, and has strong anti-cancer effects and other physiological effects. Current studies have shown that the use of baicalin ophthalmic preparations has a good therapeutic effect on cataracts.

[0004] Since baicalin is relatively unstable in aqueous solution, most of the baicalin preparations currently used in clinical practice are solid preparations. In view of the poor stability of baicalin aqueous solution, the general technical solutions in the prior art include: adding antioxidants, adding stabilizers, inclusion complex technology, etc.

[0005] According to current research, when adding antioxidants (such as sodium pyrosulfite), when the antioxidant concentration is 10 times that of baicalin (i.e., sodium pyrosulfite concentration is 0.1 mg / ml, baicalin concentration is 0.01 mg / ml), adding antioxidants has a certain effect on the stability of baicalin in solution. However, this method requires maintaining a high concentration of antioxidants and a low concentration of baicalin, which has certain limitations. In addition, in pharmaceutical preparations, the concentration of baicalin needs to reach a high level to play a better role in cataracts. If the concentration of baicalin in the above study is used, it will not play a role in the treatment of cataracts, and it is still unknown whether an excessively high concentration of antioxidants will have an impact on the eyes; but if the concentration of baicalin is increased, it is still unknown whether the added antioxidants can improve the stability of the baicalin solution.

[0006] Therefore, further research is needed to improve the stability of baicalin in ophthalmic preparations containing baicalin so that the ophthalmic preparations can have a better therapeutic effect on cataracts. Summary of the invention

[0007] In order to solve the problem of how to improve the stability of baicalin in baicalin ophthalmic preparations, the present application provides an eye drop composition containing baicalin, a preparation method and application thereof.

[0008] In the first aspect, the present application provides the following technical solutions: An eye drop composition containing baicalin, wherein the raw materials of the eye drop composition are composed of baicalin, sodium hyaluronate, an antioxidant, a buffer, an osmotic pressure regulator, a pH regulator, and a solvent. The weight volume ratio of the baicalin is 0.5-1.0%; the weight volume ratio of the sodium hyaluronate is 0.05-0.2%; the weight volume ratio of the antioxidant is 0-0.08%; The pH value of the eye drop composition is 4.5-7.0.

[0009] In the present application, the pH value of the eye drop composition is maintained within the range of 4.5-7.0, which is beneficial to improving the dissolution effect of baicalin in the eye drop composition and is less likely to cause irritation during use.

[0010] In the present application, sodium hyaluronate and baicalin are used in combination with each other, and the amount of the two is limited, which effectively delays the possibility of degradation of baicalin in the eye drop composition containing baicalin during the storage process, thereby improving the stability of baicalin in the eye drop composition.

[0011] In order to make the eye drop composition have a therapeutic effect on cataracts, the addition amount of baicalin is controlled at 0.5-1.0% in the present application; in order to make the eye drop composition have a moderate viscosity and at the same time achieve the effect of keeping the corresponding added amount of baicalin stable, the addition amount of sodium hyaluronate is controlled in the present application, so that the eye drop composition in the present application has good stability and stays in the eye for a certain time, thereby improving the prevention and treatment effect of cataracts.

[0012] In the present application, an antioxidant may be used in combination with sodium hyaluronate and baicalin, or no antioxidant may be used. Relatively speaking, the use of an antioxidant in combination with sodium hyaluronate is more conducive to improving the overall stability of the composition, and is less likely to cause baicalin to be degraded, thereby being more conducive to improving the preventive and therapeutic effects of the composition on early cataracts. When no antioxidant is used, the eye drop composition can have better stability in the short term, but it is not conducive to preserving the eye drop composition for a long time.

[0013] Meanwhile, the solvent used in this application is generally pure water.

[0014] Furthermore, the weight average molecular weight of the sodium hyaluronate is not less than 400,000.

[0015] In the present application, the weight average molecular weight of sodium hyaluronate actually used in the preparation of the eye drop composition is much higher than 400,000. Since sodium hyaluronate will continue to degrade during storage and transportation, the weight average molecular weight will gradually decrease, and finally the viscosity will decrease. Therefore, a lower limit of the weight average molecular weight is set to specify the lowest weight average molecular weight of sodium hyaluronate during the shelf life, that is, the weight average molecular weight of sodium hyaluronate is required to be not less than 400,000 during the shelf life.

[0016] Furthermore, the antioxidant is at least one of L-cysteine ​​and sodium pyrosulfite.

[0017] Furthermore, the buffer is at least one or more of potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium hydroxide, and dilute hydrochloric acid.

[0018] Furthermore, the buffer is potassium dihydrogen phosphate and dipotassium hydrogen phosphate.

[0019] Furthermore, the osmotic pressure regulator is at least one of sodium chloride, potassium chloride and mannitol.

[0020] Furthermore, the pH adjuster is at least one of a sodium hydroxide solution and a dilute hydrochloric acid solution.

[0021] Furthermore, the pH value of the eye drop composition is preferably 4.5-6.5; the pH value of the eye drop composition is more preferably 5.6-6.2.

[0022] When the pH value of the composition is within the range of 5.6-6.2, the solubility of baicalin is significantly improved compared with the pH value less than 5.6. The composition of the present application can dissolve baicalin 1 mg / ml, which is higher than the solubility of baicalin at the same pH value reported in the literature, and baicalin is more stable in the pH range of 5.6-6.2 than in an environment with a pH value greater than 6.2, because baicalin degrades more rapidly in an alkaline solution.

[0023] In the second aspect, the present application provides the following technical solutions: A method for preparing an eye drop composition containing baicalin comprises the following steps: Step 1, taking 90% of the solvent at 20-30° C., adding a buffer to the solvent after nitrogen filling for 30 minutes, and mixing thoroughly to obtain a buffer; Step 2: Mix the sodium hyaluronate, antioxidant, and osmotic pressure regulator thoroughly and then add them to the buffer solution, continue to mix thoroughly, then add baicalin and mix evenly, finally add the pH regulator, stir until the solution is clear, continue to mix for 60 minutes, make up to volume with a solvent, mix for another 30 minutes, and obtain an eye drop composition after filtering.

[0024] By adopting the above technical solution, after sodium hyaluronate, antioxidants, and osmotic pressure regulators are added to the buffer solution, they are fully mixed so that the baicalin added later can fully contact the entire liquid system and is more easily dissolved in the entire liquid system. After adding the pH regulator and after the solvent is fixed to volume, stirring is continued in order to allow the added raw materials to be fully dissolved and mixed more evenly, thereby exerting a more stable effect.

[0025] In the third aspect, the present application provides the following technical solutions: Application of an eye drop composition containing baicalin in the preparation of a medicine for preventing and treating the early stage of cataract.

[0026] The eye drop composition in the present application can be used as a drug for treating and preventing early cataracts, and can have a good effect on the prevention and treatment of cataracts.

[0027] In summary, this application has the following beneficial effects: 1. The main ingredients of the eye drop composition used in the present application are baicalin and sodium hyaluronate, which may or may not be combined with an antioxidant. Although the remaining excipients include an osmotic pressure regulator, a buffer, and a pH regulator, the entire formula composition and preparation method are relatively simple. The obtained eye drop composition has high stability and can be stored for 3-6 months at 40°C. Even if heated at 80°C, it can achieve good stability in a short period of time, which shows that the raw materials in the present application can greatly reduce the possibility of baicalin degradation under mutual compatibility; at the same time, the eye drop composition in the present application has been confirmed by animal experiments to have no mucosal irritation and no visible adverse reactions, and can play a certain role in delaying and inhibiting the progression of the disease in the early stage of cataract. This shows that a higher concentration of baicalin can be stably present in the composition and play a better role in inhibiting or preventing cataracts, and has a high prospect for commercial production.

[0028] 2. The weight average molecular weight of sodium hyaluronate is limited in the present application so that the obtained eye drop composition has a moderate viscosity, which allows the eye drop composition to stay in the eye for a longer time during use and is not likely to affect the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1The weight growth curve of each group of suckling mice during the drug intervention period (blank control group, model group, Example 6 group, control example 1 group, control example 2 group); Figure 2 Cataract score curves of both eyes during drug intervention (blank control group, model group, Example 6 group, control example 1 group, control example 2 group). DETAILED DESCRIPTION

[0030] Preparation Example Preparation Example 1: Preparation of Phosphate Buffer Weigh 8.34 g of potassium dihydrogen phosphate and 0.87 g of dipotassium hydrogen phosphate, add water to dissolve to 1000 ml to obtain a phosphate buffer solution, and the pH value of the phosphate buffer solution is about 5.8. Example

[0031] The raw materials used in this application are all commercially available materials, as follows: Baicalin, chemical formula is C21H18O11, CAS registration number is 21967-41-9; Sodium metabisulfite, chemical formula is Na2S2O5, CAS registration number is 7681-57-4; Sodium hyaluronate is an acid mucopolysaccharide extracted from cockscomb or the fermentation broth of microorganism [Streptococcus equine]. It is a sodium salt of glycosaminoglycan composed of D-glucuronic acid and N-acetyl-D-glucosamine disaccharide units. Its chemical formula is (C14H20NNaO11) n ; CAS registration number is 9067-32-7; Other materials used are commercially available products.

[0032] Example 1: An eye drop composition containing baicalin, wherein the ingredients contained are as shown in Table 1.

[0033] Under nitrogen protection, take 90 ml of the phosphate buffer prepared in Preparation Example 1, add 0.56 g of an osmotic pressure regulator (sodium chloride), stir to dissolve, add sodium hyaluronate and stir for 30 minutes to dissolve, add baicalin and then add dropwise a 10% sodium hydroxide solution as a pH regulator until the solution is clear, stir for 30 minutes, add the phosphate buffer obtained in Preparation Example 1 to 100 ml, and obtain an eye drop composition.

[0034] The weight average molecular weight of the sodium hyaluronate used in Example 1 is 1,260,000.

[0035] Example 2: An eye drop composition containing baicalin, which differs from Example 1 in that an antioxidant is also used, and the antioxidant is 0.02 g of L-cysteine. The ingredients contained therein are shown in Table 1.

[0036] The preparation method of the eye drop composition is as follows: Under nitrogen protection, 90 ml of the phosphate buffer prepared in Preparation Example 1 was measured, sodium chloride, sodium hyaluronate, and L-cysteine ​​were added, and stirred for 45 minutes. After baicalin was added and stirred and dispersed, a 10% sodium hydroxide solution was added dropwise as a pH adjuster until the baicalin was dissolved, stirred for 60 minutes, and the phosphate buffer obtained in Preparation Example 1 was added to the scale to obtain.

[0037] Example 3: An eye drop composition containing baicalin, which is different from Example 1 in that an antioxidant is also used, and the antioxidant is 0.020g of sodium metabisulfite, and the ingredients contained therein are shown in Table 1.

[0038] The preparation method of the eye drop composition is as follows: Under nitrogen protection, 90 ml of the phosphate buffer prepared in Preparation Example 1 was measured, sodium chloride, sodium pyrosulfite, and sodium hyaluronate were added, and the mixture was stirred for 45 min. Baicalin was added and stirred to disperse. A 10% sodium hydroxide solution was added dropwise as a pH adjuster until the solution was clear. The mixture was stirred for 60 min, and the phosphate buffer obtained in Preparation Example 1 was added to the scale to obtain.

[0039] Example 4-7: An eye drop composition containing baicalin, which is different from Example 1 in that the addition amount of the antioxidant sodium pyrosulfite is set, and the specific addition amounts of the components are shown in Table 1.

[0040] Example 8: An eye drop composition containing baicalin, which is different from Example 1 in that the amounts of sodium chloride and sodium hyaluronate are different. The specific amounts of the components added are shown in Table 1.

[0041] The preparation method of the eye drop composition of Example 4-8 is as follows: Under nitrogen protection, 90 ml of the phosphate buffer prepared in Preparation Example 1 was measured, sodium chloride, sodium pyrosulfite, and sodium hyaluronate were added, and the mixture was stirred for 45 min. Baicalin was added and stirred to disperse. A 10% sodium hydroxide solution was added dropwise as a pH adjuster until the solution was clarified. The mixture was stirred for 60 min. The phosphate buffer obtained in Preparation Example 1 was added to 100 ml, and the mixture was stirred evenly. The mixture was filtered using a 0.22 μm filter membrane to obtain the product.

[0042] Example 9-10: An eye drop composition containing baicalin, which is different from Example 1 in that the amount of sodium hyaluronate is increased, and an antioxidant sodium metabisulfite is also added in Example 9. The specific amounts of the components added are shown in Table 1.

[0043] Example 11: An eye drop composition containing baicalin, which is different from Example 1 in that mannitol is used instead of sodium chloride as an osmotic pressure regulator, and the specific addition amounts of the components are shown in Table 1.

[0044] The preparation method of the eye drop composition of Examples 9-11 is as follows: Under nitrogen protection, 900 ml of the phosphate buffer prepared in Preparation Example 1 was measured, sodium chloride, sodium pyrosulfite, and sodium hyaluronate were added, and the mixture was stirred for 45 min. Baicalin was added and stirred to disperse. A 10% sodium hydroxide solution was added dropwise as a pH adjuster until the solution was clarified. The mixture was stirred for 60 min. The phosphate buffer obtained in Preparation Example 1 was added to 1000 ml, and the mixture was stirred evenly. The mixture was filtered using a 0.22 μm filter membrane to obtain the product.

[0045] Examples 12-15: An eye drop composition containing baicalin, which differs from Example 1 in that the amount of baicalin is adjusted, the amount of sodium chloride is adjusted according to the osmotic pressure, the amount of sodium hyaluronate is reduced, and 0.08 g / 100 ml of sodium pyrosulfite is used. The pH value is adjusted differently in each example, and the specific ingredients are shown in Table 1.

[0046] The preparation method of the eye drop composition of Examples 12-15 is as follows: Under nitrogen protection, 90 ml of the phosphate buffer prepared in Preparation Example 1 was measured, sodium chloride, sodium pyrosulfite, and sodium hyaluronate were added, and the mixture was stirred for 45 min. Baicalin was added and stirred to disperse, and a 10% sodium hydroxide solution was added dropwise as a pH adjuster until the solution was clear, and the mixture was stirred for 60 min. The phosphate buffer obtained in Preparation Example 1 was added to 100 ml, and the mixture was stirred evenly. The pH value of Examples 12 and 13 was adjusted to about 5.60, and the pH value of Examples 14 and 15 was adjusted to 6.20. Finally, the mixture was filtered with a 0.22 μm filter membrane to obtain the mixture.

[0047] Table 1 Ingredients and dosages used in Examples 1-15 Characterization test: 1. Determination method of baicalin eye drops and related substances, baicalin The assay method is described as follows: Octadecylsilane bonded silica gel was used as filler (Kromasil C18 4.6×150mm 5μm or a chromatographic column with equivalent performance); methanol-water-phosphoric acid (42:58:0.2) was used as mobile phase; column temperature was 30°C; detection wavelength was 280nm; flow rate was 1.0ml per minute; injection volume was 10μl.

[0048] Test solution: Accurately measure an appropriate amount of baicalin eye drops and dilute with pH 6.2 phosphate buffer to make a solution containing approximately 60 μg of baicalin per 1 ml.

[0049] Reference solution: Take about 12 mg of baicalin reference substance, accurately weigh it, place it in a 20 ml volumetric flask, add methanol to dissolve and dilute to the scale, shake well, accurately measure 1 ml, place it in a 10 ml volumetric flask, dilute to the scale with pH 6.2 phosphate buffer, and shake well.

[0050] The relevant substance inspection methods are described as follows: Octadecylsilane bonded silica gel was used as filler (YMC ODS-AQ C18 4.6×250mm, 5μm or chromatographic column with equivalent performance); acetonitrile-0.1% phosphoric acid solution (20:80) was used as mobile phase; the flow rate was 0.8ml per minute; the column temperature was 20°C; the detection wavelength was 280nm; and the injection volume was 10μl.

[0051] Test solution: Accurately measure 3 ml of baicalin eye drops, place in a 50 ml volumetric flask, dilute to the scale with pH 6.2 phosphate buffer, and shake well.

[0052] Reference solution: Take an appropriate amount of baicalin reference, weigh accurately, add pH 6.2 phosphate buffer to dissolve and quantitatively dilute to make a solution containing approximately 6 μg per 1 ml.

[0053] The baicalein test method is described as follows: Use octadecylsilane bonded silica gel as filler (ACE Excel 5C18-AQ 4.6×250mm 5μm or chromatographic column with equivalent performance); use acetonitrile-0.1% phosphoric acid solution (70:30) as mobile phase A, and acetonitrile-0.1% phosphoric acid solution (30:70) as mobile phase B, and perform gradient elution according to the table below; the flow rate is 1.0 ml per minute; the column temperature is 40°C; the detection wavelength is 280nm; the injection volume is 10μl.

[0054] Test solution: Accurately measure 3 ml of baicalin eye drops, place in a 50 ml volumetric flask, dilute to the scale with pH 6.2 phosphate buffer, and shake well.

[0055] Reference solution: Take an appropriate amount of baicalin reference substance, weigh it accurately, dissolve it in methanol and dilute it quantitatively to make a solution containing about 120μg per 1ml as the baicalin reference substance stock solution. Accurately measure an appropriate amount of the above reference substance stock solution and dilute it quantitatively with pH 6.2 phosphate buffer to make a solution containing about 1.2μg per 1ml.

[0056] Test method: The pH value of Example 1 was tested, and the mixture was heated at 80° C. for 10 h. After cooling, the pH value, content and related substances (including the specific impurity baicalein) were measured in turn. The specific results are shown in Table 2.

[0057] Table 2 pH value, content and related substances of Example 1 before and after heating at 80°C for 10 hours From the data in the above table, it can be seen that after being heated at 80°C for 10 hours, the content, related substances, baicalin and viscosity in Example 1 did not change significantly. This result shows that after adding sodium hyaluronate, the stability of baicalin is improved to a certain extent.

[0058] Furthermore, the pH value of Example 2-3 was tested, and the mixture was heated at 80°C for 10 h. After cooling, the pH value, content and related substances (including the specific impurity baicalein) were measured in turn. The specific results are shown in Table 3.

[0059] Table 3 pH value, content and related substances of Example 2-3 before and after heating at 80°C for 10 hours The main difference between Example 2 and Example 3 and Example 1 is that the amount of sodium hyaluronate added in Examples 2 and 3 is 0.05g, which is half of the amount added in Example 1, and 0.20g of antioxidant L-cysteine ​​is also added in Example 2, while 0.02g of antioxidant sodium pyrosulfite is added in Example 3. It can be seen from the above table that after Example 2 is heated at 80°C for 10h, precipitation occurs at the bottom of the solution, but it does not occur in Example 3; and in Example 2 and Example 3, the content, related substances, and baicalin do not change significantly. The results show that the combination of sodium hyaluronate and antioxidant L-cysteine ​​or sodium pyrosulfite has a certain promoting effect on the stability of baicalin, and sodium pyrosulfite has a better effect on promoting the stability of baicalin solution.

[0060] Furthermore, the pH values ​​of Examples 4-8 and 12-15 were tested, and accelerated tests were conducted at 40°C. Samples were taken at the end of March and June to observe the appearance and properties, and to determine the contents and related substances. The specific results are shown in Table 4.

[0061] Table 4 pH value, content and related substances of Examples 4-8, 12-15 after 3 months and 6 months at 40°C In Examples 4-8, the addition amounts of baicalin, phosphate buffer, sodium chloride, and sodium hyaluronate are the same, and the main difference is that the amount of sodium pyrosulfite added therein is different. Combined with the test results in the table, in Example 4-5, crystals will precipitate in the 3rd or 6th month, which indicates that when the addition amount of sodium pyrosulfite is greater than 0.08%, as the storage time increases, baicalin crystals will precipitate, resulting in a sharp decrease in the content in Example 4-5. Analysis and identification of the precipitate components revealed the presence of baicalin sulfonate in the precipitate, which is the result of the action of sodium pyrosulfite and baicalin. This further indicates that sodium pyrosulfite does not improve the stability of baicalin in the sense that the higher the amount of sodium pyrosulfite used, the better, which is contrary to the data teaching of existing literature.

[0062] Take Examples 6, 7 and 8, and measure the viscosity at room temperature of 25°C, using rotor No. 18 and a speed of 200 rpm. The results are 2.10 centipoise, 2.02 centipoise and 2.48 centipoise respectively. This shows that when the concentration of sodium hyaluronate is 0.05%, the viscosity of the eye drop composition is about 2 centipoise, but when the amount of sodium hyaluronate added is less than 0.05%, the viscosity of the eye drop composition is lower, resulting in a shorter stay time of the eye drop composition in the eye, which is not conducive to the efficacy of baicalin; if the amount of sodium hyaluronate added is greater than 0.2%, the viscosity of the eye drop composition will be too high and affect the fluidity, and also affect the use experience to a certain extent. In Examples 2-9 and 12-15, the solution viscosity is in the range of 2.04 to 2.78 centipoise.

[0063] Examples 12-15 show that when the baicalin content is 0.5% and 0.8%, and the pH value is in the range of 5.6-6.2, the baicalin eye drops are subjected to an accelerated test at 40°C, and the baicalin content is stable and the degradation substances are less, reflecting that within this range, under the specific ratio of baicalin, sodium hyaluronate and sodium metabisulfite, the stability of the baicalin solution is effectively improved.

[0064] The sample of Example 6 was placed at 40° C. for 6 months, and the molecular weight of sodium hyaluronate was measured by multi-angle laser light scattering coupled with size exclusion chromatography, and the result was 398,500, indicating that the weight average molecular weight of sodium hyaluronate in baicalin eye drops is not less than 400,000.

[0065] Furthermore, the pH value of Examples 9-10 was tested, and an accelerated test was conducted at 40°C. Samples were taken at the end of March and June to observe the appearance and properties, and to determine the content and related substances. The specific results are shown in Table 5.

[0066] Table 5 pH value, content and related substances of Examples 9-10 after 3 months and 6 months at 40°C In the accelerated test process of Example 9 and Example 10, although there were no unfavorable changes in texture, pH value, content, and related substances, Example 9 and Example 10 were prepared into 1L volume solutions, and the time for filtering through a filter membrane with a pore size of 0.22μm was 42min and 51min respectively. It can be seen that the filtration process is time-consuming, and the filter is subjected to a large pressure difference, which is not conducive to the sterilization operation and effect in industrial production, and thus affects the safety of eye drops in microbial control. In terms of content and related substances, the use of sodium hyaluronate at a higher level did not improve the product stability more beneficially. Referring to the prescription ratio of Example 6, when the amount of sodium hyaluronate was changed to 0.2%, the viscosity of the prepared baicalin eye drops was 18.9 centipoise, and the stability of the formula was still good. After being placed at 40°C for 6 months, the content decreased by less than 3%, and the related substances were less than 2%. Therefore, the upper limit of the amount of sodium hyaluronate used in this application is controlled to be 0.2% (g / v).

[0067] Further, Example 11 is a yellow-green clear liquid, with a pH value of 5.89, a content of 98.20%, and a related substance detection amount of 0.85%; after being placed at 40°C for 6 months, no crystals were observed in the solution, and except that the solution color deepened to brownish yellow, the content and the determination results of related substances did not show significant changes. This result shows that both mannitol and sodium chloride can be added to the eye drop composition as osmotic pressure regulators for use.

[0068] Comparative Example Comparative Example 1-2: An eye drop composition, which differs from Example 1 in that sodium hyaluronate is not added. The specific ingredients used and the corresponding amounts are shown in Table 6.

[0069] The preparation method of Comparative Example 1-2 is as follows: Measure 180 ml of water at room temperature of 25°C, add sodium chloride under nitrogen filling conditions, stir to dissolve, add baicalin, stir to disperse, and visually no lumps, then add sodium hydroxide solution to adjust the pH value (the pH value of Comparative Example 1 is 6.75, and the pH value of Comparative Example 2 is 6.72), stir until baicalin is visually dissolved, add water to 200 ml, filter, and obtain.

[0070] Table 6 Ingredients and dosages used in Comparative Examples 1-2 Comparative Example Baicalin(g) Phosphate buffer (ml) Sodium chloride (g) Mannitol(g) Comparative Example 1 2.02 200 1.7 / Comparative Example 2 2.03 200 / 9.6 The comparative example 1-2 was placed at room temperature, and the pH value and appearance of the eye drop composition were observed on the 0th day and 3 months after placement, as shown in Table 7.

[0071] Table 7 Changes in pH value and appearance of comparative example 1-2 before and after 3 months of storage From the results of Comparative Example 1-2 in Table 7, it can be seen that after Comparative Example 1-2 was placed at room temperature for 3 months, the pH value and content showed a downward trend, and the solution color became darker and the solution became turbid, indicating that the properties of the solution had changed. This result shows that when sodium hyaluronate is not added to the eye drop composition containing 1% (g / v) baicalin, the composition is prone to poor stability and turbidity within 3 months.

[0072] Comparative Example 3-6: An eye drop composition, which differs from Example 1 in that sodium hyaluronate is not added, and different amounts of cyclodextrin are added. The specific ingredients used and the corresponding amounts are shown in Table 8.

[0073] The preparation methods of Comparative Examples 3-6 are as follows: At room temperature of 25°C and nitrogen filling, take 90 ml of the phosphate buffer obtained in Preparation Example 1, add sodium chloride first according to the amount of components added in Table 2, add the corresponding type and amount of cyclodextrin, and then add baicalin, stir for 30 minutes, in a turbid state, add a 10% sodium hydroxide solution dropwise as a pH adjuster until the solution is clear, stir for 30 minutes, and add the phosphate buffer obtained in Preparation Example 1 to the scale to obtain the product.

[0074] Table 8 Ingredients and dosages used in comparative examples 3-6 The pH values ​​of Comparative Examples 3-6 were tested respectively, and they were heated at 80° C. for 10 h. After cooling, the pH values, contents and related substances (including the specific impurity baicalin) were measured in turn. The specific results are shown in Table 9.

[0075] Table 9 pH value, content and related substances of comparative examples 3-6 before and after heating at 80°C for 10 hours Combined with the preparation method of comparative examples 3-6 and the results of comparative examples 3-6 in Table 9, it can be seen that when the concentration of baicalin is 10 mg / ml, after adding different types of cyclodextrin, baicalin in each comparative example is not completely dissolved. Therefore, different types of cyclodextrins do not play a solubilizing role, and it is still necessary to drip 10% sodium hydroxide solution to adjust the pH value so that baicalin is fully dissolved. In the inspection items of related substances and baicalin in each comparative example, after using cyclodextrin, under the condition of high temperature (80°C) destruction, the detection amount of related substances and baicalin increased significantly, which shows that in the presence of the above four cyclodextrins, the hydrolysis rate of baicalin in the solution state will be accelerated, thereby affecting the stability of the eye drop composition. Therefore, the conclusion is: when sodium hyaluronate is not used, even if cyclodextrin is used, the stability of baicalin in the eye drop composition cannot be improved.

[0076] Comparative Example 7-9: An eye drop composition, which differs from Example 1 in that sodium hyaluronate is not added, and different amounts of antioxidants are added. The specific ingredients used and the corresponding amounts are shown in Table 10.

[0077] The preparation methods of Comparative Examples 7-9 are as follows: At room temperature of 25°C and nitrogen filling, take 90 ml of the phosphate buffer obtained in Preparation Example 1, add sodium chloride, sodium pyrosulfite or L-cysteine ​​according to the amount of components added in Table 3, then add baicalin, stir for 30 minutes, in a turbid state, add a 10% sodium hydroxide solution dropwise as a pH adjuster until the solution is clear, stir for 30 minutes, and add the phosphate buffer obtained in Preparation Example 1 to the scale to obtain the solution.

[0078] Table 10 Ingredients and dosages used in comparative examples 7-9 The pH values ​​of Comparative Examples 7-9 were tested respectively, and they were heated at 80° C. for 10 h. After cooling, the pH values, contents and related substances (including the specific impurity baicalein) were measured in turn. The specific results are shown in Table 11.

[0079] Table 11 pH value, content and related substances of comparative examples 7-9 before and after heating at 80°C for 10 hours Combining the preparation methods of Comparative Examples 7-9 and the results of Comparative Examples 7-9 in Table 11, it can be seen that after heating at 80°C for 10 hours, the content and baicalin detection results of Comparative Example 7 containing sodium pyrosulfite did not change significantly except that the related substances increased to a certain extent after heating; while the color of Comparative Example 8 containing L-cysteine ​​became obviously darker, and a small amount of precipitate was generated. The baicalin detection result of Comparative Example 9 was higher than that of Comparative Example 7, and the related substance detection results of Comparative Example 9 were higher than those of Comparative Example 8. The above situation can be concluded that: relatively speaking, the use of sodium pyrosulfite as an antioxidant can achieve a better effect of improving the stability of baicalin.

[0080] The same method was used to test Example 1 and Comparative Example 9. The main difference between Comparative Example 9 and Example 1 is that sodium hyaluronate is not added in Comparative Example 9, and the pH values ​​of the two are slightly different. The other ingredients and corresponding amounts are the same.

[0081] Table 12 pH value, content and related substances of Example 1 and Comparative Example 9 before and after heating at 80°C for 10 hours By comparing the situations of Example 1 and Comparative Example 9 in Table 12, it can be seen that the test results of the two are different. The possible reason is that: Comparative Example 9 does not contain sodium hyaluronate. After heating at 80°C for 10 hours, the related substances and baicalin are significantly improved, which indicates that when sodium hyaluronate is not added in Comparative Example 9, baicalin has poor stability and is decomposed; and the viscosity of Comparative Example 9 is lower than that of Example 1.

[0082] Combined with the test results of Comparative Examples 7-8 and the test results of Example 1 and Comparative Example 9, it can be seen that without adding sodium hyaluronate to the eye drop composition, after heating at 80°C for 10 hours, the content of related substances and baicalin in the composition is easily greatly increased, indicating that sodium hyaluronate has a certain effect on improving the stability of baicalin.

[0083] Pharmacodynamics test: The above Example 6, Comparative Example 10 Bingzhen Quyi Eye Drops, Comparative Example 11 Aminiotide Eye Drops (Comparative Example 10 and Comparative Example 11 are both from commercially available preparations), and a blank of normal saline were used for an exploratory experiment on the initial prevention and treatment of selenium-type cataract animal models: Take 10 SPF Wistar pregnant mice to be delivered; use the suckling mice between 12 and 15 days old produced by the pregnant mice. According to the weight of the suckling mice, they are randomly divided into 5 groups, of which 10 are in group 1 and 12 are in groups 2 to 5. The suckling mice in groups 2 to 5 are injected with sodium selenite saline solution, and 30 minutes and 1 hour before modeling, blank saline, Example 6, Comparative Example 10 and Comparative Example 11 are administered twice by eye drops (5 μL / eye), respectively. 30 minutes after the second administration, groups 2 to 5 are subcutaneously injected with sodium selenite saline solution at a dosage of 5.76 mg / kg (30 μmol / kg; administration volume 6.00 ml / kg) for modeling, and group 1 is given 6.00 ml / kg of saline. 2-5 groups were administered with eye drops (5 μL / eye) of blank saline, Example 6, Comparative Example 10 and Comparative Example 11 at 3 hours and 5 hours after modeling was completed on the same day. 1 group was administered with eye drops (5 μL / eye) of blank saline at the same time. Thereafter, in 2-7 days, each group was administered with eye drops (5 μL / eye) of each of the above drugs at 9:00 a.m. and 11:00 a.m., 13:00 p.m. and 15:00 p.m. every day. Every two days, each group of suckling mice was weighed, and the weight change curve of suckling mice during the whole administration was prepared with the average weight of each group of suckling mice and the observation date, and the difference analysis between the groups was performed. On the first and last day of the test, after the mydriasis was dilated by eye drops of tropicamide eye drops at 5 μL / eye / time every day, the turbidity of the lens of each suckling mouse was examined by a slit lamp to evaluate the symptoms of cataract.

[0084] Before euthanizing the experimental mice, take 10 μL of 1% sodium fluorescein solution and drop it into the conjunctival sac of the fornix. Close the eyelids and press gently. After 1 to 2 minutes, observe whether the damaged corneal epithelium is colored or the intact epithelium is not colored. Use a slit lamp to take pictures and score the eyes. This is used to evaluate local toxicity.

[0085] The weight growth trend curve of suckling mice during the experimental investigation is as follows Figure 1 The weight of the suckling mice in each group showed an increasing trend. There was no significant difference in the weight of the suckling mice in Example 6, Comparative Example 10 and Comparative Example 11.

[0086] Cataract scores of the two eyes of the suckling mice during the experimental observation period were as follows Figure 2 As shown. Compared with the blank model group, the score of Example 6 group was lower, which was significant. There was no significant difference between the comparison group 10 and the comparison group 11 and the blank model group. Compared with the comparison group 10 and the comparison group 11, the cataract score of Example 6 group was significantly reduced. During the experiment, the incidence of cataract in the suckling mice in the blank model group, the comparison group 10 and the comparison group 11 showed an upward trend, and the area of ​​​​opaqueness in the inner kernel of the lens gradually increased. The incidence of the above three groups reached 100% in the period from the 5th to the 6th day. After the peak value of 83.33% of the incidence in the Example 6 group was reached on the fifth day, the incidence did not continue to increase, and with the increase of time, the area of ​​​​opaqueness in the inner kernel of the lens showed a trend of reduction.

[0087] Compared with the blank model group, the iris score of the two eyes of the suckling mice in the control group 1 was significantly increased by 54.17% (P=0.0005), and the iris score of the two eyes of the suckling mice in the embodiment 6 group and the comparative example 11 group was reduced by 36.36% and increased by 27.27%, respectively, with no significant difference. Compared with the blank model group, there was no significant difference in the corneal score of the two eyes of the suckling mice in the embodiment 6 group, the comparative example 10 group, and the comparative example 11 group. The results show that the embodiment 6 has no mucosal irritation and visible adverse reactions. By monitoring the weight of suckling mice, cataract symptom evaluation and local toxicity, the embodiment 6 has a certain delay and inhibition effect in the early stage of selenium cataract, and no intolerable toxic side effects are observed.

[0088] The test results of the remaining embodiments are similar to those of Embodiment 6.

[0089] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An eye drop composition containing baicalin, characterized in that: The raw materials of the eye drop composition are composed of baicalin, sodium hyaluronate, antioxidant, buffer, osmotic pressure regulator, pH regulator and solvent. The weight volume ratio of the baicalin is 0.5-1.0%; the weight volume ratio of the sodium hyaluronate is 0.05-0.2%; the weight volume ratio of the antioxidant is 0-0.08%; The pH value of the eye drop composition is 4.5-7.

0.

2. The eye drop composition containing baicalin according to claim 1, characterized in that: The weight average molecular weight of the sodium hyaluronate is not less than 400,000.

3. The eye drop composition containing baicalin according to claim 1, characterized in that: The antioxidant is at least one of L-cysteine ​​and sodium pyrosulfite.

4. The eye drop composition containing baicalin according to claim 1, characterized in that: The buffer is at least one or more of potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium hydroxide, and dilute hydrochloric acid.

5. The eye drop composition containing baicalin according to claim 4, characterized in that: The buffer is potassium dihydrogen phosphate and dipotassium hydrogen phosphate.

6. The eye drop composition containing baicalin according to claim 1, characterized in that: The osmotic pressure regulator is at least one of sodium chloride, potassium chloride and mannitol.

7. The eye drop composition containing baicalin according to claim 1, characterized in that: The pH adjuster is at least one of a sodium hydroxide solution and a dilute hydrochloric acid solution.

8. The eye drop composition containing baicalin according to claim 1, characterized in that: The pH value of the eye drop composition is preferably 4.5-6.5; the pH value of the eye drop composition is more preferably 5.6-6.

2.

9. A method for preparing a baicalin-containing eye drop composition according to any one of claims 1 to 8, characterized in that: The steps include: Step 1, taking 90% of the solvent at 20-30° C., adding a buffer to the solvent after nitrogen filling for 30 minutes, and mixing thoroughly to obtain a buffer; Step 2: Mix the sodium hyaluronate, antioxidant, and osmotic pressure regulator thoroughly and then add them to the buffer solution, continue to mix thoroughly, then add baicalin and mix evenly, finally add the pH regulator, stir until the solution is clear, continue to mix for 60 minutes, make up to volume with a solvent, mix for another 30 minutes, and obtain an eye drop composition after filtering.

10. Use of the baicalin-containing eye drop composition according to any one of claims 1 to 9 in the preparation of a drug for preventing and treating the early stage of cataract.

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