An eye drop composition, a method of preparing the same, and use thereof

Abstract

The application provides a kind of eye drop composition and its preparation method and application, belong to ophthalmic preparation technical field.The eye drop composition used in the application includes the following components: brimonidine tartrate, hyaluronic acid, collagen, trehalose, injection water;By compounding each component, a kind of eye drop capable of realizing brimonidine tartrate sustained release, prolonging the time of antihypertensive effect, and having the characteristics of reducing blinking discomfort, long-acting moisturizing, anti-inflammatory soothing, mild antiseptic, etc. is prepared;The eye drop of the application is helpful to glaucoma, high eye pressure, dry eye, postoperative inflammation or allergy, preservative-sensitive or preservative-allergic population, improves the quality of life, relieves the disease.

Description

Technical Field

[0001] This invention relates to the field of ophthalmic formulation technology, and more particularly to an eye drop composition, its preparation method, and its application. Background Technology

[0002] In recent years, with the increase in screen time, the incidence of glaucoma has also increased significantly. Glaucoma can be classified into primary open-angle glaucoma and primary angle-closure glaucoma. Symptoms of primary open-angle glaucoma often include headache, eye strain, and blurred vision, while symptoms of primary angle-closure glaucoma often include nausea and blurred vision. Glaucoma is a chronic optic neuropathy characterized by damage to the optic disc and retinal nerve fiber layer. It is a leading cause of blindness, the second leading cause of blindness worldwide after cataracts, and the leading cause of irreversible blindness. During glaucoma treatment, ocular surface diseases are often present, manifesting as dry eyes, burning pain, photophobia, decreased vision, corneal damage, and conjunctival congestion. To improve the quality of life for glaucoma patients, alleviate symptoms, and help them recover, eye drops are currently one of the recognized treatment methods for glaucoma.

[0003] Patent CN101797223 B discloses an ophthalmic formulation of huperzine A and its application. The main active ingredient is huperzine A, and the excipients are an in-situ gel matrix, a humectant, and a chelating agent. It is used to treat glaucoma by gelling the liquid in vitro into the eye. However, due to individual differences in ocular environment, such as tear pH and ocular surface temperature, the phase transition stability of the in-situ gel may be affected, resulting in incomplete or premature phase transition, which affects the uniformity of drug spread and retention time, and reduces bioavailability.

[0004] Patent CN115068416 A discloses a method for preparing brimonidine tartrate eye drops, using polyvinyl alcohol (PVA) as a humectant. However, PVA, a synthetic polymer, is a Newtonian fluid. While thickening the eye, it can make the eyelids less prone to blinking and irritate the conjunctiva. Furthermore, PVA requires a complex and time-consuming process of first swelling at low temperatures and then dissolving at high temperatures. The dissolution temperature and time also affect the viscosity of the final product, increasing the risk to product quality. Additionally, its pH decreases during the stability period, causing the brimonidine tartrate eye drops to lighten in color. The method uses cationic surfactants such as benzalkonium chloride as preservatives, which ensures antibacterial efficacy after opening, but benzalkonium chloride is irritating to the ocular mucosa and may worsen eye discomfort. Summary of the Invention

[0005] This invention provides an eye drop composition, its preparation method, and its application. One objective is to address the current lack of a viscoelastic network formed by hyaluronic acid and collagen to achieve a sustained-release effect of brimonidine tartrate, prolonging its hypotensive effect, and, with the synergistic effect of trehalose, to stabilize its functional activity, forming a more durable protective film and providing long-lasting moisturizing and lubrication. Another objective of this invention is to improve the chemical stability of the composition, enabling it to act on ocular surface tissue cells, effectively exert anti-inflammatory and soothing effects, and simultaneously release antibacterial active substances for gentle preservation and improved comfort.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An eye drop composition comprising the following components: 0.01-2% (w / v) brimonidine tartrate, 0.01-3% (w / v) hyaluronic acid, 0.1-5% (w / v) collagen, 0.01-5% (w / v) trehalose, with the balance being water for injection.

[0008] Brimonidine tartrate is a selective α2-adrenergic receptor agonist that acts on α2 receptors in the ciliary body epithelium, reducing aqueous humor production and increasing aqueous humor outflow via the uveal-scleral pathway. It is the main active substance for lowering intraocular pressure and can be used to treat glaucoma and ocular hypertension.

[0009] Hyaluronic acid is widely distributed in human tissues and the extracellular matrix, with high concentrations in the vitreous humor and aqueous humor of the eye. Its random coiled state in solution and non-Newtonian fluid dynamics endow it with many important physical properties, such as high viscoelasticity, plasticity, permeability, and good biocompatibility. Among these, its unique water-retention function is particularly important. Unlike polyvinyl alcohol, a commonly used moisturizer in eye drops, hyaluronic acid can improve the adhesion of eye drops to the eye, prolong retention time, increase drug viscosity, and overcome the drawback of eyelids not blinking easily. Under normal circumstances, naturally occurring hyaluronic acid on the ocular surface forms a film covering the corneal epithelium. Because the corneal epithelium has specific binding sites for hyaluronic acid, drugs containing hyaluronic acid can remain on the ocular surface for a long time, facilitating long-term and effective absorption by ocular tissues, thereby increasing drug bioavailability. Simultaneously, hyaluronic acid is readily soluble in water and has stable pH properties.

[0010] Collagen can form a hydrophilic protective film on the surface of the eye, physically isolating it from external stimuli, reducing water evaporation, protecting the corneal epithelium, providing an extracellular matrix-like environment, and promoting the migration and repair of corneal epithelial cells.

[0011] Trehalose stabilizes cell membrane structure, protecting corneal epithelial cells from damage caused by osmotic pressure changes and oxidative stress. It also has certain hygroscopic and moisturizing properties, maintaining the isotonicity of eye drops and tears, reducing irritation. At the same time, it can inhibit the release of inflammatory factors, alleviate ocular surface inflammation, scavenge free radicals, and protect ocular tissues from oxidative damage.

[0012] In this invention, long-chain hyaluronic acid molecules can interact with collagen through physical entanglement and intermolecular hydrogen bonds, particularly with hydrolyzed collagen peptides. Under near-neutral pH conditions, hyaluronic acid carries a strong negative charge, while collagen is nearly electrically neutral, enabling the formation of a relatively stable viscoelastic network structure. This significantly increases solution viscosity, prolongs retention time on the ocular surface, enhances moisturizing effects, and forms a long-lasting and stable protective film. Because brimonidine tartrate carries a positive charge under near-neutral conditions, it can be encapsulated by electrostatic adsorption within a framework of long-chain hyaluronic acid and cross-linked by small-molecule collagen peptides. In the viscoelastic network formed, brimonidine tartrate can be bound in the gaps of the network formed by the combination of carboxyl groups and hydrogen bonds. Due to the positive and negative ionic bonds generated, it can be slowly released, achieving a sustained-release effect, which may prolong the antihypertensive effect and exert a sustained effect without the need for frequent dosing. Small molecule trehalose can fill the viscoelastic network structure, making the network more uniform and stable, further stabilizing brimonidine tartrate, while protecting collagen molecules from aggregation or denaturation in solution or during the drying process of the ocular surface, thus maintaining their functional activity.

[0013] Preferably, the product comprises the following components: 0.05-1% (w / v) brimonidine tartrate, 0.05-1.5% (w / v) hyaluronic acid, 0.15-3% (w / v) collagen, 0.1-4% (w / v) trehalose, with the balance being water for injection.

[0014] As a preferred embodiment, it comprises the following components: 0.1-0.2% (w / v) brimonidine tartrate, 0.1-0.3% (w / v) hyaluronic acid, 0.5-1.5% (w / v) collagen, 1-3% (w / v) trehalose, and the balance being water for injection.

[0015] Preferably, the components further include: 0.05-0.1% (w / v) dipotassium glycyrrhizate and 0.1-2% (w / v) borate buffer pair.

[0016] In this invention, a borate buffer is used to maintain a stable near-neutral pH environment, which enhances the solubility of dipotassium glycyrrhizate and improves its chemical stability, enabling it to effectively exert its anti-inflammatory and soothing effects, inhibit phospholipase A2 activity, reduce the production of inflammatory mediators such as prostaglandins and leukotrienes, and inhibit histamine release and allergic reactions. Dipotassium glycyrrhizate dissolves in a viscoelastic network structure and, upon remaining on the ocular surface, acts on ocular surface tissue cells, synergistically enhancing the local anti-inflammatory effect with trehalose. The borate buffer stabilizes the pH while regulating osmotic pressure, allowing the active ingredients of the eye drops to function effectively; it also releases free boric acid molecules, producing an antibacterial effect, unlike preservatives used in existing technologies such as benzalkonium chloride, reducing the risk of preservative toxicity, achieving a mild preservative effect, and alleviating discomfort such as redness, itching, and burning caused by drugs, dry eyes, or irritation on the ocular surface.

[0017] Preferably, in the components, the ratio of brimonidine tartrate to hyaluronic acid is 1:1-2; and the ratio of hyaluronic acid to collagen is 1:1-10.

[0018] When the dosage of hyaluronic acid is too low, an effective viscoelastic network cannot be formed, making it difficult to ensure tear film stability. The drug is easily washed away, reducing bioavailability and resulting in poor relief of dry eye. When the dosage is too high, it can cause discomfort when blinking after instillation, induce reflexive tearing, and damage corneal epithelial cells due to the long-term high osmotic pressure environment. When the dosage of collagen is too low, the slow-release viscoelastic network becomes loose, reducing corneal epithelial adhesion and slowing down the repair process. When the dosage is too high, it can cause protein aggregation to form microparticles, mechanically rubbing against the cornea and potentially activating an immune response, inducing inflammation.

[0019] Preferably, the collagen is one of type III human collagen, porcine tendon extract, or bovine tendon extract.

[0020] Preferably, in the components, the hyaluronic acid has a molecular weight of 1-1.5 MDa; and when the collagen is type III human collagen, the molecular weight is not higher than 10 kDa.

[0021] Hyaluronic acid, through its high molecular weight, can form a three-dimensional network of hydration film on the ocular surface. It captures a large amount of water through hydrogen bonds, prolonging the drug's residence time, improving bioavailability, reducing mechanical friction from blinking, and relieving dry eye symptoms. Type III human collagen has a sequence identical to the body's own type III collagen, does not cause immune rejection, is suitable for long-term use, and has high safety for sensitive dry eye patients. Furthermore, small molecule peptides can penetrate and permeate the corneal epithelial space, acting on basal cells, stimulating mucin secretion, repairing the three-layer structure of the tear film, enhancing the strength of the viscoelastic network formed with hyaluronic acid, and maintaining the integrity of the moisturizing film, unlike large molecule collagen which only enhances moisturizing or lubrication. The molecular weights of hyaluronic acid and collagen can exceed the optimal range.

[0022] Preferably, the ratio of dipotassium glycyrrhizate to hyaluronic acid in the components is 1:5-30.

[0023] The main function of dipotassium glycyrrhizate is anti-inflammatory, which can effectively reduce the irritation of brimonidine tartrate. However, when the dosage is insufficient, it is difficult to inhibit phospholipase A2 and increase the release of prostaglandins, resulting in a burning sensation after instillation. At the same time, excessive dosage will damage the lipid layer of the tear film and inhibit corneal cell proliferation.

[0024] The present invention also employs another technical solution:

[0025] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0026] Add borate buffer, hyaluronic acid, collagen, brimonidine tartrate, trehalose, and dipotassium glycyrrhizate to the injection water in sequence, stir thoroughly until dissolved, add injection water to make up the volume, and then filter, sterilize, and dispense.

[0027] Preferably, in the above steps, trehalose is used to adjust the osmotic pressure to 280-310 mOsm / kg; and a borate buffer is used to adjust the pH to 6.8-7.8.

[0028] This invention regulates osmotic pressure to maintain the hydration balance of corneal epithelial cells, creating a near-isotonic environment, close to the osmotic pressure of tears. This avoids cell edema and rupture due to hypotonicity or cell dehydration caused by hypertonicity, protecting the tightness of corneal epithelial junctions and preventing irritation from deep tissues after instillation. It effectively reduces potential stinging or other discomfort after instillation. Simultaneously, by regulating osmotic pressure, it avoids disrupting the stability of the tear film lipid layer, alleviating dry eye symptoms. The resulting viscoelastic network enhances the durability of the moisturizing film. It also increases the corneal permeability of brimonidine tartrate, reducing reflexive tear secretion that washes away active substances and lowers bioavailability. Adjusting the pH to near neutral improves component solubility, promotes the formation of the viscoelastic network structure, and enhances user comfort, preventing reflexive eye closure or tear flushing and reducing residence time. By promoting the release of free boric acid, it enhances antibacterial properties, avoiding the use of traditional preservatives that can cause corneal toxicity.

[0029] The present invention also employs another technical solution:

[0030] The use of an eye drop composition in the preparation of ophthalmic preparations for lowering intraocular pressure.

[0031] The active substances in this invention have the property of lowering intraocular pressure, making them suitable for people with glaucoma and high intraocular pressure; the formed viscoelastic network structure can provide long-lasting hydration and promote ocular surface repair, which is helpful for people with dry eye syndrome; and its anti-inflammatory effect is also suitable for people with postoperative inflammation or allergies, providing a soothing effect; at the same time, no traditional preservatives are added, and there is no preservative toxicity, so people who are sensitive to or allergic to preservatives can use it.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] This invention forms a stable viscoelastic network structure to encapsulate brimonidine tartrate, increasing the viscosity of the eye drops, prolonging the retention time on the ocular surface, enhancing the moisturizing effect, maintaining the durability of the moisturizing film, synergistically providing triple moisturizing with trehalose, and promoting the migration and repair of corneal epithelial cells.

[0034] This invention can maintain the stability of the tear film, reduce discomfort or irritation caused by blinking after instillation, avoid inducing reflexive tearing, flush out active substances, and reduce bioavailability.

[0035] This invention does not use traditional preservatives, effectively reducing the risk of ocular surface toxicity and enhancing antibacterial properties. This invention is suitable for individuals with glaucoma, high intraocular pressure, dry eye syndrome, postoperative inflammation or allergies, or those sensitive to or allergic to preservatives. Detailed Implementation

[0036] The present invention will now be described through specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of the inventive concept are included in the present invention, and the scope of protection of the present invention is defined by the appended claims and any equivalents thereof.

[0037] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Unless otherwise specified, the raw materials and equipment used in this invention are conventional in the art and can be obtained through conventional commercial means; unless otherwise specified, the methods used in this invention are conventional methods in the art.

[0038] The specific embodiments and test evaluations conducted by the applicant of this invention are as follows:

[0039] Example 1

[0040] An eye drop composition comprising the following components: 0.15% (w / v) brimonidine tartrate, 0.15% (w / v) hyaluronic acid, 1% (w / v) collagen, 1.5% (w / v) trehalose, 0.1% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer, and water for injection.

[0041] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0042] S1: Weigh each component for later use;

[0043] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0044] S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved;

[0045] S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved;

[0046] S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg.

[0047] S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0048] Example 2

[0049] An eye drop composition comprising the following components: 0.15% (w / v) brimonidine tartrate, 0.15% (w / v) hyaluronic acid, 1% (w / v) collagen, 1.5% (w / v) trehalose, 0.05% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer, and water for injection.

[0050] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0051] S1: Weigh each component for later use;

[0052] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0053] S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved;

[0054] S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved;

[0055] S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg.

[0056] S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0057] Example 3

[0058] An eye drop composition comprising the following components: 0.1% (w / v) brimonidine tartrate, 0.1% (w / v) hyaluronic acid, 0.5% (w / v) collagen, 0.5% (w / v) trehalose, 0.05% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer, and water for injection.

[0059] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0060] S1: Weigh each component for later use;

[0061] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0062] S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved;

[0063] S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved;

[0064] S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg.

[0065] S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0066] Example 4

[0067] An eye drop composition comprising the following components: 0.2% (w / v) brimonidine tartrate, 0.3% (w / v) hyaluronic acid, 1.5% (w / v) collagen, 1% (w / v) trehalose, 0.1% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer, and water for injection.

[0068] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0069] S1: Weigh each component for later use;

[0070] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0071] S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved;

[0072] S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved;

[0073] S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg.

[0074] S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0075] Example 5

[0076] An eye drop composition comprising the following components: 1% (w / v) brimonidine tartrate, 1% (w / v) hyaluronic acid, 2.5% (w / v) collagen, 3% (w / v) trehalose, 0.1% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer, and water for injection.

[0077] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0078] S1: Weigh each component for later use;

[0079] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0080] S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved;

[0081] S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved;

[0082] S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg.

[0083] S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0084] Example 6

[0085] An eye drop composition comprising the following components: 1% (w / v) brimonidine tartrate, 1.5% (w / v) hyaluronic acid, 3% (w / v) collagen, 4% (w / v) trehalose, 0.1% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer, and water for injection.

[0086] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0087] S1: Weigh each component for later use;

[0088] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0089] S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved;

[0090] S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved;

[0091] S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg.

[0092] S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0093] Example 7

[0094] An eye drop composition comprising the following components: 2% (w / v) brimonidine tartrate, 3% (w / v) hyaluronic acid, 5% (w / v) collagen, 5% (w / v) trehalose, 0.1% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer, and water for injection.

[0095] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0096] S1: Weigh each component for later use;

[0097] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0098] S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved;

[0099] S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved;

[0100] S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg.

[0101] S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0102] Comparative Example 1

[0103] An eye drop composition comprising the following components: 0.15% (w / v) brimonidine tartrate, 1% (w / v) collagen, 1.5% (w / v) trehalose, 0.1% (w / v) dipotassium glycyrrhizate, not more than 2% (w / v) borate buffer pair, and water for injection.

[0104] Based on the above-mentioned eye drop composition, a method for preparing eye drops includes the following steps:

[0105] S1: Weigh each component for later use;

[0106] S2: Dissolve the borate buffer in water for injection and adjust the pH;

[0107] S3: Add collagen and brimonidine tartrate to the solution obtained in step S2 in sequence, and stir thoroughly until dissolved;

[0108] S4: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S3, stir thoroughly until dissolved, add water for injection to make up the volume, and control the pH to 6.8-7.8 and the osmotic pressure to 280-310 mOsm / kg;

[0109] S5: Filter the solution obtained in step S4 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

[0110] Comparative Example 2

[0111] The difference between this comparative example and Example 1 is that no collagen is added.

[0112] Comparative Example 3

[0113] The difference between this comparative example and Example 1 is that dipotassium glycyrrhizate is not added.

[0114] Comparative Example 4

[0115] The difference between this comparative example and Example 4 is the addition of 4% (w / v) hyaluronic acid.

[0116] Comparative Example 5

[0117] The difference between this comparative example and Example 4 is the addition of 6% (w / v) collagen.

[0118] Comparative Example 6

[0119] The difference between this comparative example and Example 4 is the addition of 0.5% (w / v) dipotassium glycyrrhizate.

[0120] Detention time evaluation

[0121] Sodium fluorescein was used as the chromogenic agent to test the in vivo corneal retention time of eye drops in Examples 1-7 and Comparative Examples 1-6. Rabbits were used as the test subjects. The rabbits' heads were fixed, the lower eyelids were lifted, and the conjunctival sac was pulled into a ring shape. 0.1 mL of eye drops containing 0.1% sodium fluorescein solution was instilled into each rabbit. The left eye served as the control eye. After instillation, the rabbits' eyes were closed for 1 minute. The fluorescence fading time of sodium fluorescein in the cornea and conjunctival sac was observed and recorded using a slit lamp. The results are shown in Table 1 below.

[0122] Corneal dwell time (min ± SD) Conjunctival sac retention time (min ± SD) Example 1 66±5 109±7 Example 2 67±8 109±9 Example 3 62±2 102±5 Example 4 68±3 111±6 Example 5 74±2 126±4 Example 6 74±9 122±2 Example 7 76±2 128±1 Comparative Example 1 22±1 19±9 Comparative Example 2 34±4 32±3 Comparative Example 3 61±7 99±9 Comparative Example 4 59±7 88±4 Comparative Example 5 57±4 84±1 Comparative Example 6 60±9 92±8

[0123] As shown in Table 1, the eye drops of the present invention can prolong the retention time on the ocular surface. The present invention utilizes the interaction between hyaluronic acid and collagen through carboxyl groups and hydrogen bonds to form a stable hydrophilic protective film that covers the corneal epithelial surface, thereby improving the adhesion of the eye drops in the eye, prolonging the retention time, and increasing the viscosity of the drug.

[0124] Compared to Example 1, Comparative Example 1, without the addition of hyaluronic acid, showed a significant reduction in corneal retention time and conjunctival sac retention time. This indicates that hyaluronic acid, in synergy with collagen, can enhance its binding ability with the corneal epithelium, effectively prolong its retention time on the ocular surface, and form a stable hydration film that acts as an adhesive barrier. This film can adhere to the ocular surface for a long time, which helps with eyelid blinking and reduces the tear flushing speed.

[0125] Compared to Example 1, Comparative Example 2, without the addition of collagen, showed a significant decrease in corneal retention time and conjunctival sac retention time. This indicates that although hyaluronic acid can specifically bind to the binding sites of the corneal epithelium, the structure of hyaluronic acid itself can be damaged by mechanical shear forces such as blinking, making it difficult to remain on the ocular surface for a long time. The addition of collagen can effectively change this situation. The two can interact to form a stable viscoelastic network with a dense structure, which can remain on the ocular surface for a long time, which is conducive to the long-term and effective absorption of drugs by ocular tissue.

[0126] Experimental results show that dipotassium glycyrrhizate, through its soothing and anti-inflammatory effects, can enhance local anti-inflammatory effects in conjunction with trehalose, reducing tear secretion induced by brimonidine tartrate stimulation, thus allowing the eye drops of this invention to remain on the ocular surface for a longer period of time. When the amount added is insufficient or not added at all, a slight stimulation reflex will occur, tear secretion will increase, and flushing will lead to a decrease in corneal retention time and conjunctival sac retention time. However, excessive use will cause damage to the tear film lipid layer, and the corneal epithelium may become dehydrated, thereby affecting the ocular surface retention time and reducing corneal retention time and conjunctival sac retention time.

[0127] Compared to Example 4, Comparative Example 4 shows that when too much hyaluronic acid is used, the viscosity of the hydrogel film formed on the ocular surface is too high, which can cause discomfort and a foreign body sensation in the eyes, leading to excessive reflexive tear secretion during blinking, damaging corneal epithelial cells, affecting the retention time of eye drops, and reducing corneal retention time and conjunctival sac retention time. It is worth noting that, according to the experimental results, if too little hyaluronic acid is used, the tightness of the viscoelastic network structure formed by it and collagen will be reduced, the solution viscosity will be insufficient, and the ocular surface retention time will decrease.

[0128] Compared to Example 4, in Comparative Example 5, excessive collagen led to protein aggregation and increased particle size, resulting in solution turbidity. This increased mechanical friction from blinking stimulated reflexes, causing tear flushing and reducing corneal and conjunctival sac retention times. It may also have caused inflammation, further affecting the ocular surface retention time of the eye drops. It is worth noting that, according to the experimental results, if...

[0129] If too little collagen is used, the slow-release viscoelastic network formed between collagen and hyaluronic acid will become loose due to insufficient cross-linking, thus reducing corneal epithelial adhesion and decreasing corneal retention time and conjunctival sac retention time.

[0130] Evaluation of intraocular pressure changes

[0131] Rabbits were used as experimental subjects to establish a high intraocular pressure model. 1% methylcellulose was injected into the anterior chamber of rabbits in small amounts and multiple times. The control group was injected with injection water. Drug administration began 12 hours later. The drug administration frequency was 3 times / day, 25μL / time, for a period of 7 days. The results of intraocular pressure testing are shown in Table 2 below.

[0132] Initial intraocular pressure (kPa) 12h (kPa) 1d(kPa) 3d(kPa) 5d(kPa) 7d(kPa) Example 1 2.8-3.2 7.7-8.5 6.2-7.1 5.1-5.9 3.8-4.4 2.8-3.3 Example 2 2.8-3.1 8.2-8.4 6.0-7.3 5.8-6.2 4.7-4.9 2.9-3.3 Example 3 2.7-3.3 7.3-8.7 6.4-7.9 5.7-7.3 4.7-6.1 2.8-3.5 Example 4 3.1-3.3 8.3-8.7 6.7-7.0 5.4-5.8 3.9-4.6 3.0-3.2 Example 5 2.7-3.3 7.5-8.7 5.7-7.1 4.5-5.2 3.9-4.1 2.7-3.1 Example 6 2.7-3.1 7.4-8.8 5.5-6.9 4.6-5.0 3.8-4.1 2.6-3.0 Example 7 2.9-3.3 7.9-8.5 5.9-6.3 4.2-5.6 3.7-3.9 2.8-3.1 Comparative Example 1 2.7-3.3 7.2-8.8 6.8-8.2 6.2-7.9 5.7-7.1 4.4-6.2 Comparative Example 2 2.9-3.3 8.1-8.3 7.6-7.9 6.9-7.3 5.2-6.4 4.2-5.7 Comparative Example 3 2.7-3.2 7.9-8.7 6.6-8.2 5.9-7.4 4.8-6.2 3.0-3.9 Comparative Example 4 2.8-3.0 7.6-8.4 7.0-7.7 6.7-7.2 6.1-6.6 5.2-5.7 Comparative Example 5 2.8-3.1 7.7-8.7 7.2-8.1 6.9-7.7 6.1-7.0 5.3-5.9 Comparative Example 6 3.0-3.2 7.9-8.4 7.3-7.6 6.2-6.9 5.4-6.2 4.7-5.3

[0133] As shown in Table 2, the eye drops of this invention can effectively improve intraocular pressure, reduce high intraocular pressure, and relieve symptoms such as headache, eye strain, blurred vision, and nausea caused by high intraocular pressure, thereby improving people's quality of life. This invention uses brimonidine tartrate as the main active substance for lowering intraocular pressure. It acts on the α2 receptors of the ciliary epithelium, reducing aqueous humor production and increasing aqueous humor outflow through the uveal-scleral pathway, thus achieving the effect of lowering intraocular pressure. To avoid the irritation inherent in brimonidine tartrate itself, this invention combines it with hyaluronic acid, collagen, trehalose, and dipotassium glycyrrhizate. Hyaluronic acid and collagen form a stable network structure through carboxyl-hydrogen bonds, which can bind brimonidine tartrate within the network through ionic bonds, allowing for slow release rather than direct release onto the ocular surface. This avoids stimulating excessive reflexive tear secretion, damaging corneal epithelial cells, and thus preventing the achievement of the effect of lowering intraocular pressure or even corneal damage.

[0134] The experimental results show that the amount of hyaluronic acid added has a significant impact on the effect of lowering intraocular pressure. Comparative Example 1, compared to Example 1 without added hyaluronic acid, showed a poorer effect in lowering high intraocular pressure. This was because the viscoelastic network capable of encapsulating brimonidine tartrate was not formed, resulting in reduced tear film stability, increased drug flushing speed, and significantly reduced bioavailability. Comparative Example 4, compared to Example 4, increased the amount of hyaluronic acid added, leading to excessive dosage and increased solution concentration. This foreign body sensation caused excessive tear secretion, and the active substances that lower intraocular pressure could not be released, rendering them ineffective.

[0135] The experimental results showed that the amount of collagen added had a significant impact on the effect of lowering intraocular pressure. In Comparative Example 2, compared to Example 1 without added collagen, the intraocular pressure did not decrease to a normal level after 7 days, indicating insufficient corneal permeability, affecting corneal epithelial cell repair and weakening aqueous humor regulation. In Comparative Example 5, compared to Example 4, excessive collagen was used, causing protein aggregates in the eye drops to form microparticles, increasing eye irritation, promoting blinking, and causing drug loss while rubbing against the cornea, potentially even triggering inflammation. This led to increased aqueous humor production and weakened the pressure-lowering effect.

[0136] This invention further reduces the irritating effect of brimonidine tartrate by adding dipotassium glycyrrhizate, avoiding the induction of inflammatory factors and weakening the intraocular pressure-lowering effect. The experimental results show that Comparative Example 3, without the addition of dipotassium glycyrrhizate, only lowered the intraocular pressure to near normal levels compared to Example 1. The eye drops may have an irritating effect after administration, leading to increased aqueous humor and affecting the retention time of the eye drops, thus slightly reducing the pressure-lowering effect. Comparative Example 6, compared to Comparative Example 4, added excessive dipotassium glycyrrhizate, which may have damaged the tear film, affecting corneal cell growth and thus hindering collagen repair. Even though trehalose can protect cell membranes and enhance the anti-damage resistance of corneal epithelial cells, the intraocular pressure-lowering effect was still reduced, preventing the intraocular pressure from returning to normal levels.

[0137] Eye irritation evaluation in a single-dose trial: Rabbits that met the ophthalmological requirements were selected, divided into groups, and 0.1 mL was administered to the right eye of each rabbit. Ophthalmological slit-lamp examination of the conjunctiva, cornea, iris, and secretions was performed at 1, 3, 24, and 72 hours after administration.

[0138] 7-day drug administration experiment: Rabbits from the previous batch were fed for 7 days. After ophthalmological examination showed that both eyes were completely normal, the left eye was given the drug 4 times / day for 7 consecutive days. After 7 days, an ophthalmological slit-lamp examination was performed on the conjunctiva, cornea, iris, and secretions.

[0139] In Example 1 of this invention, after administration of the eye drops, the rabbit eyes showed no edema, the cornea was transparent, the iris texture was clear, and the pupil reacted sensitively to light. The test results showed that none of the groups were irritating. In Example 7, after administration of the eye drops, some rabbit eyes had a small amount of secretion and mild conjunctival congestion. Therefore, the dosage of the components of the eye drops of this invention can be adjusted according to the degree of eye discomfort.

[0140] The above description is merely the preferred embodiment of the present invention and is not intended to limit the invention. Modifications, equivalent substitutions, and optimizations made within the spirit and principles of the present invention should all be considered within the scope of protection of the present invention. The scope of protection claimed by the present invention is determined by the claims.

Claims

1. An eye drop composition, characterized in that, It includes the following components: 0.01-2% (w / v) brimonidine tartrate, 0.01-3% (w / v) hyaluronic acid, 0.1-5% (w / v) collagen, 0.01-5% (w / v) trehalose, 0.05-0.1% (w / v) dipotassium glycyrrhizate, 0.1-2% (w / v) borate buffer, with the balance being water for injection; In the components, the ratio of brimonidine tartrate to hyaluronic acid is 1:1-2; the ratio of hyaluronic acid to collagen is 1:1-10. The osmotic pressure was adjusted to 280-310 mOsm / kg using trehalose; the pH was adjusted to 6.8-7.8 using a borate buffer.

2. The eye drop composition according to claim 1, characterized in that, It includes the following components: 0.05-1% (w / v) brimonidine tartrate, 0.05-1.5% (w / v) hyaluronic acid, 0.15-3% (w / v) collagen, 0.1-4% (w / v) trehalose, 0.05-0.1% (w / v) dipotassium glycyrrhizate, 0.1-2% (w / v) borate buffer, and the balance is water for injection.

3. An eye drop composition according to claim 1 or 2, characterized in that, It includes the following components: 0.1-0.2% (w / v) brimonidine tartrate, 0.1-0.3% (w / v) hyaluronic acid, 0.5-1.5% (w / v) collagen, 1-3% (w / v) trehalose, 0.05-0.1% (w / v) dipotassium glycyrrhizate, 0.1-2% (w / v) borate buffer, and the balance is water for injection.

4. The eye drop composition according to claim 1, characterized in that, The hyaluronic acid in the component has a molecular weight of 1-1.5 MDa.

5. An eye drop composition according to claim 1 or 4, characterized in that, When the collagen in the components is type III human collagen, its molecular weight is not higher than 10 kDa.

6. The eye drop composition according to claim 1, characterized in that, In the components, the ratio of dipotassium glycyrrhizate to hyaluronic acid is 1:5-30.

7. A method for preparing eye drops, characterized in that, The eye drop composition according to any one of claims 1-6 comprises the following steps: S1: Weigh each component for later use; S2: Dissolve the borate buffer in water for injection and adjust the pH; S3: Add hyaluronic acid to the solution obtained in step S2, and stir at low speed to avoid generating bubbles until completely dissolved; S4: Add collagen and brimonidine tartrate to the solution obtained in step S3 in sequence, and stir thoroughly until dissolved; S5: Add trehalose and dipotassium glycyrrhizate to the solution obtained in step S4, stir thoroughly until dissolved, and then add water for injection to make up to volume. S6: Filter the solution obtained in step S5 through a 0.1-0.3μm microporous membrane for sterilization, and then fill it in a sterile environment.

8. The use of the eye drop composition according to any one of claims 1-6 in the preparation of ophthalmic preparations for lowering intraocular pressure.