Ophthalmic components

Abstract

The objective of this invention is to provide an ophthalmic formulation that has excellent permeability-promoting effects on corneal epithelial cells and low cytotoxicity. [Solution] The ophthalmic composition of the present invention, which solves the above problems, is characterized by combining a specific cationic lipid and an anionic lipid. This makes it possible to provide an ophthalmic composition that has a high permeability-promoting effect on corneal epithelial cells and low cytotoxicity.

Description

[Technical Field]

[0001] This invention relates to an ophthalmic formulation that exhibits excellent corneal epithelial permeability and low cytotoxicity. More specifically, this invention relates to an ophthalmic formulation that improves the corneal permeability of riboflavin (vitamin B2), which is used as a pharmacoactive ingredient in the corrective treatment of the cornea in patients with keratoconus, and is also highly safe. [Background technology]

[0002] Keratoconus is an eye disease in which a portion of the cornea thins, and this thinned portion can no longer withstand intraocular pressure and protrudes forward. Keratoconus is characterized primarily by corneal thinning and deformation, but its cause is not clearly understood. Patients with keratoconus experience progressive visual impairment such as decreased vision and astigmatism, and as the disease progresses, corneal transplantation becomes the only treatment option.

[0003] An effective treatment method is refractive surgery, which involves infusing riboflavin into the corneal tissue and then irradiating it with ultraviolet light to cross-link the collagen fibers that make up the cornea, thereby increasing the strength of the cornea and fixing it in place. Corneal cross-linking involves keeping the patient's eye open and dripping riboflavin solution from a cylindrical reservoir placed on the cornea, allowing it to penetrate the cornea.

[0004] There are two cross-linking methods: the EPI-OFF method, which involves detaching the corneal epithelium when riboflavin is infiltrated, and the EPI-ON method, which preserves the corneal epithelium without detachment. Although the EPI-OFF method allows for high riboflavin penetration, it carries a high risk of infection due to pain from corneal epithelial detachment, persistent epithelial defects, and corneal lysis. Therefore, the EPI-ON method, which does not involve the removal of epithelial cells, was developed.

[0005] However, the EPI-ON method has the disadvantage of low riboflavin permeability to corneal epithelial cells. To date, studies have been reported using calcium-blocking compounds, cyclodextrin derivatives, nanostructured lipid carriers, and channel-forming peptides to improve riboflavin permeability to the corneal epithelium.

[0006] MedioCross® is a commercially available ophthalmic formulation used in the EPI-ON method, which is the most widely used method in clinical applications. While there are several formulations depending on the application, the riboflavin concentration is set at 0.1-0.25%, and MedioCross® TE, which is mainly used for the clinical treatment of keratoconus, has the highest riboflavin content at 0.25%. If the riboflavin concentration is further increased, the amount of riboflavin transported through the corneal epithelium will increase.

[0007] The above formulation contains 0.01% benzalkonium chloride. Benzalkonium chloride is commonly used as a preservative, but it also has the effect of improving corneal permeability. While it has the effect of loosening tight junctions, which are adhesive structures between corneal epithelial cells that prevent the passage of substances, it has also been observed to damage corneal epithelial cells, and side effects such as corneal cell damage and cytotoxicity have been reported. Therefore, there is a need for a new ophthalmic formulation that is safer and has superior corneal permeability as an alternative. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Special Publication No. 2019-511493 [Patent Document 2] Japanese Patent Publication No. 2004-2358 [Non-patent literature]

[0009] [Non-Patent Document 1] EHHughes, M. Pretorius, H. Eleftheriadis, et.al., Long-term recovery of the human corneal endothelium after toxic injury by benzalkonium chloride Br J. Ophthalmol., Vol. 91 (2007, Nov.) p. 1460~1463 [Overview of the project] [Problems that the invention aims to solve]

[0010] Patent Document 1 describes corneal collagen cross-crosslinking therapy, in which riboflavin drops are applied to the corneal epithelium as a treatment method for keratoconus, and mainly concerns the cross-crosslinking agent. It also describes the use of benzalkonium chloride as a preservative (Patent Document 1, paragraphs

[0030] and

[0048] of the specification).

[0011] Patent Document 2 describes an invention relating to an ophthalmic composition with improved corneal permeability. The specification states that "most of the drugs that are instilled into the eye and move into the eye do so through the cornea" and that "corneal permeability of water-soluble drugs is extremely important in developing ophthalmic compositions" (Patent Document 2, Specification paragraph

[0003] ). The text states, "For example, it has been reported that substances such as ionic surfactants, certain drugs, benzalkonium chloride (a commonly used preservative in ophthalmology), etc., can damage the corneal epithelium and increase the corneal permeability of drugs," and "this increased permeability of the corneal epithelial layer also has the drawback of potentially causing cytotoxicity during use, which can lead to cell damage in the corneal epithelial layer."

[0012] Furthermore, Non-Patent Document 1 describes the toxic damage to the corneal endothelium caused by benzalkonium chloride inadvertently administered intraocularly during cataract surgery and its long-term effects. As can be seen from the descriptions in Patent Documents 1, 2 and Non-Patent Document 1, benzalkonium chloride enhances the corneal permeability of drugs while having cytotoxicity to corneal epithelial and endothelial cells. The commercially available MedioCross (registered trademark) TE preparation used in the EPI-ON method for cross-linking treatment of keratoconus contains 0.01% benzalkonium chloride.

[0013] Therefore, an object of the present invention is to provide an ophthalmic preparation that is excellent in the effect of promoting the permeability of corneal epithelial cells and has low cytotoxicity.

Means for Solving the Problems

[0014] As a result of intensive studies on the above problems, the present inventors have found that by combining a specific (A) cationic lipid and (B) anionic lipid, an ophthalmic composition excellent in the effect of promoting the permeability of corneal epithelial cells and having low cytotoxicity can be obtained, and thus completed the present invention. That is, the present invention is an ophthalmic composition characterized by the following.

[0015] The ophthalmic composition of the present invention for solving the above problems contains (A) a cationic lipid and (B) an anionic lipid, the cationic lipid is liquid at 25°C and has a hydrocarbon group having 8 or more carbon atoms, and the anionic lipid is liquid at 25°C and has a hydrocarbon group having 8 or more carbon atoms. According to this ophthalmic composition, it is possible to provide an ophthalmic preparation excellent in the effect of promoting the permeability of corneal epithelial cells and having low cytotoxicity.

[0016] Further, as an embodiment of the ophthalmic composition of the present invention, it contains the following components (A) and (B). Component (A) is liquid at 25°C and is a compound represented by any of the following formulas (A-1) and (A-2).

Chemical Formula

[0017] Furthermore, in one embodiment of the ophthalmic composition of the present invention, in the compound of component (A) above, R 1 and R 2 It is characterized by being an unsaturated hydrocarbon group. This characteristic makes it possible to provide an ophthalmic formulation that has an even better effect in promoting the permeability of corneal epithelial cells and has less cytotoxicity, because it is a compound that has a high molecular weight hydrocarbon group and is liquid at room temperature.

[0018] Furthermore, one embodiment of the ophthalmic composition of the present invention is characterized in that the higher fatty acid as component (B) is a branched saturated fatty acid or an unsaturated fatty acid. According to these characteristics, the drug has excellent stability due to being a branched saturated fatty acid, and because it is a compound that is liquid at room temperature and has a high molecular weight hydrocarbon group, or because it is an unsaturated fatty acid and is liquid at room temperature, it is possible to provide an ophthalmic formulation that has an even better effect on promoting the permeability of corneal epithelial cells and has less cytotoxicity.

[0019] Furthermore, one embodiment of the ophthalmic composition of the present invention is characterized by containing, as a pharmacoactive ingredient, at least one of riboflavin-related substances consisting of riboflavin, riboflavin phosphate ester, riboflavin butyrate ester, or riboflavin phosphate sodium salt, riboflavin phosphate potassium salt, or riboflavin phosphate calcium salt. This characteristic makes it possible to provide an ophthalmic composition that promotes the penetration of riboflavin, the active ingredient in the treatment of keratoconus, and suppresses cytotoxicity.

[0020] Furthermore, one embodiment of the ophthalmic composition of the present invention is characterized in that the concentration of the riboflavin analog solution is 0.1% by mass or more. This characteristic makes it possible to provide an ophthalmic composition that enhances efficacy by promoting the penetration and increasing the concentration of riboflavin, the active ingredient in keratoconus treatment, while also suppressing cytotoxicity.

[0021] Furthermore, one embodiment of the ophthalmic composition of the present invention is an ophthalmic composition for the treatment of keratoconus, which contains 1,2-dioleoyl-3-dimethylammoniumpropane (DODAP) or 1,2-dioleoyloxy-3-dimethylaminopropane (DODMA) and isostearic acid (ISA), myristoleic acid (MA), or palmitoleic acid (PA), and is characterized by containing at least one of riboflavin-related substances as a pharmacoactive ingredient, consisting of riboflavin, riboflavin phosphate ester, riboflavin butyrate ester, or riboflavin phosphate sodium salt, riboflavin phosphate potassium salt, or riboflavin phosphate calcium salt. This characteristic makes it possible to provide an ophthalmic composition in which DODAP or DODMA, which are cationic lipids with affinity for cells, are excellent at promoting the penetration of riboflavin, the active ingredient in keratoconus treatment, without causing significant damage to cells, and whose effectiveness can be further enhanced by increasing its concentration, while suppressing cytotoxicity. [Effects of the Invention]

[0022] According to the present invention, it is possible to provide an ophthalmic composition that has a high permeability-promoting effect on corneal epithelial cells and low cytotoxicity. [Brief explanation of the drawing]

[0023] [Figure 1]This is a schematic diagram illustrating the evaluation kit for a human three-dimensional cultured corneal epithelium model used in the corneal epithelial cell permeability test and transepithelial membrane electrical resistance measurement in the embodiments of the present invention. [Figure 2] The results of tests comparing the DODAP / ISA combination with DODAP or ISA alone in terms of corneal epithelial cell permeability are shown. [Figure 3] The results of tests comparing corneal epithelial cell permeability using DODAP / ISA combinations, arginine / lactic acid combination test solutions, and commercially available formulations are shown. [Figure 4] The results of transepithelial electrical resistance tests comparing the DODAP / ISA combination, the arginine / lactic acid combination, and commercially available formulations are shown. [Figure 5] This paper shows the results of corneal epithelial cell permeability tests comparing the DODAP / ISA combination with riboflavin concentrations of 0.25% and 2.5%, and the commercially available formulation. [Figure 6] The results of transepithelial electrical resistance tests comparing the DODAP / ISA combination with riboflavin concentrations of 0.25% and 2.5% with commercially available formulations are shown. [Figure 7] The results of tests comparing the corneal epithelial cell permeability of the DODAP / ISA combination and the DODAP / SA combination are shown. [Figure 8] The results of tests comparing corneal epithelial cell permeability using DODAP / ISA combination and DODMA / ISA combination test solutions are shown. [Figure 9] The results of transepithelial electrical resistance tests comparing the DODAP / ISA combination with the DODMA / ISA combination test solution and a commercially available formulation are shown. [Figure 10] The results of corneal epithelial cell permeability tests comparing the DODAP / ISA combination with the DODAP / MA and DODAP / PA combinations are shown. [Figure 11] The results of transepithelial electrical resistance tests comparing the DODAP / ISA combination with test solutions of the DODAP / MA and DODAP / PA combinations, as well as commercially available formulations, are shown. [Modes for carrying out the invention]

[0024] Hereinafter, embodiments of the ophthalmic composition according to the present invention will be described in detail with reference to the drawings. The ophthalmic compositions described in the embodiments are merely examples used to illustrate the ophthalmic compositions according to the present invention and are not limited thereto.

[0025] [(A) Cationic lipids, (B) Anionic lipids] In the present invention, (A) cationic lipids are compounds that are liquid at 25°C and have a lipid affinity region containing a hydrocarbon group having 8 or more carbon atoms and a hydrophilic region containing a cationic functional group. (B) anionic lipids are compounds that are liquid at 25°C and have a lipid affinity region containing a hydrocarbon group having 8 or more carbon atoms and a hydrophilic region containing anionic functional groups. However, compounds having both cationic and anionic functional groups are excluded. Examples of cationic functional groups in (A) cationic lipids in the present invention include basic components such as ammonium, amine, imine, imidazolium, and pyrrolidinium, and examples of anionic functional groups in (B) anionic lipids include carboxylic acid-based, sulfonic acid-based, phosphate-based, and borate-based fatty acids.

[0026] [(A) component] Component (A) in the present invention is a compound represented by either formula (A-1) or (A-2) below. [ka] These compounds have an alkane structure with 2 to 5 carbon atoms, an N atom at one end, an ammonium or amine structure, and independently a higher fatty acid or oxyhydrocarbon group at the other two carbon atoms. In the formula, n is an integer between 0 and 3, but is preferably 1 or 2, and more preferably a propane skeleton structure where n=1. In the formula, R 1 and R2 independently represents a hydrocarbon group having 8 or more carbon atoms, R 3 and R 4 each independently represents one selected from a hydrogen atom, a methyl group, and an ethyl group, and is preferably a hydrogen atom or a methyl group.

[0027] <(A-1) component> In the formula of the (A-1) component in the present invention, R 1 and R 2 are hydrocarbon groups having 8 or more carbon atoms, preferably 12 or more carbon atoms, more preferably 14 or more carbon atoms, and still more preferably 16 or more carbon atoms. In the formula of the (A-1) component in the present invention, R 1 and R 2 are preferably unsaturated hydrocarbons. For example, as shown in the following formula (2), the following examples can be cited as unsaturated hydrocarbon groups having 18 carbon atoms including the carbon of the carboxy group. 1,2-dioleoyl-3-dimethylammonium-propane (DODAP)

Chemical formula

[0028] <(A-2) component> In the formula of the (A-2) component in the present invention, R 1 and R 2 are hydrocarbon groups having 8 or more carbon atoms, preferably 12 or more carbon atoms, more preferably 14 or more carbon atoms, and still more preferably 16 or more carbon atoms. In the formula of the (A-2) component in the present invention, R 1 and R 2 are preferably unsaturated hydrocarbons. For example, as shown in the following formula (3), the following examples can be cited as unsaturated hydrocarbon groups having 18 carbon atoms. 1,2-dioleyloxy-3-dimethylaminopropane (DODMA)

Chemical formula

[0029] [(B) Component] Component (B) in the present invention is a higher fatty acid having 8 or more carbon atoms, preferably having 12 or more carbon atoms, more preferably 14 or more carbon atoms, and even more preferably 16 or more carbon atoms. In the present invention, the higher fatty acid of component (B) is preferably a branched saturated fatty acid or an unsaturated fatty acid. For example, the following are examples of branched saturated higher fatty acids with 18 carbon atoms, as shown in formula (4) below. Isostearic acid (ISA) [ka]

[0030] [Preparation of ophthalmic compositions] The compounds (A) cationic lipid and (B) anionic lipid of the present invention are mixed with purified water to prepare an aqueous suspension to a predetermined concentration of the contained compounds. <Concentration of component (A) and component (B)> The concentration of each component when used as an ophthalmic composition is 0.01 mM to 1000 mM, preferably 0.1 mM to 100 mM, more preferably 1 mM to 50 mM, and even more preferably 5 mM to 30 mM. The concentrations of (A) cationic lipids and (B) anionic lipids are adjusted to be equimolar, with the ratio of (concentration of component A / concentration of component B) being preferably 0.5 to 2.0, more preferably 0.7 to 1.5, and even more preferably 0.95 to 1.05.

[0031] [Active ingredient: Riboflavin-related substance] The riboflavin-related substances in the present invention are riboflavin or its derivative compounds used to include riboflavin as a pharmacoactive ingredient in the ophthalmic composition of the present invention. Specifically, these include riboflavin, riboflavin phosphate ester, and riboflavin butyrate ester. Of these, riboflavin phosphate ester is preferred in terms of solubility. Examples of the salt include riboflavin phosphate sodium salt, riboflavin phosphate potassium salt, and riboflavin phosphate calcium salt, but the sodium salt is preferably used.

[0032] <Preparation of ophthalmic compositions containing riboflavin> The compound of the present invention is mixed with purified water to adjust the concentration of the compound to a predetermined level, and then riboflavin sodium phosphate is added and dissolved to a predetermined level to prepare a riboflavin-containing preparation. <Riboflavin concentration> The concentration of riboflavin as the pharmacoactive ingredient contained in the ophthalmic composition of the present invention is 0.1% by mass or more, preferably 0.25% by mass or more, more preferably 0.5% or more, and even more preferably 1.0% or more. There is no particular upper limit, but it is 10% or less, preferably 5% or less.

[0033] <Other medicinal ingredients> In addition to riboflavin as described above, the ophthalmic composition of the present invention may contain various pharmacoactive ingredients used in ophthalmic treatments. Examples include ciliary muscle regulators, various vitamins, amino acids, anti-myopia drugs, cataract medications, miotics, glaucoma medications, parasympathetic nerve blockers, intraocular pressure lowering drugs, sugars, anti-inflammatory drugs, astringents, antibacterial drugs, antihistamines, anti-allergic drugs, and vasoconstrictors.

[0034] <Other> The pH of the ophthalmic composition of the present invention is preferably in the range of 3 to 9 from the viewpoint of corneal permeability and biocompatibility. More preferably, the pH is adjusted to the range of 4 to 8.5, and even more preferably, to the range of 5 to 8. The ophthalmic composition of the present invention may contain water-soluble substances that are soluble in water in the pH range of approximately 3 to 9. In addition to the above-mentioned active pharmaceutical ingredients, surfactants, lower alcohols, viscosity modifiers, buffers, thickeners, inorganic salts, preservatives, stabilizers, cooling agents, antioxidants, colorants, isotonic agents, fragrances, etc., may be included as needed. Benzalkonium chloride may also be included within the acceptable range of cytotoxicity for the present invention. [Examples]

[0035] Next, examples of the ophthalmic composition of the present invention and corneal epithelial cell permeability tests and cytotoxicity evaluations using the same are shown below. However, the present invention is not limited to these examples, and various modifications are possible within the technical concept of the present invention.

[0036] [Medications used] Table 1 shows the chemicals and compounds used in the following examples. Note that other substances used were of research reagent grade. [Table 1]

[0037] <Method for preparing a riboflavin-containing test solution> First, various compounds were mixed in distilled water to prepare a solution with a concentration of 10 mM. Then, riboflavin-containing test solutions were prepared by adding and dissolving riboflavin sodium phosphate to concentrations of 0.25% or 2.5%, respectively.

[0038] [Commercially available formulations] The experiment was conducted using MedioCross® TE, a commercially available formulation used in the treatment of keratoconus, as a control sample. MedioCross® TE is said to contain the following components. Riboflavin 0.25% Hydroxypropylmethylcellulose (HPMC) 1.2% Benzalkoniumchloride 0.01% Sodium Chloride Disodium hydrogenphosphate × 12H2O Sodium dihydrogenphosphate × 2H2O

[0039] [Evaluation Method] <Corneal epithelial cell permeability test> Using the human three-dimensional cultured corneal epithelial model shown in Figure 1, a fixed amount of test solution containing a certain concentration of riboflavin was added to the culture cup. Next, the solution that permeated through the human corneal epithelial cell layer and exuded under the membrane filter was sampled periodically (after 1, 2, 4, 8, and 24 hours), and the permeability was evaluated by measuring the riboflavin concentration (unit: μg / mL) in the permeated solution using high-performance liquid chromatography (HPLC). For the human 3D cultured corneal epithelial cell model, we used the LabCyte CORNEA-MODEL24 evaluation kit manufactured by Japan Tissue Engineering Co., Ltd. Concentration was measured by HPLC using a Shimadzu HPLC system (LC2050) with a Waters Xterra MS c-18 column (4.6 mm x 150 mm, 5 m) in isocratic elution mode (mobile phase A (893 mL of 8.0 mM sodium 1-hexanesulfonate solution, adjusted to pH 3.0 with 7.5 mL of glacial acetic acid and diethylamine, 100 mL of methanol) / mobile phase B (methanol)).

[0040] <Cytotoxicity assessment: Transepithelial membrane electrical resistance (TEER) measurement> Transepithelial electrical resistance (TEER) measures the strength of intercellular junctions in epithelial tissue as electrical resistance. Since intercellular junctions break down as cell morphology changes during cell death, measuring the TEER value after drug introduction allows for evaluation of cytotoxicity. A lower TEER value indicates more cell death and higher cytotoxicity. Using the human 3D cultured corneal epithelial cell model shown in Figure 1, the transepithelial membrane electrical resistance (unit: Ω / cm²) between membrane filters was measured for the sample before addition and after 24 hours of culture. 2 ) was measured. The LabCyte CORNEA-MODEL24 evaluation kit manufactured by Japan Tissue Engineering Co., Ltd. was used as the human 3D cultured corneal epithelial model. Electrical resistance was measured using Millicell EXS-2 (Millipre).

[0041] [1. Experiment 1: Comparison of the combined effects of DODAP / ISA] [Example 1] DODAP / ISA combination test solution, [Comparative Example 1] DODAP single test solution, [Comparative Example 2] ISA-only test solution, In this invention, component (A) is DODAP, which is component (A-1), and component (B) is ISA, and the effects of the combination of both components were compared. Specifically, the three test solutions described above were each prepared at a concentration of 10 mM, and then riboflavin phosphate sodium was added and dissolved to a concentration of 0.25%. <Corneal epithelial permeability test results> As shown in Figure 2, when comparing the results of the test solution using DODAP / ISA in combination with the test solutions of DODAP and ISA alone, the test solution combining DODAP and ISA of the present invention promoted the permeability of riboflavin in corneal epithelial cells, confirming the permeability-enhancing effect of combining both components (A) and (B).

[0042] [2. Experiment 2: Combinations of compounds without fatty acid side chains, compared with commercially available formulations] [Example 1] DODAP / ISA combination test solution, [Comparative Example 3] Arginine / Lactic Acid Combination Test Solution [Conventional Example 1] MedioCross(registered trademark) TE, Unlike the present invention, as a comparative example of compound combinations lacking fatty acid side chains or oxyhydrocarbon groups, a combination using arginine (Arg) as the cationic component and lactic acid (LA) as the anionic component was presented as Comparative Example 3, and a commercially available formulation was used as a control sample as a conventional example. The two test solutions described above were each prepared at a concentration of 10 mM, and then riboflavin phosphate sodium was added and dissolved to a concentration of 0.25%. The commercially available formulation was used as is. <Corneal epithelial permeability test results> As shown in Figure 3, when the test solution using DODAP / ISA was compared with the arginine / lactic acid combination test solution, the DODAP and ISA combination test solution of the present invention significantly promoted riboflavin permeability in corneal epithelial cells. Furthermore, when the DODAP / ISA combination test solution was compared with a commercially available formulation, it showed almost equivalent permeability from the start to 8 hours. However, at 24 hours, the commercially available formulation showed higher permeability. <Cytotoxicity Evaluation Results> As shown in Figure 4, the transepithelial membrane electrical resistance values ​​of cells cultured with commercially available formulations were significantly lower after 24 hours of incubation than those of the DODAP / ISA and Arg / LA combination test solutions. This indicates that the cytotoxicity of the DODAP / ISA combination test solution of the present invention is clearly less than that of commercially available formulations.

[0043] [3. Experiment 3: Comparison with commercially available formulations when riboflavin concentration is changed] [Example 1] DODAP / ISA combination test solution (riboflavin concentration 0.25%) [Example 2] DODAP / ISA combined test solution (riboflavin concentration 2.5%) [Conventional Example 1] MedioCross(registered trademark) TE, In the test solution combining DODAP and ISA of the present invention, the concentration of riboflavin was changed to prepare two types of test solutions at a concentration of 10 mM, and then riboflavin phosphate sodium was added and dissolved to concentrations of 0.25% and 2.5%, respectively. A commercially available formulation was used as a conventional example for comparison. <Corneal epithelial permeability test results> As shown in Figure 5, the test solution containing 2.5% riboflavin of the present invention combined with DODAP / ISA promoted riboflavin permeation into corneal epithelial cells more effectively than the test solution containing 0.25% riboflavin combined with DODAP / ISA, and showed greater riboflavin permeation than commercially available formulations. <Cytotoxicity Evaluation Results> As shown in Figure 6, the transepithelial membrane electrical resistance of the test solution containing 0.25% or 2.5% riboflavin of the present invention, after 24 hours of incubation, was significantly higher than that of commercially available formulations, indicating less cytotoxicity.

[0044] [4. Experiment 4 (B) Comparison with linear saturated higher fatty acids as components] [Example 1] DODAP / ISA combination test solution, [Comparative Example 4] DODAP / SA combination test solution, The test solutions combining DODAP and ISA of the present invention were compared by changing component (B) from isostearic acid (ISA), a branched saturated fatty acid, to stearic acid (SA), a straight-chain saturated higher fatty acid. Each test solution was prepared at a concentration of 10 mM, and then riboflavin phosphate sodium was added and dissolved to a concentration of 0.25%. <Corneal epithelial permeability test results> As shown in Figure 7, the DODAP / ISA combination test solution of the present invention showed higher permeability to corneal epithelial cells than the test solution of Comparative Example 4, in which component (B) was replaced with the straight-chain saturated fatty acid SA from ISA. This indicates that the branched saturated fatty acid component (B) promotes the permeability of riboflavin.

[0045] [5. Experiment 5 (A-2) DODMA / ISA combination of the present invention using component (A-2)] [Example 1] DODAP / ISA combination test solution, [Example 3] DODMA / ISA combination test solution, [Conventional Example 1] MedioCross(registered trademark) TE, This study evaluated a DODMA / ISA combination in which component (A) is component (A-2) compared to a test solution combining DODMA and ISA in an example where component (A) is component (A-1) of the present invention. Each solution was prepared at a concentration of 10 mM, and then riboflavin phosphate sodium was added and dissolved to a concentration of 0.25%. A commercially available formulation was used as a conventional example for comparison. <Corneal epithelial permeability test results> As shown in Figure 8, the DODMA / ISA combination test solution using component (A-2) of the present invention showed almost the same permeability as the DODAP / ISA combination using component (A-1). <Cytotoxicity Evaluation Results> As shown in Figure 9, the transepithelial electrical resistance value of the DODMA / ISA combination test solution using component (A-2) of the present invention after 24 hours of incubation was higher than that of the DODAP / ISA combination using component (A-1), and significantly higher than that of commercially available formulations, indicating very low cytotoxicity.

[0046] [6. Experiment 6 (B) Comparison with unsaturated fatty acids as components] [Example 1] DODAP / ISA combination test solution, [Example 4] DODAP / MA combination test solution, [Example 5] DODAP / PA combination test solution, [Conventional Example 1] MedioCross(registered trademark) TE, A test solution combining DODAP and ISA, where component (A) of the present invention is component (A-1), was compared by changing component (B) from isostearic acid (ISA), a branched saturated fatty acid, to myristoleic acid (MA) and palmitoleic acid (PA), both unsaturated fatty acids. Each test solution was prepared at a concentration of 10 mM, and then riboflavin phosphate sodium was added and dissolved to a concentration of 0.25%. A commercially available formulation was used as a conventional example for comparison. <Corneal epithelial permeability test results> As shown in Figure 10, the DODAP / MA and DODAP / PA combination test solutions, which use an unsaturated fatty acid as component (B) of the present invention, showed almost the same permeability as the DODAP / ISA combination. <Cytotoxicity Evaluation Results> As shown in Figure 11, the transepithelial electrical resistance values ​​of the DODAP / MA and DODAP / PA combination test solutions, which use an unsaturated fatty acid as component (B) of the present invention, after 24 hours of incubation were higher than those of the DODAP / ISA combination and significantly higher than those of commercially available formulations, indicating very low cytotoxicity. [Industrial applicability]

[0047] By using the ophthalmic composition of the present invention, it is possible to improve the permeability of riboflavin in treatment methods that do not exfoliate the corneal epithelium of keratoconus, and also to improve the permeability of various drugs that enter the eye through the corneal epithelium while suppressing cytotoxicity, thereby making it suitable for use in various ophthalmic treatments. [Explanation of symbols]

[0048] 10. Evaluation kit for corneal epithelial cell models 20 culture cups 21 Human corneal epithelial cells 22 Membrane filters

Claims

1. An ophthalmic composition comprising (A) cationic lipids and (B) anionic lipids, The cationic lipid is liquid at 25°C and has a hydrocarbon group having 8 or more carbon atoms. The anionic lipid is characterized by being liquid at 25°C and having a hydrocarbon group with 8 or more carbon atoms. Ophthalmic composition.

2. The aforementioned component (A) is a compound represented by either of the following formulas (A-1) or (A-2): 【Chemistry 1】 (In formulas (A-1) and (A-2), R １ and R ２ R independently forms a hydrocarbon group with 8 or more carbon atoms. 3 and R 4 (where n represents one element independently selected from a hydrogen atom, a methyl group, and an ethyl group, and n represents the number of carbon atoms in the alkylene chain, and n is an integer between 0 and 3.) The aforementioned component (B) is characterized by being a higher fatty acid. The ophthalmic composition according to claim 1.

3. In the compound of component (A) described above, R １ and R ２ Characterized by being an unsaturated hydrocarbon group, The ophthalmic composition according to claim 1 or 2.

4. The aforementioned higher fatty acid is characterized in that it is a branched saturated fatty acid or an unsaturated fatty acid. The ophthalmic composition according to claim 1 or 2.

5. The ophthalmic composition is characterized by containing, as a pharmacoactive ingredient, at least one of the following riboflavin-related substances: riboflavin, riboflavin phosphate ester, riboflavin butyrate ester, or riboflavin phosphate sodium salt, riboflavin phosphate potassium salt, or riboflavin phosphate calcium salt. The ophthalmic composition according to claim 1 or 2.

6. The content of the riboflavin analog is 0.1% by mass or more, characterized in that The ophthalmic composition according to claim 5.

7. An ophthalmic composition for the treatment of keratoconus, 1,2-Dioleoyl-3-dimethylammoniumpropane, or 1,2-Dioreoyloxy-3-dimethylaminopropane, It contains isostearic acid, myristoleic acid, or palmitoleic acid. The active ingredient is characterized by containing at least one of the following riboflavin-related substances: riboflavin, riboflavin phosphate ester, riboflavin butyrate ester, or riboflavin phosphate sodium salt, riboflavin phosphate potassium salt, or riboflavin phosphate calcium salt. Ophthalmic composition.

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