JP2006348024A - Neurocyte-protecting agent comprising amidino derivative as effective ingredient - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a neurocyte-protecting agent as a preventive or therapeutic agent particularly used for ophthalmic diseases accompanying optic nerve disorder such as retinal diseases or glaucoma. <P>SOLUTION: The neurocyte-protecting agent comprises as an effective ingredient a compound represented by general formula [I] (wherein R<SB>1</SB>, R<SB>2</SB>and R<SB>3</SB>are the same or different and are each a hydrogen atom or an alkyl group, and R<SB>1</SB>and R<SB>3</SB>can be bonded together to form a ring having one or a plurality of double bonds) or a salt thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention is a protective agent for nerve cells comprising a compound represented by the general formula [I] or a salt thereof as an active ingredient, and particularly relates to a prophylactic or therapeutic agent for ophthalmic diseases associated with optic nerve disorders such as retinal diseases and glaucoma.

  The retina has a function of receiving light from the outside, and plays an important role in terms of visual function. Structurally, it is a tissue having a thickness of 0.1 to 0.5 mm composed of 10 layers such as a retinal pigment epithelium layer, an inner plexiform layer, a ganglion cell layer, and a nerve fiber layer. In the inner plexiform layer, there is a neuron that forms a synapse by pairing with a ganglion cell process called amacrine cell, but it responds well at the beginning and end of light irradiation. It is thought to work as a detector. In the ganglion cell layer, there is a ganglion cell (hereinafter referred to as “RGC”) located on the innermost side of the retina, and is deeply involved in motor vision, peripheral vision, color vision, morphological vision, and the like. In the nerve fiber layer, retinal blood vessels, which are branches of the central retinal arteriovenous vein, run and supply oxygen and nutrients to retinal neurons.

  By the way, when the retinal blood vessel is blocked or narrowed due to factors such as spasm, thrombus, arteriosclerosis, the retinal blood circulation is impaired, and the supply of oxygen and nutrients to the retina and optic nerve is closed. Retinal blood circulation disorders occupy a particularly important position among retinal diseases. Typical examples of symptoms associated with retinal blood circulation disorders are retinal vascular occlusion in which retinal veins and retinal arteries are occluded or constricted, diabetic retinopathy that contributes to retinal detachment, and ischemic optic nerve in which visual dysfunction appears. I have a symptom. Furthermore, it is considered that this ganglion cell death is deeply involved in the onset in macular degeneration, retinitis pigmentosa, label disease and the like.

Glaucoma is one of eye diseases that cause serious visual dysfunction leading to blindness if not properly treated. In glaucoma, RGCs in particular are selectively damaged among retinal neurons, and optic nerve damage is caused. As a result, it progresses to visual field damage. Therefore, a treatment for preventing or minimizing RGC damage can be considered. The idea of so-called “neuroprotection” that leads to the ultimate glaucoma treatment is being established (Non-patent Document 1)
The detailed mechanism of glaucomatous optic neuropathy is not yet clear, but the circulatory disorder that the optic nerve is directly compressed by increased intraocular pressure and the optic nerve atrophy is caused and the circulatory disorder of the optic disc is the main cause of optic atrophy. Theories have been proposed, and it is thought that both mechanisms based on these mechanical and circulatory disorders are involved in a complex manner. Both mechanical disorders and circulatory disorders cause optic nerve axon transport disorders, and the supply of neurotrophic factors is considered to contribute to RGC disorders due to this axon transport disorder. (Non-Patent Document 2). In addition, glutamate is one of the neurotransmitters in the retina, but it is considered that excessive activation of this glutamate signal cascade for some reason is also a cause of RGC disorder (Non-patent Document 3). .

  From the above, if there is a drug having a protective effect on retinal nerve cells such as RGC, retinal vascular diseases such as retinal vascular occlusion, ischemic optic neuropathy, retinitis pigmentosa and label disease, glaucoma, etc. It is expected to be useful for the prevention and treatment of eye diseases associated with other optic neuropathies.

On the other hand, Patent Document 1 and Patent Document 2 describe that the compound represented by the general formula [I] or a salt thereof has trypsin inhibitory activity and is effective in the treatment of pancreatitis. However, it has not been studied at all what pharmacological action the compound exhibits for eye diseases such as retinal diseases and glaucoma.
Japanese Patent Laid-Open No. 57-053454 JP-A-61-33173 Ophthalmology, 40, 251-273, 1998 Ophthalmology, 44, 1413-1416, 2002 Surv. Ophthalmol. 48, S38-S46, 2003

  It is a very interesting subject to search for new pharmaceutical uses for the compound represented by the general formula [I] or salts thereof.

  The present inventors have reported that the compound represented by the general formula [I] or a salt thereof is N-methyl-D-aspartic acid (hereinafter referred to as “NMDA”), which is a type of excitatory amino acid and glutamate receptor of retinal neurons. ) It was found that the NMDA, which is an activator of the receptor, exerts an excellent cell death inhibitory effect on the rat retinal injury model, and the present invention has been achieved.

That is, the present invention relates to a protective agent for retinal nerve cells such as RGC, which contains a compound represented by the general formula [I] or a salt thereof (hereinafter collectively referred to as “the present compound”) as an active ingredient. And such compounds prevent or prevent eye diseases associated with optic neuropathies such as retinal vascular occlusion, diabetic retinopathy, ischemic optic neuropathy, macular degeneration, retinitis pigmentosa, and Rebel disease and glaucoma. It is useful as a therapeutic agent. In addition, since this compound has a protective effect on nerve cells, senile dementia, Alzheimer's disease, Parkinson's disease, Huntington's disease, ALS, spinal cord injury, multiple sclerosis, neurodegeneration, muscle atrophy, motor neuron damage, acute It is also useful as a preventive or therapeutic agent for central nervous system disorders such as central nervous system damage, muscular dystrophy and prion diseases.

[Wherein R ₁ , R ₂ and R ₃ are the same or different and each represents a hydrogen atom or an alkyl group, or R ₁ and R ₃ may be bonded to form a ring having one or more double bonds. Good. ]
Specific examples of the preferred compound include 6′-amidino-2′-naphthyl-4-guanidinobenzoate dimethanesulfonate (hereinafter referred to as “nafamostat”) represented by the following formula [Ia], and the following formula [ Ib] 6′-amidino-2′-naphthyl- (4- (4,5-dihydro-1H-2-imidazolyl) amino) benzoate dimethanesulfonate (hereinafter referred to as “FUT-187”) Is mentioned.

  This compound can be produced according to a usual method in the field of synthetic organic chemistry, and Patent Document 2 describes a detailed production method.

  Here, each group and wording prescribed | regulated in this specification are shown below. “Alkyl” means straight or branched alkyl having 1 to 6 carbon atoms, and specific examples include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, isopropyl, isobutyl. , Sec-butyl, tert-butyl, isopentyl and the like. In addition, “may form a ring having one or more double bonds” means 2-imidazolyl, 4,5-dihydro-1H-2-imidazolyl, 2-pyrimidyl, 1,4,5,6 -It means that a ring such as tetrahydro-2-pyrimidyl may be formed.

  The present compounds can take the form of “prodrugs”. The term “prodrug” as used herein means a compound obtained by modifying the present compound with a group capable of leaving in vivo. In particular, a group containing an acylatable nitrogen atom such as an amino group or a guanidino group is acylated or formed. Mention may be made of prodrugs in the form of carbamate derivatives.

  The salt of this compound may be any pharmaceutically acceptable organic or inorganic acid addition salt, such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, acetic acid, phosphoric acid, lactic acid, citric acid, Examples thereof include organic acids such as methanesulfonic acid, fumaric acid, maleic acid, mandelic acid, citric acid, tartaric acid, and salicylic acid.

  This compound has optical isomers and, in some cases, diastereomeric isomers, and those containing these as active ingredients are also included in the present invention. Further, the present compound may take the form of a solvate, for example, a hydrate.

  The protective effect of the present compound on retinal nerve cells is that the compound represented by the above general formula [I] or a salt thereof exhibits an excellent inhibitory effect on retinal nerve cell death in a pharmacological test against rat NMDA-induced retinal damage described later. It is based on.

  The compound can be formulated as necessary by adding a pharmaceutically acceptable additive and using a technique widely used as a single preparation or a combined preparation.

  When this compound is used for the prevention or treatment of these eye diseases, it can be administered to patients orally or parenterally. As the dosage form, oral administration, topical administration to the eye (eye drops, Intravitreal administration, subconjunctival administration, subtenon administration, etc.), intravenous administration, transdermal administration, etc., and dosage forms suitable for administration with pharmaceutically acceptable additives as necessary To be formulated. Examples of dosage forms suitable for oral administration include tablets, capsules, granules, powders, and the like, and dosage forms suitable for parenteral administration include, for example, injections, eye drops, eye ointments, gels, Examples include nasal drops and suppositories. These can be prepared using conventional techniques widely used in the field. In addition to these preparations, the present compound can also be made into preparations for DDS (drug delivery system) such as preparations for intraocular implants and microspheres.

  For example, the tablet is an excipient such as lactose, glucose, D-mannitol, anhydrous calcium hydrogen phosphate, starch, sucrose; carboxymethylcellulose, carboxymethylcellulose calcium, croscarmellose sodium, crospovidone, starch, partially pregelatinized starch , Disintegrating agents such as low-substituted hydroxypropylcellulose; binders such as hydroxypropylcellulose, ethylcellulose, gum arabic, starch, partially pregelatinized starch, polyvinylpyrrolidone, polyvinyl alcohol; magnesium stearate, calcium stearate, talc, hydrous silicon dioxide , Lubricants such as hydrogenated oil; refined sucrose, hydroxypropylmethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, polyvinyl Coating agents pyrrolidone; citric acid, aspartame, using ascorbic acid, appropriately selected and the like flavoring agent such as menthol, can be prepared.

  Injections can be prepared using sterile purified water and sodium chloride for isotonicity.

  Eye drops include isotonic agents such as sodium chloride and concentrated glycerin; buffering agents such as sodium phosphate and sodium acetate; surface activity such as polyoxyethylene sorbitan monooleate, polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil Agents; Stabilizers such as sodium citrate and sodium edetate; Preservatives such as benzalkonium chloride and paraben can be selected and used as necessary, and pH is acceptable for ophthalmic preparations Although it should just exist in the range, the inside of the range of 4-8 is preferable normally.

  The preparation for intraocular implant can be prepared using a biodegradable polymer, for example, a biodegradable polymer such as polylactic acid, polyglycolic acid, lactic acid / glycolic acid copolymer, and hydroxypropylcellulose.

  The dose of the compound represented by the general formula [I] or a salt thereof can be appropriately changed depending on the dosage form, the severity of the patient's symptom to be administered, age, weight, doctor's judgment, etc. In the case of administration, generally 0.01 to 2000 mg per day can be administered to adults in one or several divided doses. In the case of injections, generally 0.01 to 0.01 mg per day for adults. -200 mg can be administered once or divided into several times, and in the case of eye drops, the active ingredient concentration of 0.01 to 10% (w / v) is usually once a day Or it can be instilled several times. Furthermore, in the case of an intraocular implant preparation, an intraocular implant preparation containing 0.01 to 2000 mg for an adult can be implanted in the eye.

  As will be described in detail in the section of the pharmacological test described later, when the action of the compound represented by the above general formula [I] or a salt thereof on rat NMDA-induced retinal damage is examined, it is represented by the above general formula [I]. The compound or its salts showed a remarkable cell death inhibitory effect on RGC. Therefore, the compound represented by the above general formula [I] or a salt thereof of the present invention is a protective agent for retinal nerve cells, retinal vascular occlusion, diabetic retinopathy, ischemic optic neuropathy, macular degeneration, retina. It can be seen that the composition is useful as a prophylactic or therapeutic agent for ophthalmic diseases associated with optic nerve disorders such as retinal diseases and glaucoma typified by pigment degeneration and Label disease. In addition, although the same test was done also about the known compound approximated with this compound, this compound showed a much higher effect compared with those known compounds, and was supporting the outstanding usefulness of this compound.

  Hereinafter, the present invention will be described in detail with reference to pharmacological tests and formulation examples, but these are for better understanding of the present invention and do not limit the scope of the present invention.

1. Pharmacological test In order to examine the protective effect of the compound represented by the general formula [I] or a salt thereof on retinal nerve cells, the compound represented by the general formula [I] or a salt thereof, nafamostat and rat NMDA of FUT-187 The effect on induced retinal damage was examined. As comparative compounds, camostat (N, N-dimethylcarbamoylmethyl-4- (4-guanidinobenzoyloxy) phenylacetate methanesulfonate) represented by the following formula [II] and gabexate represented by the following formula [III] ( Ethyl-4- (6-guadininohexanoyloxy) benzoate methanesulfonate) was used.

  Comparing the chemical structure of camostat and gabexate with nafamostat and FUT-187, they are common in that they have a guanidino group and an aromatic ring, but others have different chemical structures. Camostat and gabexate are known to have trypsin inhibitory activity and to be effective in the treatment of pancreatitis. As described in the background section, nafamostat and FUT-187 have the same activity. , Camostat and gabexate are in common with the above three compounds according to the present invention.

(Preparation of test compound-containing solution)
NMDA, nafamostat and FUT-187 were each dissolved in distilled water to obtain an NMDA solution, a nafamostat solution and an aqueous FUT-187 solution. Next, a 4 mM NMDA + 2 mM nafamostat aqueous solution (hereinafter referred to as “test solution 1”) and a 4 mM NMDA + 2 mM FUT-187 aqueous solution (hereinafter referred to as “test solution 2”) are obtained by appropriately mixing the obtained solutions. It was. In the same manner, a 4 mM NMDA + 20 mM camostat aqueous solution (hereinafter referred to as “Comparative Test Solution 1”) and a 4 mM NMDA + 20 mM gabexate aqueous solution (hereinafter referred to as “Comparative Test Solution 2”) were obtained. Further, the NMDA solution and distilled water were mixed to obtain a 4 mM NMDA solution (hereinafter referred to as “NMDA solution”).
Rats were dilated with 0.5% (W / V) tropicamide-0.5% phenylephrine hydrochloride ophthalmic solution, anesthetized with 3% halothane and maintained with 1% halothane (halothane was oxygen 0.5 L / min) , It was vaporized at laughter 1.5L / min). Next, the surface of the eyeball is anesthetized by instilling 0.4% (W / V) oxybuprocaine hydrochloride ophthalmic solution, and 5 μl of the test solution 1 is administered into the vitreous body under a surgical microscope using a 32 G Hamilton micro syringe. did. Moreover, the test liquid 1 was replaced with distilled water, the NMDA liquid, the test liquid 2, the comparative test liquid 1, and the comparative test liquid 2 sequentially, and the same operation as the above was performed. 14 days after administration, the eyeball was removed, fixed in 2.5% glutaraldehyde-10% neutral buffered formalin for 1 day, the cornea and lens were excised, and 2.5% glutaraldehyde-10% neutral buffered formalin was removed. Replaced with 10% neutral buffered formalin. At a later date, dehydration was performed, paraffin-embedded, sliced, and stained with hematoxylin-eosin (HE) to prepare a pathological tissue section (3 μm thick). Arbitrary 3 sections were selected from 8 sections prepared at intervals of 15 μm so that the optic disc was inserted per eye, and a photograph of the retina between 1 and 1.5 mm from the optic disc to the left or right was selected for the selected section. The number of cells in the ganglion cell layer (GCL) in the retina (RGC number) and the thickness of the inner plexiform layer (IPL) were measured. From these measured values, according to Formula 1 and Formula 2, the node cell death suppression rate and the IPL thinning suppression rate were produced. These results are shown in Table 1. In Table 1, Formula 1 and Formula 2, a group administered with distilled water, a group administered with NMDA solution, a group administered with test solution 1, a group administered with test solution 2, a group administered with comparative test solution 1 And the group to which the comparative test solution 2 was administered were respectively referred to as “distilled water administration group”, “NMDA administration group”, “test solution 1 administration group”, “test solution 2 administration group”, “comparison test solution 1 administration group” and This is shown as “Comparison test solution 2 administration group”. The number of cases in each administration group is 3-5.

Formula 1
Node cell death inhibition rate = (Ax−Ab) / (Aa−Ab) × 100
Aa: Number of RGCs in the distilled water administration group Ab: Number of RGCs in the NMDA administration group Ax: Number of RGCs in the test solution or comparison test solution administration group Formula 2
IPL thinning suppression rate = (Ax−Ab) / (Aa−Ab) × 100
Aa: IPL thickness of the distilled water administration group Ab: IPL thickness of the NMDA administration group Ax: IPL thickness of the test solution or comparative test solution administration group

(Results and Discussion)
As is clear from the results in Table 1, both nafamostat and FUT-187 exhibited high node cell death inhibition rates and IPL thinning inhibition rates. Moreover, compared with camostat and gabexate, nafamostat and FUT-187 showed a high inhibition rate. Therefore, it was found that nafamostat and FUT-187 are particularly excellent in the effect of suppressing RGC reduction and thinning of the inner mesh layer. That is, it was found that the compound represented by the general formula [I] represented by nafamostat and FUT-187 or a salt thereof is useful as a protective agent for retinal nerve cells.

  Next, the pharmaceutical agent of the present invention will be described more specifically with reference to formulation examples, but the present invention is not limited to these formulation examples.

2. Formulation Example Formulation Example 1 Eye drops (in 1 ml)
Nafamostat 1mg
Concentrated glycerin 250mg
Polysorbate 80 200mg
Sodium dihydrogen phosphate dihydrate 20mg
1N sodium hydroxide appropriate amount 1N hydrochloric acid appropriate amount sterilized purified water appropriate amount Nafamostat and other ingredients mentioned above are added to sterilized purified water, and these are mixed well to make eye drops.

Formulation Example 2 Tablet (in 100 mg)
FUT-187 1mg
Lactose 66.4mg
Maize starch 20mg
Carboxymethylcellulose calcium 6mg
Hydroxypropylcellulose 6mg
Magnesium stearate 0.6mg
FUT-187 and lactose are mixed in a mixer, carboxymethylcellulose calcium and hydroxypropylcellulose are added thereto, this mixture is granulated, the resulting granule is dried and granulated, and stearic acid is added to the granulated granule. Magnesium is added and mixed, and the mixture is tableted with a tableting machine.

Formulation Example 3 Injection (in 10 ml)
FUT-187 10mg
Sodium chloride 90mg
Sterilized purified water appropriate amount FUT-187 and sodium chloride are dissolved in sterile purified water to make an injection solution.

A desired formulation can be obtained by appropriately changing the types and amounts of the present compound and additives including the above-mentioned formulations.

Claims (8)

A protective agent for nerve cells comprising a compound represented by the following general formula [I] or a salt thereof as an active ingredient.

[Where:
R ₁ , R ₂ and R ₃ are the same or different and each represents a hydrogen atom or an alkyl group,
Alternatively, R ₁ and R ₃ may combine to form a ring having one or more double bonds. ] The compound represented by the general formula [I] is 6′-amidino-2′-naphthyl-4-guanidinobenzoate or 6′-amidino-2′-naphthyl- (4- (4,5-dihydro-1H-2- The nerve cell protecting agent according to claim 1, which is imidazolyl) amino) benzoate. A prophylactic or therapeutic agent for ophthalmic diseases associated with optic neuropathy, comprising a compound represented by the following general formula [I] or a salt thereof as an active ingredient.

[Where:
R ₁ , R ₂ and R ₃ are the same or different and each represents a hydrogen atom or an alkyl group,
Alternatively, R ₁ and R ₃ may combine to form a ring having one or more double bonds. ] The preventive or therapeutic agent according to claim 3, wherein the eye disease is glaucoma. The preventive or therapeutic agent according to claim 3, wherein the eye disease is a retinal disease. 6. The preventive or therapeutic agent according to claim 5, wherein the retinal disease is retinitis pigmentosa or label disease. A prophylactic or therapeutic agent for senile dementia, Alzheimer's disease, Parkinson's disease, Huntington's disease, ALS, spinal cord injury or multiple sclerosis comprising a compound represented by the following general formula [I] or a salt thereof as an active ingredient.

[Where:
R ₁ , R ₂ and R ₃ are the same or different and each represents a hydrogen atom or an alkyl group,
Alternatively, R ₁ and R ₃ may combine to form a ring having one or more double bonds. ] The agent for protecting a nerve cell according to claim 1 or 2, or a preventive or therapeutic agent according to any one of 3 to 7, wherein the dosage form is an oral preparation, an injection, an eye drop or a preparation for intraocular implant.